http://wiki.polycount.com/w/api.php?action=feedcontributions&feedformat=atom&user=Dustinbrownpolycount - User contributions [en]2026-05-23T21:33:07ZUser contributionsMediaWiki 1.23.2http://wiki.polycount.com/wiki/Normal_Map_Technical_DetailsNormal Map Technical Details2017-02-08T22:54:28Z<p>Dustinbrown: </p>
<hr />
<div>[[Normal map]]s can be improved greatly by learning the implementation details. <br />
<br />
== Synched Workflow ==<br />
To eliminate seams and shading artifacts, the game engine and the normal map [[Texture Baking|baking tool]] should use the same [[Normal_Map_Technical_Details#Tangent_Basis|tangent basis]].<br />
<br />
For more information about a synched workflow see the Polycount Forum thread [http://polycount.com/discussion/107196/youre-making-me-hard-making-sense-of-hard-edges-uvs-normal-maps-and-vertex-counts/p1 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts].<br />
<br />
When you export a model from your baking tool, it is best to choose a format like FBX which can store the tangents. This insures the same tangents which were used for baking, will be used for rendering. <br />
<br />
[http://www.handplane3d.com/ Handplane] is a free utility that converts an object-space normal map + model into different tangent spaces. This allows a synced workflow with various tools.<br />
<br />
* [http://polycount.com/discussion/174385/synced-tangent-basis-workflow-from-3ds-max-to-unity-5 Synced tangent basis workflow from 3ds Max to Unity 5?] Polycount Forum thread.<br />
* [http://polycount.com/discussion/175538/is-my-tangent-basis-un-synced Is my tangent basis un-synced?] Polycount Forum thread, using Maya and Substance Painter.<br />
<br />
{| class="wikitable sortable" style="color:grey;"<br />
|- <br />
! Renderer !! Normal map baker !! Handplane support<br />
|-<br />
| 3d Coat || ? || ?<br />
|-<br />
| 3ds Max || 3ds Max || Yes<br />
|-<br />
| Blender || ? || ?<br />
|-<br />
| Creation Engine || ? || Yes<br />
|-<br />
| CryEngine || ? || ?<br />
|-<br />
| Knald || ? || ?<br />
|-<br />
| Marmoset Toolbag || 3ds Max, Maya, [http://www.xnormal.net/ Xnormal] || ?<br />
|-<br />
| Maya || Maya || Yes<br />
|-<br />
| Source || Maya ([http://www.polycount.com/forum/showpost.php?p=2224653&postcount=28]) || Yes<br />
|-<br />
| Starcraft II || ? || Yes<br />
|-<br />
| Substance Designer || ? || ?<br />
|-<br />
| Unity ([http://www.polycount.com/forum/showpost.php?p=2224781&postcount=29], [http://www.polycount.com/forum/showthread.php?p=2194353#post2194353]) || [http://www.xnormal.net/ Xnormal] || Yes<br />
|-<br />
| Unreal Engine 4 || [http://www.xnormal.net/ Xnormal] ([http://www.polycount.com/forum/showpost.php?p=2224402&postcount=20]) || Yes<br />
|-<br />
| Xnormal || [http://www.xnormal.net/ Xnormal] || ?<br />
|}<br />
<br />
==Tangent-Space vs. Object-Space==<br />
[[Normal map]]s can be made in either of two basic flavors: tangent-space or object-space. World-space is basically the same as object-space, except it requires the model to remain in its original orientation, neither rotating nor deforming, so it's almost never used.<br />
<br />
===Tangent-space normal map===<br />
[[image:normalmap_tangentspace.jpg|frame|none|A tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Predominantly-blue colors. Object can rotate and deform. Good for deforming meshes, like characters, animals, flags, etc.<br />
<br />
Pros:<br />
* Maps can be reused easily, like on differently-shaped meshes.<br />
* Maps can be tiled and mirrored easily, though some games might not support mirroring very well.<br />
* Easier to overlay painted details.<br />
* Easier to use image compression.<br />
<br />
Cons:<br />
* More difficult to avoid smoothing problems from the low-poly vertex normals (see Smoothing Groups and Hard Edges).<br />
* Slightly slower performance than an object-space map (but not by much).<br />
<br />
===Object-space normal map===<br />
[[image:normalmap_worldspace.jpg|frame|none|An object-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Rainbow colors. Objects can rotate, but usually shouldn't be deformed, unless the shader has been modified to support deformation. Object-space is also called local-space or model-space. <br />
<br />
Pros:<br />
* Easier to generate high-quality curvature because it completely ignores the crude smoothing of the low-poly vertex normals.<br />
* Slightly better performance than a tangent-space map (but not by much).<br />
<br />
Cons:<br />
* Can't easily reuse maps, different mesh shapes require unique maps.<br />
* Difficult to tile properly, and mirroring requires specific shader support.<br />
* Harder to overlay painted details because the base colors vary across the surface of the mesh. Painted details must be converted into Object Space to be combined properly with the OS map.<br />
* They don't compress very well, since the blue channel can't be recreated in the shader like with tangent-space maps. Also the three color channels contain very different data which doesn't compress well, creating many artifacts. Using a half-resolution object-space map is one option. <br />
<br />
<br clear="all"/><br />
<br />
=== Converting Between Spaces ===<br />
Normal maps can be converted between object space and tangent space, in order to use them with different blending tools and shaders, which require one type or the other. <br />
<br />
Object space maps can also be converted to maps with different tangent bases, to better match the normal maps with the renderer and thus avoid lighting errors.<br />
<br />
* [http://www.handplane3d.com Handplane] by [http://www.shiningrocksoftware.com/ Luke Hodorowicz] and [http://www.alecmoody.com/ Alec Moody] is a tool that converts object space maps into a variety of tangent spaces: 3ds Max, Creation Engine, Maya, Source, Unity, Unreal, etc. See the Polycount Forum thread [http://www.polycount.com/forum/showthread.php?t=116899 Official handplane support thread - Now freeware!!].<br />
<br />
[[File:handplane_illus_1.jpg|frame|none|Handplane interface. <br>Image by [http://www.alecmoody.com/ Alec Moody].]]<br />
<br />
<br />
* [http://boards.polycount.net/showthread.php?p=1072599#post1072599 NSpace] by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] is a tool that converts an object-space normal map into a tangent-space map, which then works seamlessly in the 3ds Max viewport. He converts the map by using the same tangent basis that 3ds Max uses for its hardware shader. To see the results, load the converted map via the ''Normal Bump'' map and enable "Show Hardware Map in Viewport". [http://gameartist.nl/ Osman "osman" Tsjardiwal] created a GUI for NSpace, you can [http://boards.polycount.net/showthread.php?p=1075143#post1075143 download it here], just put it in the same folder as the NSpace exe and run it. <br />
<br />
[[File:NSpace_Gui_osman.png|frame|none|NSpace interface. <br>Image by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] and [http://gameartist.nl Osman "osman" Tsjardiwal].]]<br />
<br />
[http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson] said: "[8Monkey Labs has] a tool that lets you load up your reference mesh and object space map. Then load up your tangent normals, and adjust some sliders for things like tile and amount. We need to load up a mesh to know how to correctly orient the tangent normals or else things will come out upside down or reverse etc. It mostly works, but it tends to "bend" the resulting normals, so you gotta split the mesh up into some smoothing groups before you run it, and then I usually will just composite this "combo" texture over my orig map in Photoshop."<br />
<br />
<span id="RGBC"></span><span id="RGBChannels"></span><br />
<br />
== RGB Channels ==<br />
Shaders can use different techniques to render tangent-space normal maps, but the normal map directions are usually consistent within a game. Usually the red channel of a tangent-space normal map stores the X axis (pointing the normals predominantly leftwards or rightwards), the green channel stores the Y axis (pointing the normals predominantly upwards or downwards), and the blue channel stores the Z axis (pointing the normals outwards away from the surface).<br />
<br />
[[image:tangentspace_rgb.jpg|frame|none|The red, green, and blue channels of a tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you see lighting coming from the wrong angle when you're looking at your normal-mapped model, and the model is using a tangent-space normal map, the normal map shader might be expecting the red or green channel (or both) to point in the opposite direction. To fix this either change the shader, or simply invert the appropriate color channels in an image editor, so that the black pixels become white and the white pixels become black.<br />
<br />
Some shaders expect the color channels to be swapped or re-arranged to work with a particular [[Normal Map Compression|compression format]]. This re-arranging of the normal map axes is called [[ChannelPacking#Swizzle|swizzling]]. For example the DXT5_nm format usually expects the X axis to be in the alpha channel, the Y axis to be in the green channel, and the red and blue channels to be empty.<br />
<br />
== Tangent Basis ==<br />
[[Normal_Map_Technical_Details#Tangent-Space_vs._Object-Space|Tangent-space]] normal maps use a special kind of vertex data called the ''tangent basis''. This is similar to UV coordinates except it provides directionality across the surface, it forms a surface-relative coordinate system for the per-pixel normals stored in the normal map. This coordinate system is required to light a normal mapped surface.<br />
<br />
Each vertex in the tangent basis is a combination of three things: the mesh vertex's normal (influenced by smoothing), the vertex's tangent (usually derived from the V texture coordinate), and the vertex's bitangent (derived in code, also called the binormal). These three vectors create an axis for each vertex, giving it a specific orientation in the tangent space. These axes are used to properly transform the incoming lighting from world space into tangent space, so your normal-mapped model will be lit correctly.<br />
<br />
Light rays are in world space, but the normals stored in the normal map are in tangent space. When the model is being rendered, the light rays must be converted from world space into tangent space, using the tangent basis to get there. At that point the incoming light rays are compared against the directions of the normals in the normal map, and this determines how much each pixel is going to be lit. Alternatively, instead of converting the light rays some shaders will convert the normals in the normal map from tangent space into world space. Then those world-space normals are compared against the light rays, and the model is lit appropriately. The method depends on who wrote the shader, but the end result is the same. Both methods require a tangent basis to transform the lighting.<br />
<br />
When a triangle's vertex normals are pointing straight out, and a pixel in the normal map is neutral blue (128,128,255) this means the pixel's normal will be pointing straight out from the surface of the low-poly mesh. When that pixel normal is tilted towards the left or the right in the tangent coordinate space, it will get either more or less red color, depending on whether the normal map is set to store the X axis as either a positive or a negative value. Same goes for when the normal is tilted up or down in tangent space, it will either get more or less green color. If the vertex normals aren't exactly perpendicular to the triangle, the normal map pixels will be tinted away from neutral blue as well.<br />
<br />
Unfortunately for artists, there are many different ways to calculate the tangent basis: [http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping 3ds Max], [http://download.autodesk.com/us/maya/2011help/index.html?url=./files/Appendix_A_Tangent_and_binormal_vectors.htm,topicNumber=d0e227193 Maya], [http://www.codesampler.com/dx9src/dx9src_4.htm#dx9_dot3_bump_mapping DirectX 9], [http://www.nvidia.com/object/NVMeshMender.html NVMeshMender], [http://www.terathon.com/code/tangent.html Eric Lengyel], a custom solution, etc. This means a normal map baked in one application probably won't shade correctly in another. Artists must do some testing with different [[Texture Baking|baking tools]] to find which works best with their output. When the renderer (or game engine) renders your game model, [[Shaders|the shader]] must use the same tangent basis as the normal map baker, otherwise you'll get incorrect lighting, especially across the seams between UV shells.<br />
<br />
The [http://www.xnormal.net/ xNormal] SDK supports custom tangent basis methods. When a programmer uses it to implement their renderer's own tangent basis, artists can then use Xnormal to bake normal maps that will match their renderer perfectly.<br />
<br />
== UV Coordinates ==<br />
[[image:tangentseams.jpg|frame|none|When shared edges are at different angles in UV space, different colors will show up<br />
along the seam. The tangent basis uses these colors to light the model properly. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
When you look at a tangent-space normal map for a character, you typically see different colors along the UV seams. This is because the UV shells are often oriented at different angles on the mesh, a necessary evil when translating the 3D mesh into 2D textures. The body might be mapped with a vertical shell, and the arm mapped with a horizontal one. This requires the normals in the normal map to be twisted for the different orientations of those UV shells. The UVs are twisted, so the normals must be twisted in order to compensate. The tangent basis helps reorient (twist) the lighting as it comes into the surface's local space, so the lighting will then look uniform across the normal mapped mesh.<br />
<br />
When an artist tiles a tangent-space normal map across an arbitrary mesh, like a landscape, this tends to shade correctly because the mesh has a uniform direction in tangent space. If the mesh has discontinuous UV coordinates (UV seams), or the normal map has large directional gradients across it, the tangent space won't be uniform anymore so the surface will probably have shading seams.<br />
<br />
== Common Swizzle Coordinates ==<br />
3D Software capable of displaying tangent space normal maps will have a native required direction, or "handedness" for the RGB channels in a normal map, sometimes referred to as "Swizzle Coordinates," though [[Shaders]] can often be written to override this native handedness. You may hear developers refer to "flipping the green channel" in order to get a normal map to display correctly, and this simply indicates that when the normal map was baked, it was authored with the incorrect handedness in the green channel. Right handedness, which coincides with OpenGL is indicated with a plus sign (ex. +Y), whereas Left handedness, which coincides with DirectX, is indicated with a negative sign (ex. -Y)<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
| '''Software''' <br />
| '''Red''' <br />
| '''Green''' <br />
| '''Blue''' <br />
|-<br />
|<#000000>| 3ds Max<br />
| X+<br />
| Y-<br />
| Z+ <br />
|-<br />
|<#000000>| [http://wiki.blender.org/index.php/Doc:2.6/Manual/Textures/Influence/Material/Bump_and_Normal Blender]<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| [http://docs.cryengine.com/display/SDKDOC2/Normal+Maps CryENGINE]<br />
| X+<br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Maya<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| Modo<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| [https://developer.valvesoftware.com/wiki/Bump_map Source]<br />
| X+<br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Toolbag<br />
| X+<br />
| Y+ <br />
| Z+<br />
|-<br />
|<#000000>| [http://docs.unity3d.com/Manual/HOWTO-bumpmap.html Unity]<br />
| X+<br />
| Y+<br />
| Z+<br />
|-<br />
|<#000000>| [https://docs.unrealengine.com/latest/INT/Engine/Content/Types/Textures/Properties/index.html Unreal Engine]<br />
| X+ <br />
| Y-<br />
| Z+<br />
|-<br />
|}<br />
<br />
== More Information ==<br />
* [[Normal map]]<br />
* [[Normal Map Compression]]<br />
<br />
----<br />
[[Category:TextureTypes]] [[Category:Bump map]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Polycounter_Job_CensusPolycounter Job Census2016-12-23T20:39:49Z<p>Dustinbrown: </p>
<hr />
<div>A list of game development studios, and the Polycount members who are employed there. <br />
<br />
<br>'''<font color="green" size="3">2k Australia (Canberra, Australia)</font>'''<br />
<br />
* sprunghunt<br />
<br />
<br>'''<font color="green" size="3">2k Czech (Prague, Czech Republic)</font>'''<br />
<br />
* searinox<br />
<br />
<br>'''<font color="green" size="3">2k Games / Hangar 13 (Novato, CA)</font>'''<br />
<br />
* MooseCommander<br />
<br />
<br>'''<font color="green" size="3">22 Cans (Guildford, United Kingdom)</font>'''<br />
<br />
* feanix<br />
* Flynny<br />
<br />
<br>'''<font color="green" size="3">3Point Studios</font>'''<br />
<br />
* perna<br />
<br />
<br>'''<font color="green" size="3">343 Industries (Redmond, WA)</font>'''<br />
<br />
* AlexCatMasterSupreme<br />
* JDinges<br />
* KolbyJukes<br />
* Shanthosa<br />
* Thegodzero<br />
* tottot<br />
* vemadesign<br />
<br />
<br>'''<font color="green" size="3">5TH Cell (Bellevue, WA)</font>'''<br />
<br />
* boomz<br />
* Funky Bunnies<br />
<br />
<br>'''<font color="green" size="3">6waves Lolapps (Dallas, TX)</font>'''<br />
<br />
* BradMyers82<br />
* jlewis<br />
* Junkie_XL<br />
<br />
<br>'''<font color="green" size="3">AAD Productions (Seattle, WA)</font>'''<br />
<br />
* bgivenb<br />
<br />
<br>'''<font color="green" size="3">Adhesive Games (Los Angeles, CA)</font>'''<br />
<br />
* wester<br />
<br />
<br>'''<font color="green" size="3">Amaze Entertainment (Austin, TX)</font>'''<br />
<br />
* jpgourley<br />
<br />
<br>'''<font color="green" size="3">Allegorithmic (Clermont-Ferrand, France)</font>'''<br />
<br />
* Froyok<br />
<br />
<br>'''<font color="green" size="3">Another Castle Studios (Charlottetown, Canada)</font>'''<br />
<br />
* Canadian Ink<br />
<br />
<br>'''<font color="green" size="3">ArenaNet (Bellevue, WA)</font>'''<br />
<br />
* stoofoo<br />
* Truth<br />
* Perlinfalcon<br />
<br />
<br>'''<font color="green" size="3">Armature Studios (Austin, TX)</font>'''<br />
<br />
* Cap<br />
<br />
<br>'''<font color="green" size="3">Art Bully Productions (NY)</font>'''<br />
<br />
* Kitteh<br />
<br />
<br>'''<font color="green" size="3">Arrowhead Game Studios (Stockholm, Sweden)</font>'''<br />
<br />
* Carl Brannstorm<br />
* jimsvanberg<br />
<br />
<br>'''<font color="green" size="3">Atomic Games (Raleigh, NC)</font>'''<br />
<br />
* Jet_Pilot<br />
<br />
<br>'''<font color="green" size="3">Avalanche Studios (Stockholm, Sweden)</font>'''<br />
<br />
* Jon Jones<br />
* sltrOlsson<br />
* poly_bob<br />
<br />
<br>'''<font color="green" size="3">Backflip Studios (Boulder, CO)</font>'''<br />
<br />
* Eclipse<br />
<br />
<br>'''<font color="green" size="3">Barbaroga (Chicago, IL)</font>'''<br />
<br />
* Heather.Hughes<br />
<br />
<br>'''<font color="green" size="3">BattleCry Studios (Austin, TX)</font>'''<br />
<br />
* Jon Rush<br />
<br />
<br>'''<font color="green" size="3">Beenox (Quebec City, Quebec)</font>'''<br />
<br />
* Boyso<br />
* JRancourt<br />
* kaktuzlime<br />
* kremrhi<br />
* Lepothier<br />
<br />
<br>'''<font color="green" size="3">Behaviour (Montréal, BC)</font>'''<br />
<br />
* Bruno Afonseca<br />
<br />
<br>'''<font color="green" size="3">Bend Studio (Bend, OR)</font>'''<br />
<br />
* biofrost<br />
* iangoold3d<br />
* Rurouni Strife<br />
<br />
<br>'''<font color="green" size="3">Bethesda Game Studios (Rockville, MD)</font>'''<br />
<br />
* aajohnny<br />
* doc_rob<br />
* e_x<br />
* Geezus<br />
* Higuy<br />
<br />
<br>'''<font color="green" size="3">Big Ant Studios (Melbourne, Australia)</font>'''<br />
<br />
* DMoz<br />
* duncan<br />
<br />
<br>'''<font color="green" size="3">Big Bang Entertainment (Phoenix, AZ)</font>'''<br />
<br />
* Aldo<br />
<br />
<br>'''<font color="green" size="3">Big Sandwich Games (Vancouver, BC)</font>'''<br />
<br />
* Quasar<br />
* shinobix<br />
* TS_Falcon<br />
<br />
<br>'''<font color="green" size="3">BigPark Inc (Vancouver, BC)</font>'''<br />
<br />
* malcolm<br />
<br />
<br>'''<font color="green" size="3">Bioware (Austin, TX)</font>'''<br />
<br />
* Ben Cloward<br />
* Goat Justice<br />
* Rob Galanakis<br />
<br />
<br>'''<font color="green" size="3">Bioware (Edmonton, Canada)</font>'''<br />
<br />
* Hazed_blue<br />
<br />
<br>'''<font color="green" size="3">Bioware (Montréal, BC)</font>'''<br />
<br />
* Bad-Koala<br />
* Grassetti<br />
<br />
<br>'''<font color="green" size="3">Bioware Mythic (Fairfax, VA)</font>'''<br />
<br />
* Polymonkey<br />
<br />
<br>'''<font color="green" size="3">Blackbeard Games (Stockholm, Sweden)</font>'''<br />
<br />
* Deadly Nightshade<br />
<br />
<br>'''<font color="green" size="3">Blizzard Entertainment (Irvine, CA)</font>'''<br />
<br />
* [HP]<br />
* Darkrusader<br />
* Dom<br />
* Dusty<br />
* Empty<br />
* foreverendering<br />
* Hamish Bode<br />
* IxenonI<br />
* jarrede<br />
* jbrophy<br />
*Jeff Parrott<br />
* Jessica Dinh<br />
* KyleJensen<br />
* MartinH<br />
* mheyman<br />
* Minos<br />
* moof<br />
* murph<br />
* obson<br />
* Peris<br />
* Ravenslayer<br />
* Renaud Galand<br />
* Rory_M<br />
* Saiainoshi<br />
* seven<br />
* Soul<br />
* T-Bone<br />
* [SF]Three9<br />
* turpedo<br />
* Tully<br />
<br />
<br>'''<font color="green" size="3">Blur Studio (Culver City, CA)</font>'''<br />
<br />
* jaaso<br />
<br />
<br>'''<font color="green" size="3">Bohemia Interactive Simulations (Hampshire, United Kingdom)</font>'''<br />
<br />
* benji<br />
<br />
<br>'''<font color="green" size="3">Born Ready (Guildford, United Kingdom)</font>'''<br />
<br />
* Millenia<br />
<br />
<br>'''<font color="green" size="3">Brain In A Jar (Tarporley, Cheshire, United Kingdom)</font>'''<br />
<br />
* A-N-P<br />
<br />
<br>'''<font color="green" size="3">Bungie Studios (Bellevue, WA)</font>'''<br />
<br />
* Axiao<br />
* Axios<br />
* breakneck<br />
* FatAssasin<br />
* Grimm_Wrecking<br />
* Haiasi<br />
* PoopSock<br />
* Pope Adam<br />
* mLichy<br />
* reverendK<br />
* Spug<br />
<br />
<br>'''<font color="green" size="3">Buzz Monkey Software (Eugene, OR)</font>'''<br />
<br />
* natetheartist<br />
<br />
<br>'''<font color="green" size="3">Capcom (Vancouver, Canada)</font>'''<br />
<br />
* glib<br />
* Selaznog<br />
<br />
<br>'''<font color="green" size="3">Carbine Studios (Aliso Viejo, CA)</font>'''<br />
<br />
* Arkadius<br />
* homes44<br />
* Mrandk<br />
* POFFINGTON<br />
* Reverenddevil<br />
<br />
<br>'''<font color="green" size="3">Caspian Learning (Newcastle Upon Tyne, United Kingdom)</font>'''<br />
<br />
* gateian<br />
<br />
<br>'''<font color="green" size="3">Cat Daddy Games (Kirkland, WA)</font>'''<br />
<br />
* ebagg<br />
<br />
<br>'''<font color="green" size="3">CI Games (Warsaw, Poland)</font>'''<br />
<br />
<br>'''<font color="green" size="3">CCP (Reykjav�k, Iceland)</font>'''<br />
<br />
* Flava-Fly<br />
* undoz<br />
<br />
<br>'''<font color="green" size="3">CD Projekt Red (Warsaw, Poland)</font>'''<br />
<br />
* MiAlx<br />
<br />
<br>'''<font color="green" size="3">CDRIN (Quebec, Canada)</font>'''<br />
<br />
* Felixenfeu<br />
* LeRenart<br />
<br />
<br>'''<font color="green" size="3">Certain Affinity (Austin, TX)</font>'''<br />
<br />
* Flewda<br />
<br />
<br>'''<font color="green" size="3">CGBot (Monterrey N.L., Mexico)</font>'''<br />
<br />
* Justo<br />
* lincqk<br />
<br />
<br>'''<font color="green" size="3">Chaotic Moon Studios (Austin, TX)</font>'''<br />
<br />
* oobersli<br />
<br />
<br />
<br>'''<font color="green" size="3">Cloud Imperium Games (Austin, TX)</font>'''<br />
<br />
* Elijah<br />
* Lee3Dee<br />
<br />
<br>'''<font color="green" size="3">Cmune (Bejing, China)</font>'''<br />
<br />
* cox<br />
<br />
<br>'''<font color="green" size="3">The Coalition Studio (Vancouver, Canada)</font>'''<br />
<br />
* malcolm<br />
<br />
<br>'''<font color="green" size="3">Codemasters (Southam, Warwickshire, United Kingdom)</font>'''<br />
<br />
* urgaffel<br />
<br />
<br>'''<font color="green" size="3">Cold Iron Studios (Santa Clara, California)</font>'''<br />
<br />
* BradMyers82<br />
<br />
<br>'''<font color="green" size="3">Colossal Games (London, United Kingdom)</font>'''<br />
<br />
* Yozora<br />
<br />
<br>'''<font color="green" size="3">Crazy Bump Software (Austin, TX)</font>'''<br />
<br />
* Ryan Clark<br />
<br />
<br>'''<font color="green" size="3">The Creative Assembly (Horsham, United Kingdom)</font>'''<br />
<br />
* Baj Singh<br />
* jestersheepy<br />
* JohnnyRaptor<br />
* marks<br />
* Mr_Smo<br />
* Rob_Blight<br />
* PogoP<br />
* saturnfive<br />
* Sugus<br />
* wallasaurus<br />
* woogity<br />
<br />
<br>'''<font color="green" size="3">Cryptic Studios (Los Gatos, CA)</font>'''<br />
<br />
* cman2k<br />
* JnasconeArt<br />
* Matt Fagan<br />
* Tumerboy<br />
<br />
<br>'''<font color="green" size="3">Crytek (Frankfurt, Germany)</font>'''<br />
<br />
* Bart<br />
* Criminal<br />
* e-freak<br />
* freakadelle<br />
* MaYdaY<br />
* luke<br />
<br />
<br>'''<font color="green" size="3">Crytek (Nottingham, United Kingdom)</font>'''<br />
<br />
* EzMeow<br />
* Zubrowka<br />
<br />
<br>'''<font color="green" size="3">Cubic Corporation (San Diego, CA)</font>'''<br />
<br />
* ghost123238<br />
<br />
<br>'''<font color="green" size="3">Curve Studios (London, United Kingdom)</font>'''<br />
<br />
* GeeDave<br />
<br />
<br>'''<font color="green" size="3">Dadako Studios (Tokyo, Japan)</font>'''<br />
<br />
* hawken <br />
<br />
<br>'''<font color="green" size="3">Dapper Ram</font>'''<br />
<br />
* Marshal Banana<br />
<br />
<br>'''<font color="green" size="3">Day 1 Studios (Chicago, IL)</font>'''<br />
<br />
* kaburan<br />
<br />
<br>'''<font color="green" size="3">Design Mill, Inc. (Dubuque, IA)</font>'''<br />
<br />
* MegaMoogle<br />
<br />
<br>'''<font color="green" size="3">DICE - EA Digital Illusions CE (Stockholm, Sweden)</font>'''<br />
<br />
* Cubik<br />
* motives<br />
* o2car<br />
* Rens<br />
* Synthesizer<br />
* Wahlgren<br />
* Xoliul<br />
* zenpat<br />
<br />
<br>'''<font color="green" size="3">Digital Extremes (London, Ontario)</font>'''<br />
<br />
* Fuse<br />
* jordan.kocon<br />
* kary<br />
* mathes<br />
* Pogo_Daddy<br />
* shinobix<br />
* StrangeFate<br />
* tyl3r<br />
<br />
<br>'''<font color="green" size="3">Dinosaur Games (Austin, TX)</font>'''<br />
<br />
* skankerzero<br />
<br />
<br>'''<font color="green" size="3">Direwolf Digital (Denver, CO)</font>'''<br />
<br />
* Rayph<br />
<br />
<br>'''<font color="green" size="3">Disney Interactive (Glendale, CA)</font>'''<br />
<br />
* .polygon<br />
* Archanex<br />
* Grumpntug<br />
* hosfeph<br />
* misterboogie<br />
* Power_Mustache<br />
* Wells<br />
<br />
<br>'''<font color="green" size="3">Dovetail Games (SE England, United Kingdom)</font>'''<br />
<br />
* Perry Stringer (pez_11)<br />
* sheckee<br />
<br />
<br>'''<font color="green" size="3">Dream Forge Entertainment (Ruston, LA)</font>'''<br />
<br />
* RyanTaylor3D<br />
<br />
<br>'''<font color="green" size="3">EA Canada (Barnaby, BC)</font>'''<br />
<br />
* B18<br />
* pangarang<br />
* timotronprime<br />
<br />
<br>'''<font color="green" size="3">EA Firemonkeys (Melbourne, Australia)</font>'''<br />
<br />
* Emil Mujanovic<br />
<br />
<br>'''<font color="green" size="3">EA Montréal (Montréal, BC) </font>'''<br />
<br />
* Marcan<br />
<br />
<br>'''<font color="green" size="3">EA Tiburon (Orlando, FL)</font>'''<br />
<br />
* Kewon Decam<br />
<br />
<br>'''<font color="green" size="3">EA Sports (Vancouver, BC)</font>'''<br />
<br />
* R3D<br />
<br />
<br>'''<font color="green" size="3">Edge of Reality (Austin, TX)</font>'''<br />
<br />
* FunkaDelicDass<br />
<br />
<br>'''<font color="green" size="3">Eidos (Montréal, BC)</font>'''<br />
<br />
* Fred2303<br />
* Matroskin<br />
* JacqueChoi<br />
* Nysuatro<br />
<br />
<br>'''<font color="green" size="3">Electrified Games (San Francisco, CA)</font>'''<br />
<br />
* 3shold<br />
<br />
<br>'''<font color="green" size="3">Emerald City Games (Vancouver, BC)</font>'''<br />
<br />
* Uberren<br />
<br />
<br>'''<font color="green" size="3">Engine Software (Doetinchem, Netherlands)</font>'''<br />
<br />
* EVIL<br />
<br />
<br>'''<font color="green" size="3">Epic Games (Raleigh, NC)</font>'''<br />
<br />
* animatr<br />
* da_milkman<br />
* Frank<br />
* JordanW<br />
* kernersvillan<br />
* Kevin Johnstone<br />
* Moose<br />
* osman<br />
* paulsvoboda<br />
* rawkstar<br />
* rv_el<br />
* scotthomer<br />
* WarrenMarshall<br />
<br />
<br>'''<font color="green" size="3">Eurocom (Derby, United Kingdom)</font>'''<br />
<br />
* Mister Sentient<br />
* Searlee<br />
<br />
<br>'''<font color="green" size="3">Evolution Studios (Runcorn, United Kingdom)</font>'''<br />
<br />
* nathdevlin<br />
<br />
<br>'''<font color="green" size="3">Exis Interactive (Baltimore, MD)</font>'''<br />
<br />
* NeoprofZ<br />
* PeterK<br />
* retardedmonkey<br />
* shadows<br />
<br />
<br>'''<font color="green" size="3">Ubisoft Montréal (Montréal, BC)</font>'''<br />
<br />
* wizo<br />
<br />
<br>'''<font color="green" size="3">Ubisoft Paris (Paris, France)</font>'''<br />
<br />
* bobmartien<br />
<br />
<br>'''<font color="green" size="3">Ubisoft (Singapore)</font>'''<br />
<br />
* MrNinjitsu<br />
<br />
<br>'''<font color="green" size="3">Fatshark (Stockholm, Sweden)</font>'''<br />
<br />
* Belltann<br />
* PixelGoat<br />
<br />
<br>'''<font color="green" size="3">Frima (Quebec City, Canada)</font>'''<br />
<br />
* Odow<br />
<br />
<br>'''<font color="green" size="3">Frozenbyte (Helsinki, Finland)</font>'''<br />
<br />
* sande<br />
<br />
<br>'''<font color="green" size="3">Funcom (Oslo, Norway)</font>'''<br />
<br />
* CgMonkey<br />
<br />
<br>'''<font color="green" size="3">Funcom (Montréal, BC)</font>'''<br />
<br />
* CGMonkey<br />
* Crash<br />
<br />
<br>'''<font color="green" size="3">Funcom (Durham, NC)</font>'''<br />
<br />
* nyx702<br />
* flakked<br />
<br />
<br>'''<font color="green" size="3">Future Games of London (London, United Kingdom)</font>'''<br />
<br />
* torch<br />
<br />
<br>'''<font color="green" size="3">Gameloft (Auckland, New Zealand)</font>'''<br />
<br />
* TehSplatt<br />
* The Flying Monk<br />
<br />
<br>'''<font color="green" size="3">Gameloft (Cluj-Napoca, Romania)</font>'''<br />
<br />
* Mime<br />
<br />
<br>'''<font color="green" size="3">Gameloft (Montréal, BC)</font>'''<br />
<br />
* alexk<br />
* arkhange<br />
* fonfa<br />
* guedin<br />
* hobodactyl<br />
* jocz<br />
* kyalie<br />
<br />
<br>'''<font color="green" size="3">Gameloft (New Orleans, LA)</font>'''<br />
<br />
* JamesHall<br />
<br />
<br>'''<font color="green" size="3">Gamerizon (Montréal, BC)</font>'''<br />
<br />
* rorozilla<br />
<br />
<br>'''<font color="green" size="3">GameWorld7 (Haverfordwest, Wales, United Kingdom)</font>'''<br />
<br />
* KRakarth<br />
<br />
<br>'''<font color="green" size="3">Game Mechanic Studios (Tarzana, CA)</font>'''<br />
<br />
* G3L<br />
<br />
<br>'''<font color="green" size="3">Gearbox Software (Plano, TX)</font>'''<br />
<br />
* AstroZombie<br />
* Bbox85<br />
* ceebee<br />
* Chemical Alia<br />
* Drywall<br />
* mLink<br />
* s6<br />
<br />
<br>'''<font color="green" size="3">Gentle Giant Studios (Burbank, CA)</font>'''<br />
<br />
* r4ptur3<br />
<br />
<br>'''<font color="green" size="3">Giants Software (Zurich, Switzerland)</font>'''<br />
<br />
* MaVCArt<br />
<br />
<br>'''<font color="green" size="3">Glu Mobile (Portland, OR)</font>'''<br />
<br />
* octokitty<br />
<br />
<br>'''<font color="green" size="3">Griptonite Games (Kirkland, WA)</font>'''<br />
<br />
* PixelFish<br />
<br />
<br>'''<font color="green" size="3">Guerrilla Games SCEE (Amsterdam, Netherlands)</font>'''<br />
<br />
* fabiomsilva<br />
* Arno<br />
<br />
<br>'''<font color="green" size="3">Gumi America (Austin, TX)</font>'''<br />
<br />
* Jason Young<br />
<br />
<br>'''<font color="green" size="3">Gunfire Games (Austin, TX)</font>'''<br />
<br />
* Progg<br />
<br />
<br>'''<font color="green" size="3">Gusto Games (Banbury, Oxfordshire, United Kingdom)</font>'''<br />
<br />
* Mimp<br />
<br />
<br>'''<font color="green" size="3">Hatalom Systems (Orlando, FL)</font>'''<br />
<br />
* seforin<br />
<br />
<br>'''<font color="green" size="3">Havok (Dublin, Ireland)</font>'''<br />
<br />
* Mangled Poly<br />
<br />
<br>'''<font color="green" size="3">Her Interactive (Bellevue, WA)</font>'''<br />
<br />
* Karmageddon<br />
<br />
<br>'''<font color="green" size="3">Hi-Rez Studios (Alpharetta, GA)</font>'''<br />
<br />
* 3DK.P.<br />
* Daven<br />
* Scott_W<br />
* Sean McBride<br />
* skylebones<br />
* Slipstream<br />
* Xelan101<br />
<br />
<br>'''<font color="green" size="3">Hibernum Creations (Montréal, BC)</font>'''<br />
<br />
* Pioldes<br />
<br />
<br>'''<font color="green" size="3">High Moon Studios (San Diego, CA)</font>'''<br />
<br />
* BradleyWascher<br />
* NerfBatNinja<br />
* opiumunknown<br />
* Ott<br />
<br />
<br>'''<font color="green" size="3">Hidden Path Entertainment (Bellvue, WA)</font>'''<br />
<br />
* adam crockett<br />
<br />
<br>'''<font color="green" size="3">Hoplon Infotainment (Florianopolis, Brazil)</font>'''<br />
<br />
* cox<br />
* felipealves<br />
* felipefrango<br />
* funkdelic<br />
<br />
<br>'''<font color="green" size="3">Human Head (Madison, WI)</font>'''<br />
<br />
* leibarg<br />
<br />
<br>'''<font color="green" size="3">Icarus Studios (Cary, NC)</font>'''<br />
<br />
* Rainyn<br />
* spiderDude<br />
* XenoAcid<br />
<br />
<br>'''<font color="green" size="3">id Software (Mesquite, TX)</font>'''<br />
<br />
* DanK<br />
* Lear<br />
* roosterMAP<br />
* Spark<br />
* SquirrelyJones<br />
* struve<br />
* ZombieWells<br />
* HitmonInfinity<br />
<br />
<br>'''<font color="green" size="3">Illfonic (Denver, CO)</font>'''<br />
<br />
* heboltz3<br />
* Kedhrin<br />
* konstruct<br />
<br />
<br>'''<font color="green" size="3">Imagination Technologies (Kings Langley, United Kingdom)</font>'''<br />
<br />
* barnesy<br />
<br />
<br>'''<font color="green" size="3">Industry Games (Gilbert, AZ)</font>'''<br />
<br />
* killingpeople<br />
<br />
<br>'''<font color="green" size="3">Infinity Ward (Los Angeles, CA)</font>'''<br />
<br />
* 00Zero<br />
* josh_lynch<br />
* seth.<br />
<br />
<br>'''<font color="green" size="3">iNiS (Tokyo, Japan)</font>'''<br />
<br />
* Jonas Ronnegard<br />
<br />
<br>'''<font color="green" size="3">Insomniac Games (Burbank, CA)</font>'''<br />
<br />
* Arshlevon<br />
* BlvdNights<br />
* dustinbrown<br />
* Gav<br />
* jam-i-am<br />
* N-gon<br />
* Swizzle<br />
<br />
<br>'''<font color="green" size="3">Insomniac Games (Durham, NC)</font>'''<br />
<br />
* Neolight<br />
<br />
<br>'''<font color="green" size="3">Interwave Studios (Sittard, Netherlands)</font>'''<br />
<br />
* MightyPea<br />
<br />
<br>'''<font color="green" size="3">inXile Entertainment (Newport Beach, CA)</font>'''<br />
<br />
* Brian "Panda" Choi<br />
* richkid<br />
<br />
<br>'''<font color="green" size="3">IO Interactive (Copenhagen, Denmark)</font>'''<br />
<br />
* warby<br />
<br />
<br>'''<font color="green" size="3">Iron Tiger Studios / NCSoft (San Mateo, CA)</font>'''<br />
<br />
* chronic<br />
<br />
<br>'''<font color="green" size="3">ISOTX (Luxembourg)</font>'''<br />
<br />
* Kratilim<br />
<br />
<br>'''<font color="green" size="3">Jagex (Cambridge, United Kingdom)</font>'''<br />
<br />
* lysaara<br />
<br />
<br>'''<font color="green" size="3">Jakks Pacific (Malibu, CA)</font>'''<br />
<br />
* gilesruscoe<br />
<br />
<br>'''<font color="green" size="3">Jet Set Games (Las Vegas, NV)</font>'''<br />
<br />
* McBradd<br />
<br />
<br>'''<font color="green" size="3">Just Add Water Ltd (Otley, United Kingdom)</font>'''<br />
<br />
* tda<br />
<br />
<br>'''<font color="green" size="3">Kandu Studios (New York, NY)</font>'''<br />
<br />
* Kandu<br />
<br />
<br>'''<font color="green" size="3">Kojima Productions (Tokyo, Japan)</font>'''<br />
<br />
* David Brumbley<br />
<br />
<br>'''<font color="green" size="3">Krillbite Studio (Hamar, Norway)</font>'''<br />
<br />
* Volantk<br />
<br />
<br>'''<font color="green" size="3">Kuju (London, United Kingdom)</font>'''<br />
<br />
* ukresistant<br />
<br />
<br>'''<font color="green" size="3">Larian Studios (Ghent, Belgium)</font>'''<br />
<br />
* DimSum<br />
<br />
<br>'''<font color="green" size="3">Lionhead Studios (Guildford, Surrey, United Kingdom)</font>'''<br />
<br />
* ghib<br />
<br />
<br>'''<font color="green" size="3">Liquid Development (Portland, OR)</font>'''<br />
<br />
* CJE<br />
* cyborgguineapig<br />
* glottis8<br />
* nacire<br />
<br />
<br>'''<font color="green" size="3">Machine Games (Uppsala, Sweden)</font>'''<br />
<br />
* o2_is_alright<br />
* Stertman<br />
<br />
<br>'''<font color="green" size="3">Marmoset Co (Kansas City, MO)</font>'''<br />
<br />
* GetAwesome<br />
* MonkeyScience<br />
* jeffdr<br />
* EarthQuake<br />
<br />
<br>'''<font color="green" size="3">Massive Entertainment (Malmo, Sweden)</font>'''<br />
<br />
* chrisradsby<br />
* Frozan<br />
* Matthew O<br />
* TheWinterLord<br />
* z0ltan<br />
<br />
<br>'''<font color="green" size="3">Microsoft Game Studios, Turn 10 (Redmond, WA)</font>'''<br />
<br />
* Joshua Stubbles<br />
<br />
<br>'''<font color="green" size="3">Moji Moji Design (Worcester, United Kingdom)</font>'''<br />
<br />
* Chunkey<br />
<br />
<br>'''<font color="green" size="3">MonkeyScience Adhesive Games (Los Angeles, CA)</font>'''<br />
<br />
* Wengyuqiu<br />
<br />
<br>'''<font color="green" size="3">Moving Picture Company (Vancouver, Canada)</font>'''<br />
<br />
* RWolf<br />
<br />
<br>'''<font color="green" size="3">Music Mastermind (Calabasas, CA)</font>'''<br />
<br />
* kream<br />
* timwiese<br />
<br />
<br>'''<font color="green" size="3">N-Space (Orlando, FL)</font>'''<br />
<br />
* ScubaSteve<br />
<br />
<br>'''<font color="green" size="3">Nadeo (Paris, France)</font>'''<br />
<br />
* OgrO<br />
<br />
<br>'''<font color="green" size="3">Naked Sky Entertainment (Los Angeles, CA)</font>'''<br />
<br />
* maltuna<br />
<br />
<br>'''<font color="green" size="3">Naughty Dog (Santa Monica, CA)</font>'''<br />
<br />
* Autocon<br />
* d1ver<br />
<br />
<br>'''<font color="green" size="3">nDreams (Farnborough, United Kingdom)</font>'''<br />
<br />
* kypo<br />
<br />
<br>'''<font color="green" size="3">Neon Play (Cirencester, United Kingdom)</font>'''<br />
<br />
* Ged<br />
<br />
<br>'''<font color="green" size="3">Nerjyzed Entertainment (Baton Rouge, LA)</font>'''<br />
<br />
* Pencilninja<br />
<br />
<br>'''<font color="green" size="3">Neversoft Entertainment (Los Angeles, CA)</font>'''<br />
<br />
* DrumBum<br />
* mvelasquez<br />
* Savage<br />
* SuperOstrich<br />
* ThatDon<br />
<br />
<br>'''<font color="green" size="3">New World Interactive (Denver, CO)</font>'''<br />
<br />
* Steppenwolf<br />
<br />
<br>'''<font color="green" size="3">Ninja Theory (Cambridge, United Kingdom)</font>'''<br />
<br />
* BigErn<br />
<br />
<br>'''<font color="green" size="3">NVIDIA (Germany)</font>'''<br />
<br />
* Crazybutcher<br />
<br />
<br>'''<font color="green" size="3">Obsidian Entertainment (Irvine, CA)</font>'''<br />
<br />
* leleuxart<br />
* SouthpawSid<br />
<br />
<br>'''<font color="green" size="3">OMNOM! workshop (Austin, TX)</font>'''<br />
<br />
* BoBo_the_seal<br />
* BrianP<br />
* Damytria<br />
* Justin Meisse<br />
<br />
<br>'''<font color="green" size="3">Other Ocean Interactive (Charlottetown, PEI, Canada)</font>'''<br />
<br />
* JeremyK<br />
* Kolgrima<br />
* Winthrop<br />
<br />
<br>'''<font color="green" size="3">OutAct (Marlborough, MA)</font>'''<br />
<br />
* Eric Chadwick<br />
<br />
<br>'''<font color="green" size="3">Outso (Nottingham, United Kingdom)</font>'''<br />
<br />
* Massbot<br />
<br />
<br>'''<font color="green" size="3">Pandemic Studios (Los Angeles, CA)</font>'''<br />
<br />
* Luxury<br />
<br />
<br>'''<font color="green" size="3">Paradigm (Carrolton, TX)</font>'''<br />
<br />
* Foehammer<br />
<br />
<br>'''<font color="green" size="3">Pelesys (Richmond, BC, Canada</font>'''<br />
<br />
* pliang<br />
<br />
<br>'''<font color="green" size="3">People Can Fly (Warsaw, Poland)</font>'''<br />
<br />
* Hatred<br />
<br />
<br>'''<font color="green" size="3">Petroglyph (Las Vegas, NV)</font>'''<br />
<br />
* sprunghunt<br />
* Xenobond<br />
<br />
<br>'''<font color="green" size="3">Phantom EFX (Cedar Falls, IA)</font>'''<br />
<br />
* Tigerfeet<br />
<br />
<br>'''<font color="green" size="3">Piranha Bytes (Ruhr, Germany)</font>'''<br />
<br />
* aphexx<br />
<br />
<br>'''<font color="green" size="3">Pirhana Games (Vancouver, BC, Canada)</font>'''<br />
<br />
* ae.<br />
<br />
<br>'''<font color="green" size="3">Pitbull Studios (Guildford, United Kingdom)</font>'''<br />
<br />
* ambershee<br />
<br />
<br>'''<font color="green" size="3">Pixelante Game Studios</font>'''<br />
<br />
* acc<br />
<br />
<br>'''<font color="green" size="3">PlatinumGames (Osaka, Japan)</font>'''<br />
<br />
* Mik2121<br />
<br />
<br>'''<font color="green" size="3">PlaySide VR (Melbourne, Victoria)</font>'''<br />
<br />
* Steve Schulze<br />
<br />
<br>'''<font color="green" size="3">Playful Corp (McKinney, TX)</font>''<br />
<br />
* EvanL<br />
<br />
<br>'''<font color="green" size="3">Polarbit (Stockholm, Sweden)</font>'''<br />
<br />
* Deadly Nightshade<br />
<br />
<br>'''<font color="green" size="3">Polygonal Design (France)</font>'''<br />
<br />
* Thierry86<br />
<br />
<br>'''<font color="green" size="3">Psyonix (San Diego, CA)</font>'''<br />
<br />
* ErichWK<br />
* gamedev<br />
* MorganFX<br />
<br />
<br>'''<font color="green" size="3">Pushbutton Labs</font>'''<br />
<br />
* Ajax<br />
<br />
<br>'''<font color="green" size="3">Quantic Dream (Paris, France)</font>'''<br />
<br />
* Bal<br />
<br />
<br>'''<font color="green" size="3">Rabbit Hole Interactive (Vancouver, CA)</font>'''<br />
<br />
* ScudzAlmighty<br />
<br />
<br>'''<font color="green" size="3">Rainmaker Entertainment (Vancouver, Canada)</font>'''<br />
<br />
* Ryswick<br />
<br />
<br>'''<font color="green" size="3">Rare (Coventry, United Kingdom)</font>'''<br />
<br />
* Leyvin<br />
<br />
<br>'''<font color="green" size="3">Raven Software (Madison, WI)</font>'''<br />
<br />
* Cojax<br />
* Jbradford<br />
<br />
<br>'''<font color="green" size="3">Reactor Zero (Ann Arbor, MI)</font>'''<br />
<br />
* 8-bit<br />
<br />
<br>'''<font color="green" size="3">Ready At Dawn Studios (Irvine, CA)</font>'''<br />
<br />
* Alberto Rdrgz<br />
* LLamaStar<br />
<br />
<br>'''<font color="green" size="3">Real U (Singapore)</font>'''<br />
<br />
* LoTekK<br />
* sandman<br />
* Snowfly<br />
<br />
<br>'''<font color="green" size="3">Rebellion (Oxford, United Kingdom)</font>'''<br />
<br />
* Optinium<br />
* Nelis<br />
* tharle<br />
<br />
<br>'''<font color="green" size="3">Redemption Games (Carlsbad, CA)</font>'''<br />
<br />
* MeshModeler<br />
<br />
<br>'''<font color="green" size="3">Red 5 Studios (Irvine, CA)</font>'''<br />
<br />
* acanaday<br />
<br />
<br>'''<font color="green" size="3">Red Fly Studio (Austin, TX)</font>'''<br />
<br />
* Andrew Morris<br />
<br />
<br>'''<font color="green" size="3">Red Storm Entertainment (Cary, NC )</font>'''<br />
<br />
* dtschultz<br />
<br />
<br>'''<font color="green" size="3">Red Tribe (Melbourne, Australia)</font>'''<br />
<br />
* DavidCoen<br />
<br />
<br>'''<font color="green" size="3">Redjade (London, ON)</font>'''<br />
<br />
* airbursh<br />
<br />
<br>'''<font color="green" size="3">Relic Entertainment (Vancouver, B.C.)</font>'''<br />
<br />
* Goldo_O<br />
* Tulkamir<br />
<br />
<br>'''<font color="green" size="3">Reloaded Productions (Edinburgh, United Kingdom)</font>'''<br />
<br />
* BeardyDan<br />
* SaferDan<br />
<br />
<br>'''<font color="green" size="3">Remedy Entertainment (Espoo, Finland)</font>'''<br />
<br />
* 3dwit<br />
<br />
<br>'''<font color="green" size="3">Respawn Entertainment</font>'''<br />
<br />
* Papa_Austin<br />
* jaythurm<br />
<br />
<br>'''<font color="green" size="3">Retro Studios (Austin, TX)</font>'''<br />
<br />
* OrganizedChaos<br />
* onelung<br />
<br />
<br>'''<font color="green" size="3">Rhythm and Hues</font>'''<br />
<br />
* Archanex<br />
<br />
<br>'''<font color="green" size="3">Riot Games (Culver City, CA)</font>'''<br />
<br />
* bugo<br />
* ChaosEidolon<br />
* Drachis<br />
* Josh_Singh<br />
* Parasite7<br />
* TerraBite<br />
* STRIKER<br />
* X-Convict<br />
<br />
<br>'''<font color="green" size="3">Robotoki (Los Angeles, CA)</font>'''<br />
<br />
* cmgillett<br />
<br />
<br>'''<font color="green" size="3">Rocket Gaming Systems (Las Vegas, NV)</font>'''<br />
<br />
* UNCCheezy<br />
<br />
<br>'''<font color="green" size="3">Rocksteady Studios (London, United Kingdom)</font>'''<br />
<br />
* ImSlightlyBored<br />
* Karl Stjernberg<br />
* vik<br />
<br />
<br>'''<font color="green" size="3">Rockstar Leeds (Leeds, United Kingdom)</font>'''<br />
<br />
* danr<br />
* Dazz3r<br />
* guplik<br />
* prs-phil<br />
* Talon<br />
<br />
<br>'''<font color="green" size="3">Rockstar New England (Andover, MA)</font>'''<br />
<br />
* RexM<br />
* Silva_Spoon<br />
<br />
<br>'''<font color="green" size="3">Rockstar North (Edinburgh, United Kingdom)</font>'''<br />
<br />
* benclark<br />
* BHJ<br />
* Ex-Ray<br />
* headengine<br />
* Kilkus<br />
* Lokter<br />
* PaulP<br />
* Rick Stirling<br />
* SHEPEIRO<br />
* solar<br />
* Thermidor<br />
* Wesley<br />
<br />
<br>'''<font color="green" size="3">Rodeofx</font>'''<br />
<br />
* maze<br />
<br />
<br>'''<font color="green" size="3">Rooster Teeth Productions</font>'''<br />
<br />
* RiotForQuiet<br />
<br />
<br>'''<font color="green" size="3">Runic Games (Seattle, WA)</font>'''<br />
<br />
* Jashugan<br />
* Matabus<br />
<br />
<br>'''<font color="green" size="3">Ruffian Games</font>'''<br />
<br />
* Aneurexorcyst<br />
<br />
<br>'''<font color="green" size="3">SCE San Diego Studio</font>'''<br />
<br />
* keosar<br />
<br />
<br>'''<font color="green" size="3">Sea Ape Entertainment</font>'''<br />
<br />
* fabio brasilien<br />
<br />
<br>'''<font color="green" size="3">Seed Studios (Porto, Portugal)</font>'''<br />
<br />
* ultra<br />
<br />
<br>'''<font color="green" size="3">Shadows in Darkness (Coral Springs, FL)</font>'''<br />
<br />
* Cyberoxide<br />
* jeremiah_bigley<br />
* raithen<br />
<br />
<br>'''<font color="green" size="3">Shapefarm (Helsingborg, Sweden) </font>'''<br />
<br />
* BigErn<br />
<br />
<br>'''<font color="green" size="3">Sidhe Interactive (Wellington, New Zealand)</font>'''<br />
<br />
* Jackablade<br />
* Nizza_waaarg<br />
<br />
<br>'''<font color="green" size="3">Simian Squared (London, United Kingdom)</font>'''<br />
<br />
* Chimp<br />
<br />
<br>'''<font color="green" size="3">Slant Six Games (Vancouver, BC)</font>'''<br />
<br />
* Jay Evans<br />
<br />
<br>'''<font color="green" size="3">Sledgehammer Games (Foster City, CA)</font>'''<br />
<br />
* Amsterdam Hilton Hotel<br />
* Gonzo<br />
* MalloryW<br />
* Oniram<br />
* roderickweise<br />
<br />
<br>'''<font color="green" size="3">Slipgate Ironworks (San Mateo, CA)</font>'''<br />
<br />
* AHotHandSandwich<br />
* Bashomaru<br />
<br />
<br>'''<font color="green" size="3">Sony Computer Entertainment America (Foster City, CA)</font>'''<br />
<br />
* HellMark<br />
<br />
<br>'''<font color="green" size="3">Sony Computer Entertainment Japan (Tokyo, Japan)</font>'''<br />
<br />
* rasmus<br />
<br />
<br>'''<font color="green" size="3">Sony Computer Entertainment London (London, United Kingdom)</font>'''<br />
<br />
* Crack Panda<br />
* Del<br />
* Mr Bear<br />
* polycrunch<br />
<br />
<br>'''<font color="green" size="3">Sony Online Entertainment(Austin, TX)</font>'''<br />
<br />
* r13<br />
<br />
<br>'''<font color="green" size="3">Sony Santa Monica (Santa Monica, CA)</font>'''<br />
<br />
* grassetti<br />
* Kbrom12<br />
<br />
<br>'''<font color="green" size="3">Spacetime Studios (Austin, TX)</font>'''<br />
<br />
* Kevin Albers<br />
<br />
<br>'''<font color="green" size="3">Spark Unlimited (Los Angeles, CA)</font>'''<br />
<br />
* Orgoth02<br />
<br />
<br>'''<font color="green" size="3">Splash Damage (London, United Kingdom)</font>'''<br />
<br />
* JFletcher<br />
* Jsargent<br />
* Kimono<br />
* MoP<br />
* Myles<br />
* spacemonkey<br />
* Vahl<br />
<br />
<br>'''<font color="green" size="3">Square Enix (Montréal, BC)</font>'''<br />
<br />
* Arcanox<br />
<br />
<br>'''<font color="green" size="3">Stainless Games (Newport, Isle of Wight, United Kingdom)</font>'''<br />
<br />
* A-N-P<br />
<br />
<br>'''<font color="green" size="3">Starbreeze / Overkill (Stockholm, Sweden)</font>'''<br />
<br />
* Brygelsmack<br />
* Generalvivi<br />
* maxivz<br />
<br />
<br>'''<font color="green" size="3">Storm8 (Redwood City, CA)</font>'''<br />
<br />
* haZe<br />
<br />
<br>'''<font color="green" size="3">Sucker Punch Productions (Bellevue, WA)</font>'''<br />
<br />
* Filbot<br />
<br />
<br>'''<font color="green" size="3">Sumo Digital (Sheffield, United Kingdom)</font>'''<br />
<br />
* kymbyli<br />
<br />
<br>'''<font color="green" size="3">TabTale (Tel Aviv, Israel)</font>'''<br />
<br />
* Sukotto<br />
<br />
<br>'''<font color="green" size="3">Tantalus Interactive (Melbourne, Australia)</font>'''<br />
<br />
* Conor<br />
* Junkers<br />
<br />
<br>'''<font color="green" size="3">Tarsier Studios (Malmo, Sweden)</font>'''<br />
<br />
* AimBiz<br />
* c0ldhands<br />
<br />
<br>'''<font color="green" size="3">Techland (Wroclaw, Poland)</font>'''<br />
<br />
* e=mc^2<br />
<br />
<br>'''<font color="green" size="3">Telos Entertainment (Charlottetown, Canada)</font>'''<br />
<br />
* Canadian Ink<br />
<br />
<br>'''<font color="green" size="3">Threewave Software (Vancouver, BC)</font>'''<br />
<br />
* jouste<br />
* Dakkon<br />
* Renalicious<br />
<br />
<br>'''<font color="green" size="3">Torn Banner Studios (Toronto, Canada)</font>'''<br />
<br />
* darbeenbo<br />
* Dylan Brady<br />
* JasonLavoie<br />
<br />
<br>'''<font color="green" size="3">Toys for Bob (Novato, CA)</font>'''<br />
<br />
* gauravcm<br />
<br />
<br>'''<font color="green" size="3">Traveller's Tales (Maidenhead, United Kingdom)</font>'''<br />
<br />
* AdamE87<br />
<br />
<br>'''<font color="green" size="3">Trendy Entertainment (Gainesville, Florida)</font>'''<br />
<br />
* GabrielP<br />
<br />
<br>'''<font color="green" size="3">Treyarch (Santa Monica, CA)</font>'''<br />
<br />
* Jesse Moody<br />
* beefaroni<br />
<br />
<br>'''<font color="green" size="3">Trion Worlds (Redwood City, CA)</font>'''<br />
<br />
* Daz<br />
* Haikai<br />
* prototyp3<br />
* shrew81<br />
<br />
<br>'''<font color="green" size="3">Tripwire Interactive (Atlanta, GA)</font>'''<br />
<br />
* ohnein<br />
<br />
<br>'''<font color="green" size="3">TT Fusion (Manchester, United Kingdom)</font>'''<br />
<br />
* East<br />
* Flynny<br />
* SirCalalot<br />
<br />
<br>'''<font color="green" size="3">Turbine, Inc (Westwood, MA)</font>'''<br />
<br />
* DLoud<br />
* HopeTorture<br />
* Fireflights<br />
<br />
<br>'''<font color="green" size="3">Turtle Rock Studios (Lake Forest, CA)</font>'''<br />
<br />
* Keen<br />
<br />
<br>'''<font color="green" size="3">U4iA Games (Bellevue, WA)</font>'''<br />
<br />
* iamtravis316<br />
* nrek<br />
<br />
<br>'''<font color="green" size="3">Ubisoft Annecy (Annecy, France)</font>'''<br />
<br />
* trebor777<br />
<br />
<br>'''<font color="green" size="3">Ubisoft BlueByte (Dusseldorf, Germany)</font>'''<br />
<br />
* Spoon<br />
<br />
<br>'''<font color="green" size="3">Ubisoft (Montréal, BC)</font>'''<br />
<br />
* A-Train<br />
* evillair<br />
* PixelMasher<br />
* LincolnHughes<br />
* imyj<br />
* megalmn2000<br />
* ShadowM8<br />
<br />
<br>'''<font color="green" size="3">Ubisoft (Toronto, Canada)</font>'''<br />
<br />
* adam<br />
* deceiver<br />
* haiddasalami<br />
* hainek<br />
* Mistry10<br />
* shabba<br />
* slipsius<br />
* Uly<br />
<br />
<br>'''<font color="green" size="3">Ubisoft (Singapore)</font>'''<br />
<br />
* akramparvez<br />
<br />
<br>'''<font color="green" size="3">Ubisoft Reflections (Newcastle, United Kingdom)</font>'''<br />
<br />
* _Calix_<br />
* Shiv<br />
* Stinger88<br />
* underfox<br />
<br />
<br>'''<font color="green" size="3">United Front Games (Vancouver, Canada)</font>'''<br />
<br />
* TWilson<br />
* Hebs<br />
<br />
<br>'''<font color="green" size="3">Valkyrie Entertainment (Seattle, WA)</font>'''<br />
<br />
* Diminished-self<br />
* ENODMI<br />
* fattkid<br />
* Ferg<br />
* isaac<br />
* okkun<br />
* Ryno<br />
<br />
<br>'''<font color="green" size="3">Valve Software (Bellevue, WA)</font>'''<br />
<br />
* kite<br />
* Paul Pepera<br />
<br />
<br>'''<font color="green" size="3">Variable State (London, United Kingdom)</font>'''<br />
<br />
* HiFiHair<br />
<br />
<br>'''<font color="green" size="3">Vicious Cycle Software (Chapel Hill, NC)</font>'''<br />
<br />
* matthewjvia<br />
<br />
<br>'''<font color="green" size="3">Vicarious Visions (Menands, NY)</font>'''<br />
<br />
* Devoid<br />
* Donavonyoung<br />
* wassum<br />
<br />
<br>'''<font color="green" size="3">Virtual 3D (Boca Raton, FL)</font>'''<br />
<br />
* Mechadus<br />
<br />
<br>'''<font color="green" size="3">Virtual Toys (Madrid, Spain)</font>'''<br />
<br />
* german01<br />
<br />
<br>'''<font color="green" size="3">Virtuos Games (Shanghai)</font>'''<br />
<br />
* akramparvez<br />
* Kwramm<br />
<br />
<br>'''<font color="green" size="3">Visceral Games</font>'''<br />
<br />
* stimpack<br />
* G3L<br />
* Sean VanGorder<br />
<br />
<br>'''<font color="green" size="3">Visual Concepts (Novato, CA)</font>'''<br />
<br />
* dnorth<br />
<br />
<br>'''<font color="green" size="3">Volition Inc</font>'''<br />
<br />
* Boraxman<br />
* Delo<br />
* Ghostscape<br />
* HarlequiN<br />
* J0NNYquid<br />
* Millah<br />
* retleks<br />
* Swampbug<br />
* Zergxes<br />
* gsokol<br />
<br />
<br>'''<font color="green" size="3">Wargaming.net (Cyprus)</font>'''<br />
<br />
* downarmy<br />
<br />
<br>'''<font color="green" size="3">Wargaming West (Chicago, IL)</font>'''<br />
<br />
* Amatobahn<br />
* skyline5gtr<br />
<br />
<br>'''<font color="green" size="3">Warner Brothers Games (Montréal, BC)</font>'''<br />
<br />
* eyo<br />
<br />
<br>'''<font color="green" size="3">WMS Gaming</font>'''<br />
<br />
* WipEout<br />
<br />
<br>'''<font color="green" size="3">Wolfire Games (Berkeley, CA)</font>'''<br />
<br />
* Ninjas<br />
<br />
<br>'''<font color="green" size="3">The Workshop (Marina Del Rey, CA)</font>'''<br />
<br />
* r4ptur3<br />
<br />
<br>'''<font color="green" size="3">YAGER Development GmbH (Berlin, Germany)</font>'''<br />
<br />
* EbolaV<br />
* JO420<br />
<br />
<br>'''<font color="green" size="3">You Kick Ass (Bellevue, WA)</font>'''<br />
<br />
* GarageBay9<br />
<br />
<br>'''<font color="green" size="3">Zenimax (Hunt Valley, MD)</font>'''<br />
<br />
* Cody<br />
* Em.<br />
* toren3d<br />
* Vidar<br />
<br />
<br />
This list was originally on the forum, in a thread named [http://polycount.com/discussion/49362/polycounter-job-census/p1 Polycounter Job Census]. When we upgraded the forum software, the latest list was lost. The list was restored from [https://web.archive.org/web/20150410044056/http://www.polycount.com/forum/showthread.php?t=49362 a backup] on the [https://archive.org/web/ Internet Archive Wayback Machine].<br />
<br />
----<br />
[[Category:Information]][[Category:GameIndustry]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Polycounter_Job_CensusPolycounter Job Census2016-10-12T16:04:13Z<p>Dustinbrown: </p>
<hr />
<div>A list of game development studios, and the Polycount members who are employed there. <br />
<br />
<br>'''<font color="green" size="3">2k Australia (Canberra, Australia)</font>'''<br />
<br />
* sprunghunt<br />
<br />
<br>'''<font color="green" size="3">2k Czech (Prague, Czech Republic)</font>'''<br />
<br />
* searinox<br />
<br />
<br>'''<font color="green" size="3">2k Games / Hangar 13 (Novato, CA)</font>'''<br />
<br />
* MooseCommander<br />
<br />
<br>'''<font color="green" size="3">22 Cans (Guildford, United Kingdom)</font>'''<br />
<br />
* feanix<br />
* Flynny<br />
<br />
<br>'''<font color="green" size="3">3Point Studios</font>'''<br />
<br />
* perna<br />
<br />
<br>'''<font color="green" size="3">343 Industries (Redmond, WA)</font>'''<br />
<br />
* AlexCatMasterSupreme<br />
* JDinges<br />
* KolbyJukes<br />
* Shanthosa<br />
* Thegodzero<br />
* tottot<br />
* vemadesign<br />
<br />
<br>'''<font color="green" size="3">5TH Cell (Bellevue, WA)</font>'''<br />
<br />
* boomz<br />
* Funky Bunnies<br />
<br />
<br>'''<font color="green" size="3">6waves Lolapps (Dallas, TX)</font>'''<br />
<br />
* BradMyers82<br />
* jlewis<br />
* Junkie_XL<br />
<br />
<br>'''<font color="green" size="3">AAD Productions (Seattle, WA)</font>'''<br />
<br />
* bgivenb<br />
<br />
<br>'''<font color="green" size="3">Adhesive Games (Los Angeles, CA)</font>'''<br />
<br />
* wester<br />
<br />
<br>'''<font color="green" size="3">Amaze Entertainment (Austin, TX)</font>'''<br />
<br />
* jpgourley<br />
<br />
<br>'''<font color="green" size="3">Allegorithmic (Clermont-Ferrand, France)</font>'''<br />
<br />
* Froyok<br />
<br />
<br>'''<font color="green" size="3">Another Castle Studios (Charlottetown, Canada)</font>'''<br />
<br />
* Canadian Ink<br />
<br />
<br>'''<font color="green" size="3">ArenaNet (Bellevue, WA)</font>'''<br />
<br />
* stoofoo<br />
* Truth<br />
* Perlinfalcon<br />
<br />
<br>'''<font color="green" size="3">Armature Studios (Austin, TX)</font>'''<br />
<br />
* Cap<br />
<br />
<br>'''<font color="green" size="3">Art Bully Productions (NY)</font>'''<br />
<br />
* Kitteh<br />
<br />
<br>'''<font color="green" size="3">Arrowhead Game Studios (Stockholm, Sweden)</font>'''<br />
<br />
* Carl Brannstorm<br />
* jimsvanberg<br />
<br />
<br>'''<font color="green" size="3">Atomic Games (Raleigh, NC)</font>'''<br />
<br />
* Jet_Pilot<br />
<br />
<br>'''<font color="green" size="3">Avalanche Studios (Stockholm, Sweden)</font>'''<br />
<br />
* Jon Jones<br />
* sltrOlsson<br />
* poly_bob<br />
<br />
<br>'''<font color="green" size="3">Backflip Studios (Boulder, CO)</font>'''<br />
<br />
* Eclipse<br />
<br />
<br>'''<font color="green" size="3">Barbaroga (Chicago, IL)</font>'''<br />
<br />
* Heather.Hughes<br />
<br />
<br>'''<font color="green" size="3">BattleCry Studios (Austin, TX)</font>'''<br />
<br />
* Jon Rush<br />
<br />
<br>'''<font color="green" size="3">Beenox (Quebec City, Quebec)</font>'''<br />
<br />
* Boyso<br />
* JRancourt<br />
* kaktuzlime<br />
* kremrhi<br />
* Lepothier<br />
<br />
<br>'''<font color="green" size="3">Behaviour (Montréal, BC)</font>'''<br />
<br />
* Bruno Afonseca<br />
<br />
<br>'''<font color="green" size="3">Bend Studio (Bend, OR)</font>'''<br />
<br />
* biofrost<br />
* iangoold3d<br />
* Rurouni Strife<br />
<br />
<br>'''<font color="green" size="3">Bethesda Game Studios (Rockville, MD)</font>'''<br />
<br />
* aajohnny<br />
* doc_rob<br />
* e_x<br />
* Geezus<br />
* Higuy<br />
<br />
<br>'''<font color="green" size="3">Big Ant Studios (Melbourne, Australia)</font>'''<br />
<br />
* DMoz<br />
* duncan<br />
<br />
<br>'''<font color="green" size="3">Big Bang Entertainment (Phoenix, AZ)</font>'''<br />
<br />
* Aldo<br />
<br />
<br>'''<font color="green" size="3">Big Sandwich Games (Vancouver, BC)</font>'''<br />
<br />
* Quasar<br />
* shinobix<br />
* TS_Falcon<br />
<br />
<br>'''<font color="green" size="3">BigPark Inc (Vancouver, BC)</font>'''<br />
<br />
* malcolm<br />
<br />
<br>'''<font color="green" size="3">Bioware (Austin, TX)</font>'''<br />
<br />
* Ben Cloward<br />
* Goat Justice<br />
* Rob Galanakis<br />
<br />
<br>'''<font color="green" size="3">Bioware (Edmonton, Canada)</font>'''<br />
<br />
* Hazed_blue<br />
<br />
<br>'''<font color="green" size="3">Bioware (Montréal, BC)</font>'''<br />
<br />
* Bad-Koala<br />
* Grassetti<br />
<br />
<br>'''<font color="green" size="3">Bioware Mythic (Fairfax, VA)</font>'''<br />
<br />
* Polymonkey<br />
<br />
<br>'''<font color="green" size="3">Blackbeard Games (Stockholm, Sweden)</font>'''<br />
<br />
* Deadly Nightshade<br />
<br />
<br>'''<font color="green" size="3">Blizzard Entertainment (Irvine, CA)</font>'''<br />
<br />
* [HP]<br />
* Darkrusader<br />
* Dom<br />
* Dusty<br />
* Empty<br />
* foreverendering<br />
* Hamish Bode<br />
* IxenonI<br />
* jarrede<br />
* jbrophy<br />
* Jessica Dinh<br />
* KyleJensen<br />
* MartinH<br />
* mheyman<br />
* Minos<br />
* moof<br />
* murph<br />
* obson<br />
* Peris<br />
* Ravenslayer<br />
* Renaud Galand<br />
* Rory_M<br />
* Saiainoshi<br />
* seven<br />
* Soul<br />
* T-Bone<br />
* [SF]Three9<br />
* turpedo<br />
* Tully<br />
* YBourykina<br />
<br />
<br>'''<font color="green" size="3">Blur Studio (Culver City, CA)</font>'''<br />
<br />
* jaaso<br />
<br />
<br>'''<font color="green" size="3">Bohemia Interactive Simulations (Hampshire, United Kingdom)</font>'''<br />
<br />
* benji<br />
<br />
<br>'''<font color="green" size="3">Born Ready (Guildford, United Kingdom)</font>'''<br />
<br />
* Millenia<br />
<br />
<br>'''<font color="green" size="3">Brain In A Jar (Tarporley, Cheshire, United Kingdom)</font>'''<br />
<br />
* A-N-P<br />
<br />
<br>'''<font color="green" size="3">Bungie Studios (Bellevue, WA)</font>'''<br />
<br />
* Axiao<br />
* Axios<br />
* breakneck<br />
* FatAssasin<br />
* Grimm_Wrecking<br />
* Haiasi<br />
* PoopSock<br />
* Pope Adam<br />
* mLichy<br />
* reverendK<br />
* Spug<br />
<br />
<br>'''<font color="green" size="3">Buzz Monkey Software (Eugene, OR)</font>'''<br />
<br />
* natetheartist<br />
<br />
<br>'''<font color="green" size="3">Capcom (Vancouver, Canada)</font>'''<br />
<br />
* glib<br />
* Selaznog<br />
<br />
<br>'''<font color="green" size="3">Carbine Studios (Aliso Viejo, CA)</font>'''<br />
<br />
* Arkadius<br />
* homes44<br />
* Mrandk<br />
* POFFINGTON<br />
* Reverenddevil<br />
<br />
<br>'''<font color="green" size="3">Caspian Learning (Newcastle Upon Tyne, United Kingdom)</font>'''<br />
<br />
* gateian<br />
<br />
<br>'''<font color="green" size="3">Cat Daddy Games (Kirkland, WA)</font>'''<br />
<br />
* ebagg<br />
<br />
<br>'''<font color="green" size="3">CI Games (Warsaw, Poland)</font>'''<br />
<br />
<br>'''<font color="green" size="3">CCP (Reykjav�k, Iceland)</font>'''<br />
<br />
* Flava-Fly<br />
* undoz<br />
<br />
<br>'''<font color="green" size="3">CD Projekt Red (Warsaw, Poland)</font>'''<br />
<br />
* MiAlx<br />
<br />
<br>'''<font color="green" size="3">CDRIN (Quebec, Canada)</font>'''<br />
<br />
* Felixenfeu<br />
* LeRenart<br />
<br />
<br>'''<font color="green" size="3">Certain Affinity (Austin, TX)</font>'''<br />
<br />
* Flewda<br />
<br />
<br>'''<font color="green" size="3">CGBot (Monterrey N.L., Mexico)</font>'''<br />
<br />
* Justo<br />
* lincqk<br />
<br />
<br>'''<font color="green" size="3">Chaotic Moon Studios (Austin, TX)</font>'''<br />
<br />
* oobersli<br />
<br />
<br />
<br>'''<font color="green" size="3">Cloud Imperium Games (Austin, TX)</font>'''<br />
<br />
* Elijah<br />
* Lee3Dee<br />
<br />
<br>'''<font color="green" size="3">Cmune (Bejing, China)</font>'''<br />
<br />
* cox<br />
<br />
<br>'''<font color="green" size="3">The Coalition Studio (Vancouver, Canada)</font>'''<br />
<br />
* malcolm<br />
<br />
<br>'''<font color="green" size="3">Codemasters (Southam, Warwickshire, United Kingdom)</font>'''<br />
<br />
* urgaffel<br />
<br />
<br>'''<font color="green" size="3">Cold Iron Studios (Santa Clara, California)</font>'''<br />
<br />
* BradMyers82<br />
<br />
<br>'''<font color="green" size="3">Colossal Games (London, United Kingdom)</font>'''<br />
<br />
* Yozora<br />
<br />
<br>'''<font color="green" size="3">Crazy Bump Software (Austin, TX)</font>'''<br />
<br />
* Ryan Clark<br />
<br />
<br>'''<font color="green" size="3">The Creative Assembly (Horsham, United Kingdom)</font>'''<br />
<br />
* Baj Singh<br />
* jestersheepy<br />
* JohnnyRaptor<br />
* marks<br />
* Mr_Smo<br />
* Rob_Blight<br />
* PogoP<br />
* saturnfive<br />
* Sugus<br />
* wallasaurus<br />
* woogity<br />
<br />
<br>'''<font color="green" size="3">Cryptic Studios (Los Gatos, CA)</font>'''<br />
<br />
* cman2k<br />
* JnasconeArt<br />
* Matt Fagan<br />
* Tumerboy<br />
<br />
<br>'''<font color="green" size="3">Crytek (Frankfurt, Germany)</font>'''<br />
<br />
* Bart<br />
* Criminal<br />
* e-freak<br />
* freakadelle<br />
* MaYdaY<br />
* luke<br />
<br />
<br>'''<font color="green" size="3">Crytek (Nottingham, United Kingdom)</font>'''<br />
<br />
* EzMeow<br />
* Zubrowka<br />
<br />
<br>'''<font color="green" size="3">Cubic Corporation (San Diego, CA)</font>'''<br />
<br />
* ghost123238<br />
<br />
<br>'''<font color="green" size="3">Curve Studios (London, United Kingdom)</font>'''<br />
<br />
* GeeDave<br />
<br />
<br>'''<font color="green" size="3">Dadako Studios (Tokyo, Japan)</font>'''<br />
<br />
* hawken <br />
<br />
<br>'''<font color="green" size="3">Dapper Ram</font>'''<br />
<br />
* Marshal Banana<br />
<br />
<br>'''<font color="green" size="3">Day 1 Studios (Chicago, IL)</font>'''<br />
<br />
* kaburan<br />
<br />
<br>'''<font color="green" size="3">Design Mill, Inc. (Dubuque, IA)</font>'''<br />
<br />
* MegaMoogle<br />
<br />
<br>'''<font color="green" size="3">DICE - EA Digital Illusions CE (Stockholm, Sweden)</font>'''<br />
<br />
* Cubik<br />
* motives<br />
* o2car<br />
* Rens<br />
* Synthesizer<br />
* Wahlgren<br />
* Xoliul<br />
* zenpat<br />
<br />
<br>'''<font color="green" size="3">Digital Extremes (London, Ontario)</font>'''<br />
<br />
* Fuse<br />
* jordan.kocon<br />
* kary<br />
* mathes<br />
* Pogo_Daddy<br />
* shinobix<br />
* StrangeFate<br />
* tyl3r<br />
<br />
<br>'''<font color="green" size="3">Dinosaur Games (Austin, TX)</font>'''<br />
<br />
* skankerzero<br />
<br />
<br>'''<font color="green" size="3">Direwolf Digital (Denver, CO)</font>'''<br />
<br />
* Rayph<br />
<br />
<br>'''<font color="green" size="3">Disney Interactive (Glendale, CA)</font>'''<br />
<br />
* .polygon<br />
* Archanex<br />
* Grumpntug<br />
* hosfeph<br />
* misterboogie<br />
* Power_Mustache<br />
* Wells<br />
<br />
<br>'''<font color="green" size="3">Dovetail Games (SE England, United Kingdom)</font>'''<br />
<br />
* Perry Stringer (pez_11)<br />
* sheckee<br />
<br />
<br>'''<font color="green" size="3">Dream Forge Entertainment (Ruston, LA)</font>'''<br />
<br />
* RyanTaylor3D<br />
<br />
<br>'''<font color="green" size="3">EA Canada (Barnaby, BC)</font>'''<br />
<br />
* B18<br />
* pangarang<br />
* timotronprime<br />
<br />
<br>'''<font color="green" size="3">EA Firemonkeys (Melbourne, Australia)</font>'''<br />
<br />
* Emil Mujanovic<br />
<br />
<br>'''<font color="green" size="3">EA Montréal (Montréal, BC) </font>'''<br />
<br />
* Marcan<br />
<br />
<br>'''<font color="green" size="3">EA Tiburon (Orlando, FL)</font>'''<br />
<br />
* Kewon Decam<br />
<br />
<br>'''<font color="green" size="3">EA Sports (Vancouver, BC)</font>'''<br />
<br />
* R3D<br />
<br />
<br>'''<font color="green" size="3">Edge of Reality (Austin, TX)</font>'''<br />
<br />
* FunkaDelicDass<br />
<br />
<br>'''<font color="green" size="3">Eidos (Montréal, BC)</font>'''<br />
<br />
* Fred2303<br />
* Matroskin<br />
* JacqueChoi<br />
* Nysuatro<br />
<br />
<br>'''<font color="green" size="3">Electrified Games (San Francisco, CA)</font>'''<br />
<br />
* 3shold<br />
<br />
<br>'''<font color="green" size="3">Emerald City Games (Vancouver, BC)</font>'''<br />
<br />
* Uberren<br />
<br />
<br>'''<font color="green" size="3">Engine Software (Doetinchem, Netherlands)</font>'''<br />
<br />
* EVIL<br />
<br />
<br>'''<font color="green" size="3">Epic Games (Raleigh, NC)</font>'''<br />
<br />
* animatr<br />
* da_milkman<br />
* Frank<br />
* JordanW<br />
* kernersvillan<br />
* Kevin Johnstone<br />
* Moose<br />
* osman<br />
* paulsvoboda<br />
* rawkstar<br />
* rv_el<br />
* scotthomer<br />
* WarrenMarshall<br />
<br />
<br>'''<font color="green" size="3">Eurocom (Derby, United Kingdom)</font>'''<br />
<br />
* Mister Sentient<br />
* Searlee<br />
<br />
<br>'''<font color="green" size="3">Evolution Studios (Runcorn, United Kingdom)</font>'''<br />
<br />
* nathdevlin<br />
<br />
<br>'''<font color="green" size="3">Exis Interactive (Baltimore, MD)</font>'''<br />
<br />
* NeoprofZ<br />
* PeterK<br />
* retardedmonkey<br />
* shadows<br />
<br />
<br>'''<font color="green" size="3">Ubisoft Montréal (Montréal, BC)</font>'''<br />
<br />
* wizo<br />
<br />
<br>'''<font color="green" size="3">Ubisoft Paris (Paris, France)</font>'''<br />
<br />
* bobmartien<br />
<br />
<br>'''<font color="green" size="3">Ubisoft (Singapore)</font>'''<br />
<br />
* MrNinjitsu<br />
<br />
<br>'''<font color="green" size="3">Fatshark (Stockholm, Sweden)</font>'''<br />
<br />
* Belltann<br />
* PixelGoat<br />
<br />
<br>'''<font color="green" size="3">Frima (Quebec City, Canada)</font>'''<br />
<br />
* Odow<br />
<br />
<br>'''<font color="green" size="3">Frozenbyte (Helsinki, Finland)</font>'''<br />
<br />
* sande<br />
<br />
<br>'''<font color="green" size="3">Funcom (Oslo, Norway)</font>'''<br />
<br />
* CgMonkey<br />
<br />
<br>'''<font color="green" size="3">Funcom (Montréal, BC)</font>'''<br />
<br />
* CGMonkey<br />
* Crash<br />
<br />
<br>'''<font color="green" size="3">Funcom (Durham, NC)</font>'''<br />
<br />
* nyx702<br />
* flakked<br />
<br />
<br>'''<font color="green" size="3">Future Games of London (London, United Kingdom)</font>'''<br />
<br />
* torch<br />
<br />
<br>'''<font color="green" size="3">Gameloft (Auckland, New Zealand)</font>'''<br />
<br />
* TehSplatt<br />
* The Flying Monk<br />
<br />
<br>'''<font color="green" size="3">Gameloft (Cluj-Napoca, Romania)</font>'''<br />
<br />
* Mime<br />
<br />
<br>'''<font color="green" size="3">Gameloft (Montréal, BC)</font>'''<br />
<br />
* alexk<br />
* arkhange<br />
* fonfa<br />
* guedin<br />
* hobodactyl<br />
* jocz<br />
* kyalie<br />
<br />
<br>'''<font color="green" size="3">Gameloft (New Orleans, LA)</font>'''<br />
<br />
* JamesHall<br />
<br />
<br>'''<font color="green" size="3">Gamerizon (Montréal, BC)</font>'''<br />
<br />
* rorozilla<br />
<br />
<br>'''<font color="green" size="3">GameWorld7 (Haverfordwest, Wales, United Kingdom)</font>'''<br />
<br />
* KRakarth<br />
<br />
<br>'''<font color="green" size="3">Game Mechanic Studios (Tarzana, CA)</font>'''<br />
<br />
* G3L<br />
<br />
<br>'''<font color="green" size="3">Gearbox Software (Plano, TX)</font>'''<br />
<br />
* AstroZombie<br />
* Bbox85<br />
* ceebee<br />
* Chemical Alia<br />
* Drywall<br />
* mLink<br />
* s6<br />
<br />
<br>'''<font color="green" size="3">Gentle Giant Studios (Burbank, CA)</font>'''<br />
<br />
* r4ptur3<br />
<br />
<br>'''<font color="green" size="3">Giants Software (Zurich, Switzerland)</font>'''<br />
<br />
* MaVCArt<br />
<br />
<br>'''<font color="green" size="3">Glu Mobile (Portland, OR)</font>'''<br />
<br />
* octokitty<br />
<br />
<br>'''<font color="green" size="3">Griptonite Games (Kirkland, WA)</font>'''<br />
<br />
* PixelFish<br />
<br />
<br>'''<font color="green" size="3">Guerrilla Games SCEE (Amsterdam, Netherlands)</font>'''<br />
<br />
* fabiomsilva<br />
* Arno<br />
<br />
<br>'''<font color="green" size="3">Gumi America (Austin, TX)</font>'''<br />
<br />
* Jason Young<br />
<br />
<br>'''<font color="green" size="3">Gunfire Games (Austin, TX)</font>'''<br />
<br />
* Progg<br />
<br />
<br>'''<font color="green" size="3">Gusto Games (Banbury, Oxfordshire, United Kingdom)</font>'''<br />
<br />
* Mimp<br />
<br />
<br>'''<font color="green" size="3">Hatalom Systems (Orlando, FL)</font>'''<br />
<br />
* seforin<br />
<br />
<br>'''<font color="green" size="3">Havok (Dublin, Ireland)</font>'''<br />
<br />
* Mangled Poly<br />
<br />
<br>'''<font color="green" size="3">Her Interactive (Bellevue, WA)</font>'''<br />
<br />
* Karmageddon<br />
<br />
<br>'''<font color="green" size="3">Hi-Rez Studios (Alpharetta, GA)</font>'''<br />
<br />
* 3DK.P.<br />
* Daven<br />
* Scott_W<br />
* Sean McBride<br />
* skylebones<br />
* Slipstream<br />
* Xelan101<br />
<br />
<br>'''<font color="green" size="3">Hibernum Creations (Montréal, BC)</font>'''<br />
<br />
* Pioldes<br />
<br />
<br>'''<font color="green" size="3">High Moon Studios (San Diego, CA)</font>'''<br />
<br />
* BradleyWascher<br />
* NerfBatNinja<br />
* opiumunknown<br />
* Ott<br />
<br />
<br>'''<font color="green" size="3">Hidden Path Entertainment (Bellvue, WA)</font>'''<br />
<br />
* adam crockett<br />
<br />
<br>'''<font color="green" size="3">Hoplon Infotainment (Florianopolis, Brazil)</font>'''<br />
<br />
* cox<br />
* felipealves<br />
* felipefrango<br />
* funkdelic<br />
<br />
<br>'''<font color="green" size="3">Human Head (Madison, WI)</font>'''<br />
<br />
* leibarg<br />
<br />
<br>'''<font color="green" size="3">Icarus Studios (Cary, NC)</font>'''<br />
<br />
* Rainyn<br />
* spiderDude<br />
* XenoAcid<br />
<br />
<br>'''<font color="green" size="3">id Software (Mesquite, TX)</font>'''<br />
<br />
* DanK<br />
* Lear<br />
* roosterMAP<br />
* Spark<br />
* SquirrelyJones<br />
* struve<br />
* ZombieWells<br />
* HitmonInfinity<br />
<br />
<br>'''<font color="green" size="3">Illfonic (Denver, CO)</font>'''<br />
<br />
* heboltz3<br />
* Kedhrin<br />
* konstruct<br />
<br />
<br>'''<font color="green" size="3">Imagination Technologies (Kings Langley, United Kingdom)</font>'''<br />
<br />
* barnesy<br />
<br />
<br>'''<font color="green" size="3">Industry Games (Gilbert, AZ)</font>'''<br />
<br />
* killingpeople<br />
<br />
<br>'''<font color="green" size="3">Infinity Ward (Los Angeles, CA)</font>'''<br />
<br />
* 00Zero<br />
* josh_lynch<br />
* seth.<br />
<br />
<br>'''<font color="green" size="3">iNiS (Tokyo, Japan)</font>'''<br />
<br />
* Jonas Ronnegard<br />
<br />
<br>'''<font color="green" size="3">Insomniac Games (Burbank, CA)</font>'''<br />
<br />
* Arshlevon<br />
* BlvdNights<br />
* Gav<br />
* jam-i-am<br />
* N-gon<br />
* Swizzle<br />
<br />
<br>'''<font color="green" size="3">Insomniac Games (Durham, NC)</font>'''<br />
<br />
* Neolight<br />
<br />
<br>'''<font color="green" size="3">Interwave Studios (Sittard, Netherlands)</font>'''<br />
<br />
* MightyPea<br />
<br />
<br>'''<font color="green" size="3">inXile Entertainment (Newport Beach, CA)</font>'''<br />
<br />
* Brian "Panda" Choi<br />
* richkid<br />
<br />
<br>'''<font color="green" size="3">IO Interactive (Copenhagen, Denmark)</font>'''<br />
<br />
* warby<br />
<br />
<br>'''<font color="green" size="3">Iron Tiger Studios / NCSoft (San Mateo, CA)</font>'''<br />
<br />
* chronic<br />
<br />
<br>'''<font color="green" size="3">ISOTX (Luxembourg)</font>'''<br />
<br />
* Kratilim<br />
<br />
<br>'''<font color="green" size="3">Jagex (Cambridge, United Kingdom)</font>'''<br />
<br />
* lysaara<br />
<br />
<br>'''<font color="green" size="3">Jakks Pacific (Malibu, CA)</font>'''<br />
<br />
* gilesruscoe<br />
<br />
<br>'''<font color="green" size="3">Jet Set Games (Las Vegas, NV)</font>'''<br />
<br />
* McBradd<br />
<br />
<br>'''<font color="green" size="3">Just Add Water Ltd (Otley, United Kingdom)</font>'''<br />
<br />
* tda<br />
<br />
<br>'''<font color="green" size="3">Kandu Studios (New York, NY)</font>'''<br />
<br />
* Kandu<br />
<br />
<br>'''<font color="green" size="3">Kojima Productions (Tokyo, Japan)</font>'''<br />
<br />
* David Brumbley<br />
<br />
<br>'''<font color="green" size="3">Krillbite Studio (Hamar, Norway)</font>'''<br />
<br />
* Volantk<br />
<br />
<br>'''<font color="green" size="3">Kuju (London, United Kingdom)</font>'''<br />
<br />
* ukresistant<br />
<br />
<br>'''<font color="green" size="3">Larian Studios (Ghent, Belgium)</font>'''<br />
<br />
* DimSum<br />
<br />
<br>'''<font color="green" size="3">Lionhead Studios (Guildford, Surrey, United Kingdom)</font>'''<br />
<br />
* ghib<br />
<br />
<br>'''<font color="green" size="3">Liquid Development (Portland, OR)</font>'''<br />
<br />
* CJE<br />
* cyborgguineapig<br />
* glottis8<br />
* nacire<br />
<br />
<br>'''<font color="green" size="3">Machine Games (Uppsala, Sweden)</font>'''<br />
<br />
* o2_is_alright<br />
* Stertman<br />
<br />
<br>'''<font color="green" size="3">Marmoset Co (Kansas City, MO)</font>'''<br />
<br />
* GetAwesome<br />
* MonkeyScience<br />
* jeffdr<br />
* EarthQuake<br />
<br />
<br>'''<font color="green" size="3">Massive Entertainment (Malmo, Sweden)</font>'''<br />
<br />
* chrisradsby<br />
* Frozan<br />
* Matthew O<br />
* TheWinterLord<br />
* z0ltan<br />
<br />
<br>'''<font color="green" size="3">Microsoft Game Studios, Turn 10 (Redmond, WA)</font>'''<br />
<br />
* Joshua Stubbles<br />
<br />
<br>'''<font color="green" size="3">Moji Moji Design (Worcester, United Kingdom)</font>'''<br />
<br />
* Chunkey<br />
<br />
<br>'''<font color="green" size="3">MonkeyScience Adhesive Games (Los Angeles, CA)</font>'''<br />
<br />
* Wengyuqiu<br />
<br />
<br>'''<font color="green" size="3">Moving Picture Company (Vancouver, Canada)</font>'''<br />
<br />
* RWolf<br />
<br />
<br>'''<font color="green" size="3">Music Mastermind (Calabasas, CA)</font>'''<br />
<br />
* kream<br />
* timwiese<br />
<br />
<br>'''<font color="green" size="3">N-Space (Orlando, FL)</font>'''<br />
<br />
* ScubaSteve<br />
<br />
<br>'''<font color="green" size="3">Nadeo (Paris, France)</font>'''<br />
<br />
* OgrO<br />
<br />
<br>'''<font color="green" size="3">Naked Sky Entertainment (Los Angeles, CA)</font>'''<br />
<br />
* maltuna<br />
<br />
<br>'''<font color="green" size="3">Naughty Dog (Santa Monica, CA)</font>'''<br />
<br />
* Autocon<br />
* d1ver<br />
<br />
<br>'''<font color="green" size="3">nDreams (Farnborough, United Kingdom)</font>'''<br />
<br />
* kypo<br />
<br />
<br>'''<font color="green" size="3">Neon Play (Cirencester, United Kingdom)</font>'''<br />
<br />
* Ged<br />
<br />
<br>'''<font color="green" size="3">Nerjyzed Entertainment (Baton Rouge, LA)</font>'''<br />
<br />
* Pencilninja<br />
<br />
<br>'''<font color="green" size="3">Neversoft Entertainment (Los Angeles, CA)</font>'''<br />
<br />
* DrumBum<br />
* mvelasquez<br />
* Savage<br />
* SuperOstrich<br />
* ThatDon<br />
<br />
<br>'''<font color="green" size="3">New World Interactive (Denver, CO)</font>'''<br />
<br />
* Steppenwolf<br />
<br />
<br>'''<font color="green" size="3">Ninja Theory (Cambridge, United Kingdom)</font>'''<br />
<br />
* BigErn<br />
<br />
<br>'''<font color="green" size="3">NVIDIA (Germany)</font>'''<br />
<br />
* Crazybutcher<br />
<br />
<br>'''<font color="green" size="3">Obsidian Entertainment (Irvine, CA)</font>'''<br />
<br />
* leleuxart<br />
* SouthpawSid<br />
<br />
<br>'''<font color="green" size="3">OMNOM! workshop (Austin, TX)</font>'''<br />
<br />
* BoBo_the_seal<br />
* BrianP<br />
* Damytria<br />
* Justin Meisse<br />
<br />
<br>'''<font color="green" size="3">Other Ocean Interactive (Charlottetown, PEI, Canada)</font>'''<br />
<br />
* JeremyK<br />
* Kolgrima<br />
* Winthrop<br />
<br />
<br>'''<font color="green" size="3">OutAct (Marlborough, MA)</font>'''<br />
<br />
* Eric Chadwick<br />
<br />
<br>'''<font color="green" size="3">Outso (Nottingham, United Kingdom)</font>'''<br />
<br />
* Massbot<br />
<br />
<br>'''<font color="green" size="3">Pandemic Studios (Los Angeles, CA)</font>'''<br />
<br />
* Luxury<br />
<br />
<br>'''<font color="green" size="3">Paradigm (Carrolton, TX)</font>'''<br />
<br />
* Foehammer<br />
<br />
<br>'''<font color="green" size="3">Pelesys (Richmond, BC, Canada</font>'''<br />
<br />
* pliang<br />
<br />
<br>'''<font color="green" size="3">People Can Fly (Warsaw, Poland)</font>'''<br />
<br />
* Hatred<br />
<br />
<br>'''<font color="green" size="3">Petroglyph (Las Vegas, NV)</font>'''<br />
<br />
* sprunghunt<br />
* Xenobond<br />
<br />
<br>'''<font color="green" size="3">Phantom EFX (Cedar Falls, IA)</font>'''<br />
<br />
* Tigerfeet<br />
<br />
<br>'''<font color="green" size="3">Piranha Bytes (Ruhr, Germany)</font>'''<br />
<br />
* aphexx<br />
<br />
<br>'''<font color="green" size="3">Pirhana Games (Vancouver, BC, Canada)</font>'''<br />
<br />
* ae.<br />
<br />
<br>'''<font color="green" size="3">Pitbull Studios (Guildford, United Kingdom)</font>'''<br />
<br />
* ambershee<br />
<br />
<br>'''<font color="green" size="3">Pixelante Game Studios</font>'''<br />
<br />
* acc<br />
<br />
<br>'''<font color="green" size="3">PlatinumGames (Osaka, Japan)</font>'''<br />
<br />
* Mik2121<br />
<br />
<br>'''<font color="green" size="3">PlaySide VR (Melbourne, Victoria)</font>'''<br />
<br />
* Steve Schulze<br />
<br />
<br>'''<font color="green" size="3">Playful Corp (McKinney, TX)</font>''<br />
<br />
* EvanL<br />
<br />
<br>'''<font color="green" size="3">Polarbit (Stockholm, Sweden)</font>'''<br />
<br />
* Deadly Nightshade<br />
<br />
<br>'''<font color="green" size="3">Polygonal Design (France)</font>'''<br />
<br />
* Thierry86<br />
<br />
<br>'''<font color="green" size="3">Psyonix (San Diego, CA)</font>'''<br />
<br />
* ErichWK<br />
* gamedev<br />
* MorganFX<br />
<br />
<br>'''<font color="green" size="3">Pushbutton Labs</font>'''<br />
<br />
* Ajax<br />
<br />
<br>'''<font color="green" size="3">Quantic Dream (Paris, France)</font>'''<br />
<br />
* Bal<br />
<br />
<br>'''<font color="green" size="3">Rabbit Hole Interactive (Vancouver, CA)</font>'''<br />
<br />
* ScudzAlmighty<br />
<br />
<br>'''<font color="green" size="3">Rainmaker Entertainment (Vancouver, Canada)</font>'''<br />
<br />
* Ryswick<br />
<br />
<br>'''<font color="green" size="3">Rare (Coventry, United Kingdom)</font>'''<br />
<br />
* Leyvin<br />
<br />
<br>'''<font color="green" size="3">Raven Software (Madison, WI)</font>'''<br />
<br />
* Cojax<br />
* Jbradford<br />
<br />
<br>'''<font color="green" size="3">Reactor Zero (Ann Arbor, MI)</font>'''<br />
<br />
* 8-bit<br />
<br />
<br>'''<font color="green" size="3">Ready At Dawn Studios (Irvine, CA)</font>'''<br />
<br />
* Alberto Rdrgz<br />
* LLamaStar<br />
<br />
<br>'''<font color="green" size="3">Real U (Singapore)</font>'''<br />
<br />
* LoTekK<br />
* sandman<br />
* Snowfly<br />
<br />
<br>'''<font color="green" size="3">Rebellion (Oxford, United Kingdom)</font>'''<br />
<br />
* Optinium<br />
* Nelis<br />
* tharle<br />
<br />
<br>'''<font color="green" size="3">Redemption Games (Carlsbad, CA)</font>'''<br />
<br />
* MeshModeler<br />
<br />
<br>'''<font color="green" size="3">Red 5 Studios (Irvine, CA)</font>'''<br />
<br />
* acanaday<br />
<br />
<br>'''<font color="green" size="3">Red Fly Studio (Austin, TX)</font>'''<br />
<br />
* Andrew Morris<br />
<br />
<br>'''<font color="green" size="3">Red Storm Entertainment (Cary, NC )</font>'''<br />
<br />
* dtschultz<br />
<br />
<br>'''<font color="green" size="3">Red Tribe (Melbourne, Australia)</font>'''<br />
<br />
* DavidCoen<br />
<br />
<br>'''<font color="green" size="3">Redjade (London, ON)</font>'''<br />
<br />
* airbursh<br />
<br />
<br>'''<font color="green" size="3">Relic Entertainment (Vancouver, B.C.)</font>'''<br />
<br />
* Goldo_O<br />
* Tulkamir<br />
<br />
<br>'''<font color="green" size="3">Reloaded Productions (Edinburgh, United Kingdom)</font>'''<br />
<br />
* BeardyDan<br />
* SaferDan<br />
<br />
<br>'''<font color="green" size="3">Remedy Entertainment (Espoo, Finland)</font>'''<br />
<br />
* 3dwit<br />
<br />
<br>'''<font color="green" size="3">Respawn Entertainment</font>'''<br />
<br />
* Papa_Austin<br />
* jaythurm<br />
<br />
<br>'''<font color="green" size="3">Retro Studios (Austin, TX)</font>'''<br />
<br />
* OrganizedChaos<br />
* onelung<br />
<br />
<br>'''<font color="green" size="3">Rhythm and Hues</font>'''<br />
<br />
* Archanex<br />
<br />
<br>'''<font color="green" size="3">Riot Games (Culver City, CA)</font>'''<br />
<br />
* bugo<br />
* ChaosEidolon<br />
* Drachis<br />
* Josh_Singh<br />
* Parasite7<br />
* TerraBite<br />
* STRIKER<br />
* X-Convict<br />
<br />
<br>'''<font color="green" size="3">Robotoki (Los Angeles, CA)</font>'''<br />
<br />
* cmgillett<br />
<br />
<br>'''<font color="green" size="3">Rocket Gaming Systems (Las Vegas, NV)</font>'''<br />
<br />
* UNCCheezy<br />
<br />
<br>'''<font color="green" size="3">Rocksteady Studios (London, United Kingdom)</font>'''<br />
<br />
* ImSlightlyBored<br />
* Karl Stjernberg<br />
* vik<br />
<br />
<br>'''<font color="green" size="3">Rockstar Leeds (Leeds, United Kingdom)</font>'''<br />
<br />
* danr<br />
* Dazz3r<br />
* guplik<br />
* prs-phil<br />
* Talon<br />
<br />
<br>'''<font color="green" size="3">Rockstar New England (Andover, MA)</font>'''<br />
<br />
* RexM<br />
* Silva_Spoon<br />
<br />
<br>'''<font color="green" size="3">Rockstar North (Edinburgh, United Kingdom)</font>'''<br />
<br />
* benclark<br />
* BHJ<br />
* Ex-Ray<br />
* headengine<br />
* Kilkus<br />
* Lokter<br />
* PaulP<br />
* Rick Stirling<br />
* SHEPEIRO<br />
* solar<br />
* Thermidor<br />
* Wesley<br />
<br />
<br>'''<font color="green" size="3">Rodeofx</font>'''<br />
<br />
* maze<br />
<br />
<br>'''<font color="green" size="3">Rooster Teeth Productions</font>'''<br />
<br />
* RiotForQuiet<br />
<br />
<br>'''<font color="green" size="3">Runic Games (Seattle, WA)</font>'''<br />
<br />
* Jashugan<br />
* Matabus<br />
<br />
<br>'''<font color="green" size="3">Ruffian Games</font>'''<br />
<br />
* Aneurexorcyst<br />
<br />
<br>'''<font color="green" size="3">SCE San Diego Studio</font>'''<br />
<br />
* keosar<br />
<br />
<br>'''<font color="green" size="3">Sea Ape Entertainment</font>'''<br />
<br />
* fabio brasilien<br />
<br />
<br>'''<font color="green" size="3">Seed Studios (Porto, Portugal)</font>'''<br />
<br />
* ultra<br />
<br />
<br>'''<font color="green" size="3">Shadows in Darkness (Coral Springs, FL)</font>'''<br />
<br />
* Cyberoxide<br />
* jeremiah_bigley<br />
* raithen<br />
<br />
<br>'''<font color="green" size="3">Shapefarm (Helsingborg, Sweden) </font>'''<br />
<br />
* BigErn<br />
<br />
<br>'''<font color="green" size="3">Sidhe Interactive (Wellington, New Zealand)</font>'''<br />
<br />
* Jackablade<br />
* Nizza_waaarg<br />
<br />
<br>'''<font color="green" size="3">Simian Squared (London, United Kingdom)</font>'''<br />
<br />
* Chimp<br />
<br />
<br>'''<font color="green" size="3">Slant Six Games (Vancouver, BC)</font>'''<br />
<br />
* Jay Evans<br />
<br />
<br>'''<font color="green" size="3">Sledgehammer Games (Foster City, CA)</font>'''<br />
<br />
* Amsterdam Hilton Hotel<br />
* Gonzo<br />
* MalloryW<br />
* Oniram<br />
* roderickweise<br />
<br />
<br>'''<font color="green" size="3">Slipgate Ironworks (San Mateo, CA)</font>'''<br />
<br />
* AHotHandSandwich<br />
* Bashomaru<br />
<br />
<br>'''<font color="green" size="3">Sony Computer Entertainment America (Foster City, CA)</font>'''<br />
<br />
* HellMark<br />
<br />
<br>'''<font color="green" size="3">Sony Computer Entertainment Japan (Tokyo, Japan)</font>'''<br />
<br />
* rasmus<br />
<br />
<br>'''<font color="green" size="3">Sony Computer Entertainment London (London, United Kingdom)</font>'''<br />
<br />
* Crack Panda<br />
* Del<br />
* Mr Bear<br />
* polycrunch<br />
<br />
<br>'''<font color="green" size="3">Sony Online Entertainment(Austin, TX)</font>'''<br />
<br />
* r13<br />
<br />
<br>'''<font color="green" size="3">Sony San Diego (San Diego, CA)</font>'''<br />
<br />
* dkorch<br />
* dustinbrown<br />
<br />
<br />
<br>'''<font color="green" size="3">Sony Santa Monica (Santa Monica, CA)</font>'''<br />
<br />
* grassetti<br />
* Kbrom12<br />
<br />
<br>'''<font color="green" size="3">Spacetime Studios (Austin, TX)</font>'''<br />
<br />
* Kevin Albers<br />
<br />
<br>'''<font color="green" size="3">Spark Unlimited (Los Angeles, CA)</font>'''<br />
<br />
* Orgoth02<br />
<br />
<br>'''<font color="green" size="3">Splash Damage (London, United Kingdom)</font>'''<br />
<br />
* JFletcher<br />
* Jsargent<br />
* Kimono<br />
* MoP<br />
* Myles<br />
* spacemonkey<br />
* Vahl<br />
<br />
<br>'''<font color="green" size="3">Square Enix (Montréal, BC)</font>'''<br />
<br />
* Arcanox<br />
<br />
<br>'''<font color="green" size="3">Stainless Games (Newport, Isle of Wight, United Kingdom)</font>'''<br />
<br />
* A-N-P<br />
<br />
<br>'''<font color="green" size="3">Starbreeze / Overkill (Stockholm, Sweden)</font>'''<br />
<br />
* Brygelsmack<br />
* Generalvivi<br />
* maxivz<br />
<br />
<br>'''<font color="green" size="3">Storm8 (Redwood City, CA)</font>'''<br />
<br />
* haZe<br />
<br />
<br>'''<font color="green" size="3">Sucker Punch Productions (Bellevue, WA)</font>'''<br />
<br />
* Filbot<br />
<br />
<br>'''<font color="green" size="3">Sumo Digital (Sheffield, United Kingdom)</font>'''<br />
<br />
* kymbyli<br />
<br />
<br>'''<font color="green" size="3">TabTale (Tel Aviv, Israel)</font>'''<br />
<br />
* Sukotto<br />
<br />
<br>'''<font color="green" size="3">Telltale Games (San Rafael, California)</font>'''<br />
<br />
* Jeff Parrott<br />
<br />
<br>'''<font color="green" size="3">Tantalus Interactive (Melbourne, Australia)</font>'''<br />
<br />
* Conor<br />
* Junkers<br />
<br />
<br>'''<font color="green" size="3">Tarsier Studios (Malmo, Sweden)</font>'''<br />
<br />
* AimBiz<br />
* c0ldhands<br />
<br />
<br>'''<font color="green" size="3">Techland (Wroclaw, Poland)</font>'''<br />
<br />
* e=mc^2<br />
<br />
<br>'''<font color="green" size="3">Telos Entertainment (Charlottetown, Canada)</font>'''<br />
<br />
* Canadian Ink<br />
<br />
<br>'''<font color="green" size="3">Threewave Software (Vancouver, BC)</font>'''<br />
<br />
* jouste<br />
* Dakkon<br />
* Renalicious<br />
<br />
<br>'''<font color="green" size="3">Torn Banner Studios (Toronto, Canada)</font>'''<br />
<br />
* darbeenbo<br />
* Dylan Brady<br />
* JasonLavoie<br />
<br />
<br>'''<font color="green" size="3">Toys for Bob (Novato, CA)</font>'''<br />
<br />
* gauravcm<br />
<br />
<br>'''<font color="green" size="3">Traveller's Tales (Maidenhead, United Kingdom)</font>'''<br />
<br />
* AdamE87<br />
<br />
<br>'''<font color="green" size="3">Trendy Entertainment (Gainesville, Florida)</font>'''<br />
<br />
* GabrielP<br />
<br />
<br>'''<font color="green" size="3">Treyarch (Santa Monica, CA)</font>'''<br />
<br />
* Jesse Moody<br />
* beefaroni<br />
<br />
<br>'''<font color="green" size="3">Trion Worlds (Redwood City, CA)</font>'''<br />
<br />
* Daz<br />
* Haikai<br />
* prototyp3<br />
* shrew81<br />
<br />
<br>'''<font color="green" size="3">Tripwire Interactive (Atlanta, GA)</font>'''<br />
<br />
* ohnein<br />
<br />
<br>'''<font color="green" size="3">TT Fusion (Manchester, United Kingdom)</font>'''<br />
<br />
* East<br />
* Flynny<br />
* SirCalalot<br />
<br />
<br>'''<font color="green" size="3">Turbine, Inc (Westwood, MA)</font>'''<br />
<br />
* DLoud<br />
* HopeTorture<br />
* Fireflights<br />
<br />
<br>'''<font color="green" size="3">Turtle Rock Studios (Lake Forest, CA)</font>'''<br />
<br />
* Keen<br />
<br />
<br>'''<font color="green" size="3">U4iA Games (Bellevue, WA)</font>'''<br />
<br />
* iamtravis316<br />
* nrek<br />
<br />
<br>'''<font color="green" size="3">Ubisoft Annecy (Annecy, France)</font>'''<br />
<br />
* trebor777<br />
<br />
<br>'''<font color="green" size="3">Ubisoft BlueByte (Dusseldorf, Germany)</font>'''<br />
<br />
* Spoon<br />
<br />
<br>'''<font color="green" size="3">Ubisoft (Montréal, BC)</font>'''<br />
<br />
* A-Train<br />
* evillair<br />
* PixelMasher<br />
* LincolnHughes<br />
* imyj<br />
* megalmn2000<br />
* ShadowM8<br />
<br />
<br>'''<font color="green" size="3">Ubisoft (Toronto, Canada)</font>'''<br />
<br />
* adam<br />
* deceiver<br />
* haiddasalami<br />
* hainek<br />
* Mistry10<br />
* shabba<br />
* slipsius<br />
* Uly<br />
<br />
<br>'''<font color="green" size="3">Ubisoft (Singapore)</font>'''<br />
<br />
* akramparvez<br />
<br />
<br>'''<font color="green" size="3">Ubisoft Reflections (Newcastle, United Kingdom)</font>'''<br />
<br />
* _Calix_<br />
* Shiv<br />
* Stinger88<br />
* underfox<br />
<br />
<br>'''<font color="green" size="3">United Front Games (Vancouver, Canada)</font>'''<br />
<br />
* TWilson<br />
* Hebs<br />
<br />
<br>'''<font color="green" size="3">Valkyrie Entertainment (Seattle, WA)</font>'''<br />
<br />
* Diminished-self<br />
* ENODMI<br />
* fattkid<br />
* Ferg<br />
* isaac<br />
* okkun<br />
* Ryno<br />
<br />
<br>'''<font color="green" size="3">Valve Software (Bellevue, WA)</font>'''<br />
<br />
* kite<br />
* Paul Pepera<br />
<br />
<br>'''<font color="green" size="3">Variable State (London, United Kingdom)</font>'''<br />
<br />
* HiFiHair<br />
<br />
<br>'''<font color="green" size="3">Vicious Cycle Software (Chapel Hill, NC)</font>'''<br />
<br />
* matthewjvia<br />
<br />
<br>'''<font color="green" size="3">Vicarious Visions (Menands, NY)</font>'''<br />
<br />
* Devoid<br />
* Donavonyoung<br />
* wassum<br />
<br />
<br>'''<font color="green" size="3">Virtual 3D (Boca Raton, FL)</font>'''<br />
<br />
* Mechadus<br />
<br />
<br>'''<font color="green" size="3">Virtual Toys (Madrid, Spain)</font>'''<br />
<br />
* german01<br />
<br />
<br>'''<font color="green" size="3">Virtuos Games (Shanghai)</font>'''<br />
<br />
* akramparvez<br />
* Kwramm<br />
<br />
<br>'''<font color="green" size="3">Visceral Games</font>'''<br />
<br />
* stimpack<br />
* G3L<br />
* Sean VanGorder<br />
<br />
<br>'''<font color="green" size="3">Visual Concepts (Novato, CA)</font>'''<br />
<br />
* dnorth<br />
<br />
<br>'''<font color="green" size="3">Volition Inc</font>'''<br />
<br />
* Boraxman<br />
* Delo<br />
* Ghostscape<br />
* HarlequiN<br />
* J0NNYquid<br />
* Millah<br />
* retleks<br />
* Swampbug<br />
* Zergxes<br />
* gsokol<br />
<br />
<br>'''<font color="green" size="3">Wargaming.net (Cyprus)</font>'''<br />
<br />
* downarmy<br />
<br />
<br>'''<font color="green" size="3">Wargaming West (Chicago, IL)</font>'''<br />
<br />
* Amatobahn<br />
* skyline5gtr<br />
<br />
<br>'''<font color="green" size="3">Warner Brothers Games (Montréal, BC)</font>'''<br />
<br />
* eyo<br />
<br />
<br>'''<font color="green" size="3">WMS Gaming</font>'''<br />
<br />
* WipEout<br />
<br />
<br>'''<font color="green" size="3">Wolfire Games (Berkeley, CA)</font>'''<br />
<br />
* Ninjas<br />
<br />
<br>'''<font color="green" size="3">The Workshop (Marina Del Rey, CA)</font>'''<br />
<br />
* r4ptur3<br />
<br />
<br>'''<font color="green" size="3">YAGER Development GmbH (Berlin, Germany)</font>'''<br />
<br />
* EbolaV<br />
* JO420<br />
<br />
<br>'''<font color="green" size="3">You Kick Ass (Bellevue, WA)</font>'''<br />
<br />
* GarageBay9<br />
<br />
<br>'''<font color="green" size="3">Zenimax (Hunt Valley, MD)</font>'''<br />
<br />
* Cody<br />
* Em.<br />
* toren3d<br />
* Vidar<br />
<br />
<br />
This list was originally on the forum, in a thread named [http://polycount.com/discussion/49362/polycounter-job-census/p1 Polycounter Job Census]. When we upgraded the forum software, the latest list was lost. The list was restored from [https://web.archive.org/web/20150410044056/http://www.polycount.com/forum/showthread.php?t=49362 a backup] on the [https://archive.org/web/ Internet Archive Wayback Machine].<br />
<br />
----<br />
[[Category:Information]][[Category:GameIndustry]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Game_IndustryGame Industry2016-08-02T16:49:43Z<p>Dustinbrown: /* Education */</p>
<hr />
<div><br />
Links and articles about the game industry: how to get game jobs, how to manage your role, etc.<br />
<br />
__TOC__<br />
<br />
== How to Get In ==<br />
* [http://polycount.com/discussion/168727/im-finding-it-impossible-to-land-a-job I'm finding it impossible to land a job] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=157738 Game Industry Recruiter Taking In Questions] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=134547 Getting that first job] Polycount Forum thread. Good advice for an artist trying to enter a game studio.<br />
* [http://www.polycount.com/forum/showthread.php?t=89972 Getting into the Game Industry (Inspiration of a different kind)] - Polycount Forum thread. Amazing thread full of information from working game artists about how they got into the industry.<br />
* [http://www.ineedtomakegames.com How to Break Into the Industry] - by [http://www.linkedin.com/pub/destin-bales/1/2aa/95b Destin Bales] A treasure trove of great advice by a veteran game developer. Multiple topics covered: understanding the industry, education, resumes and portfolios, finding jobs, interview prep, career development, etc. <br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16967104&gid=59205 Why is it hard to find a job in game industry?] Discussion on LinkedIn about what it takes to get that first game industry job.<br />
* [http://athey.deviantart.com/art/Game-Industry-Advice-to-studen-145619882 Game Industry Advice to students] - by [http://athey.deviantart.com/ Athey Moravetz] A great article by a 5-year veteran game artist about what it takes to get into a game artist job. Very straightforward and accurate.<br />
<br />
== Being a Developer ==<br />
* [http://polycount.com/discussion/174205/job-security-question Job Security Question] Polycount Forum thread. <br />
* [http://www.polycount.com/forum/showthread.php?t=137206 What has the games industry been like for you?] Polycount Forum thread. Game art veterans share what it's really like to be working in game development.<br />
* [http://archive.is/B7o90 Is the games industry really dying?] by Dan Teasdale, diving deep into game industry layoff data.<br />
* [http://www.valvetime.net/threads/valve-employee-hand-book-released.189828/ Valve Employee Hand Book] Greg Coomer says "We wrote this book to make it as easy as we could for new people to join the company. It was fun to capture these thoughts and put them all in one place. Let us know what you think." Cached: [[file:Valve_Employee_Handbook.pdf]]<br />
* [http://www.gdcvault.com/play/1012343/The-Belly-of-the-Whale The Belly of the Whale: Living a Creative Life in the Game Industry] - by [http://www.bobbates.com/ Bob Bates] GDC 2010 lecture about how creative types can survive and thrive in the game industry. Highly recommended [http://www.polycount.com/forum/showthread.php?t=74876 by many Polycounters].<br />
* [http://www.thejonjones.com/2010/08/09/how-not-to-hire-an-artist/ How NOT to hire an artist] - by [http://www.thejonjones.com Jon Jones] Response to the inflammatory article [http://kaitol.com/how-to-hire-an-artist/ How to hire an artist] by [http://kaitol.com/about/ Christopher 'xdragonx10' Gregorio].<br />
* [http://www.polycount.com/2010/08/11/the-co-worker/ The Co-worker] - by [http://www.adambromell.com/ Adam Bromell] Polycount News article about what makes a good team co-worker.<br />
<br />
== Art Disciplines ==<br />
* [[:Category:Discipline]] lists the various artist roles in game development.<br />
* [http://polycount.com/discussion/171014 Specializing or not ?] Polycount forum thread<br />
* [http://polycount.com/discussion/134325 Leadership in the Games Industry] Polycount forum thread<br />
* [http://polycount.com/discussion/81832 What Game artist career is more difficult?] Polycount forum thread<br />
* [[PortfolioContents]] has summaries for what each type of artist should show in their portfolio.<br />
<br />
== Education ==<br />
The basic argument in the Polycount community is between going the self-taught route or going the formal education route. The best path seems to depend on what kind of person you are: self-motivated or team-motivated.<br />
<br />
Artists on Polycount generally agree it is rare to find schools that teach current high-quality game art techniques. The web and forums are often the best places to learn these, maybe even [[:Category:Tutorials|our wiki]] |-) . We see it time and again... the students who succeed at entering the work force after graduation are almost exclusively those that work on their own side projects, beyond the course material. Would they have been better served without using a school? <br />
<br />
If you want to work in a different country, the visa process may require a college or university degree. This is a good reason to seek a degree program.<br />
<br />
Beware of education scams and debt! Schools can cost a lot of money and some promise easy employment afterwards, but unfortunately the reality is not so forgiving. Student loan debt can also be a crushing burden for many years, especially with the relatively low wages most game artists make. See the blog post [https://medium.com/i-m-h-o/138c5efd45e9 Don’t go to art school], the Polycount forum thread [http://www.polycount.com/forum/showthread.php?t=75796 Profit Schools - Can we condemn them publicly?], and the Penny Arcade episode [http://penny-arcade.com/patv/episode/on-game-schools "On Game Schools"].<br />
<br />
* [https://flippednormals.com/blog/creative-students-handbook-schools/ The Creative Student’s Handbook – Schools!] - by [http://k0k0k0.wordpress.com/ Henning Sanden] A primer on how to choose the right school for your career goals, and red flags to look out for when considering schools.<br />
<br />
* [http://www.polycount.com/forum/showthread.php?t=108342 Education In The Games Industry: Yes or No?] on the Polycount Forum is a great list of threads about game art education. You can also do a [http://polycount.com/search?Search forum search] for ''education''.<br />
<br />
* [http://k0k0k0.wordpress.com/51-things-every-game-student-should-know/ 100 Things Every Game Student Should Know] - by [http://k0k0k0.wordpress.com/ Kaye Elling] 100 fugly slides of things that every budding game developer (who is studying at university) should know. Read it!<br />
<br />
== Portfolios ==<br />
* [[Portfolio]] has links to tutorials and advice about creating an artist portfolio for a career in game development.<br />
<br />
== Resumes ==<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
* [http://windmillnetworking.com/2009/08/11/linkedin-profile-tips-the-10-mistakes-you-want-to-avoid-and-why/ LinkedIn Profile Tips: The 10 Mistakes You Want to Avoid and Why] - by ''[http://windmillnetworking.com/about/ Neal Schaffer]''<br />
* [http://www.joelonsoftware.com/articles/ResumeRead.html Getting Your Résumé Read] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
* [http://www.joelonsoftware.com/articles/SortingResumes.html Sorting Resumes] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
<br />
== Cover Letters ==<br />
* [http://www.polycount.com/forum/showthread.php?t=41014 Writing that all important cover letter?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=85192 Cover Letter] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=118092 Resume / Cover Letter Critique request - Riot Games] Polycount Forum thread<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
<br />
== Job Searching ==<br />
Most game developers get their jobs by word of mouth, this industry puts personal contacts first and foremost. Networking is key; keep in contact with your friends and former co-workers.<br />
* [[Company job boards]]<br />
* [http://www.polycount.com/forum/forumdisplay.php?f=39 Work Opportunities] Polycount Sub-Forum. <br />
* [https://orcahq.com/jobs?tags=Art orca] Game dev news and jobs, every day.<br />
* [http://www.polycount.com/forum/showthread.php?t=134982 Another website to find a video game industry job] Polycount Forum thread has several links.<br />
* [http://boards.polycount.net/showthread.php?t=38472 Game and Mod Development Article] and [http://boards.polycount.net/showthread.php?t=42157 Some mod guidelines] Polycount Forum threads have advice about joining a mod team.<br />
* [http://www.facebook.com/note.php?note_id=195778565716 Industry tips: How to find a job in the game industry] - by ''[http://www.boomzap.com/ Christopher Natsuume]'' has some frank advice about job searching.<br />
* [http://www.joelonsoftware.com/articles/ThePhoneScreen.html The Phone Screen] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]'' has info about how companies weed out applicants.<br />
* [http://www.polycount.com/forum/showthread.php?t=99400 It seems to be impossible to find a job as a Modeler in this industry] - this Polycount forum thread has good advice about how to actually get hired as an artist in game development. <br />
* [http://gamedevmap.com gamedevmap] - map of game development companies.<br />
<br />
== Going to Conferences ==<br />
Attending a game conference or developer event is a great way to connect with people working in game development. Connections often lead to work opportunities!<br />
<br />
A few notable conferences:<br />
* [http://www.gdconf.com/aboutgdc/ Game Developer's Conference] (GDC), GDC Europe, GDC China.<br />
* [http://prime.paxsite.com/what-is-pax PAX Prime], PAX East, PAX South, PAX Aus.<br />
* [http://www.e3expo.com/show-info/2541/about-e3/ Electronic Entertainment Expo] (E3).<br />
* [http://www.gameconfs.com/ Gameconfs] - a directory of game industry events.<br />
<br />
<br />
{| style="border:2px solid #111;background-color:#222;"<br />
|-<br />
! style="text-align:left;"|Advice from seasoned Indie [http://ichiro.us/ Ichiro Lambe] about how he goes to GDC:<br />
|-<br />
|1. '''Get connected beforehand.''' We always pulled together lists of devs who were going, to connect folks. For instance, we had a Google Form where everyone put down their names, games, companies, interests, Twitter handles, etc., and that all got spat out into a publicly viewable spreadsheet. We then tweeted that form/spreadsheet to everyone, and got a bazillion responses. We'd then reach out to subsets of those people and say, "Hey, we have common interests. Let's all meet." Instant GDC community.<br />
|-<br />
|2. '''Stay connected during.''' We also did a GDC Google Hangout or Facebook group for mobile users once out there. That allowed, for example, a friend to text a hundred devs with, "Hey, I'm completely drunk at Pinecrest. Who wants to meet?" Or, we'd Katamari a bunch of devs and go to a bar and chat dev. Katamaris work great -- meet one dev, and ask them to invite two friends. And so forth.<br />
|-<br />
|3. '''Set up meetings.''' Are there folks you want to meet out there? E-mail them and see what they're up to. Schedule lunch or coffee with a group of mobile game designers. Have them invite colleagues. Rinse. Repeat. Figure out why you're interesting and unique, and approach people with that. Don't be shy about it.<br />
|-<br />
|4. '''Plan.''' Write out your GDC plan beforehand. You can deviate from this entirely, but it's useful because it shows where there are scheduling gaps. It also forces you to identify your goals and objectives. I go to GDC primarily to connect myself and other devs with platform holders. Ergo, I'll want to set up meetings with Colecovision and Vectrex, and have pitches ready for them. Your goals may differ, but your plan should derive from those goals.<br />
|-<br />
|5. '''Get a pass.''' Go write each of the IGF finalists, tell them how amazing you are and how you're not an asshole, and ask them if they need help manning their booths in exchange for an expo pass.<br />
|-<br />
|6. '''Avoid the big, loud parties.''' 300 game developers at a loud dance club is silly. It's fun to go to these things and get free booze and food, but it's often more profitable to meet with Intellivision over quiet drinks, and more creatively stimulating to meet with a group of other developers in a quiet hotel lobby.<br />
|}<br />
<br />
== Interviews ==<br />
* [http://www.polycount.com/forum/showthread.php?t=106081 Job Interview in a hour or so, what questions should I expect?] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=105266 When eyeballing a studio...] thread on the Polycount forum (what questions should you ask during your interview).<br />
* [http://www.polycount.com/forum/showthread.php?t=69142 Interview Advice] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=80507 In need of interview advice] thread on the Polycount forum.<br />
* [http://www.boston.com/bostonworks/galleries/job_interview_tips?pg=2 10 Tips for Your First Interview] - by ''Dave Sanford'' Time-tested interview strategies:<br />
*# Research<br />
*# Practice<br />
*# Clothing<br />
*# Get there early<br />
*# Observe<br />
*# Know thyself<br />
*# Handshake<br />
*# Listen<br />
*# Finishing<br />
*# Follow up<br />
* [http://hotjobs.yahoo.com/career-experts-four_steps_to_a_better_job_interview-51 Four Steps to a Better Job Interview] - by ''Brad Karsh'' Four simple things to improve your interviews.<br />
*# Relax, not a battle of wits.<br />
*# Job description = questions that you'll be asked.<br />
*# Have answers about why you did certain things.<br />
*# Have questions about them.<br />
* [http://www.jobbankusa.com/interviews/articles_tips/10_follow_up_rules.html Ten Tips for the Interview Follow Up] - by ''Carole Martin'' How to avoid a non-response after your interview.<br />
* [http://boards.polycount.net/showthread.php?t=57317 job interview, 2-3 hours, why so long?] Polycount forum thread Game developers talking about the interview process they do, or have been through.<br />
<br />
== Art Tests ==<br />
Game companies often ask their art applicants to complete an art test, to gauge their talent relative to that company's particular needs, and to make sure you can actually do the work (portfolios can be faked or stolen).<br />
<br />
Beware doing an unpaid art test. A company can ask you to spend a long time on it, but then plagiarize the results, never respond after submission, etc.<br />
<br />
* [http://forum.gameartisans.org/forums/showthread.php?t=5970 Art Test Master List] GameArtisans forum thread has some example art tests.<br />
* [http://www.polycount.com/forum/showthread.php?t=157057 Paid Art Test?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?p=1795799#post1795799 Art Tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=87657 Jagex Art Test] Polycount Forum thread<br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16136725&gid=1842071 "Large art tests as the first stage of candidate selection. Acceptable?"] LinkedIn discussion<br />
* [http://www.polycount.com/forum/showthread.php?t=84418 Environment Art Test advice?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81681 Art test and no response, normal?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81015 Is it bad to ask for tips on an art test? There isn't an NDA] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=80861 Art tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=77279 Art Tests : How much time to spend?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=76208 Art Test Help/Suggestions] Polycount Forum thread<br />
<br />
== Salary Research ==<br />
Do the research to figure out what a fair offer is for your skill level and geographic area.<br />
* [http://h1bdata.info/index.php H1-B Visa Salary Database]<br />
* [https://orcahq.com/blog/game-industry-salary-explorer Game Industry Salary Explorer] - from [https://orcahq.com/ Orca HQ]. See the Polycount Forum thread [http://polycount.com/discussion/165337/game-industry-salary-explorer Game Industry Salary Explorer].<br />
* [http://www.gamecareerguide.com/features/1108/game_developer_salary_survey_2012.php 2012 Game Industry Salary Survey] - from ''[http://www.gdmag.com/ Game Developer magazine]'' (mostly USA). See also [http://gamedeveloper.texterity.com/gamedeveloper/201104#pg9 2010], [http://gamedeveloper.texterity.com/gamedeveloper/2009fall/#pg33 2009], [http://gamedeveloper.texterity.com/gamedeveloper/2008careerguide/#pg13 2008], [http://www.gamecareerguide.com/features/416/the_game_industry_salary_survey_.php?page=1 2007], [http://www.gamecareerguide.com/features/266/are_you_in_demand_2006_game_.php?page=1 2006].<br />
* [http://www.glassdoor.com/Salaries/us-computer-software-senior-artist-salary-SRCH_IL.0,2_IN1_II1121.3,20_KO21,34_SDAS.htm# Senior Artist Salaries at Computer Software companies in United States] - from ''[http://www.glassdoor.com Glassdoor.com]'' (USA) Customize your search, and enter your salary data for full access.<br />
* [http://www.payscale.com/research/US/Job=3d_Artist/Salary 3D Artist Salaries in the United States] - from ''[http://www.payscale.com Payscale.com]'' (other countries available)<br />
* [http://www.flcdatacenter.com/CaseH1B.aspx The Foreign Labor Certification Data Center - Online Wage Library] (H1B Visa Applications) - from the ''[http://www.doleta.gov/ US Department of Labor]'' (USA)<br />
* [http://vfxsoldier.wordpress.com/2010/08/16/wages-in-the-vfx-animation-and-games-industry/ Wages In The VFX, Animation, And Games Industry] - by [http://vfxsoldier.wordpress.com 'VFX Soldier'] features a spreadsheet of wage data mined from the H1B Visa database.<br />
* [http://www.mcvuk.com/news/read/uk-games-industry-salary-survey-what-are-you-worth/0110018 2012 UK Games Industry Salary Survey]. See also [http://www.develop-online.net/features/429/The-2009-UK-Games-Development-Salary-Survey 2009] (UK)<br />
* [http://www.vfxwages.com/ VFXWages] - a global database of hourly monetary rates of people in the film and television visual effects, animation, motion graphics, and gaming industry. <br />
* [[Freelance#Freelance_Rates]]<br />
<br />
== Negotiation ==<br />
Salary negotiation is an essential skill that will be put to the test after a successful interview. <br />
* [https://medium.freecodecamp.com/youre-underpaid-here-s-how-you-can-get-the-pay-raise-you-deserve-fafcf52956d6#.gz4yl4hpe Getting a raise comes down to one thing: Leverage.] - by ''[https://medium.freecodecamp.com/@quincylarson Quincy Larson]''<br />
* [http://realtimecollisiondetection.net/blog/?p=70 Salary of a game programmer (artist, designer, or producer)] - by ''[http://realtimecollisiondetection.net Christer Ericcson]'', Sony Computer Entertainment<br />
* [https://www.facebook.com/note.php?note_id=191791235716 Industry tips: How to not ask for money] - by ''[http://www.boomzap.com/ Christopher Natsuume]''<br />
* [http://www.kclabor.org/kyrmpp.htm Know Your Rights - The Myth of Pay Privacy] - by ''[http://www.kclabor.org KC Labor]'' (USA)<br />
* [http://www.amazon.com/Bargaining-Advantage-Negotiation-Strategies-Reasonable/dp/0143036971 Bargaining for Advantage: Negotiation Strategies for Reasonable People] ($) - by ''[http://www.amazon.com/G.-Richard-Shell/e/B001H6KG6E G. Richard Shell]''<br />
* [http://www.polycount.com/forum/showthread.php?p=2067860 New Job Negotiations]<br />
<br />
== Relocation ==<br />
* [http://www.polycount.com/forum/showthread.php?t=99113 The game industry and relocation, how bad is it?] - Polycount Forum thread. Insight into the relocation process.<br />
<br />
== Employee Rights ==<br />
* [http://docontract.com/ contract( )] (pronounced 'do contract') generates free, plain English agreements for and between game developers. See the article [http://www.gamesindustry.biz/articles/2015-03-13-taking-the-fear-out-of-contracts Taking the fear out of contracts] on gamesindustry.biz.<br />
* [http://www.graphicartistsguild.org/handbook/ Graphic Artists Guild Handbook: Pricing & Ethical Guidelines] is an excellent resource on a great range of employment issues. Pricing guidelines, legal info, copyright law, sample contracts, how to negotiate, and more. Highly recommended!<br />
* [http://www.nlrb.gov/about_us/overview/national_labor_relations_act.aspx National Labor Relations Board] (USA)<br />
* [http://www.acas.org.uk/index.aspx?articleid=1390 ACAS: Advisory, Conciliation and Arbitration Service] (UK)<br />
* [http://www.direct.gov.uk/en/Employment/Employees/index.htm Directgov Employment Terms and Conditions] (UK)<br />
* [http://www.kclabor.org/know_your_rights1.htm Know Your Rights] - by [http://www.kclabor.org KC Labor] (USA)<br />
* [http://polycount.com/discussion/71929/discussing-issues-at-work-grounds-for-firing/p1 Discussing issues at work, grounds for firing?] Polycount forum thread has information about workers discussing their compensation with one another.<br />
* [http://www.polycount.com/forum/showthread.php?t=97910 EA rumored to layoff 500+] Polycount forum thread with cautionary tales about what happens when people get laid off or fired, or when companies close. Back up your work regularly, for portfolio use!<br />
<br />
== Going Indie ==<br />
Indie means developing, marketing, and publishing a game independently.<br />
* [http://forums.tigsource.com/index.php?topic=18.msg147#msg147 How to Start an Indie Game Business (WIP)] TIGSource Forum thread with links to resources <br />
<br />
== Freelancing ==<br />
Freelancing means creating assets for pay, working alone as an individual. See [[Freelance]].<br />
<br />
<br />
----<br />
[[Category:Information]] [[Category:GameIndustry]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Game_IndustryGame Industry2016-08-02T16:48:36Z<p>Dustinbrown: /* Education */</p>
<hr />
<div><br />
Links and articles about the game industry: how to get game jobs, how to manage your role, etc.<br />
<br />
__TOC__<br />
<br />
== How to Get In ==<br />
* [http://polycount.com/discussion/168727/im-finding-it-impossible-to-land-a-job I'm finding it impossible to land a job] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=157738 Game Industry Recruiter Taking In Questions] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=134547 Getting that first job] Polycount Forum thread. Good advice for an artist trying to enter a game studio.<br />
* [http://www.polycount.com/forum/showthread.php?t=89972 Getting into the Game Industry (Inspiration of a different kind)] - Polycount Forum thread. Amazing thread full of information from working game artists about how they got into the industry.<br />
* [http://www.ineedtomakegames.com How to Break Into the Industry] - by [http://www.linkedin.com/pub/destin-bales/1/2aa/95b Destin Bales] A treasure trove of great advice by a veteran game developer. Multiple topics covered: understanding the industry, education, resumes and portfolios, finding jobs, interview prep, career development, etc. <br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16967104&gid=59205 Why is it hard to find a job in game industry?] Discussion on LinkedIn about what it takes to get that first game industry job.<br />
* [http://athey.deviantart.com/art/Game-Industry-Advice-to-studen-145619882 Game Industry Advice to students] - by [http://athey.deviantart.com/ Athey Moravetz] A great article by a 5-year veteran game artist about what it takes to get into a game artist job. Very straightforward and accurate.<br />
<br />
== Being a Developer ==<br />
* [http://polycount.com/discussion/174205/job-security-question Job Security Question] Polycount Forum thread. <br />
* [http://www.polycount.com/forum/showthread.php?t=137206 What has the games industry been like for you?] Polycount Forum thread. Game art veterans share what it's really like to be working in game development.<br />
* [http://archive.is/B7o90 Is the games industry really dying?] by Dan Teasdale, diving deep into game industry layoff data.<br />
* [http://www.valvetime.net/threads/valve-employee-hand-book-released.189828/ Valve Employee Hand Book] Greg Coomer says "We wrote this book to make it as easy as we could for new people to join the company. It was fun to capture these thoughts and put them all in one place. Let us know what you think." Cached: [[file:Valve_Employee_Handbook.pdf]]<br />
* [http://www.gdcvault.com/play/1012343/The-Belly-of-the-Whale The Belly of the Whale: Living a Creative Life in the Game Industry] - by [http://www.bobbates.com/ Bob Bates] GDC 2010 lecture about how creative types can survive and thrive in the game industry. Highly recommended [http://www.polycount.com/forum/showthread.php?t=74876 by many Polycounters].<br />
* [http://www.thejonjones.com/2010/08/09/how-not-to-hire-an-artist/ How NOT to hire an artist] - by [http://www.thejonjones.com Jon Jones] Response to the inflammatory article [http://kaitol.com/how-to-hire-an-artist/ How to hire an artist] by [http://kaitol.com/about/ Christopher 'xdragonx10' Gregorio].<br />
* [http://www.polycount.com/2010/08/11/the-co-worker/ The Co-worker] - by [http://www.adambromell.com/ Adam Bromell] Polycount News article about what makes a good team co-worker.<br />
<br />
== Art Disciplines ==<br />
* [[:Category:Discipline]] lists the various artist roles in game development.<br />
* [http://polycount.com/discussion/171014 Specializing or not ?] Polycount forum thread<br />
* [http://polycount.com/discussion/134325 Leadership in the Games Industry] Polycount forum thread<br />
* [http://polycount.com/discussion/81832 What Game artist career is more difficult?] Polycount forum thread<br />
* [[PortfolioContents]] has summaries for what each type of artist should show in their portfolio.<br />
<br />
== Education ==<br />
The basic argument in the Polycount community is between going the self-taught route or going the formal education route. The best path seems to depend on what kind of person you are: self-motivated or team-motivated.<br />
<br />
Artists on Polycount generally agree it is rare to find schools that teach current high-quality game art techniques. The web and forums are often the best places to learn these, maybe even [[:Category:Tutorials|our wiki]] |-) . We see it time and again... the students who succeed at entering the work force after graduation are almost exclusively those that work on their own side projects, beyond the course material. Would they have been better served without using a school? <br />
<br />
If you want to work in a different country, the visa process may require a college or university degree. This is a good reason to seek a degree program.<br />
<br />
Beware of education scams and debt! Schools can cost a lot of money and some promise easy employment afterwards, but unfortunately the reality is not so forgiving. Student loan debt can also be a crushing burden for many years, especially with the relatively low wages most game artists make. See the blog post [https://medium.com/i-m-h-o/138c5efd45e9 Don’t go to art school], the Polycount forum thread [http://www.polycount.com/forum/showthread.php?t=75796 Profit Schools - Can we condemn them publicly?], and the Penny Arcade episode [http://penny-arcade.com/patv/episode/on-game-schools "On Game Schools"].<br />
<br />
* [https://flippednormals.com/blog/creative-students-handbook-schools/ The Creative Student’s Handbook – Schools!] - by [http://k0k0k0.wordpress.com/ Henning Sanden] The Creative Student’s Handbook – Schools!<br />
<br />
* [http://www.polycount.com/forum/showthread.php?t=108342 Education In The Games Industry: Yes or No?] on the Polycount Forum is a great list of threads about game art education. You can also do a [http://polycount.com/search?Search forum search] for ''education''.<br />
<br />
* [http://k0k0k0.wordpress.com/51-things-every-game-student-should-know/ 100 Things Every Game Student Should Know] - by [http://k0k0k0.wordpress.com/ Kaye Elling] 100 fugly slides of things that every budding game developer (who is studying at university) should know. Read it!<br />
<br />
== Portfolios ==<br />
* [[Portfolio]] has links to tutorials and advice about creating an artist portfolio for a career in game development.<br />
<br />
== Resumes ==<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
* [http://windmillnetworking.com/2009/08/11/linkedin-profile-tips-the-10-mistakes-you-want-to-avoid-and-why/ LinkedIn Profile Tips: The 10 Mistakes You Want to Avoid and Why] - by ''[http://windmillnetworking.com/about/ Neal Schaffer]''<br />
* [http://www.joelonsoftware.com/articles/ResumeRead.html Getting Your Résumé Read] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
* [http://www.joelonsoftware.com/articles/SortingResumes.html Sorting Resumes] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
<br />
== Cover Letters ==<br />
* [http://www.polycount.com/forum/showthread.php?t=41014 Writing that all important cover letter?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=85192 Cover Letter] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=118092 Resume / Cover Letter Critique request - Riot Games] Polycount Forum thread<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
<br />
== Job Searching ==<br />
Most game developers get their jobs by word of mouth, this industry puts personal contacts first and foremost. Networking is key; keep in contact with your friends and former co-workers.<br />
* [[Company job boards]]<br />
* [http://www.polycount.com/forum/forumdisplay.php?f=39 Work Opportunities] Polycount Sub-Forum. <br />
* [https://orcahq.com/jobs?tags=Art orca] Game dev news and jobs, every day.<br />
* [http://www.polycount.com/forum/showthread.php?t=134982 Another website to find a video game industry job] Polycount Forum thread has several links.<br />
* [http://boards.polycount.net/showthread.php?t=38472 Game and Mod Development Article] and [http://boards.polycount.net/showthread.php?t=42157 Some mod guidelines] Polycount Forum threads have advice about joining a mod team.<br />
* [http://www.facebook.com/note.php?note_id=195778565716 Industry tips: How to find a job in the game industry] - by ''[http://www.boomzap.com/ Christopher Natsuume]'' has some frank advice about job searching.<br />
* [http://www.joelonsoftware.com/articles/ThePhoneScreen.html The Phone Screen] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]'' has info about how companies weed out applicants.<br />
* [http://www.polycount.com/forum/showthread.php?t=99400 It seems to be impossible to find a job as a Modeler in this industry] - this Polycount forum thread has good advice about how to actually get hired as an artist in game development. <br />
* [http://gamedevmap.com gamedevmap] - map of game development companies.<br />
<br />
== Going to Conferences ==<br />
Attending a game conference or developer event is a great way to connect with people working in game development. Connections often lead to work opportunities!<br />
<br />
A few notable conferences:<br />
* [http://www.gdconf.com/aboutgdc/ Game Developer's Conference] (GDC), GDC Europe, GDC China.<br />
* [http://prime.paxsite.com/what-is-pax PAX Prime], PAX East, PAX South, PAX Aus.<br />
* [http://www.e3expo.com/show-info/2541/about-e3/ Electronic Entertainment Expo] (E3).<br />
* [http://www.gameconfs.com/ Gameconfs] - a directory of game industry events.<br />
<br />
<br />
{| style="border:2px solid #111;background-color:#222;"<br />
|-<br />
! style="text-align:left;"|Advice from seasoned Indie [http://ichiro.us/ Ichiro Lambe] about how he goes to GDC:<br />
|-<br />
|1. '''Get connected beforehand.''' We always pulled together lists of devs who were going, to connect folks. For instance, we had a Google Form where everyone put down their names, games, companies, interests, Twitter handles, etc., and that all got spat out into a publicly viewable spreadsheet. We then tweeted that form/spreadsheet to everyone, and got a bazillion responses. We'd then reach out to subsets of those people and say, "Hey, we have common interests. Let's all meet." Instant GDC community.<br />
|-<br />
|2. '''Stay connected during.''' We also did a GDC Google Hangout or Facebook group for mobile users once out there. That allowed, for example, a friend to text a hundred devs with, "Hey, I'm completely drunk at Pinecrest. Who wants to meet?" Or, we'd Katamari a bunch of devs and go to a bar and chat dev. Katamaris work great -- meet one dev, and ask them to invite two friends. And so forth.<br />
|-<br />
|3. '''Set up meetings.''' Are there folks you want to meet out there? E-mail them and see what they're up to. Schedule lunch or coffee with a group of mobile game designers. Have them invite colleagues. Rinse. Repeat. Figure out why you're interesting and unique, and approach people with that. Don't be shy about it.<br />
|-<br />
|4. '''Plan.''' Write out your GDC plan beforehand. You can deviate from this entirely, but it's useful because it shows where there are scheduling gaps. It also forces you to identify your goals and objectives. I go to GDC primarily to connect myself and other devs with platform holders. Ergo, I'll want to set up meetings with Colecovision and Vectrex, and have pitches ready for them. Your goals may differ, but your plan should derive from those goals.<br />
|-<br />
|5. '''Get a pass.''' Go write each of the IGF finalists, tell them how amazing you are and how you're not an asshole, and ask them if they need help manning their booths in exchange for an expo pass.<br />
|-<br />
|6. '''Avoid the big, loud parties.''' 300 game developers at a loud dance club is silly. It's fun to go to these things and get free booze and food, but it's often more profitable to meet with Intellivision over quiet drinks, and more creatively stimulating to meet with a group of other developers in a quiet hotel lobby.<br />
|}<br />
<br />
== Interviews ==<br />
* [http://www.polycount.com/forum/showthread.php?t=106081 Job Interview in a hour or so, what questions should I expect?] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=105266 When eyeballing a studio...] thread on the Polycount forum (what questions should you ask during your interview).<br />
* [http://www.polycount.com/forum/showthread.php?t=69142 Interview Advice] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=80507 In need of interview advice] thread on the Polycount forum.<br />
* [http://www.boston.com/bostonworks/galleries/job_interview_tips?pg=2 10 Tips for Your First Interview] - by ''Dave Sanford'' Time-tested interview strategies:<br />
*# Research<br />
*# Practice<br />
*# Clothing<br />
*# Get there early<br />
*# Observe<br />
*# Know thyself<br />
*# Handshake<br />
*# Listen<br />
*# Finishing<br />
*# Follow up<br />
* [http://hotjobs.yahoo.com/career-experts-four_steps_to_a_better_job_interview-51 Four Steps to a Better Job Interview] - by ''Brad Karsh'' Four simple things to improve your interviews.<br />
*# Relax, not a battle of wits.<br />
*# Job description = questions that you'll be asked.<br />
*# Have answers about why you did certain things.<br />
*# Have questions about them.<br />
* [http://www.jobbankusa.com/interviews/articles_tips/10_follow_up_rules.html Ten Tips for the Interview Follow Up] - by ''Carole Martin'' How to avoid a non-response after your interview.<br />
* [http://boards.polycount.net/showthread.php?t=57317 job interview, 2-3 hours, why so long?] Polycount forum thread Game developers talking about the interview process they do, or have been through.<br />
<br />
== Art Tests ==<br />
Game companies often ask their art applicants to complete an art test, to gauge their talent relative to that company's particular needs, and to make sure you can actually do the work (portfolios can be faked or stolen).<br />
<br />
Beware doing an unpaid art test. A company can ask you to spend a long time on it, but then plagiarize the results, never respond after submission, etc.<br />
<br />
* [http://forum.gameartisans.org/forums/showthread.php?t=5970 Art Test Master List] GameArtisans forum thread has some example art tests.<br />
* [http://www.polycount.com/forum/showthread.php?t=157057 Paid Art Test?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?p=1795799#post1795799 Art Tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=87657 Jagex Art Test] Polycount Forum thread<br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16136725&gid=1842071 "Large art tests as the first stage of candidate selection. Acceptable?"] LinkedIn discussion<br />
* [http://www.polycount.com/forum/showthread.php?t=84418 Environment Art Test advice?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81681 Art test and no response, normal?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81015 Is it bad to ask for tips on an art test? There isn't an NDA] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=80861 Art tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=77279 Art Tests : How much time to spend?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=76208 Art Test Help/Suggestions] Polycount Forum thread<br />
<br />
== Salary Research ==<br />
Do the research to figure out what a fair offer is for your skill level and geographic area.<br />
* [http://h1bdata.info/index.php H1-B Visa Salary Database]<br />
* [https://orcahq.com/blog/game-industry-salary-explorer Game Industry Salary Explorer] - from [https://orcahq.com/ Orca HQ]. See the Polycount Forum thread [http://polycount.com/discussion/165337/game-industry-salary-explorer Game Industry Salary Explorer].<br />
* [http://www.gamecareerguide.com/features/1108/game_developer_salary_survey_2012.php 2012 Game Industry Salary Survey] - from ''[http://www.gdmag.com/ Game Developer magazine]'' (mostly USA). See also [http://gamedeveloper.texterity.com/gamedeveloper/201104#pg9 2010], [http://gamedeveloper.texterity.com/gamedeveloper/2009fall/#pg33 2009], [http://gamedeveloper.texterity.com/gamedeveloper/2008careerguide/#pg13 2008], [http://www.gamecareerguide.com/features/416/the_game_industry_salary_survey_.php?page=1 2007], [http://www.gamecareerguide.com/features/266/are_you_in_demand_2006_game_.php?page=1 2006].<br />
* [http://www.glassdoor.com/Salaries/us-computer-software-senior-artist-salary-SRCH_IL.0,2_IN1_II1121.3,20_KO21,34_SDAS.htm# Senior Artist Salaries at Computer Software companies in United States] - from ''[http://www.glassdoor.com Glassdoor.com]'' (USA) Customize your search, and enter your salary data for full access.<br />
* [http://www.payscale.com/research/US/Job=3d_Artist/Salary 3D Artist Salaries in the United States] - from ''[http://www.payscale.com Payscale.com]'' (other countries available)<br />
* [http://www.flcdatacenter.com/CaseH1B.aspx The Foreign Labor Certification Data Center - Online Wage Library] (H1B Visa Applications) - from the ''[http://www.doleta.gov/ US Department of Labor]'' (USA)<br />
* [http://vfxsoldier.wordpress.com/2010/08/16/wages-in-the-vfx-animation-and-games-industry/ Wages In The VFX, Animation, And Games Industry] - by [http://vfxsoldier.wordpress.com 'VFX Soldier'] features a spreadsheet of wage data mined from the H1B Visa database.<br />
* [http://www.mcvuk.com/news/read/uk-games-industry-salary-survey-what-are-you-worth/0110018 2012 UK Games Industry Salary Survey]. See also [http://www.develop-online.net/features/429/The-2009-UK-Games-Development-Salary-Survey 2009] (UK)<br />
* [http://www.vfxwages.com/ VFXWages] - a global database of hourly monetary rates of people in the film and television visual effects, animation, motion graphics, and gaming industry. <br />
* [[Freelance#Freelance_Rates]]<br />
<br />
== Negotiation ==<br />
Salary negotiation is an essential skill that will be put to the test after a successful interview. <br />
* [https://medium.freecodecamp.com/youre-underpaid-here-s-how-you-can-get-the-pay-raise-you-deserve-fafcf52956d6#.gz4yl4hpe Getting a raise comes down to one thing: Leverage.] - by ''[https://medium.freecodecamp.com/@quincylarson Quincy Larson]''<br />
* [http://realtimecollisiondetection.net/blog/?p=70 Salary of a game programmer (artist, designer, or producer)] - by ''[http://realtimecollisiondetection.net Christer Ericcson]'', Sony Computer Entertainment<br />
* [https://www.facebook.com/note.php?note_id=191791235716 Industry tips: How to not ask for money] - by ''[http://www.boomzap.com/ Christopher Natsuume]''<br />
* [http://www.kclabor.org/kyrmpp.htm Know Your Rights - The Myth of Pay Privacy] - by ''[http://www.kclabor.org KC Labor]'' (USA)<br />
* [http://www.amazon.com/Bargaining-Advantage-Negotiation-Strategies-Reasonable/dp/0143036971 Bargaining for Advantage: Negotiation Strategies for Reasonable People] ($) - by ''[http://www.amazon.com/G.-Richard-Shell/e/B001H6KG6E G. Richard Shell]''<br />
* [http://www.polycount.com/forum/showthread.php?p=2067860 New Job Negotiations]<br />
<br />
== Relocation ==<br />
* [http://www.polycount.com/forum/showthread.php?t=99113 The game industry and relocation, how bad is it?] - Polycount Forum thread. Insight into the relocation process.<br />
<br />
== Employee Rights ==<br />
* [http://docontract.com/ contract( )] (pronounced 'do contract') generates free, plain English agreements for and between game developers. See the article [http://www.gamesindustry.biz/articles/2015-03-13-taking-the-fear-out-of-contracts Taking the fear out of contracts] on gamesindustry.biz.<br />
* [http://www.graphicartistsguild.org/handbook/ Graphic Artists Guild Handbook: Pricing & Ethical Guidelines] is an excellent resource on a great range of employment issues. Pricing guidelines, legal info, copyright law, sample contracts, how to negotiate, and more. Highly recommended!<br />
* [http://www.nlrb.gov/about_us/overview/national_labor_relations_act.aspx National Labor Relations Board] (USA)<br />
* [http://www.acas.org.uk/index.aspx?articleid=1390 ACAS: Advisory, Conciliation and Arbitration Service] (UK)<br />
* [http://www.direct.gov.uk/en/Employment/Employees/index.htm Directgov Employment Terms and Conditions] (UK)<br />
* [http://www.kclabor.org/know_your_rights1.htm Know Your Rights] - by [http://www.kclabor.org KC Labor] (USA)<br />
* [http://polycount.com/discussion/71929/discussing-issues-at-work-grounds-for-firing/p1 Discussing issues at work, grounds for firing?] Polycount forum thread has information about workers discussing their compensation with one another.<br />
* [http://www.polycount.com/forum/showthread.php?t=97910 EA rumored to layoff 500+] Polycount forum thread with cautionary tales about what happens when people get laid off or fired, or when companies close. Back up your work regularly, for portfolio use!<br />
<br />
== Going Indie ==<br />
Indie means developing, marketing, and publishing a game independently.<br />
* [http://forums.tigsource.com/index.php?topic=18.msg147#msg147 How to Start an Indie Game Business (WIP)] TIGSource Forum thread with links to resources <br />
<br />
== Freelancing ==<br />
Freelancing means creating assets for pay, working alone as an individual. See [[Freelance]].<br />
<br />
<br />
----<br />
[[Category:Information]] [[Category:GameIndustry]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Game_IndustryGame Industry2016-08-02T16:48:01Z<p>Dustinbrown: /* Education */</p>
<hr />
<div><br />
Links and articles about the game industry: how to get game jobs, how to manage your role, etc.<br />
<br />
__TOC__<br />
<br />
== How to Get In ==<br />
* [http://polycount.com/discussion/168727/im-finding-it-impossible-to-land-a-job I'm finding it impossible to land a job] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=157738 Game Industry Recruiter Taking In Questions] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=134547 Getting that first job] Polycount Forum thread. Good advice for an artist trying to enter a game studio.<br />
* [http://www.polycount.com/forum/showthread.php?t=89972 Getting into the Game Industry (Inspiration of a different kind)] - Polycount Forum thread. Amazing thread full of information from working game artists about how they got into the industry.<br />
* [http://www.ineedtomakegames.com How to Break Into the Industry] - by [http://www.linkedin.com/pub/destin-bales/1/2aa/95b Destin Bales] A treasure trove of great advice by a veteran game developer. Multiple topics covered: understanding the industry, education, resumes and portfolios, finding jobs, interview prep, career development, etc. <br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16967104&gid=59205 Why is it hard to find a job in game industry?] Discussion on LinkedIn about what it takes to get that first game industry job.<br />
* [http://athey.deviantart.com/art/Game-Industry-Advice-to-studen-145619882 Game Industry Advice to students] - by [http://athey.deviantart.com/ Athey Moravetz] A great article by a 5-year veteran game artist about what it takes to get into a game artist job. Very straightforward and accurate.<br />
<br />
== Being a Developer ==<br />
* [http://polycount.com/discussion/174205/job-security-question Job Security Question] Polycount Forum thread. <br />
* [http://www.polycount.com/forum/showthread.php?t=137206 What has the games industry been like for you?] Polycount Forum thread. Game art veterans share what it's really like to be working in game development.<br />
* [http://archive.is/B7o90 Is the games industry really dying?] by Dan Teasdale, diving deep into game industry layoff data.<br />
* [http://www.valvetime.net/threads/valve-employee-hand-book-released.189828/ Valve Employee Hand Book] Greg Coomer says "We wrote this book to make it as easy as we could for new people to join the company. It was fun to capture these thoughts and put them all in one place. Let us know what you think." Cached: [[file:Valve_Employee_Handbook.pdf]]<br />
* [http://www.gdcvault.com/play/1012343/The-Belly-of-the-Whale The Belly of the Whale: Living a Creative Life in the Game Industry] - by [http://www.bobbates.com/ Bob Bates] GDC 2010 lecture about how creative types can survive and thrive in the game industry. Highly recommended [http://www.polycount.com/forum/showthread.php?t=74876 by many Polycounters].<br />
* [http://www.thejonjones.com/2010/08/09/how-not-to-hire-an-artist/ How NOT to hire an artist] - by [http://www.thejonjones.com Jon Jones] Response to the inflammatory article [http://kaitol.com/how-to-hire-an-artist/ How to hire an artist] by [http://kaitol.com/about/ Christopher 'xdragonx10' Gregorio].<br />
* [http://www.polycount.com/2010/08/11/the-co-worker/ The Co-worker] - by [http://www.adambromell.com/ Adam Bromell] Polycount News article about what makes a good team co-worker.<br />
<br />
== Art Disciplines ==<br />
* [[:Category:Discipline]] lists the various artist roles in game development.<br />
* [http://polycount.com/discussion/171014 Specializing or not ?] Polycount forum thread<br />
* [http://polycount.com/discussion/134325 Leadership in the Games Industry] Polycount forum thread<br />
* [http://polycount.com/discussion/81832 What Game artist career is more difficult?] Polycount forum thread<br />
* [[PortfolioContents]] has summaries for what each type of artist should show in their portfolio.<br />
<br />
== Education ==<br />
The basic argument in the Polycount community is between going the self-taught route or going the formal education route. The best path seems to depend on what kind of person you are: self-motivated or team-motivated.<br />
<br />
Artists on Polycount generally agree it is rare to find schools that teach current high-quality game art techniques. The web and forums are often the best places to learn these, maybe even [[:Category:Tutorials|our wiki]] |-) . We see it time and again... the students who succeed at entering the work force after graduation are almost exclusively those that work on their own side projects, beyond the course material. Would they have been better served without using a school? <br />
<br />
If you want to work in a different country, the visa process may require a college or university degree. This is a good reason to seek a degree program.<br />
<br />
Beware of education scams and debt! Schools can cost a lot of money and some promise easy employment afterwards, but unfortunately the reality is not so forgiving. Student loan debt can also be a crushing burden for many years, especially with the relatively low wages most game artists make. See the blog post [https://medium.com/i-m-h-o/138c5efd45e9 Don’t go to art school], the Polycount forum thread [http://www.polycount.com/forum/showthread.php?t=75796 Profit Schools - Can we condemn them publicly?], and the Penny Arcade episode [http://penny-arcade.com/patv/episode/on-game-schools "On Game Schools"].<br />
<br />
* [https://flippednormals.com/blog/creative-students-handbook-schools/] - by [http://k0k0k0.wordpress.com/ Henning Sanden] The Creative Student’s Handbook – Schools!<br />
<br />
* [http://www.polycount.com/forum/showthread.php?t=108342 Education In The Games Industry: Yes or No?] on the Polycount Forum is a great list of threads about game art education. You can also do a [http://polycount.com/search?Search forum search] for ''education''.<br />
<br />
* [http://k0k0k0.wordpress.com/51-things-every-game-student-should-know/ 100 Things Every Game Student Should Know] - by [http://k0k0k0.wordpress.com/ Kaye Elling] 100 fugly slides of things that every budding game developer (who is studying at university) should know. Read it!<br />
<br />
== Portfolios ==<br />
* [[Portfolio]] has links to tutorials and advice about creating an artist portfolio for a career in game development.<br />
<br />
== Resumes ==<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
* [http://windmillnetworking.com/2009/08/11/linkedin-profile-tips-the-10-mistakes-you-want-to-avoid-and-why/ LinkedIn Profile Tips: The 10 Mistakes You Want to Avoid and Why] - by ''[http://windmillnetworking.com/about/ Neal Schaffer]''<br />
* [http://www.joelonsoftware.com/articles/ResumeRead.html Getting Your Résumé Read] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
* [http://www.joelonsoftware.com/articles/SortingResumes.html Sorting Resumes] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
<br />
== Cover Letters ==<br />
* [http://www.polycount.com/forum/showthread.php?t=41014 Writing that all important cover letter?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=85192 Cover Letter] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=118092 Resume / Cover Letter Critique request - Riot Games] Polycount Forum thread<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
<br />
== Job Searching ==<br />
Most game developers get their jobs by word of mouth, this industry puts personal contacts first and foremost. Networking is key; keep in contact with your friends and former co-workers.<br />
* [[Company job boards]]<br />
* [http://www.polycount.com/forum/forumdisplay.php?f=39 Work Opportunities] Polycount Sub-Forum. <br />
* [https://orcahq.com/jobs?tags=Art orca] Game dev news and jobs, every day.<br />
* [http://www.polycount.com/forum/showthread.php?t=134982 Another website to find a video game industry job] Polycount Forum thread has several links.<br />
* [http://boards.polycount.net/showthread.php?t=38472 Game and Mod Development Article] and [http://boards.polycount.net/showthread.php?t=42157 Some mod guidelines] Polycount Forum threads have advice about joining a mod team.<br />
* [http://www.facebook.com/note.php?note_id=195778565716 Industry tips: How to find a job in the game industry] - by ''[http://www.boomzap.com/ Christopher Natsuume]'' has some frank advice about job searching.<br />
* [http://www.joelonsoftware.com/articles/ThePhoneScreen.html The Phone Screen] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]'' has info about how companies weed out applicants.<br />
* [http://www.polycount.com/forum/showthread.php?t=99400 It seems to be impossible to find a job as a Modeler in this industry] - this Polycount forum thread has good advice about how to actually get hired as an artist in game development. <br />
* [http://gamedevmap.com gamedevmap] - map of game development companies.<br />
<br />
== Going to Conferences ==<br />
Attending a game conference or developer event is a great way to connect with people working in game development. Connections often lead to work opportunities!<br />
<br />
A few notable conferences:<br />
* [http://www.gdconf.com/aboutgdc/ Game Developer's Conference] (GDC), GDC Europe, GDC China.<br />
* [http://prime.paxsite.com/what-is-pax PAX Prime], PAX East, PAX South, PAX Aus.<br />
* [http://www.e3expo.com/show-info/2541/about-e3/ Electronic Entertainment Expo] (E3).<br />
* [http://www.gameconfs.com/ Gameconfs] - a directory of game industry events.<br />
<br />
<br />
{| style="border:2px solid #111;background-color:#222;"<br />
|-<br />
! style="text-align:left;"|Advice from seasoned Indie [http://ichiro.us/ Ichiro Lambe] about how he goes to GDC:<br />
|-<br />
|1. '''Get connected beforehand.''' We always pulled together lists of devs who were going, to connect folks. For instance, we had a Google Form where everyone put down their names, games, companies, interests, Twitter handles, etc., and that all got spat out into a publicly viewable spreadsheet. We then tweeted that form/spreadsheet to everyone, and got a bazillion responses. We'd then reach out to subsets of those people and say, "Hey, we have common interests. Let's all meet." Instant GDC community.<br />
|-<br />
|2. '''Stay connected during.''' We also did a GDC Google Hangout or Facebook group for mobile users once out there. That allowed, for example, a friend to text a hundred devs with, "Hey, I'm completely drunk at Pinecrest. Who wants to meet?" Or, we'd Katamari a bunch of devs and go to a bar and chat dev. Katamaris work great -- meet one dev, and ask them to invite two friends. And so forth.<br />
|-<br />
|3. '''Set up meetings.''' Are there folks you want to meet out there? E-mail them and see what they're up to. Schedule lunch or coffee with a group of mobile game designers. Have them invite colleagues. Rinse. Repeat. Figure out why you're interesting and unique, and approach people with that. Don't be shy about it.<br />
|-<br />
|4. '''Plan.''' Write out your GDC plan beforehand. You can deviate from this entirely, but it's useful because it shows where there are scheduling gaps. It also forces you to identify your goals and objectives. I go to GDC primarily to connect myself and other devs with platform holders. Ergo, I'll want to set up meetings with Colecovision and Vectrex, and have pitches ready for them. Your goals may differ, but your plan should derive from those goals.<br />
|-<br />
|5. '''Get a pass.''' Go write each of the IGF finalists, tell them how amazing you are and how you're not an asshole, and ask them if they need help manning their booths in exchange for an expo pass.<br />
|-<br />
|6. '''Avoid the big, loud parties.''' 300 game developers at a loud dance club is silly. It's fun to go to these things and get free booze and food, but it's often more profitable to meet with Intellivision over quiet drinks, and more creatively stimulating to meet with a group of other developers in a quiet hotel lobby.<br />
|}<br />
<br />
== Interviews ==<br />
* [http://www.polycount.com/forum/showthread.php?t=106081 Job Interview in a hour or so, what questions should I expect?] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=105266 When eyeballing a studio...] thread on the Polycount forum (what questions should you ask during your interview).<br />
* [http://www.polycount.com/forum/showthread.php?t=69142 Interview Advice] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=80507 In need of interview advice] thread on the Polycount forum.<br />
* [http://www.boston.com/bostonworks/galleries/job_interview_tips?pg=2 10 Tips for Your First Interview] - by ''Dave Sanford'' Time-tested interview strategies:<br />
*# Research<br />
*# Practice<br />
*# Clothing<br />
*# Get there early<br />
*# Observe<br />
*# Know thyself<br />
*# Handshake<br />
*# Listen<br />
*# Finishing<br />
*# Follow up<br />
* [http://hotjobs.yahoo.com/career-experts-four_steps_to_a_better_job_interview-51 Four Steps to a Better Job Interview] - by ''Brad Karsh'' Four simple things to improve your interviews.<br />
*# Relax, not a battle of wits.<br />
*# Job description = questions that you'll be asked.<br />
*# Have answers about why you did certain things.<br />
*# Have questions about them.<br />
* [http://www.jobbankusa.com/interviews/articles_tips/10_follow_up_rules.html Ten Tips for the Interview Follow Up] - by ''Carole Martin'' How to avoid a non-response after your interview.<br />
* [http://boards.polycount.net/showthread.php?t=57317 job interview, 2-3 hours, why so long?] Polycount forum thread Game developers talking about the interview process they do, or have been through.<br />
<br />
== Art Tests ==<br />
Game companies often ask their art applicants to complete an art test, to gauge their talent relative to that company's particular needs, and to make sure you can actually do the work (portfolios can be faked or stolen).<br />
<br />
Beware doing an unpaid art test. A company can ask you to spend a long time on it, but then plagiarize the results, never respond after submission, etc.<br />
<br />
* [http://forum.gameartisans.org/forums/showthread.php?t=5970 Art Test Master List] GameArtisans forum thread has some example art tests.<br />
* [http://www.polycount.com/forum/showthread.php?t=157057 Paid Art Test?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?p=1795799#post1795799 Art Tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=87657 Jagex Art Test] Polycount Forum thread<br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16136725&gid=1842071 "Large art tests as the first stage of candidate selection. Acceptable?"] LinkedIn discussion<br />
* [http://www.polycount.com/forum/showthread.php?t=84418 Environment Art Test advice?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81681 Art test and no response, normal?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81015 Is it bad to ask for tips on an art test? There isn't an NDA] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=80861 Art tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=77279 Art Tests : How much time to spend?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=76208 Art Test Help/Suggestions] Polycount Forum thread<br />
<br />
== Salary Research ==<br />
Do the research to figure out what a fair offer is for your skill level and geographic area.<br />
* [http://h1bdata.info/index.php H1-B Visa Salary Database]<br />
* [https://orcahq.com/blog/game-industry-salary-explorer Game Industry Salary Explorer] - from [https://orcahq.com/ Orca HQ]. See the Polycount Forum thread [http://polycount.com/discussion/165337/game-industry-salary-explorer Game Industry Salary Explorer].<br />
* [http://www.gamecareerguide.com/features/1108/game_developer_salary_survey_2012.php 2012 Game Industry Salary Survey] - from ''[http://www.gdmag.com/ Game Developer magazine]'' (mostly USA). See also [http://gamedeveloper.texterity.com/gamedeveloper/201104#pg9 2010], [http://gamedeveloper.texterity.com/gamedeveloper/2009fall/#pg33 2009], [http://gamedeveloper.texterity.com/gamedeveloper/2008careerguide/#pg13 2008], [http://www.gamecareerguide.com/features/416/the_game_industry_salary_survey_.php?page=1 2007], [http://www.gamecareerguide.com/features/266/are_you_in_demand_2006_game_.php?page=1 2006].<br />
* [http://www.glassdoor.com/Salaries/us-computer-software-senior-artist-salary-SRCH_IL.0,2_IN1_II1121.3,20_KO21,34_SDAS.htm# Senior Artist Salaries at Computer Software companies in United States] - from ''[http://www.glassdoor.com Glassdoor.com]'' (USA) Customize your search, and enter your salary data for full access.<br />
* [http://www.payscale.com/research/US/Job=3d_Artist/Salary 3D Artist Salaries in the United States] - from ''[http://www.payscale.com Payscale.com]'' (other countries available)<br />
* [http://www.flcdatacenter.com/CaseH1B.aspx The Foreign Labor Certification Data Center - Online Wage Library] (H1B Visa Applications) - from the ''[http://www.doleta.gov/ US Department of Labor]'' (USA)<br />
* [http://vfxsoldier.wordpress.com/2010/08/16/wages-in-the-vfx-animation-and-games-industry/ Wages In The VFX, Animation, And Games Industry] - by [http://vfxsoldier.wordpress.com 'VFX Soldier'] features a spreadsheet of wage data mined from the H1B Visa database.<br />
* [http://www.mcvuk.com/news/read/uk-games-industry-salary-survey-what-are-you-worth/0110018 2012 UK Games Industry Salary Survey]. See also [http://www.develop-online.net/features/429/The-2009-UK-Games-Development-Salary-Survey 2009] (UK)<br />
* [http://www.vfxwages.com/ VFXWages] - a global database of hourly monetary rates of people in the film and television visual effects, animation, motion graphics, and gaming industry. <br />
* [[Freelance#Freelance_Rates]]<br />
<br />
== Negotiation ==<br />
Salary negotiation is an essential skill that will be put to the test after a successful interview. <br />
* [https://medium.freecodecamp.com/youre-underpaid-here-s-how-you-can-get-the-pay-raise-you-deserve-fafcf52956d6#.gz4yl4hpe Getting a raise comes down to one thing: Leverage.] - by ''[https://medium.freecodecamp.com/@quincylarson Quincy Larson]''<br />
* [http://realtimecollisiondetection.net/blog/?p=70 Salary of a game programmer (artist, designer, or producer)] - by ''[http://realtimecollisiondetection.net Christer Ericcson]'', Sony Computer Entertainment<br />
* [https://www.facebook.com/note.php?note_id=191791235716 Industry tips: How to not ask for money] - by ''[http://www.boomzap.com/ Christopher Natsuume]''<br />
* [http://www.kclabor.org/kyrmpp.htm Know Your Rights - The Myth of Pay Privacy] - by ''[http://www.kclabor.org KC Labor]'' (USA)<br />
* [http://www.amazon.com/Bargaining-Advantage-Negotiation-Strategies-Reasonable/dp/0143036971 Bargaining for Advantage: Negotiation Strategies for Reasonable People] ($) - by ''[http://www.amazon.com/G.-Richard-Shell/e/B001H6KG6E G. Richard Shell]''<br />
* [http://www.polycount.com/forum/showthread.php?p=2067860 New Job Negotiations]<br />
<br />
== Relocation ==<br />
* [http://www.polycount.com/forum/showthread.php?t=99113 The game industry and relocation, how bad is it?] - Polycount Forum thread. Insight into the relocation process.<br />
<br />
== Employee Rights ==<br />
* [http://docontract.com/ contract( )] (pronounced 'do contract') generates free, plain English agreements for and between game developers. See the article [http://www.gamesindustry.biz/articles/2015-03-13-taking-the-fear-out-of-contracts Taking the fear out of contracts] on gamesindustry.biz.<br />
* [http://www.graphicartistsguild.org/handbook/ Graphic Artists Guild Handbook: Pricing & Ethical Guidelines] is an excellent resource on a great range of employment issues. Pricing guidelines, legal info, copyright law, sample contracts, how to negotiate, and more. Highly recommended!<br />
* [http://www.nlrb.gov/about_us/overview/national_labor_relations_act.aspx National Labor Relations Board] (USA)<br />
* [http://www.acas.org.uk/index.aspx?articleid=1390 ACAS: Advisory, Conciliation and Arbitration Service] (UK)<br />
* [http://www.direct.gov.uk/en/Employment/Employees/index.htm Directgov Employment Terms and Conditions] (UK)<br />
* [http://www.kclabor.org/know_your_rights1.htm Know Your Rights] - by [http://www.kclabor.org KC Labor] (USA)<br />
* [http://polycount.com/discussion/71929/discussing-issues-at-work-grounds-for-firing/p1 Discussing issues at work, grounds for firing?] Polycount forum thread has information about workers discussing their compensation with one another.<br />
* [http://www.polycount.com/forum/showthread.php?t=97910 EA rumored to layoff 500+] Polycount forum thread with cautionary tales about what happens when people get laid off or fired, or when companies close. Back up your work regularly, for portfolio use!<br />
<br />
== Going Indie ==<br />
Indie means developing, marketing, and publishing a game independently.<br />
* [http://forums.tigsource.com/index.php?topic=18.msg147#msg147 How to Start an Indie Game Business (WIP)] TIGSource Forum thread with links to resources <br />
<br />
== Freelancing ==<br />
Freelancing means creating assets for pay, working alone as an individual. See [[Freelance]].<br />
<br />
<br />
----<br />
[[Category:Information]] [[Category:GameIndustry]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Game_IndustryGame Industry2016-08-02T16:47:45Z<p>Dustinbrown: /* Education */</p>
<hr />
<div><br />
Links and articles about the game industry: how to get game jobs, how to manage your role, etc.<br />
<br />
__TOC__<br />
<br />
== How to Get In ==<br />
* [http://polycount.com/discussion/168727/im-finding-it-impossible-to-land-a-job I'm finding it impossible to land a job] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=157738 Game Industry Recruiter Taking In Questions] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=134547 Getting that first job] Polycount Forum thread. Good advice for an artist trying to enter a game studio.<br />
* [http://www.polycount.com/forum/showthread.php?t=89972 Getting into the Game Industry (Inspiration of a different kind)] - Polycount Forum thread. Amazing thread full of information from working game artists about how they got into the industry.<br />
* [http://www.ineedtomakegames.com How to Break Into the Industry] - by [http://www.linkedin.com/pub/destin-bales/1/2aa/95b Destin Bales] A treasure trove of great advice by a veteran game developer. Multiple topics covered: understanding the industry, education, resumes and portfolios, finding jobs, interview prep, career development, etc. <br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16967104&gid=59205 Why is it hard to find a job in game industry?] Discussion on LinkedIn about what it takes to get that first game industry job.<br />
* [http://athey.deviantart.com/art/Game-Industry-Advice-to-studen-145619882 Game Industry Advice to students] - by [http://athey.deviantart.com/ Athey Moravetz] A great article by a 5-year veteran game artist about what it takes to get into a game artist job. Very straightforward and accurate.<br />
<br />
== Being a Developer ==<br />
* [http://polycount.com/discussion/174205/job-security-question Job Security Question] Polycount Forum thread. <br />
* [http://www.polycount.com/forum/showthread.php?t=137206 What has the games industry been like for you?] Polycount Forum thread. Game art veterans share what it's really like to be working in game development.<br />
* [http://archive.is/B7o90 Is the games industry really dying?] by Dan Teasdale, diving deep into game industry layoff data.<br />
* [http://www.valvetime.net/threads/valve-employee-hand-book-released.189828/ Valve Employee Hand Book] Greg Coomer says "We wrote this book to make it as easy as we could for new people to join the company. It was fun to capture these thoughts and put them all in one place. Let us know what you think." Cached: [[file:Valve_Employee_Handbook.pdf]]<br />
* [http://www.gdcvault.com/play/1012343/The-Belly-of-the-Whale The Belly of the Whale: Living a Creative Life in the Game Industry] - by [http://www.bobbates.com/ Bob Bates] GDC 2010 lecture about how creative types can survive and thrive in the game industry. Highly recommended [http://www.polycount.com/forum/showthread.php?t=74876 by many Polycounters].<br />
* [http://www.thejonjones.com/2010/08/09/how-not-to-hire-an-artist/ How NOT to hire an artist] - by [http://www.thejonjones.com Jon Jones] Response to the inflammatory article [http://kaitol.com/how-to-hire-an-artist/ How to hire an artist] by [http://kaitol.com/about/ Christopher 'xdragonx10' Gregorio].<br />
* [http://www.polycount.com/2010/08/11/the-co-worker/ The Co-worker] - by [http://www.adambromell.com/ Adam Bromell] Polycount News article about what makes a good team co-worker.<br />
<br />
== Art Disciplines ==<br />
* [[:Category:Discipline]] lists the various artist roles in game development.<br />
* [http://polycount.com/discussion/171014 Specializing or not ?] Polycount forum thread<br />
* [http://polycount.com/discussion/134325 Leadership in the Games Industry] Polycount forum thread<br />
* [http://polycount.com/discussion/81832 What Game artist career is more difficult?] Polycount forum thread<br />
* [[PortfolioContents]] has summaries for what each type of artist should show in their portfolio.<br />
<br />
== Education ==<br />
The basic argument in the Polycount community is between going the self-taught route or going the formal education route. The best path seems to depend on what kind of person you are: self-motivated or team-motivated.<br />
<br />
Artists on Polycount generally agree it is rare to find schools that teach current high-quality game art techniques. The web and forums are often the best places to learn these, maybe even [[:Category:Tutorials|our wiki]] |-) . We see it time and again... the students who succeed at entering the work force after graduation are almost exclusively those that work on their own side projects, beyond the course material. Would they have been better served without using a school? <br />
<br />
If you want to work in a different country, the visa process may require a college or university degree. This is a good reason to seek a degree program.<br />
<br />
Beware of education scams and debt! Schools can cost a lot of money and some promise easy employment afterwards, but unfortunately the reality is not so forgiving. Student loan debt can also be a crushing burden for many years, especially with the relatively low wages most game artists make. See the blog post [https://medium.com/i-m-h-o/138c5efd45e9 Don’t go to art school], the Polycount forum thread [http://www.polycount.com/forum/showthread.php?t=75796 Profit Schools - Can we condemn them publicly?], and the Penny Arcade episode [http://penny-arcade.com/patv/episode/on-game-schools "On Game Schools"].<br />
<br />
* [hhttps://flippednormals.com/blog/creative-students-handbook-schools/] - by [http://k0k0k0.wordpress.com/ Henning Sanden] The Creative Student’s Handbook – Schools!<br />
<br />
* [http://www.polycount.com/forum/showthread.php?t=108342 Education In The Games Industry: Yes or No?] on the Polycount Forum is a great list of threads about game art education. You can also do a [http://polycount.com/search?Search forum search] for ''education''.<br />
<br />
* [http://k0k0k0.wordpress.com/51-things-every-game-student-should-know/ 100 Things Every Game Student Should Know] - by [http://k0k0k0.wordpress.com/ Kaye Elling] 100 fugly slides of things that every budding game developer (who is studying at university) should know. Read it!<br />
<br />
== Portfolios ==<br />
* [[Portfolio]] has links to tutorials and advice about creating an artist portfolio for a career in game development.<br />
<br />
== Resumes ==<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
* [http://windmillnetworking.com/2009/08/11/linkedin-profile-tips-the-10-mistakes-you-want-to-avoid-and-why/ LinkedIn Profile Tips: The 10 Mistakes You Want to Avoid and Why] - by ''[http://windmillnetworking.com/about/ Neal Schaffer]''<br />
* [http://www.joelonsoftware.com/articles/ResumeRead.html Getting Your Résumé Read] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
* [http://www.joelonsoftware.com/articles/SortingResumes.html Sorting Resumes] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
<br />
== Cover Letters ==<br />
* [http://www.polycount.com/forum/showthread.php?t=41014 Writing that all important cover letter?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=85192 Cover Letter] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=118092 Resume / Cover Letter Critique request - Riot Games] Polycount Forum thread<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
<br />
== Job Searching ==<br />
Most game developers get their jobs by word of mouth, this industry puts personal contacts first and foremost. Networking is key; keep in contact with your friends and former co-workers.<br />
* [[Company job boards]]<br />
* [http://www.polycount.com/forum/forumdisplay.php?f=39 Work Opportunities] Polycount Sub-Forum. <br />
* [https://orcahq.com/jobs?tags=Art orca] Game dev news and jobs, every day.<br />
* [http://www.polycount.com/forum/showthread.php?t=134982 Another website to find a video game industry job] Polycount Forum thread has several links.<br />
* [http://boards.polycount.net/showthread.php?t=38472 Game and Mod Development Article] and [http://boards.polycount.net/showthread.php?t=42157 Some mod guidelines] Polycount Forum threads have advice about joining a mod team.<br />
* [http://www.facebook.com/note.php?note_id=195778565716 Industry tips: How to find a job in the game industry] - by ''[http://www.boomzap.com/ Christopher Natsuume]'' has some frank advice about job searching.<br />
* [http://www.joelonsoftware.com/articles/ThePhoneScreen.html The Phone Screen] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]'' has info about how companies weed out applicants.<br />
* [http://www.polycount.com/forum/showthread.php?t=99400 It seems to be impossible to find a job as a Modeler in this industry] - this Polycount forum thread has good advice about how to actually get hired as an artist in game development. <br />
* [http://gamedevmap.com gamedevmap] - map of game development companies.<br />
<br />
== Going to Conferences ==<br />
Attending a game conference or developer event is a great way to connect with people working in game development. Connections often lead to work opportunities!<br />
<br />
A few notable conferences:<br />
* [http://www.gdconf.com/aboutgdc/ Game Developer's Conference] (GDC), GDC Europe, GDC China.<br />
* [http://prime.paxsite.com/what-is-pax PAX Prime], PAX East, PAX South, PAX Aus.<br />
* [http://www.e3expo.com/show-info/2541/about-e3/ Electronic Entertainment Expo] (E3).<br />
* [http://www.gameconfs.com/ Gameconfs] - a directory of game industry events.<br />
<br />
<br />
{| style="border:2px solid #111;background-color:#222;"<br />
|-<br />
! style="text-align:left;"|Advice from seasoned Indie [http://ichiro.us/ Ichiro Lambe] about how he goes to GDC:<br />
|-<br />
|1. '''Get connected beforehand.''' We always pulled together lists of devs who were going, to connect folks. For instance, we had a Google Form where everyone put down their names, games, companies, interests, Twitter handles, etc., and that all got spat out into a publicly viewable spreadsheet. We then tweeted that form/spreadsheet to everyone, and got a bazillion responses. We'd then reach out to subsets of those people and say, "Hey, we have common interests. Let's all meet." Instant GDC community.<br />
|-<br />
|2. '''Stay connected during.''' We also did a GDC Google Hangout or Facebook group for mobile users once out there. That allowed, for example, a friend to text a hundred devs with, "Hey, I'm completely drunk at Pinecrest. Who wants to meet?" Or, we'd Katamari a bunch of devs and go to a bar and chat dev. Katamaris work great -- meet one dev, and ask them to invite two friends. And so forth.<br />
|-<br />
|3. '''Set up meetings.''' Are there folks you want to meet out there? E-mail them and see what they're up to. Schedule lunch or coffee with a group of mobile game designers. Have them invite colleagues. Rinse. Repeat. Figure out why you're interesting and unique, and approach people with that. Don't be shy about it.<br />
|-<br />
|4. '''Plan.''' Write out your GDC plan beforehand. You can deviate from this entirely, but it's useful because it shows where there are scheduling gaps. It also forces you to identify your goals and objectives. I go to GDC primarily to connect myself and other devs with platform holders. Ergo, I'll want to set up meetings with Colecovision and Vectrex, and have pitches ready for them. Your goals may differ, but your plan should derive from those goals.<br />
|-<br />
|5. '''Get a pass.''' Go write each of the IGF finalists, tell them how amazing you are and how you're not an asshole, and ask them if they need help manning their booths in exchange for an expo pass.<br />
|-<br />
|6. '''Avoid the big, loud parties.''' 300 game developers at a loud dance club is silly. It's fun to go to these things and get free booze and food, but it's often more profitable to meet with Intellivision over quiet drinks, and more creatively stimulating to meet with a group of other developers in a quiet hotel lobby.<br />
|}<br />
<br />
== Interviews ==<br />
* [http://www.polycount.com/forum/showthread.php?t=106081 Job Interview in a hour or so, what questions should I expect?] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=105266 When eyeballing a studio...] thread on the Polycount forum (what questions should you ask during your interview).<br />
* [http://www.polycount.com/forum/showthread.php?t=69142 Interview Advice] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=80507 In need of interview advice] thread on the Polycount forum.<br />
* [http://www.boston.com/bostonworks/galleries/job_interview_tips?pg=2 10 Tips for Your First Interview] - by ''Dave Sanford'' Time-tested interview strategies:<br />
*# Research<br />
*# Practice<br />
*# Clothing<br />
*# Get there early<br />
*# Observe<br />
*# Know thyself<br />
*# Handshake<br />
*# Listen<br />
*# Finishing<br />
*# Follow up<br />
* [http://hotjobs.yahoo.com/career-experts-four_steps_to_a_better_job_interview-51 Four Steps to a Better Job Interview] - by ''Brad Karsh'' Four simple things to improve your interviews.<br />
*# Relax, not a battle of wits.<br />
*# Job description = questions that you'll be asked.<br />
*# Have answers about why you did certain things.<br />
*# Have questions about them.<br />
* [http://www.jobbankusa.com/interviews/articles_tips/10_follow_up_rules.html Ten Tips for the Interview Follow Up] - by ''Carole Martin'' How to avoid a non-response after your interview.<br />
* [http://boards.polycount.net/showthread.php?t=57317 job interview, 2-3 hours, why so long?] Polycount forum thread Game developers talking about the interview process they do, or have been through.<br />
<br />
== Art Tests ==<br />
Game companies often ask their art applicants to complete an art test, to gauge their talent relative to that company's particular needs, and to make sure you can actually do the work (portfolios can be faked or stolen).<br />
<br />
Beware doing an unpaid art test. A company can ask you to spend a long time on it, but then plagiarize the results, never respond after submission, etc.<br />
<br />
* [http://forum.gameartisans.org/forums/showthread.php?t=5970 Art Test Master List] GameArtisans forum thread has some example art tests.<br />
* [http://www.polycount.com/forum/showthread.php?t=157057 Paid Art Test?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?p=1795799#post1795799 Art Tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=87657 Jagex Art Test] Polycount Forum thread<br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16136725&gid=1842071 "Large art tests as the first stage of candidate selection. Acceptable?"] LinkedIn discussion<br />
* [http://www.polycount.com/forum/showthread.php?t=84418 Environment Art Test advice?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81681 Art test and no response, normal?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81015 Is it bad to ask for tips on an art test? There isn't an NDA] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=80861 Art tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=77279 Art Tests : How much time to spend?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=76208 Art Test Help/Suggestions] Polycount Forum thread<br />
<br />
== Salary Research ==<br />
Do the research to figure out what a fair offer is for your skill level and geographic area.<br />
* [http://h1bdata.info/index.php H1-B Visa Salary Database]<br />
* [https://orcahq.com/blog/game-industry-salary-explorer Game Industry Salary Explorer] - from [https://orcahq.com/ Orca HQ]. See the Polycount Forum thread [http://polycount.com/discussion/165337/game-industry-salary-explorer Game Industry Salary Explorer].<br />
* [http://www.gamecareerguide.com/features/1108/game_developer_salary_survey_2012.php 2012 Game Industry Salary Survey] - from ''[http://www.gdmag.com/ Game Developer magazine]'' (mostly USA). See also [http://gamedeveloper.texterity.com/gamedeveloper/201104#pg9 2010], [http://gamedeveloper.texterity.com/gamedeveloper/2009fall/#pg33 2009], [http://gamedeveloper.texterity.com/gamedeveloper/2008careerguide/#pg13 2008], [http://www.gamecareerguide.com/features/416/the_game_industry_salary_survey_.php?page=1 2007], [http://www.gamecareerguide.com/features/266/are_you_in_demand_2006_game_.php?page=1 2006].<br />
* [http://www.glassdoor.com/Salaries/us-computer-software-senior-artist-salary-SRCH_IL.0,2_IN1_II1121.3,20_KO21,34_SDAS.htm# Senior Artist Salaries at Computer Software companies in United States] - from ''[http://www.glassdoor.com Glassdoor.com]'' (USA) Customize your search, and enter your salary data for full access.<br />
* [http://www.payscale.com/research/US/Job=3d_Artist/Salary 3D Artist Salaries in the United States] - from ''[http://www.payscale.com Payscale.com]'' (other countries available)<br />
* [http://www.flcdatacenter.com/CaseH1B.aspx The Foreign Labor Certification Data Center - Online Wage Library] (H1B Visa Applications) - from the ''[http://www.doleta.gov/ US Department of Labor]'' (USA)<br />
* [http://vfxsoldier.wordpress.com/2010/08/16/wages-in-the-vfx-animation-and-games-industry/ Wages In The VFX, Animation, And Games Industry] - by [http://vfxsoldier.wordpress.com 'VFX Soldier'] features a spreadsheet of wage data mined from the H1B Visa database.<br />
* [http://www.mcvuk.com/news/read/uk-games-industry-salary-survey-what-are-you-worth/0110018 2012 UK Games Industry Salary Survey]. See also [http://www.develop-online.net/features/429/The-2009-UK-Games-Development-Salary-Survey 2009] (UK)<br />
* [http://www.vfxwages.com/ VFXWages] - a global database of hourly monetary rates of people in the film and television visual effects, animation, motion graphics, and gaming industry. <br />
* [[Freelance#Freelance_Rates]]<br />
<br />
== Negotiation ==<br />
Salary negotiation is an essential skill that will be put to the test after a successful interview. <br />
* [https://medium.freecodecamp.com/youre-underpaid-here-s-how-you-can-get-the-pay-raise-you-deserve-fafcf52956d6#.gz4yl4hpe Getting a raise comes down to one thing: Leverage.] - by ''[https://medium.freecodecamp.com/@quincylarson Quincy Larson]''<br />
* [http://realtimecollisiondetection.net/blog/?p=70 Salary of a game programmer (artist, designer, or producer)] - by ''[http://realtimecollisiondetection.net Christer Ericcson]'', Sony Computer Entertainment<br />
* [https://www.facebook.com/note.php?note_id=191791235716 Industry tips: How to not ask for money] - by ''[http://www.boomzap.com/ Christopher Natsuume]''<br />
* [http://www.kclabor.org/kyrmpp.htm Know Your Rights - The Myth of Pay Privacy] - by ''[http://www.kclabor.org KC Labor]'' (USA)<br />
* [http://www.amazon.com/Bargaining-Advantage-Negotiation-Strategies-Reasonable/dp/0143036971 Bargaining for Advantage: Negotiation Strategies for Reasonable People] ($) - by ''[http://www.amazon.com/G.-Richard-Shell/e/B001H6KG6E G. Richard Shell]''<br />
* [http://www.polycount.com/forum/showthread.php?p=2067860 New Job Negotiations]<br />
<br />
== Relocation ==<br />
* [http://www.polycount.com/forum/showthread.php?t=99113 The game industry and relocation, how bad is it?] - Polycount Forum thread. Insight into the relocation process.<br />
<br />
== Employee Rights ==<br />
* [http://docontract.com/ contract( )] (pronounced 'do contract') generates free, plain English agreements for and between game developers. See the article [http://www.gamesindustry.biz/articles/2015-03-13-taking-the-fear-out-of-contracts Taking the fear out of contracts] on gamesindustry.biz.<br />
* [http://www.graphicartistsguild.org/handbook/ Graphic Artists Guild Handbook: Pricing & Ethical Guidelines] is an excellent resource on a great range of employment issues. Pricing guidelines, legal info, copyright law, sample contracts, how to negotiate, and more. Highly recommended!<br />
* [http://www.nlrb.gov/about_us/overview/national_labor_relations_act.aspx National Labor Relations Board] (USA)<br />
* [http://www.acas.org.uk/index.aspx?articleid=1390 ACAS: Advisory, Conciliation and Arbitration Service] (UK)<br />
* [http://www.direct.gov.uk/en/Employment/Employees/index.htm Directgov Employment Terms and Conditions] (UK)<br />
* [http://www.kclabor.org/know_your_rights1.htm Know Your Rights] - by [http://www.kclabor.org KC Labor] (USA)<br />
* [http://polycount.com/discussion/71929/discussing-issues-at-work-grounds-for-firing/p1 Discussing issues at work, grounds for firing?] Polycount forum thread has information about workers discussing their compensation with one another.<br />
* [http://www.polycount.com/forum/showthread.php?t=97910 EA rumored to layoff 500+] Polycount forum thread with cautionary tales about what happens when people get laid off or fired, or when companies close. Back up your work regularly, for portfolio use!<br />
<br />
== Going Indie ==<br />
Indie means developing, marketing, and publishing a game independently.<br />
* [http://forums.tigsource.com/index.php?topic=18.msg147#msg147 How to Start an Indie Game Business (WIP)] TIGSource Forum thread with links to resources <br />
<br />
== Freelancing ==<br />
Freelancing means creating assets for pay, working alone as an individual. See [[Freelance]].<br />
<br />
<br />
----<br />
[[Category:Information]] [[Category:GameIndustry]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Game_IndustryGame Industry2016-07-08T15:17:00Z<p>Dustinbrown: /* Negotiation */</p>
<hr />
<div><br />
Links and articles about the game industry: how to get game jobs, how to manage your role, etc.<br />
<br />
__TOC__<br />
<br />
== How to Get In ==<br />
* [http://polycount.com/discussion/168727/im-finding-it-impossible-to-land-a-job I'm finding it impossible to land a job] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=157738 Game Industry Recruiter Taking In Questions] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=134547 Getting that first job] Polycount Forum thread. Good advice for an artist trying to enter a game studio.<br />
* [http://www.polycount.com/forum/showthread.php?t=89972 Getting into the Game Industry (Inspiration of a different kind)] - Polycount Forum thread. Amazing thread full of information from working game artists about how they got into the industry.<br />
* [http://www.ineedtomakegames.com How to Break Into the Industry] - by [http://www.linkedin.com/pub/destin-bales/1/2aa/95b Destin Bales] A treasure trove of great advice by a veteran game developer. Multiple topics covered: understanding the industry, education, resumes and portfolios, finding jobs, interview prep, career development, etc. <br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16967104&gid=59205 Why is it hard to find a job in game industry?] Discussion on LinkedIn about what it takes to get that first game industry job.<br />
* [http://athey.deviantart.com/art/Game-Industry-Advice-to-studen-145619882 Game Industry Advice to students] - by [http://athey.deviantart.com/ Athey Moravetz] A great article by a 5-year veteran game artist about what it takes to get into a game artist job. Very straightforward and accurate.<br />
<br />
== Being a Developer ==<br />
* [http://www.polycount.com/forum/showthread.php?t=137206 What has the games industry been like for you?] Polycount Forum thread. Game art veterans share what it's really like to be working in game development.<br />
* [http://archive.is/B7o90 Is the games industry really dying?] by Dan Teasdale, diving deep into game industry layoff data.<br />
* [http://www.valvetime.net/threads/valve-employee-hand-book-released.189828/ Valve Employee Hand Book] Greg Coomer says "We wrote this book to make it as easy as we could for new people to join the company. It was fun to capture these thoughts and put them all in one place. Let us know what you think." Cached: [[file:Valve_Employee_Handbook.pdf]]<br />
* [http://www.gdcvault.com/play/1012343/The-Belly-of-the-Whale The Belly of the Whale: Living a Creative Life in the Game Industry] - by [http://www.bobbates.com/ Bob Bates] GDC 2010 lecture about how creative types can survive and thrive in the game industry. Highly recommended [http://www.polycount.com/forum/showthread.php?t=74876 by many Polycounters].<br />
* [http://www.thejonjones.com/2010/08/09/how-not-to-hire-an-artist/ How NOT to hire an artist] - by [http://www.thejonjones.com Jon Jones] Response to the inflammatory article [http://kaitol.com/how-to-hire-an-artist/ How to hire an artist] by [http://kaitol.com/about/ Christopher 'xdragonx10' Gregorio].<br />
* [http://www.polycount.com/2010/08/11/the-co-worker/ The Co-worker] - by [http://www.adambromell.com/ Adam Bromell] Polycount News article about what makes a good team co-worker.<br />
<br />
== Art Disciplines ==<br />
* [[:Category:Discipline]] lists the various artist roles in game development.<br />
* [http://polycount.com/discussion/171014 Specializing or not ?] Polycount forum thread<br />
* [http://polycount.com/discussion/134325 Leadership in the Games Industry] Polycount forum thread<br />
* [http://polycount.com/discussion/81832 What Game artist career is more difficult?] Polycount forum thread<br />
* [[PortfolioContents]] has summaries for what each type of artist should show in their portfolio.<br />
<br />
== Education ==<br />
The basic argument in the Polycount community is between going the self-taught route or going the formal education route. The best path seems to depend on what kind of person you are: self-motivated or team-motivated.<br />
<br />
Artists on Polycount generally agree it is rare to find schools that teach current high-quality game art techniques. The web and forums are often the best places to learn these, maybe even [[:Category:Tutorials|our wiki]] |-) . We see it time and again... the students who succeed at entering the work force after graduation are almost exclusively those that work on their own side projects, beyond the course material. Would they have been better served without using a school? <br />
<br />
If you want to work in a different country, the visa process may require a college or university degree. This is a good reason to seek a degree program.<br />
<br />
Beware of education scams and debt! Schools can cost a lot of money and some promise easy employment afterwards, but unfortunately the reality is not so forgiving. Student loan debt can also be a crushing burden for many years, especially with the relatively low wages most game artists make. See the blog post [https://medium.com/i-m-h-o/138c5efd45e9 Don’t go to art school], the Polycount forum thread [http://www.polycount.com/forum/showthread.php?t=75796 Profit Schools - Can we condemn them publicly?], and the Penny Arcade episode [http://penny-arcade.com/patv/episode/on-game-schools "On Game Schools"].<br />
<br />
* [http://www.polycount.com/forum/showthread.php?t=108342 Education In The Games Industry: Yes or No?] on the Polycount Forum is a great list of threads about game art education. You can also do a [http://polycount.com/search?Search forum search] for ''education''.<br />
<br />
* [http://k0k0k0.wordpress.com/51-things-every-game-student-should-know/ 100 Things Every Game Student Should Know] - by [http://k0k0k0.wordpress.com/ Kaye Elling] 100 fugly slides of things that every budding game developer (who is studying at university) should know. Read it!<br />
<br />
== Portfolios ==<br />
* [[Portfolio]] has links to tutorials and advice about creating an artist portfolio for a career in game development.<br />
<br />
== Resumes ==<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
* [http://windmillnetworking.com/2009/08/11/linkedin-profile-tips-the-10-mistakes-you-want-to-avoid-and-why/ LinkedIn Profile Tips: The 10 Mistakes You Want to Avoid and Why] - by ''[http://windmillnetworking.com/about/ Neal Schaffer]''<br />
* [http://www.joelonsoftware.com/articles/ResumeRead.html Getting Your Résumé Read] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
* [http://www.joelonsoftware.com/articles/SortingResumes.html Sorting Resumes] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
<br />
== Cover Letters ==<br />
* [http://www.polycount.com/forum/showthread.php?t=41014 Writing that all important cover letter?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=85192 Cover Letter] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=118092 Resume / Cover Letter Critique request - Riot Games] Polycount Forum thread<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
<br />
== Job Searching ==<br />
Most game developers get their jobs by word of mouth, this industry puts personal contacts first and foremost. Networking is key; keep in contact with your friends and former co-workers.<br />
* [[Company job boards]]<br />
* [http://www.polycount.com/forum/forumdisplay.php?f=39 Work Opportunities] Polycount Sub-Forum. <br />
* [https://orcahq.com/jobs?tags=Art orca] Game dev news and jobs, every day.<br />
* [http://www.polycount.com/forum/showthread.php?t=134982 Another website to find a video game industry job] Polycount Forum thread has several links.<br />
* [http://boards.polycount.net/showthread.php?t=38472 Game and Mod Development Article] and [http://boards.polycount.net/showthread.php?t=42157 Some mod guidelines] Polycount Forum threads have advice about joining a mod team.<br />
* [http://www.facebook.com/note.php?note_id=195778565716 Industry tips: How to find a job in the game industry] - by ''[http://www.boomzap.com/ Christopher Natsuume]'' has some frank advice about job searching.<br />
* [http://www.joelonsoftware.com/articles/ThePhoneScreen.html The Phone Screen] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]'' has info about how companies weed out applicants.<br />
* [http://www.polycount.com/forum/showthread.php?t=99400 It seems to be impossible to find a job as a Modeler in this industry] - this Polycount forum thread has good advice about how to actually get hired as an artist in game development. <br />
* [http://gamedevmap.com gamedevmap] - map of game development companies.<br />
<br />
== Going to Conferences ==<br />
Attending a game conference or developer event is a great way to connect with people working in game development. Connections often lead to work opportunities!<br />
<br />
A few notable conferences:<br />
* [http://www.gdconf.com/aboutgdc/ Game Developer's Conference] (GDC), GDC Europe, GDC China.<br />
* [http://prime.paxsite.com/what-is-pax PAX Prime], PAX East, PAX South, PAX Aus.<br />
* [http://www.e3expo.com/show-info/2541/about-e3/ Electronic Entertainment Expo] (E3).<br />
* [http://www.gameconfs.com/ Gameconfs] - a directory of game industry events.<br />
<br />
<br />
{| style="border:2px solid #111;background-color:#222;"<br />
|-<br />
! style="text-align:left;"|Advice from seasoned Indie [http://ichiro.us/ Ichiro Lambe] about how he goes to GDC:<br />
|-<br />
|1. '''Get connected beforehand.''' We always pulled together lists of devs who were going, to connect folks. For instance, we had a Google Form where everyone put down their names, games, companies, interests, Twitter handles, etc., and that all got spat out into a publicly viewable spreadsheet. We then tweeted that form/spreadsheet to everyone, and got a bazillion responses. We'd then reach out to subsets of those people and say, "Hey, we have common interests. Let's all meet." Instant GDC community.<br />
|-<br />
|2. '''Stay connected during.''' We also did a GDC Google Hangout or Facebook group for mobile users once out there. That allowed, for example, a friend to text a hundred devs with, "Hey, I'm completely drunk at Pinecrest. Who wants to meet?" Or, we'd Katamari a bunch of devs and go to a bar and chat dev. Katamaris work great -- meet one dev, and ask them to invite two friends. And so forth.<br />
|-<br />
|3. '''Set up meetings.''' Are there folks you want to meet out there? E-mail them and see what they're up to. Schedule lunch or coffee with a group of mobile game designers. Have them invite colleagues. Rinse. Repeat. Figure out why you're interesting and unique, and approach people with that. Don't be shy about it.<br />
|-<br />
|4. '''Plan.''' Write out your GDC plan beforehand. You can deviate from this entirely, but it's useful because it shows where there are scheduling gaps. It also forces you to identify your goals and objectives. I go to GDC primarily to connect myself and other devs with platform holders. Ergo, I'll want to set up meetings with Colecovision and Vectrex, and have pitches ready for them. Your goals may differ, but your plan should derive from those goals.<br />
|-<br />
|5. '''Get a pass.''' Go write each of the IGF finalists, tell them how amazing you are and how you're not an asshole, and ask them if they need help manning their booths in exchange for an expo pass.<br />
|-<br />
|6. '''Avoid the big, loud parties.''' 300 game developers at a loud dance club is silly. It's fun to go to these things and get free booze and food, but it's often more profitable to meet with Intellivision over quiet drinks, and more creatively stimulating to meet with a group of other developers in a quiet hotel lobby.<br />
|}<br />
<br />
== Interviews ==<br />
* [http://www.polycount.com/forum/showthread.php?t=106081 Job Interview in a hour or so, what questions should I expect?] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=105266 When eyeballing a studio...] thread on the Polycount forum (what questions should you ask during your interview).<br />
* [http://www.polycount.com/forum/showthread.php?t=69142 Interview Advice] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=80507 In need of interview advice] thread on the Polycount forum.<br />
* [http://www.boston.com/bostonworks/galleries/job_interview_tips?pg=2 10 Tips for Your First Interview] - by ''Dave Sanford'' Time-tested interview strategies:<br />
*# Research<br />
*# Practice<br />
*# Clothing<br />
*# Get there early<br />
*# Observe<br />
*# Know thyself<br />
*# Handshake<br />
*# Listen<br />
*# Finishing<br />
*# Follow up<br />
* [http://hotjobs.yahoo.com/career-experts-four_steps_to_a_better_job_interview-51 Four Steps to a Better Job Interview] - by ''Brad Karsh'' Four simple things to improve your interviews.<br />
*# Relax, not a battle of wits.<br />
*# Job description = questions that you'll be asked.<br />
*# Have answers about why you did certain things.<br />
*# Have questions about them.<br />
* [http://www.jobbankusa.com/interviews/articles_tips/10_follow_up_rules.html Ten Tips for the Interview Follow Up] - by ''Carole Martin'' How to avoid a non-response after your interview.<br />
* [http://boards.polycount.net/showthread.php?t=57317 job interview, 2-3 hours, why so long?] Polycount forum thread Game developers talking about the interview process they do, or have been through.<br />
<br />
== Art Tests ==<br />
Game companies often ask their art applicants to complete an art test, to gauge their talent relative to that company's particular needs, and to make sure you can actually do the work (portfolios can be faked or stolen).<br />
<br />
Beware doing an unpaid art test. A company can ask you to spend a long time on it, but then plagiarize the results, never respond after submission, etc.<br />
<br />
* [http://forum.gameartisans.org/forums/showthread.php?t=5970 Art Test Master List] GameArtisans forum thread has some example art tests.<br />
* [http://www.polycount.com/forum/showthread.php?t=157057 Paid Art Test?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?p=1795799#post1795799 Art Tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=87657 Jagex Art Test] Polycount Forum thread<br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16136725&gid=1842071 "Large art tests as the first stage of candidate selection. Acceptable?"] LinkedIn discussion<br />
* [http://www.polycount.com/forum/showthread.php?t=84418 Environment Art Test advice?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81681 Art test and no response, normal?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81015 Is it bad to ask for tips on an art test? There isn't an NDA] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=80861 Art tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=77279 Art Tests : How much time to spend?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=76208 Art Test Help/Suggestions] Polycount Forum thread<br />
<br />
== Salary Research ==<br />
Do the research to figure out what a fair offer is for your skill level and geographic area.<br />
* [http://h1bdata.info/index.php H1-B Visa Salary Database]<br />
* [https://orcahq.com/blog/game-industry-salary-explorer Game Industry Salary Explorer] - from [https://orcahq.com/ Orca HQ]. See the Polycount Forum thread [http://polycount.com/discussion/165337/game-industry-salary-explorer Game Industry Salary Explorer].<br />
* [http://www.gamecareerguide.com/features/1108/game_developer_salary_survey_2012.php 2012 Game Industry Salary Survey] - from ''[http://www.gdmag.com/ Game Developer magazine]'' (mostly USA). See also [http://gamedeveloper.texterity.com/gamedeveloper/201104#pg9 2010], [http://gamedeveloper.texterity.com/gamedeveloper/2009fall/#pg33 2009], [http://gamedeveloper.texterity.com/gamedeveloper/2008careerguide/#pg13 2008], [http://www.gamecareerguide.com/features/416/the_game_industry_salary_survey_.php?page=1 2007], [http://www.gamecareerguide.com/features/266/are_you_in_demand_2006_game_.php?page=1 2006].<br />
* [http://www.glassdoor.com/Salaries/us-computer-software-senior-artist-salary-SRCH_IL.0,2_IN1_II1121.3,20_KO21,34_SDAS.htm# Senior Artist Salaries at Computer Software companies in United States] - from ''[http://www.glassdoor.com Glassdoor.com]'' (USA) Customize your search, and enter your salary data for full access.<br />
* [http://www.payscale.com/research/US/Job=3d_Artist/Salary 3D Artist Salaries in the United States] - from ''[http://www.payscale.com Payscale.com]'' (other countries available)<br />
* [http://www.flcdatacenter.com/CaseH1B.aspx The Foreign Labor Certification Data Center - Online Wage Library] (H1B Visa Applications) - from the ''[http://www.doleta.gov/ US Department of Labor]'' (USA)<br />
* [http://vfxsoldier.wordpress.com/2010/08/16/wages-in-the-vfx-animation-and-games-industry/ Wages In The VFX, Animation, And Games Industry] - by [http://vfxsoldier.wordpress.com 'VFX Soldier'] features a spreadsheet of wage data mined from the H1B Visa database.<br />
* [http://www.mcvuk.com/news/read/uk-games-industry-salary-survey-what-are-you-worth/0110018 2012 UK Games Industry Salary Survey]. See also [http://www.develop-online.net/features/429/The-2009-UK-Games-Development-Salary-Survey 2009] (UK)<br />
* [http://www.vfxwages.com/ VFXWages] - a global database of hourly monetary rates of people in the film and television visual effects, animation, motion graphics, and gaming industry. <br />
* [[Freelance#Freelance_Rates]]<br />
<br />
== Negotiation ==<br />
Salary negotiation is an essential skill that will be put to the test after a successful interview. <br />
* [https://medium.freecodecamp.com/youre-underpaid-here-s-how-you-can-get-the-pay-raise-you-deserve-fafcf52956d6#.gz4yl4hpe Getting a raise comes down to one thing: Leverage.] - by ''[https://medium.freecodecamp.com/@quincylarson Quincy Larson]''<br />
* [http://realtimecollisiondetection.net/blog/?p=70 Salary of a game programmer (artist, designer, or producer)] - by ''[http://realtimecollisiondetection.net Christer Ericcson]'', Sony Computer Entertainment<br />
* [https://www.facebook.com/note.php?note_id=191791235716 Industry tips: How to not ask for money] - by ''[http://www.boomzap.com/ Christopher Natsuume]''<br />
* [http://www.kclabor.org/kyrmpp.htm Know Your Rights - The Myth of Pay Privacy] - by ''[http://www.kclabor.org KC Labor]'' (USA)<br />
* [http://www.amazon.com/Bargaining-Advantage-Negotiation-Strategies-Reasonable/dp/0143036971 Bargaining for Advantage: Negotiation Strategies for Reasonable People] ($) - by ''[http://www.amazon.com/G.-Richard-Shell/e/B001H6KG6E G. Richard Shell]''<br />
* [http://www.polycount.com/forum/showthread.php?p=2067860 New Job Negotiations]<br />
<br />
== Relocation ==<br />
* [http://www.polycount.com/forum/showthread.php?t=99113 The game industry and relocation, how bad is it?] - Polycount Forum thread. Insight into the relocation process.<br />
<br />
== Employee Rights ==<br />
* [http://docontract.com/ contract( )] (pronounced 'do contract') generates free, plain English agreements for and between game developers. See the article [http://www.gamesindustry.biz/articles/2015-03-13-taking-the-fear-out-of-contracts Taking the fear out of contracts] on gamesindustry.biz.<br />
* [http://www.graphicartistsguild.org/handbook/ Graphic Artists Guild Handbook: Pricing & Ethical Guidelines] is an excellent resource on a great range of employment issues. Pricing guidelines, legal info, copyright law, sample contracts, how to negotiate, and more. Highly recommended!<br />
* [http://www.nlrb.gov/about_us/overview/national_labor_relations_act.aspx National Labor Relations Board] (USA)<br />
* [http://www.acas.org.uk/index.aspx?articleid=1390 ACAS: Advisory, Conciliation and Arbitration Service] (UK)<br />
* [http://www.direct.gov.uk/en/Employment/Employees/index.htm Directgov Employment Terms and Conditions] (UK)<br />
* [http://www.kclabor.org/know_your_rights1.htm Know Your Rights] - by [http://www.kclabor.org KC Labor] (USA)<br />
* [http://polycount.com/discussion/71929/discussing-issues-at-work-grounds-for-firing/p1 Discussing issues at work, grounds for firing?] Polycount forum thread has information about workers discussing their compensation with one another.<br />
* [http://www.polycount.com/forum/showthread.php?t=97910 EA rumored to layoff 500+] Polycount forum thread with cautionary tales about what happens when people get laid off or fired, or when companies close. Back up your work regularly, for portfolio use!<br />
<br />
== Going Indie ==<br />
Indie means developing, marketing, and publishing a game independently.<br />
* [http://forums.tigsource.com/index.php?topic=18.msg147#msg147 How to Start an Indie Game Business (WIP)] TIGSource Forum thread with links to resources <br />
<br />
== Freelancing ==<br />
Freelancing means creating assets for pay, working alone as an individual. See [[Freelance]].<br />
<br />
<br />
----<br />
[[Category:Information]] [[Category:GameIndustry]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Game_IndustryGame Industry2016-07-08T15:16:31Z<p>Dustinbrown: /* Negotiation */</p>
<hr />
<div><br />
Links and articles about the game industry: how to get game jobs, how to manage your role, etc.<br />
<br />
__TOC__<br />
<br />
== How to Get In ==<br />
* [http://polycount.com/discussion/168727/im-finding-it-impossible-to-land-a-job I'm finding it impossible to land a job] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=157738 Game Industry Recruiter Taking In Questions] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=134547 Getting that first job] Polycount Forum thread. Good advice for an artist trying to enter a game studio.<br />
* [http://www.polycount.com/forum/showthread.php?t=89972 Getting into the Game Industry (Inspiration of a different kind)] - Polycount Forum thread. Amazing thread full of information from working game artists about how they got into the industry.<br />
* [http://www.ineedtomakegames.com How to Break Into the Industry] - by [http://www.linkedin.com/pub/destin-bales/1/2aa/95b Destin Bales] A treasure trove of great advice by a veteran game developer. Multiple topics covered: understanding the industry, education, resumes and portfolios, finding jobs, interview prep, career development, etc. <br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16967104&gid=59205 Why is it hard to find a job in game industry?] Discussion on LinkedIn about what it takes to get that first game industry job.<br />
* [http://athey.deviantart.com/art/Game-Industry-Advice-to-studen-145619882 Game Industry Advice to students] - by [http://athey.deviantart.com/ Athey Moravetz] A great article by a 5-year veteran game artist about what it takes to get into a game artist job. Very straightforward and accurate.<br />
<br />
== Being a Developer ==<br />
* [http://www.polycount.com/forum/showthread.php?t=137206 What has the games industry been like for you?] Polycount Forum thread. Game art veterans share what it's really like to be working in game development.<br />
* [http://archive.is/B7o90 Is the games industry really dying?] by Dan Teasdale, diving deep into game industry layoff data.<br />
* [http://www.valvetime.net/threads/valve-employee-hand-book-released.189828/ Valve Employee Hand Book] Greg Coomer says "We wrote this book to make it as easy as we could for new people to join the company. It was fun to capture these thoughts and put them all in one place. Let us know what you think." Cached: [[file:Valve_Employee_Handbook.pdf]]<br />
* [http://www.gdcvault.com/play/1012343/The-Belly-of-the-Whale The Belly of the Whale: Living a Creative Life in the Game Industry] - by [http://www.bobbates.com/ Bob Bates] GDC 2010 lecture about how creative types can survive and thrive in the game industry. Highly recommended [http://www.polycount.com/forum/showthread.php?t=74876 by many Polycounters].<br />
* [http://www.thejonjones.com/2010/08/09/how-not-to-hire-an-artist/ How NOT to hire an artist] - by [http://www.thejonjones.com Jon Jones] Response to the inflammatory article [http://kaitol.com/how-to-hire-an-artist/ How to hire an artist] by [http://kaitol.com/about/ Christopher 'xdragonx10' Gregorio].<br />
* [http://www.polycount.com/2010/08/11/the-co-worker/ The Co-worker] - by [http://www.adambromell.com/ Adam Bromell] Polycount News article about what makes a good team co-worker.<br />
<br />
== Art Disciplines ==<br />
* [[:Category:Discipline]] lists the various artist roles in game development.<br />
* [http://polycount.com/discussion/171014 Specializing or not ?] Polycount forum thread<br />
* [http://polycount.com/discussion/134325 Leadership in the Games Industry] Polycount forum thread<br />
* [http://polycount.com/discussion/81832 What Game artist career is more difficult?] Polycount forum thread<br />
* [[PortfolioContents]] has summaries for what each type of artist should show in their portfolio.<br />
<br />
== Education ==<br />
The basic argument in the Polycount community is between going the self-taught route or going the formal education route. The best path seems to depend on what kind of person you are: self-motivated or team-motivated.<br />
<br />
Artists on Polycount generally agree it is rare to find schools that teach current high-quality game art techniques. The web and forums are often the best places to learn these, maybe even [[:Category:Tutorials|our wiki]] |-) . We see it time and again... the students who succeed at entering the work force after graduation are almost exclusively those that work on their own side projects, beyond the course material. Would they have been better served without using a school? <br />
<br />
If you want to work in a different country, the visa process may require a college or university degree. This is a good reason to seek a degree program.<br />
<br />
Beware of education scams and debt! Schools can cost a lot of money and some promise easy employment afterwards, but unfortunately the reality is not so forgiving. Student loan debt can also be a crushing burden for many years, especially with the relatively low wages most game artists make. See the blog post [https://medium.com/i-m-h-o/138c5efd45e9 Don’t go to art school], the Polycount forum thread [http://www.polycount.com/forum/showthread.php?t=75796 Profit Schools - Can we condemn them publicly?], and the Penny Arcade episode [http://penny-arcade.com/patv/episode/on-game-schools "On Game Schools"].<br />
<br />
* [http://www.polycount.com/forum/showthread.php?t=108342 Education In The Games Industry: Yes or No?] on the Polycount Forum is a great list of threads about game art education. You can also do a [http://polycount.com/search?Search forum search] for ''education''.<br />
<br />
* [http://k0k0k0.wordpress.com/51-things-every-game-student-should-know/ 100 Things Every Game Student Should Know] - by [http://k0k0k0.wordpress.com/ Kaye Elling] 100 fugly slides of things that every budding game developer (who is studying at university) should know. Read it!<br />
<br />
== Portfolios ==<br />
* [[Portfolio]] has links to tutorials and advice about creating an artist portfolio for a career in game development.<br />
<br />
== Resumes ==<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
* [http://windmillnetworking.com/2009/08/11/linkedin-profile-tips-the-10-mistakes-you-want-to-avoid-and-why/ LinkedIn Profile Tips: The 10 Mistakes You Want to Avoid and Why] - by ''[http://windmillnetworking.com/about/ Neal Schaffer]''<br />
* [http://www.joelonsoftware.com/articles/ResumeRead.html Getting Your Résumé Read] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
* [http://www.joelonsoftware.com/articles/SortingResumes.html Sorting Resumes] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
<br />
== Cover Letters ==<br />
* [http://www.polycount.com/forum/showthread.php?t=41014 Writing that all important cover letter?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=85192 Cover Letter] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=118092 Resume / Cover Letter Critique request - Riot Games] Polycount Forum thread<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
<br />
== Job Searching ==<br />
Most game developers get their jobs by word of mouth, this industry puts personal contacts first and foremost. Networking is key; keep in contact with your friends and former co-workers.<br />
* [[Company job boards]]<br />
* [http://www.polycount.com/forum/forumdisplay.php?f=39 Work Opportunities] Polycount Sub-Forum. <br />
* [https://orcahq.com/jobs?tags=Art orca] Game dev news and jobs, every day.<br />
* [http://www.polycount.com/forum/showthread.php?t=134982 Another website to find a video game industry job] Polycount Forum thread has several links.<br />
* [http://boards.polycount.net/showthread.php?t=38472 Game and Mod Development Article] and [http://boards.polycount.net/showthread.php?t=42157 Some mod guidelines] Polycount Forum threads have advice about joining a mod team.<br />
* [http://www.facebook.com/note.php?note_id=195778565716 Industry tips: How to find a job in the game industry] - by ''[http://www.boomzap.com/ Christopher Natsuume]'' has some frank advice about job searching.<br />
* [http://www.joelonsoftware.com/articles/ThePhoneScreen.html The Phone Screen] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]'' has info about how companies weed out applicants.<br />
* [http://www.polycount.com/forum/showthread.php?t=99400 It seems to be impossible to find a job as a Modeler in this industry] - this Polycount forum thread has good advice about how to actually get hired as an artist in game development. <br />
* [http://gamedevmap.com gamedevmap] - map of game development companies.<br />
<br />
== Going to Conferences ==<br />
Attending a game conference or developer event is a great way to connect with people working in game development. Connections often lead to work opportunities!<br />
<br />
A few notable conferences:<br />
* [http://www.gdconf.com/aboutgdc/ Game Developer's Conference] (GDC), GDC Europe, GDC China.<br />
* [http://prime.paxsite.com/what-is-pax PAX Prime], PAX East, PAX South, PAX Aus.<br />
* [http://www.e3expo.com/show-info/2541/about-e3/ Electronic Entertainment Expo] (E3).<br />
* [http://www.gameconfs.com/ Gameconfs] - a directory of game industry events.<br />
<br />
<br />
{| style="border:2px solid #111;background-color:#222;"<br />
|-<br />
! style="text-align:left;"|Advice from seasoned Indie [http://ichiro.us/ Ichiro Lambe] about how he goes to GDC:<br />
|-<br />
|1. '''Get connected beforehand.''' We always pulled together lists of devs who were going, to connect folks. For instance, we had a Google Form where everyone put down their names, games, companies, interests, Twitter handles, etc., and that all got spat out into a publicly viewable spreadsheet. We then tweeted that form/spreadsheet to everyone, and got a bazillion responses. We'd then reach out to subsets of those people and say, "Hey, we have common interests. Let's all meet." Instant GDC community.<br />
|-<br />
|2. '''Stay connected during.''' We also did a GDC Google Hangout or Facebook group for mobile users once out there. That allowed, for example, a friend to text a hundred devs with, "Hey, I'm completely drunk at Pinecrest. Who wants to meet?" Or, we'd Katamari a bunch of devs and go to a bar and chat dev. Katamaris work great -- meet one dev, and ask them to invite two friends. And so forth.<br />
|-<br />
|3. '''Set up meetings.''' Are there folks you want to meet out there? E-mail them and see what they're up to. Schedule lunch or coffee with a group of mobile game designers. Have them invite colleagues. Rinse. Repeat. Figure out why you're interesting and unique, and approach people with that. Don't be shy about it.<br />
|-<br />
|4. '''Plan.''' Write out your GDC plan beforehand. You can deviate from this entirely, but it's useful because it shows where there are scheduling gaps. It also forces you to identify your goals and objectives. I go to GDC primarily to connect myself and other devs with platform holders. Ergo, I'll want to set up meetings with Colecovision and Vectrex, and have pitches ready for them. Your goals may differ, but your plan should derive from those goals.<br />
|-<br />
|5. '''Get a pass.''' Go write each of the IGF finalists, tell them how amazing you are and how you're not an asshole, and ask them if they need help manning their booths in exchange for an expo pass.<br />
|-<br />
|6. '''Avoid the big, loud parties.''' 300 game developers at a loud dance club is silly. It's fun to go to these things and get free booze and food, but it's often more profitable to meet with Intellivision over quiet drinks, and more creatively stimulating to meet with a group of other developers in a quiet hotel lobby.<br />
|}<br />
<br />
== Interviews ==<br />
* [http://www.polycount.com/forum/showthread.php?t=106081 Job Interview in a hour or so, what questions should I expect?] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=105266 When eyeballing a studio...] thread on the Polycount forum (what questions should you ask during your interview).<br />
* [http://www.polycount.com/forum/showthread.php?t=69142 Interview Advice] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=80507 In need of interview advice] thread on the Polycount forum.<br />
* [http://www.boston.com/bostonworks/galleries/job_interview_tips?pg=2 10 Tips for Your First Interview] - by ''Dave Sanford'' Time-tested interview strategies:<br />
*# Research<br />
*# Practice<br />
*# Clothing<br />
*# Get there early<br />
*# Observe<br />
*# Know thyself<br />
*# Handshake<br />
*# Listen<br />
*# Finishing<br />
*# Follow up<br />
* [http://hotjobs.yahoo.com/career-experts-four_steps_to_a_better_job_interview-51 Four Steps to a Better Job Interview] - by ''Brad Karsh'' Four simple things to improve your interviews.<br />
*# Relax, not a battle of wits.<br />
*# Job description = questions that you'll be asked.<br />
*# Have answers about why you did certain things.<br />
*# Have questions about them.<br />
* [http://www.jobbankusa.com/interviews/articles_tips/10_follow_up_rules.html Ten Tips for the Interview Follow Up] - by ''Carole Martin'' How to avoid a non-response after your interview.<br />
* [http://boards.polycount.net/showthread.php?t=57317 job interview, 2-3 hours, why so long?] Polycount forum thread Game developers talking about the interview process they do, or have been through.<br />
<br />
== Art Tests ==<br />
Game companies often ask their art applicants to complete an art test, to gauge their talent relative to that company's particular needs, and to make sure you can actually do the work (portfolios can be faked or stolen).<br />
<br />
Beware doing an unpaid art test. A company can ask you to spend a long time on it, but then plagiarize the results, never respond after submission, etc.<br />
<br />
* [http://forum.gameartisans.org/forums/showthread.php?t=5970 Art Test Master List] GameArtisans forum thread has some example art tests.<br />
* [http://www.polycount.com/forum/showthread.php?t=157057 Paid Art Test?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?p=1795799#post1795799 Art Tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=87657 Jagex Art Test] Polycount Forum thread<br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16136725&gid=1842071 "Large art tests as the first stage of candidate selection. Acceptable?"] LinkedIn discussion<br />
* [http://www.polycount.com/forum/showthread.php?t=84418 Environment Art Test advice?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81681 Art test and no response, normal?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81015 Is it bad to ask for tips on an art test? There isn't an NDA] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=80861 Art tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=77279 Art Tests : How much time to spend?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=76208 Art Test Help/Suggestions] Polycount Forum thread<br />
<br />
== Salary Research ==<br />
Do the research to figure out what a fair offer is for your skill level and geographic area.<br />
* [http://h1bdata.info/index.php H1-B Visa Salary Database]<br />
* [https://orcahq.com/blog/game-industry-salary-explorer Game Industry Salary Explorer] - from [https://orcahq.com/ Orca HQ]. See the Polycount Forum thread [http://polycount.com/discussion/165337/game-industry-salary-explorer Game Industry Salary Explorer].<br />
* [http://www.gamecareerguide.com/features/1108/game_developer_salary_survey_2012.php 2012 Game Industry Salary Survey] - from ''[http://www.gdmag.com/ Game Developer magazine]'' (mostly USA). See also [http://gamedeveloper.texterity.com/gamedeveloper/201104#pg9 2010], [http://gamedeveloper.texterity.com/gamedeveloper/2009fall/#pg33 2009], [http://gamedeveloper.texterity.com/gamedeveloper/2008careerguide/#pg13 2008], [http://www.gamecareerguide.com/features/416/the_game_industry_salary_survey_.php?page=1 2007], [http://www.gamecareerguide.com/features/266/are_you_in_demand_2006_game_.php?page=1 2006].<br />
* [http://www.glassdoor.com/Salaries/us-computer-software-senior-artist-salary-SRCH_IL.0,2_IN1_II1121.3,20_KO21,34_SDAS.htm# Senior Artist Salaries at Computer Software companies in United States] - from ''[http://www.glassdoor.com Glassdoor.com]'' (USA) Customize your search, and enter your salary data for full access.<br />
* [http://www.payscale.com/research/US/Job=3d_Artist/Salary 3D Artist Salaries in the United States] - from ''[http://www.payscale.com Payscale.com]'' (other countries available)<br />
* [http://www.flcdatacenter.com/CaseH1B.aspx The Foreign Labor Certification Data Center - Online Wage Library] (H1B Visa Applications) - from the ''[http://www.doleta.gov/ US Department of Labor]'' (USA)<br />
* [http://vfxsoldier.wordpress.com/2010/08/16/wages-in-the-vfx-animation-and-games-industry/ Wages In The VFX, Animation, And Games Industry] - by [http://vfxsoldier.wordpress.com 'VFX Soldier'] features a spreadsheet of wage data mined from the H1B Visa database.<br />
* [http://www.mcvuk.com/news/read/uk-games-industry-salary-survey-what-are-you-worth/0110018 2012 UK Games Industry Salary Survey]. See also [http://www.develop-online.net/features/429/The-2009-UK-Games-Development-Salary-Survey 2009] (UK)<br />
* [http://www.vfxwages.com/ VFXWages] - a global database of hourly monetary rates of people in the film and television visual effects, animation, motion graphics, and gaming industry. <br />
* [[Freelance#Freelance_Rates]]<br />
<br />
== Negotiation ==<br />
Salary negotiation is an essential skill that will be put to the test after a successful interview. <br />
* [https://medium.freecodecamp.com/youre-underpaid-here-s-how-you-can-get-the-pay-raise-you-deserve-fafcf52956d6#.gz4yl4hpe Getting a raise comes down to one thing: Leverage.] - by [https://medium.freecodecamp.com/@quincylarson Quincy Larson]<br />
* [http://realtimecollisiondetection.net/blog/?p=70 Salary of a game programmer (artist, designer, or producer)] - by ''[http://realtimecollisiondetection.net Christer Ericcson]'', Sony Computer Entertainment<br />
* [https://www.facebook.com/note.php?note_id=191791235716 Industry tips: How to not ask for money] - by ''[http://www.boomzap.com/ Christopher Natsuume]''<br />
* [http://www.kclabor.org/kyrmpp.htm Know Your Rights - The Myth of Pay Privacy] - by ''[http://www.kclabor.org KC Labor]'' (USA)<br />
* [http://www.amazon.com/Bargaining-Advantage-Negotiation-Strategies-Reasonable/dp/0143036971 Bargaining for Advantage: Negotiation Strategies for Reasonable People] ($) - by ''[http://www.amazon.com/G.-Richard-Shell/e/B001H6KG6E G. Richard Shell]''<br />
* [http://www.polycount.com/forum/showthread.php?p=2067860 New Job Negotiations]<br />
<br />
== Relocation ==<br />
* [http://www.polycount.com/forum/showthread.php?t=99113 The game industry and relocation, how bad is it?] - Polycount Forum thread. Insight into the relocation process.<br />
<br />
== Employee Rights ==<br />
* [http://docontract.com/ contract( )] (pronounced 'do contract') generates free, plain English agreements for and between game developers. See the article [http://www.gamesindustry.biz/articles/2015-03-13-taking-the-fear-out-of-contracts Taking the fear out of contracts] on gamesindustry.biz.<br />
* [http://www.graphicartistsguild.org/handbook/ Graphic Artists Guild Handbook: Pricing & Ethical Guidelines] is an excellent resource on a great range of employment issues. Pricing guidelines, legal info, copyright law, sample contracts, how to negotiate, and more. Highly recommended!<br />
* [http://www.nlrb.gov/about_us/overview/national_labor_relations_act.aspx National Labor Relations Board] (USA)<br />
* [http://www.acas.org.uk/index.aspx?articleid=1390 ACAS: Advisory, Conciliation and Arbitration Service] (UK)<br />
* [http://www.direct.gov.uk/en/Employment/Employees/index.htm Directgov Employment Terms and Conditions] (UK)<br />
* [http://www.kclabor.org/know_your_rights1.htm Know Your Rights] - by [http://www.kclabor.org KC Labor] (USA)<br />
* [http://polycount.com/discussion/71929/discussing-issues-at-work-grounds-for-firing/p1 Discussing issues at work, grounds for firing?] Polycount forum thread has information about workers discussing their compensation with one another.<br />
* [http://www.polycount.com/forum/showthread.php?t=97910 EA rumored to layoff 500+] Polycount forum thread with cautionary tales about what happens when people get laid off or fired, or when companies close. Back up your work regularly, for portfolio use!<br />
<br />
== Going Indie ==<br />
Indie means developing, marketing, and publishing a game independently.<br />
* [http://forums.tigsource.com/index.php?topic=18.msg147#msg147 How to Start an Indie Game Business (WIP)] TIGSource Forum thread with links to resources <br />
<br />
== Freelancing ==<br />
Freelancing means creating assets for pay, working alone as an individual. See [[Freelance]].<br />
<br />
<br />
----<br />
[[Category:Information]] [[Category:GameIndustry]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Game_IndustryGame Industry2016-07-08T15:14:21Z<p>Dustinbrown: /* Salary Research */</p>
<hr />
<div><br />
Links and articles about the game industry: how to get game jobs, how to manage your role, etc.<br />
<br />
__TOC__<br />
<br />
== How to Get In ==<br />
* [http://polycount.com/discussion/168727/im-finding-it-impossible-to-land-a-job I'm finding it impossible to land a job] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=157738 Game Industry Recruiter Taking In Questions] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=134547 Getting that first job] Polycount Forum thread. Good advice for an artist trying to enter a game studio.<br />
* [http://www.polycount.com/forum/showthread.php?t=89972 Getting into the Game Industry (Inspiration of a different kind)] - Polycount Forum thread. Amazing thread full of information from working game artists about how they got into the industry.<br />
* [http://www.ineedtomakegames.com How to Break Into the Industry] - by [http://www.linkedin.com/pub/destin-bales/1/2aa/95b Destin Bales] A treasure trove of great advice by a veteran game developer. Multiple topics covered: understanding the industry, education, resumes and portfolios, finding jobs, interview prep, career development, etc. <br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16967104&gid=59205 Why is it hard to find a job in game industry?] Discussion on LinkedIn about what it takes to get that first game industry job.<br />
* [http://athey.deviantart.com/art/Game-Industry-Advice-to-studen-145619882 Game Industry Advice to students] - by [http://athey.deviantart.com/ Athey Moravetz] A great article by a 5-year veteran game artist about what it takes to get into a game artist job. Very straightforward and accurate.<br />
<br />
== Being a Developer ==<br />
* [http://www.polycount.com/forum/showthread.php?t=137206 What has the games industry been like for you?] Polycount Forum thread. Game art veterans share what it's really like to be working in game development.<br />
* [http://archive.is/B7o90 Is the games industry really dying?] by Dan Teasdale, diving deep into game industry layoff data.<br />
* [http://www.valvetime.net/threads/valve-employee-hand-book-released.189828/ Valve Employee Hand Book] Greg Coomer says "We wrote this book to make it as easy as we could for new people to join the company. It was fun to capture these thoughts and put them all in one place. Let us know what you think." Cached: [[file:Valve_Employee_Handbook.pdf]]<br />
* [http://www.gdcvault.com/play/1012343/The-Belly-of-the-Whale The Belly of the Whale: Living a Creative Life in the Game Industry] - by [http://www.bobbates.com/ Bob Bates] GDC 2010 lecture about how creative types can survive and thrive in the game industry. Highly recommended [http://www.polycount.com/forum/showthread.php?t=74876 by many Polycounters].<br />
* [http://www.thejonjones.com/2010/08/09/how-not-to-hire-an-artist/ How NOT to hire an artist] - by [http://www.thejonjones.com Jon Jones] Response to the inflammatory article [http://kaitol.com/how-to-hire-an-artist/ How to hire an artist] by [http://kaitol.com/about/ Christopher 'xdragonx10' Gregorio].<br />
* [http://www.polycount.com/2010/08/11/the-co-worker/ The Co-worker] - by [http://www.adambromell.com/ Adam Bromell] Polycount News article about what makes a good team co-worker.<br />
<br />
== Art Disciplines ==<br />
* [[:Category:Discipline]] lists the various artist roles in game development.<br />
* [http://polycount.com/discussion/171014 Specializing or not ?] Polycount forum thread<br />
* [http://polycount.com/discussion/134325 Leadership in the Games Industry] Polycount forum thread<br />
* [http://polycount.com/discussion/81832 What Game artist career is more difficult?] Polycount forum thread<br />
* [[PortfolioContents]] has summaries for what each type of artist should show in their portfolio.<br />
<br />
== Education ==<br />
The basic argument in the Polycount community is between going the self-taught route or going the formal education route. The best path seems to depend on what kind of person you are: self-motivated or team-motivated.<br />
<br />
Artists on Polycount generally agree it is rare to find schools that teach current high-quality game art techniques. The web and forums are often the best places to learn these, maybe even [[:Category:Tutorials|our wiki]] |-) . We see it time and again... the students who succeed at entering the work force after graduation are almost exclusively those that work on their own side projects, beyond the course material. Would they have been better served without using a school? <br />
<br />
If you want to work in a different country, the visa process may require a college or university degree. This is a good reason to seek a degree program.<br />
<br />
Beware of education scams and debt! Schools can cost a lot of money and some promise easy employment afterwards, but unfortunately the reality is not so forgiving. Student loan debt can also be a crushing burden for many years, especially with the relatively low wages most game artists make. See the blog post [https://medium.com/i-m-h-o/138c5efd45e9 Don’t go to art school], the Polycount forum thread [http://www.polycount.com/forum/showthread.php?t=75796 Profit Schools - Can we condemn them publicly?], and the Penny Arcade episode [http://penny-arcade.com/patv/episode/on-game-schools "On Game Schools"].<br />
<br />
* [http://www.polycount.com/forum/showthread.php?t=108342 Education In The Games Industry: Yes or No?] on the Polycount Forum is a great list of threads about game art education. You can also do a [http://polycount.com/search?Search forum search] for ''education''.<br />
<br />
* [http://k0k0k0.wordpress.com/51-things-every-game-student-should-know/ 100 Things Every Game Student Should Know] - by [http://k0k0k0.wordpress.com/ Kaye Elling] 100 fugly slides of things that every budding game developer (who is studying at university) should know. Read it!<br />
<br />
== Portfolios ==<br />
* [[Portfolio]] has links to tutorials and advice about creating an artist portfolio for a career in game development.<br />
<br />
== Resumes ==<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
* [http://windmillnetworking.com/2009/08/11/linkedin-profile-tips-the-10-mistakes-you-want-to-avoid-and-why/ LinkedIn Profile Tips: The 10 Mistakes You Want to Avoid and Why] - by ''[http://windmillnetworking.com/about/ Neal Schaffer]''<br />
* [http://www.joelonsoftware.com/articles/ResumeRead.html Getting Your Résumé Read] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
* [http://www.joelonsoftware.com/articles/SortingResumes.html Sorting Resumes] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
<br />
== Cover Letters ==<br />
* [http://www.polycount.com/forum/showthread.php?t=41014 Writing that all important cover letter?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=85192 Cover Letter] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=118092 Resume / Cover Letter Critique request - Riot Games] Polycount Forum thread<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
<br />
== Job Searching ==<br />
Most game developers get their jobs by word of mouth, this industry puts personal contacts first and foremost. Networking is key; keep in contact with your friends and former co-workers.<br />
* [[Company job boards]]<br />
* [http://www.polycount.com/forum/forumdisplay.php?f=39 Work Opportunities] Polycount Sub-Forum. <br />
* [https://orcahq.com/jobs?tags=Art orca] Game dev news and jobs, every day.<br />
* [http://www.polycount.com/forum/showthread.php?t=134982 Another website to find a video game industry job] Polycount Forum thread has several links.<br />
* [http://boards.polycount.net/showthread.php?t=38472 Game and Mod Development Article] and [http://boards.polycount.net/showthread.php?t=42157 Some mod guidelines] Polycount Forum threads have advice about joining a mod team.<br />
* [http://www.facebook.com/note.php?note_id=195778565716 Industry tips: How to find a job in the game industry] - by ''[http://www.boomzap.com/ Christopher Natsuume]'' has some frank advice about job searching.<br />
* [http://www.joelonsoftware.com/articles/ThePhoneScreen.html The Phone Screen] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]'' has info about how companies weed out applicants.<br />
* [http://www.polycount.com/forum/showthread.php?t=99400 It seems to be impossible to find a job as a Modeler in this industry] - this Polycount forum thread has good advice about how to actually get hired as an artist in game development. <br />
* [http://gamedevmap.com gamedevmap] - map of game development companies.<br />
<br />
== Going to Conferences ==<br />
Attending a game conference or developer event is a great way to connect with people working in game development. Connections often lead to work opportunities!<br />
<br />
A few notable conferences:<br />
* [http://www.gdconf.com/aboutgdc/ Game Developer's Conference] (GDC), GDC Europe, GDC China.<br />
* [http://prime.paxsite.com/what-is-pax PAX Prime], PAX East, PAX South, PAX Aus.<br />
* [http://www.e3expo.com/show-info/2541/about-e3/ Electronic Entertainment Expo] (E3).<br />
* [http://www.gameconfs.com/ Gameconfs] - a directory of game industry events.<br />
<br />
<br />
{| style="border:2px solid #111;background-color:#222;"<br />
|-<br />
! style="text-align:left;"|Advice from seasoned Indie [http://ichiro.us/ Ichiro Lambe] about how he goes to GDC:<br />
|-<br />
|1. '''Get connected beforehand.''' We always pulled together lists of devs who were going, to connect folks. For instance, we had a Google Form where everyone put down their names, games, companies, interests, Twitter handles, etc., and that all got spat out into a publicly viewable spreadsheet. We then tweeted that form/spreadsheet to everyone, and got a bazillion responses. We'd then reach out to subsets of those people and say, "Hey, we have common interests. Let's all meet." Instant GDC community.<br />
|-<br />
|2. '''Stay connected during.''' We also did a GDC Google Hangout or Facebook group for mobile users once out there. That allowed, for example, a friend to text a hundred devs with, "Hey, I'm completely drunk at Pinecrest. Who wants to meet?" Or, we'd Katamari a bunch of devs and go to a bar and chat dev. Katamaris work great -- meet one dev, and ask them to invite two friends. And so forth.<br />
|-<br />
|3. '''Set up meetings.''' Are there folks you want to meet out there? E-mail them and see what they're up to. Schedule lunch or coffee with a group of mobile game designers. Have them invite colleagues. Rinse. Repeat. Figure out why you're interesting and unique, and approach people with that. Don't be shy about it.<br />
|-<br />
|4. '''Plan.''' Write out your GDC plan beforehand. You can deviate from this entirely, but it's useful because it shows where there are scheduling gaps. It also forces you to identify your goals and objectives. I go to GDC primarily to connect myself and other devs with platform holders. Ergo, I'll want to set up meetings with Colecovision and Vectrex, and have pitches ready for them. Your goals may differ, but your plan should derive from those goals.<br />
|-<br />
|5. '''Get a pass.''' Go write each of the IGF finalists, tell them how amazing you are and how you're not an asshole, and ask them if they need help manning their booths in exchange for an expo pass.<br />
|-<br />
|6. '''Avoid the big, loud parties.''' 300 game developers at a loud dance club is silly. It's fun to go to these things and get free booze and food, but it's often more profitable to meet with Intellivision over quiet drinks, and more creatively stimulating to meet with a group of other developers in a quiet hotel lobby.<br />
|}<br />
<br />
== Interviews ==<br />
* [http://www.polycount.com/forum/showthread.php?t=106081 Job Interview in a hour or so, what questions should I expect?] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=105266 When eyeballing a studio...] thread on the Polycount forum (what questions should you ask during your interview).<br />
* [http://www.polycount.com/forum/showthread.php?t=69142 Interview Advice] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=80507 In need of interview advice] thread on the Polycount forum.<br />
* [http://www.boston.com/bostonworks/galleries/job_interview_tips?pg=2 10 Tips for Your First Interview] - by ''Dave Sanford'' Time-tested interview strategies:<br />
*# Research<br />
*# Practice<br />
*# Clothing<br />
*# Get there early<br />
*# Observe<br />
*# Know thyself<br />
*# Handshake<br />
*# Listen<br />
*# Finishing<br />
*# Follow up<br />
* [http://hotjobs.yahoo.com/career-experts-four_steps_to_a_better_job_interview-51 Four Steps to a Better Job Interview] - by ''Brad Karsh'' Four simple things to improve your interviews.<br />
*# Relax, not a battle of wits.<br />
*# Job description = questions that you'll be asked.<br />
*# Have answers about why you did certain things.<br />
*# Have questions about them.<br />
* [http://www.jobbankusa.com/interviews/articles_tips/10_follow_up_rules.html Ten Tips for the Interview Follow Up] - by ''Carole Martin'' How to avoid a non-response after your interview.<br />
* [http://boards.polycount.net/showthread.php?t=57317 job interview, 2-3 hours, why so long?] Polycount forum thread Game developers talking about the interview process they do, or have been through.<br />
<br />
== Art Tests ==<br />
Game companies often ask their art applicants to complete an art test, to gauge their talent relative to that company's particular needs, and to make sure you can actually do the work (portfolios can be faked or stolen).<br />
<br />
Beware doing an unpaid art test. A company can ask you to spend a long time on it, but then plagiarize the results, never respond after submission, etc.<br />
<br />
* [http://forum.gameartisans.org/forums/showthread.php?t=5970 Art Test Master List] GameArtisans forum thread has some example art tests.<br />
* [http://www.polycount.com/forum/showthread.php?t=157057 Paid Art Test?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?p=1795799#post1795799 Art Tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=87657 Jagex Art Test] Polycount Forum thread<br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16136725&gid=1842071 "Large art tests as the first stage of candidate selection. Acceptable?"] LinkedIn discussion<br />
* [http://www.polycount.com/forum/showthread.php?t=84418 Environment Art Test advice?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81681 Art test and no response, normal?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81015 Is it bad to ask for tips on an art test? There isn't an NDA] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=80861 Art tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=77279 Art Tests : How much time to spend?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=76208 Art Test Help/Suggestions] Polycount Forum thread<br />
<br />
== Salary Research ==<br />
Do the research to figure out what a fair offer is for your skill level and geographic area.<br />
* [http://h1bdata.info/index.php H1-B Visa Salary Database]<br />
* [https://orcahq.com/blog/game-industry-salary-explorer Game Industry Salary Explorer] - from [https://orcahq.com/ Orca HQ]. See the Polycount Forum thread [http://polycount.com/discussion/165337/game-industry-salary-explorer Game Industry Salary Explorer].<br />
* [http://www.gamecareerguide.com/features/1108/game_developer_salary_survey_2012.php 2012 Game Industry Salary Survey] - from ''[http://www.gdmag.com/ Game Developer magazine]'' (mostly USA). See also [http://gamedeveloper.texterity.com/gamedeveloper/201104#pg9 2010], [http://gamedeveloper.texterity.com/gamedeveloper/2009fall/#pg33 2009], [http://gamedeveloper.texterity.com/gamedeveloper/2008careerguide/#pg13 2008], [http://www.gamecareerguide.com/features/416/the_game_industry_salary_survey_.php?page=1 2007], [http://www.gamecareerguide.com/features/266/are_you_in_demand_2006_game_.php?page=1 2006].<br />
* [http://www.glassdoor.com/Salaries/us-computer-software-senior-artist-salary-SRCH_IL.0,2_IN1_II1121.3,20_KO21,34_SDAS.htm# Senior Artist Salaries at Computer Software companies in United States] - from ''[http://www.glassdoor.com Glassdoor.com]'' (USA) Customize your search, and enter your salary data for full access.<br />
* [http://www.payscale.com/research/US/Job=3d_Artist/Salary 3D Artist Salaries in the United States] - from ''[http://www.payscale.com Payscale.com]'' (other countries available)<br />
* [http://www.flcdatacenter.com/CaseH1B.aspx The Foreign Labor Certification Data Center - Online Wage Library] (H1B Visa Applications) - from the ''[http://www.doleta.gov/ US Department of Labor]'' (USA)<br />
* [http://vfxsoldier.wordpress.com/2010/08/16/wages-in-the-vfx-animation-and-games-industry/ Wages In The VFX, Animation, And Games Industry] - by [http://vfxsoldier.wordpress.com 'VFX Soldier'] features a spreadsheet of wage data mined from the H1B Visa database.<br />
* [http://www.mcvuk.com/news/read/uk-games-industry-salary-survey-what-are-you-worth/0110018 2012 UK Games Industry Salary Survey]. See also [http://www.develop-online.net/features/429/The-2009-UK-Games-Development-Salary-Survey 2009] (UK)<br />
* [http://www.vfxwages.com/ VFXWages] - a global database of hourly monetary rates of people in the film and television visual effects, animation, motion graphics, and gaming industry. <br />
* [[Freelance#Freelance_Rates]]<br />
<br />
== Negotiation ==<br />
Salary negotiation is an essential skill that will be put to the test after a successful interview. <br />
* [http://realtimecollisiondetection.net/blog/?p=70 Salary of a game programmer (artist, designer, or producer)] - by ''[http://realtimecollisiondetection.net Christer Ericcson]'', Sony Computer Entertainment<br />
* [https://www.facebook.com/note.php?note_id=191791235716 Industry tips: How to not ask for money] - by ''[http://www.boomzap.com/ Christopher Natsuume]''<br />
* [http://www.kclabor.org/kyrmpp.htm Know Your Rights - The Myth of Pay Privacy] - by ''[http://www.kclabor.org KC Labor]'' (USA)<br />
* [http://www.amazon.com/Bargaining-Advantage-Negotiation-Strategies-Reasonable/dp/0143036971 Bargaining for Advantage: Negotiation Strategies for Reasonable People] ($) - by ''[http://www.amazon.com/G.-Richard-Shell/e/B001H6KG6E G. Richard Shell]''<br />
* [http://www.polycount.com/forum/showthread.php?p=2067860 New Job Negotiations]<br />
<br />
== Relocation ==<br />
* [http://www.polycount.com/forum/showthread.php?t=99113 The game industry and relocation, how bad is it?] - Polycount Forum thread. Insight into the relocation process.<br />
<br />
== Employee Rights ==<br />
* [http://docontract.com/ contract( )] (pronounced 'do contract') generates free, plain English agreements for and between game developers. See the article [http://www.gamesindustry.biz/articles/2015-03-13-taking-the-fear-out-of-contracts Taking the fear out of contracts] on gamesindustry.biz.<br />
* [http://www.graphicartistsguild.org/handbook/ Graphic Artists Guild Handbook: Pricing & Ethical Guidelines] is an excellent resource on a great range of employment issues. Pricing guidelines, legal info, copyright law, sample contracts, how to negotiate, and more. Highly recommended!<br />
* [http://www.nlrb.gov/about_us/overview/national_labor_relations_act.aspx National Labor Relations Board] (USA)<br />
* [http://www.acas.org.uk/index.aspx?articleid=1390 ACAS: Advisory, Conciliation and Arbitration Service] (UK)<br />
* [http://www.direct.gov.uk/en/Employment/Employees/index.htm Directgov Employment Terms and Conditions] (UK)<br />
* [http://www.kclabor.org/know_your_rights1.htm Know Your Rights] - by [http://www.kclabor.org KC Labor] (USA)<br />
* [http://polycount.com/discussion/71929/discussing-issues-at-work-grounds-for-firing/p1 Discussing issues at work, grounds for firing?] Polycount forum thread has information about workers discussing their compensation with one another.<br />
* [http://www.polycount.com/forum/showthread.php?t=97910 EA rumored to layoff 500+] Polycount forum thread with cautionary tales about what happens when people get laid off or fired, or when companies close. Back up your work regularly, for portfolio use!<br />
<br />
== Going Indie ==<br />
Indie means developing, marketing, and publishing a game independently.<br />
* [http://forums.tigsource.com/index.php?topic=18.msg147#msg147 How to Start an Indie Game Business (WIP)] TIGSource Forum thread with links to resources <br />
<br />
== Freelancing ==<br />
Freelancing means creating assets for pay, working alone as an individual. See [[Freelance]].<br />
<br />
<br />
----<br />
[[Category:Information]] [[Category:GameIndustry]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Game_IndustryGame Industry2016-07-08T15:13:49Z<p>Dustinbrown: /* Salary Research */</p>
<hr />
<div><br />
Links and articles about the game industry: how to get game jobs, how to manage your role, etc.<br />
<br />
__TOC__<br />
<br />
== How to Get In ==<br />
* [http://polycount.com/discussion/168727/im-finding-it-impossible-to-land-a-job I'm finding it impossible to land a job] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=157738 Game Industry Recruiter Taking In Questions] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showthread.php?t=134547 Getting that first job] Polycount Forum thread. Good advice for an artist trying to enter a game studio.<br />
* [http://www.polycount.com/forum/showthread.php?t=89972 Getting into the Game Industry (Inspiration of a different kind)] - Polycount Forum thread. Amazing thread full of information from working game artists about how they got into the industry.<br />
* [http://www.ineedtomakegames.com How to Break Into the Industry] - by [http://www.linkedin.com/pub/destin-bales/1/2aa/95b Destin Bales] A treasure trove of great advice by a veteran game developer. Multiple topics covered: understanding the industry, education, resumes and portfolios, finding jobs, interview prep, career development, etc. <br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16967104&gid=59205 Why is it hard to find a job in game industry?] Discussion on LinkedIn about what it takes to get that first game industry job.<br />
* [http://athey.deviantart.com/art/Game-Industry-Advice-to-studen-145619882 Game Industry Advice to students] - by [http://athey.deviantart.com/ Athey Moravetz] A great article by a 5-year veteran game artist about what it takes to get into a game artist job. Very straightforward and accurate.<br />
<br />
== Being a Developer ==<br />
* [http://www.polycount.com/forum/showthread.php?t=137206 What has the games industry been like for you?] Polycount Forum thread. Game art veterans share what it's really like to be working in game development.<br />
* [http://archive.is/B7o90 Is the games industry really dying?] by Dan Teasdale, diving deep into game industry layoff data.<br />
* [http://www.valvetime.net/threads/valve-employee-hand-book-released.189828/ Valve Employee Hand Book] Greg Coomer says "We wrote this book to make it as easy as we could for new people to join the company. It was fun to capture these thoughts and put them all in one place. Let us know what you think." Cached: [[file:Valve_Employee_Handbook.pdf]]<br />
* [http://www.gdcvault.com/play/1012343/The-Belly-of-the-Whale The Belly of the Whale: Living a Creative Life in the Game Industry] - by [http://www.bobbates.com/ Bob Bates] GDC 2010 lecture about how creative types can survive and thrive in the game industry. Highly recommended [http://www.polycount.com/forum/showthread.php?t=74876 by many Polycounters].<br />
* [http://www.thejonjones.com/2010/08/09/how-not-to-hire-an-artist/ How NOT to hire an artist] - by [http://www.thejonjones.com Jon Jones] Response to the inflammatory article [http://kaitol.com/how-to-hire-an-artist/ How to hire an artist] by [http://kaitol.com/about/ Christopher 'xdragonx10' Gregorio].<br />
* [http://www.polycount.com/2010/08/11/the-co-worker/ The Co-worker] - by [http://www.adambromell.com/ Adam Bromell] Polycount News article about what makes a good team co-worker.<br />
<br />
== Art Disciplines ==<br />
* [[:Category:Discipline]] lists the various artist roles in game development.<br />
* [http://polycount.com/discussion/171014 Specializing or not ?] Polycount forum thread<br />
* [http://polycount.com/discussion/134325 Leadership in the Games Industry] Polycount forum thread<br />
* [http://polycount.com/discussion/81832 What Game artist career is more difficult?] Polycount forum thread<br />
* [[PortfolioContents]] has summaries for what each type of artist should show in their portfolio.<br />
<br />
== Education ==<br />
The basic argument in the Polycount community is between going the self-taught route or going the formal education route. The best path seems to depend on what kind of person you are: self-motivated or team-motivated.<br />
<br />
Artists on Polycount generally agree it is rare to find schools that teach current high-quality game art techniques. The web and forums are often the best places to learn these, maybe even [[:Category:Tutorials|our wiki]] |-) . We see it time and again... the students who succeed at entering the work force after graduation are almost exclusively those that work on their own side projects, beyond the course material. Would they have been better served without using a school? <br />
<br />
If you want to work in a different country, the visa process may require a college or university degree. This is a good reason to seek a degree program.<br />
<br />
Beware of education scams and debt! Schools can cost a lot of money and some promise easy employment afterwards, but unfortunately the reality is not so forgiving. Student loan debt can also be a crushing burden for many years, especially with the relatively low wages most game artists make. See the blog post [https://medium.com/i-m-h-o/138c5efd45e9 Don’t go to art school], the Polycount forum thread [http://www.polycount.com/forum/showthread.php?t=75796 Profit Schools - Can we condemn them publicly?], and the Penny Arcade episode [http://penny-arcade.com/patv/episode/on-game-schools "On Game Schools"].<br />
<br />
* [http://www.polycount.com/forum/showthread.php?t=108342 Education In The Games Industry: Yes or No?] on the Polycount Forum is a great list of threads about game art education. You can also do a [http://polycount.com/search?Search forum search] for ''education''.<br />
<br />
* [http://k0k0k0.wordpress.com/51-things-every-game-student-should-know/ 100 Things Every Game Student Should Know] - by [http://k0k0k0.wordpress.com/ Kaye Elling] 100 fugly slides of things that every budding game developer (who is studying at university) should know. Read it!<br />
<br />
== Portfolios ==<br />
* [[Portfolio]] has links to tutorials and advice about creating an artist portfolio for a career in game development.<br />
<br />
== Resumes ==<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
* [http://windmillnetworking.com/2009/08/11/linkedin-profile-tips-the-10-mistakes-you-want-to-avoid-and-why/ LinkedIn Profile Tips: The 10 Mistakes You Want to Avoid and Why] - by ''[http://windmillnetworking.com/about/ Neal Schaffer]''<br />
* [http://www.joelonsoftware.com/articles/ResumeRead.html Getting Your Résumé Read] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
* [http://www.joelonsoftware.com/articles/SortingResumes.html Sorting Resumes] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
<br />
== Cover Letters ==<br />
* [http://www.polycount.com/forum/showthread.php?t=41014 Writing that all important cover letter?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=85192 Cover Letter] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=118092 Resume / Cover Letter Critique request - Riot Games] Polycount Forum thread<br />
* [http://www.bungie.net/News/content.aspx?type=topnews&cid=12496 Work at Bungie: Getting Past the Gatekeeper] details how to make the best impression on Bungie's hiring manager.<br />
<br />
== Job Searching ==<br />
Most game developers get their jobs by word of mouth, this industry puts personal contacts first and foremost. Networking is key; keep in contact with your friends and former co-workers.<br />
* [[Company job boards]]<br />
* [http://www.polycount.com/forum/forumdisplay.php?f=39 Work Opportunities] Polycount Sub-Forum. <br />
* [https://orcahq.com/jobs?tags=Art orca] Game dev news and jobs, every day.<br />
* [http://www.polycount.com/forum/showthread.php?t=134982 Another website to find a video game industry job] Polycount Forum thread has several links.<br />
* [http://boards.polycount.net/showthread.php?t=38472 Game and Mod Development Article] and [http://boards.polycount.net/showthread.php?t=42157 Some mod guidelines] Polycount Forum threads have advice about joining a mod team.<br />
* [http://www.facebook.com/note.php?note_id=195778565716 Industry tips: How to find a job in the game industry] - by ''[http://www.boomzap.com/ Christopher Natsuume]'' has some frank advice about job searching.<br />
* [http://www.joelonsoftware.com/articles/ThePhoneScreen.html The Phone Screen] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]'' has info about how companies weed out applicants.<br />
* [http://www.polycount.com/forum/showthread.php?t=99400 It seems to be impossible to find a job as a Modeler in this industry] - this Polycount forum thread has good advice about how to actually get hired as an artist in game development. <br />
* [http://gamedevmap.com gamedevmap] - map of game development companies.<br />
<br />
== Going to Conferences ==<br />
Attending a game conference or developer event is a great way to connect with people working in game development. Connections often lead to work opportunities!<br />
<br />
A few notable conferences:<br />
* [http://www.gdconf.com/aboutgdc/ Game Developer's Conference] (GDC), GDC Europe, GDC China.<br />
* [http://prime.paxsite.com/what-is-pax PAX Prime], PAX East, PAX South, PAX Aus.<br />
* [http://www.e3expo.com/show-info/2541/about-e3/ Electronic Entertainment Expo] (E3).<br />
* [http://www.gameconfs.com/ Gameconfs] - a directory of game industry events.<br />
<br />
<br />
{| style="border:2px solid #111;background-color:#222;"<br />
|-<br />
! style="text-align:left;"|Advice from seasoned Indie [http://ichiro.us/ Ichiro Lambe] about how he goes to GDC:<br />
|-<br />
|1. '''Get connected beforehand.''' We always pulled together lists of devs who were going, to connect folks. For instance, we had a Google Form where everyone put down their names, games, companies, interests, Twitter handles, etc., and that all got spat out into a publicly viewable spreadsheet. We then tweeted that form/spreadsheet to everyone, and got a bazillion responses. We'd then reach out to subsets of those people and say, "Hey, we have common interests. Let's all meet." Instant GDC community.<br />
|-<br />
|2. '''Stay connected during.''' We also did a GDC Google Hangout or Facebook group for mobile users once out there. That allowed, for example, a friend to text a hundred devs with, "Hey, I'm completely drunk at Pinecrest. Who wants to meet?" Or, we'd Katamari a bunch of devs and go to a bar and chat dev. Katamaris work great -- meet one dev, and ask them to invite two friends. And so forth.<br />
|-<br />
|3. '''Set up meetings.''' Are there folks you want to meet out there? E-mail them and see what they're up to. Schedule lunch or coffee with a group of mobile game designers. Have them invite colleagues. Rinse. Repeat. Figure out why you're interesting and unique, and approach people with that. Don't be shy about it.<br />
|-<br />
|4. '''Plan.''' Write out your GDC plan beforehand. You can deviate from this entirely, but it's useful because it shows where there are scheduling gaps. It also forces you to identify your goals and objectives. I go to GDC primarily to connect myself and other devs with platform holders. Ergo, I'll want to set up meetings with Colecovision and Vectrex, and have pitches ready for them. Your goals may differ, but your plan should derive from those goals.<br />
|-<br />
|5. '''Get a pass.''' Go write each of the IGF finalists, tell them how amazing you are and how you're not an asshole, and ask them if they need help manning their booths in exchange for an expo pass.<br />
|-<br />
|6. '''Avoid the big, loud parties.''' 300 game developers at a loud dance club is silly. It's fun to go to these things and get free booze and food, but it's often more profitable to meet with Intellivision over quiet drinks, and more creatively stimulating to meet with a group of other developers in a quiet hotel lobby.<br />
|}<br />
<br />
== Interviews ==<br />
* [http://www.polycount.com/forum/showthread.php?t=106081 Job Interview in a hour or so, what questions should I expect?] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=105266 When eyeballing a studio...] thread on the Polycount forum (what questions should you ask during your interview).<br />
* [http://www.polycount.com/forum/showthread.php?t=69142 Interview Advice] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=80507 In need of interview advice] thread on the Polycount forum.<br />
* [http://www.boston.com/bostonworks/galleries/job_interview_tips?pg=2 10 Tips for Your First Interview] - by ''Dave Sanford'' Time-tested interview strategies:<br />
*# Research<br />
*# Practice<br />
*# Clothing<br />
*# Get there early<br />
*# Observe<br />
*# Know thyself<br />
*# Handshake<br />
*# Listen<br />
*# Finishing<br />
*# Follow up<br />
* [http://hotjobs.yahoo.com/career-experts-four_steps_to_a_better_job_interview-51 Four Steps to a Better Job Interview] - by ''Brad Karsh'' Four simple things to improve your interviews.<br />
*# Relax, not a battle of wits.<br />
*# Job description = questions that you'll be asked.<br />
*# Have answers about why you did certain things.<br />
*# Have questions about them.<br />
* [http://www.jobbankusa.com/interviews/articles_tips/10_follow_up_rules.html Ten Tips for the Interview Follow Up] - by ''Carole Martin'' How to avoid a non-response after your interview.<br />
* [http://boards.polycount.net/showthread.php?t=57317 job interview, 2-3 hours, why so long?] Polycount forum thread Game developers talking about the interview process they do, or have been through.<br />
<br />
== Art Tests ==<br />
Game companies often ask their art applicants to complete an art test, to gauge their talent relative to that company's particular needs, and to make sure you can actually do the work (portfolios can be faked or stolen).<br />
<br />
Beware doing an unpaid art test. A company can ask you to spend a long time on it, but then plagiarize the results, never respond after submission, etc.<br />
<br />
* [http://forum.gameartisans.org/forums/showthread.php?t=5970 Art Test Master List] GameArtisans forum thread has some example art tests.<br />
* [http://www.polycount.com/forum/showthread.php?t=157057 Paid Art Test?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?p=1795799#post1795799 Art Tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=87657 Jagex Art Test] Polycount Forum thread<br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16136725&gid=1842071 "Large art tests as the first stage of candidate selection. Acceptable?"] LinkedIn discussion<br />
* [http://www.polycount.com/forum/showthread.php?t=84418 Environment Art Test advice?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81681 Art test and no response, normal?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81015 Is it bad to ask for tips on an art test? There isn't an NDA] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=80861 Art tests] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=77279 Art Tests : How much time to spend?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=76208 Art Test Help/Suggestions] Polycount Forum thread<br />
<br />
== Salary Research ==<br />
Do the research to figure out what a fair offer is for your skill level and geographic area.<br />
* [http://h1bdata.info/index.php H1-B Visa Salary Database] - from [https://orcahq.com/ Orca HQ]. See the Polycount Forum thread [http://polycount.com/discussion/165337/game-industry-salary-explorer Game Industry Salary Explorer].<br />
* [https://orcahq.com/blog/game-industry-salary-explorer Game Industry Salary Explorer] - from [https://orcahq.com/ Orca HQ]. See the Polycount Forum thread [http://polycount.com/discussion/165337/game-industry-salary-explorer Game Industry Salary Explorer].<br />
* [http://www.gamecareerguide.com/features/1108/game_developer_salary_survey_2012.php 2012 Game Industry Salary Survey] - from ''[http://www.gdmag.com/ Game Developer magazine]'' (mostly USA). See also [http://gamedeveloper.texterity.com/gamedeveloper/201104#pg9 2010], [http://gamedeveloper.texterity.com/gamedeveloper/2009fall/#pg33 2009], [http://gamedeveloper.texterity.com/gamedeveloper/2008careerguide/#pg13 2008], [http://www.gamecareerguide.com/features/416/the_game_industry_salary_survey_.php?page=1 2007], [http://www.gamecareerguide.com/features/266/are_you_in_demand_2006_game_.php?page=1 2006].<br />
* [http://www.glassdoor.com/Salaries/us-computer-software-senior-artist-salary-SRCH_IL.0,2_IN1_II1121.3,20_KO21,34_SDAS.htm# Senior Artist Salaries at Computer Software companies in United States] - from ''[http://www.glassdoor.com Glassdoor.com]'' (USA) Customize your search, and enter your salary data for full access.<br />
* [http://www.payscale.com/research/US/Job=3d_Artist/Salary 3D Artist Salaries in the United States] - from ''[http://www.payscale.com Payscale.com]'' (other countries available)<br />
* [http://www.flcdatacenter.com/CaseH1B.aspx The Foreign Labor Certification Data Center - Online Wage Library] (H1B Visa Applications) - from the ''[http://www.doleta.gov/ US Department of Labor]'' (USA)<br />
* [http://vfxsoldier.wordpress.com/2010/08/16/wages-in-the-vfx-animation-and-games-industry/ Wages In The VFX, Animation, And Games Industry] - by [http://vfxsoldier.wordpress.com 'VFX Soldier'] features a spreadsheet of wage data mined from the H1B Visa database.<br />
* [http://www.mcvuk.com/news/read/uk-games-industry-salary-survey-what-are-you-worth/0110018 2012 UK Games Industry Salary Survey]. See also [http://www.develop-online.net/features/429/The-2009-UK-Games-Development-Salary-Survey 2009] (UK)<br />
* [http://www.vfxwages.com/ VFXWages] - a global database of hourly monetary rates of people in the film and television visual effects, animation, motion graphics, and gaming industry. <br />
* [[Freelance#Freelance_Rates]]<br />
<br />
== Negotiation ==<br />
Salary negotiation is an essential skill that will be put to the test after a successful interview. <br />
* [http://realtimecollisiondetection.net/blog/?p=70 Salary of a game programmer (artist, designer, or producer)] - by ''[http://realtimecollisiondetection.net Christer Ericcson]'', Sony Computer Entertainment<br />
* [https://www.facebook.com/note.php?note_id=191791235716 Industry tips: How to not ask for money] - by ''[http://www.boomzap.com/ Christopher Natsuume]''<br />
* [http://www.kclabor.org/kyrmpp.htm Know Your Rights - The Myth of Pay Privacy] - by ''[http://www.kclabor.org KC Labor]'' (USA)<br />
* [http://www.amazon.com/Bargaining-Advantage-Negotiation-Strategies-Reasonable/dp/0143036971 Bargaining for Advantage: Negotiation Strategies for Reasonable People] ($) - by ''[http://www.amazon.com/G.-Richard-Shell/e/B001H6KG6E G. Richard Shell]''<br />
* [http://www.polycount.com/forum/showthread.php?p=2067860 New Job Negotiations]<br />
<br />
== Relocation ==<br />
* [http://www.polycount.com/forum/showthread.php?t=99113 The game industry and relocation, how bad is it?] - Polycount Forum thread. Insight into the relocation process.<br />
<br />
== Employee Rights ==<br />
* [http://docontract.com/ contract( )] (pronounced 'do contract') generates free, plain English agreements for and between game developers. See the article [http://www.gamesindustry.biz/articles/2015-03-13-taking-the-fear-out-of-contracts Taking the fear out of contracts] on gamesindustry.biz.<br />
* [http://www.graphicartistsguild.org/handbook/ Graphic Artists Guild Handbook: Pricing & Ethical Guidelines] is an excellent resource on a great range of employment issues. Pricing guidelines, legal info, copyright law, sample contracts, how to negotiate, and more. Highly recommended!<br />
* [http://www.nlrb.gov/about_us/overview/national_labor_relations_act.aspx National Labor Relations Board] (USA)<br />
* [http://www.acas.org.uk/index.aspx?articleid=1390 ACAS: Advisory, Conciliation and Arbitration Service] (UK)<br />
* [http://www.direct.gov.uk/en/Employment/Employees/index.htm Directgov Employment Terms and Conditions] (UK)<br />
* [http://www.kclabor.org/know_your_rights1.htm Know Your Rights] - by [http://www.kclabor.org KC Labor] (USA)<br />
* [http://polycount.com/discussion/71929/discussing-issues-at-work-grounds-for-firing/p1 Discussing issues at work, grounds for firing?] Polycount forum thread has information about workers discussing their compensation with one another.<br />
* [http://www.polycount.com/forum/showthread.php?t=97910 EA rumored to layoff 500+] Polycount forum thread with cautionary tales about what happens when people get laid off or fired, or when companies close. Back up your work regularly, for portfolio use!<br />
<br />
== Going Indie ==<br />
Indie means developing, marketing, and publishing a game independently.<br />
* [http://forums.tigsource.com/index.php?topic=18.msg147#msg147 How to Start an Indie Game Business (WIP)] TIGSource Forum thread with links to resources <br />
<br />
== Freelancing ==<br />
Freelancing means creating assets for pay, working alone as an individual. See [[Freelance]].<br />
<br />
<br />
----<br />
[[Category:Information]] [[Category:GameIndustry]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Normal_mapNormal map2015-04-23T20:17:06Z<p>Dustinbrown: /* Common Swizzle Coordinates */</p>
<hr />
<div>== Out of Date ==<br />
The information on this page is a bit old, it needs to be updated. See these links for more current information:<br />
<br />
* [http://farfarer.com/resources.htm RNM Normal Map Combiner], by [http://www.farfarer.com/ James "Farfarer" O'Hare]<br />
* [http://vincentcallebaut.com/CombineNormal.html Combine Normal], by [http://vincentcallebaut.comVincent "Vincentt" Callebaut], [http://www.polycount.com/forum/showthread.php?t=131819 Combine normal maps script for Photoshop] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showpost.php?p=2226864&postcount=51 Earthquake on separating smoothing groups in the UV]<br />
* [http://www.polycount.com/forum/showpost.php?p=2225535&postcount=40 JedTheKrampus on offsetting Mirrored UVs]<br />
* [http://www.polycount.com/forum/showthread.php?t=148303 Of Bit Depths, Banding and Normal Maps]<br />
* [http://www.polycount.com/forum/showthread.php?t=147227 Skew you buddy! Making sense of skewed normal map details.]<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games]<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh Tutorial]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?]<br />
* [http://www.laurenscorijn.com/future-xoliulshader-support.html Future Xoliulshader support] = why Xoliulshader doesn't work properly in 3ds Max 2013/2014.<br />
<br />
== Synched Workflow ==<br />
To eliminate seams and shading artifacts, the model renderer and the normal map baking tool should use the same tangent basis.<br />
<br />
FBX model format can store tangents, and some renderers use this data to synch the incoming normal maps.<br />
<br />
{| class="wikitable sortable" style="color:grey;"<br />
|- <br />
! Renderer !! Normal map baker<br />
|-<br />
| 3ds Max || 3ds Max, Handplane, ?<br />
|-<br />
| Blender || ?<br />
|-<br />
| Creation Engine || Handplane, ?<br />
|-<br />
| CryEngine || ?<br />
|-<br />
| Knald || ?<br />
|-<br />
| Marmoset Toolbag || 3ds Max, Maya, Xnormal, ?<br />
|-<br />
| Maya || Handplane, Maya, ?<br />
|-<br />
| Source || Handplane, Maya ([http://www.polycount.com/forum/showpost.php?p=2224653&postcount=28]), ?<br />
|-<br />
| Starcraft II || Handplane, ?<br />
|-<br />
| Substance Designer || ?<br />
|-<br />
| Unity([http://www.polycount.com/forum/showpost.php?p=2224781&postcount=29], [http://www.polycount.com/forum/showthread.php?p=2194353#post2194353]) || Handplane, Xnormal (via Asset Store), ?<br />
|-<br />
| Unreal Engine 4 || Handplane, Xnormal([http://www.polycount.com/forum/showpost.php?p=2224402&postcount=20]), ? <br />
|-<br />
| Xnormal || Xnormal, ?<br />
|}<br />
<br />
----<br />
<br />
== What is a Normal Map? ==<br />
A Normal Map is usually used to fake high-res geometry detail when it's mapped onto a low-res mesh. The pixels of the normal map each store a ''normal'', a vector that describes the surface slope of the original high-res mesh at that point. The red, green, and blue channels of the normal map are used to control the direction of each pixel's normal. <br />
<br />
When a normal map is applied to a low-poly mesh, the texture pixels control the direction each of the pixels on the low-poly mesh will be facing in 3D space, creating the illusion of more surface detail or better curvature. However, the silhouette of the model doesn't change. <br />
<br />
<gallery mode="packed"><br />
Whatif_normalmap_mapped2.jpg|A model with a normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_low.jpg|The model without its normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_high.jpg|The high-resolution model used to create the normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
</gallery><br />
<br />
==Tangent-Space vs. Object-Space==<br />
<br />
Normal maps can be made in either of two basic flavors: tangent-space or object-space. World-space is basically the same as object-space, except it requires the model to remain in its original orientation, neither rotating nor deforming, so it's almost never used.<br />
<br />
===Tangent-space normal map===<br />
[[image:normalmap_tangentspace.jpg|frame|none|A tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Predominantly-blue colors. Object can rotate and deform. Good for deforming meshes, like characters, animals, flags, etc.<br />
<br />
Pros:<br />
* Maps can be reused easily, like on differently-shaped meshes.<br />
* Maps can be tiled and mirrored easily, though some games might not support mirroring very well.<br />
* Easier to overlay painted details.<br />
* Easier to use image compression.<br />
<br />
Cons:<br />
* More difficult to avoid smoothing problems from the low-poly vertex normals (see Smoothing Groups and Hard Edges).<br />
* Slightly slower performance than an object-space map (but not by much).<br />
<br />
===Object-space normal map===<br />
[[image:normalmap_worldspace.jpg|frame|none|An object-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Rainbow colors. Objects can rotate, but usually shouldn't be deformed, unless the shader has been modified to support deformation. Object-space is also called local-space or model-space. <br />
<br />
Pros:<br />
* Easier to generate high-quality curvature because it completely ignores the crude smoothing of the low-poly vertex normals.<br />
* Slightly better performance than a tangent-space map (but not by much).<br />
<br />
Cons:<br />
* Can't easily reuse maps, different mesh shapes require unique maps.<br />
* Difficult to tile properly, and mirroring requires specific shader support.<br />
* Harder to overlay painted details because the base colors vary across the surface of the mesh. Painted details must be converted into Object Space to be combined properly with the OS map.<br />
* They don't compress very well, since the blue channel can't be recreated in the shader like with tangent-space maps. Also the three color channels contain very different data which doesn't compress well, creating many artifacts. Using a half-resolution object-space map is one option. <br />
<br />
<br clear="all"/><br />
<br />
=== Converting Between Spaces ===<br />
Normal maps can be converted between object space and tangent space, in order to use them with different blending tools and shaders, which require one type or the other. <br />
<br />
Object space maps can also be converted to maps with different tangent bases, to better match the normal maps with the renderer and thus avoid lighting errors.<br />
<br />
* [http://www.handplane3d.com Handplane] by [http://www.alecmoody.com/ Alec Moody] is a tool that converts object space maps into a variety of tangent spaces: 3ds Max, Creation Engine, Maya, Source, Unity, Unreal, etc. See the Polycount Forum thread [http://www.polycount.com/forum/showthread.php?t=116899 Official handplane support thread - Now freeware!!].<br />
<br />
[[File:handplane_illus_1.jpg|frame|none|Handplane interface. <br>Image by [http://www.alecmoody.com/ Alec Moody].]]<br />
<br />
<br />
* [http://boards.polycount.net/showthread.php?p=1072599#post1072599 NSpace] by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] is a tool that converts an object-space normal map into a tangent-space map, which then works seamlessly in the 3ds Max viewport. He converts the map by using the same tangent basis that 3ds Max uses for its hardware shader. To see the results, load the converted map via the ''Normal Bump'' map and enable "Show Hardware Map in Viewport". [http://gameartist.nl/ Osman "osman" Tsjardiwal] created a GUI for NSpace, you can [http://boards.polycount.net/showthread.php?p=1075143#post1075143 download it here], just put it in the same folder as the NSpace exe and run it. <br />
<br />
[[File:NSpace_Gui_osman.png|frame|none|NSpace interface. <br>Image by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] and [http://gameartist.nl Osman "osman" Tsjardiwal].]]<br />
<br />
[http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson] said: "[8Monkey Labs has] a tool that lets you load up your reference mesh and object space map. Then load up your tangent normals, and adjust some sliders for things like tile and amount. We need to load up a mesh to know how to correctly orient the tangent normals or else things will come out upside down or reverse etc. It mostly works, but it tends to "bend" the resulting normals, so you gotta split the mesh up into some smoothing groups before you run it, and then I usually will just composite this "combo" texture over my orig map in Photoshop."<br />
<br />
<span id="RGBC"></span><span id="RGBChannels"></span><br />
<br />
== RGB Channels ==<br />
Shaders can use different techniques to render tangent-space normal maps, but the normal map directions are usually consistent within a game. Usually the red channel of a tangent-space normal map stores the X axis (pointing the normals predominantly leftwards or rightwards), the green channel stores the Y axis (pointing the normals predominantly upwards or downwards), and the blue channel stores the Z axis (pointing the normals outwards away from the surface).<br />
<br />
[[image:tangentspace_rgb.jpg|frame|none|The red, green, and blue channels of a tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you see lighting coming from the wrong angle when you're looking at your normal-mapped model, and the model is using a tangent-space normal map, the normal map shader might be expecting the red or green channel (or both) to point in the opposite direction. To fix this either change the shader, or simply invert the appropriate color channels in an image editor, so that the black pixels become white and the white pixels become black.<br />
<br />
Some shaders expect the color channels to be swapped or re-arranged to work with a particular [[#NormalMapCompression|compression format]]. For example the DXT5_nm format usually expects the X axis to be in the alpha channel, the Y axis to be in the green channel, and the red and blue channels to be empty.<br />
<br />
== Tangent Basis ==<br />
[[#TangentSpaceVsObjectSpace|Tangent-space]] normal maps use a special kind of vertex data called the ''tangent basis''. This is similar to UV coordinates except it provides directionality across the surface, it forms a surface-relative coordinate system for the per-pixel normals stored in the normal map. This coordinate system is required to light a normal mapped surface.<br />
<br />
Each vertex in the tangent basis is a combination of three things: the mesh vertex's normal (influenced by smoothing), the vertex's tangent (usually derived from the V texture coordinate), and the vertex's bitangent (derived in code, also called the binormal). These three vectors create an axis for each vertex, giving it a specific orientation in the tangent space. These axes are used to properly transform the incoming lighting from world space into tangent space, so your normal-mapped model will be lit correctly.<br />
<br />
Light rays are in world space, but the normals stored in the normal map are in tangent space. When the model is being rendered, the light rays must be converted from world space into tangent space, using the tangent basis to get there. At that point the incoming light rays are compared against the directions of the normals in the normal map, and this determines how much each pixel is going to be lit. Alternatively, instead of converting the light rays some shaders will convert the normals in the normal map from tangent space into world space. Then those world-space normals are compared against the light rays, and the model is lit appropriately. The method depends on who wrote the shader, but the end result is the same. Both methods require a tangent basis to transform the lighting.<br />
<br />
When a triangle's vertex normals are pointing straight out, and a pixel in the normal map is neutral blue (128,128,255) this means the pixel's normal will be pointing straight out from the surface of the low-poly mesh. When that pixel normal is tilted towards the left or the right in the tangent coordinate space, it will get either more or less red color, depending on whether the normal map is set to store the X axis as either a positive or a negative value. Same goes for when the normal is tilted up or down in tangent space, it will either get more or less green color. If the vertex normals aren't exactly perpendicular to the triangle, the normal map pixels will be tinted away from neutral blue as well.<br />
<br />
Unfortunately for artists, there are many different ways to calculate the tangent basis: [http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping 3ds Max], [http://download.autodesk.com/us/maya/2011help/index.html?url=./files/Appendix_A_Tangent_and_binormal_vectors.htm,topicNumber=d0e227193 Maya], [http://www.codesampler.com/dx9src/dx9src_4.htm#dx9_dot3_bump_mapping DirectX 9], [http://developer.nvidia.com/object/NVMeshMender.html NVMeshMender], [http://www.terathon.com/code/tangent.html Eric Lengyel], a custom solution, etc. This means a normal map baked in one application probably won't shade correctly in another. Artists must do some testing with different [[#T|baking tools]] to find which works best with their output. When the renderer (or game engine) renders your game model, [[#ShadersAndSeams|the shader]] must use the same tangent basis as the normal map baker, otherwise you'll get incorrect lighting, especially across the seams between UV shells.<br />
<br />
The [http://www.xnormal.net/ xNormal] SDK supports custom tangent basis methods. When a programmer uses it to implement their renderer's own tangent basis, artists can then use Xnormal to bake normal maps that will match their renderer perfectly.<br />
<br />
[[image:tangentseams.jpg|frame|none|When shared edges are at different angles in UV space, different colors will show up<br />
along the seam. The tangent basis uses these colors to light the model properly. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
When you look at a tangent-space normal map for a character, you typically see different colors along the UV seams. This is because the UV shells are often oriented at different angles on the mesh, a necessary evil when translating the 3D mesh into 2D textures. The body might be mapped with a vertical shell, and the arm mapped with a horizontal one. This requires the normals in the normal map to be twisted for the different orientations of those UV shells. The UVs are twisted, so the normals must be twisted in order to compensate. The tangent basis helps reorient (twist) the lighting as it comes into the surface's local space, so the lighting will then look uniform across the normal mapped mesh.<br />
<br />
When an artist tiles a tangent-space normal map across an arbitrary mesh, like a landscape, this tends to shade correctly because the mesh has a uniform direction in tangent space. If the mesh has discontinuous UV coordinates (UV seams), or the normal map has large directional gradients across it, the tangent space won't be uniform anymore so the surface will probably have shading seams.<br />
<br />
== Common Swizzle Coordinates ==<br />
3D Software capable of displaying tangent space normal maps will have a native required direction, or "handedness" for the RGB channels in a normal map, sometimes referred to as "Swizzle Coordinates," though [[#SAS|shaders]] can often be written to override this native handedness. You may hear developers refer to "flipping the green channel" in order to get a normal map to display correctly, and this simply indicates that when the normal map was baked, it was authored with the incorrect handedness in the green channel. Left/Down handedness is indicated with a negative (-), and right/up handedness is demarcated with a (+) positive.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
| '''Software''' <br />
| '''Red''' <br />
| '''Green''' <br />
| '''Blue''' <br />
|-<br />
|<#000000>| 3ds Max<br />
| X+<br />
| Y-<br />
| Z+ <br />
|-<br />
|<#000000>| [http://wiki.blender.org/index.php/Doc:2.6/Manual/Textures/Influence/Material/Bump_and_Normal Blender]<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| [http://docs.cryengine.com/display/SDKDOC2/Normal+Maps CryENGINE]<br />
| X+<br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Maya<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| Modo<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| [https://developer.valvesoftware.com/wiki/Bump_map Source]<br />
| X+<br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Toolbag<br />
| X+<br />
| Y+ <br />
| Z+<br />
|-<br />
|<#000000>| [http://docs.unity3d.com/Manual/HOWTO-bumpmap.html Unity]<br />
| X+<br />
| Y+<br />
| Z+<br />
|-<br />
|<#000000>| [https://docs.unrealengine.com/latest/INT/Engine/Content/Types/Textures/Properties/index.html Unreal Engine]<br />
| X+ <br />
| Y-<br />
| Z+<br />
|-<br />
|}<br />
<span id="MTLPM"></span><br />
<br />
== Modeling the Low-Poly Mesh ==<br />
The in-game mesh usually needs to be carefully optimized to create a good silhouette, define edge-loops for better deformation, and minimize extreme changes between the vertex normals for better shading (see [[#SmoothingGroupsAndHardEdges|Smoothing Groups & Hard Edges]]).<br />
<br />
In order to create an optimized in-game mesh including a good silhouette and loops for deforming in animation, you can start with the 2nd subdivision level of your [[DigitalSculpting|digital sculpt]], or in some cases with the base mesh itself. Then you can just collapse edge loops or cut in new edges to add/remove detail as necessary. Or you can [[DigitalSculpting#OART|re-toplogize]] from scratch if that works better for you.<br />
<br />
See [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts] on the Polycount forum.<br />
<br />
<span id="UVC"></span><span id="UVCoordinates"></span><br />
=== UV Coordinates ===<br />
Normal map baking tools only capture normals within the 0-1 UV square, any UV bits outside this area are ignored. <br />
<br />
Only one copy of the forward-facing UVs should remain in the 0-1 UV square at baking time. If the mesh uses overlapping UVs, this will likely cause artifacts to appear in the baked map, since the baker will try render each UV shell into the map. Before baking, it's best to move all the overlaps and mirrored bits outside the 0-1 square. <br />
<br />
[[image:Normalmap_uvcoord_offset.jpg|frame|none|The mirrored UVs (in red) are offset 1 unit before baking. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you move all the overlaps and mirrored bits exactly 1 UV unit (any whole number will do), then you can leave them there after the bake and they will still be mapped correctly. You can move them back if you want, it doesn't matter to most game engines. Be aware that ZBrush does use UV offsets to manage mesh visibility, however this usually doesn't matter because the ZBrush cage mesh is often a different mesh than the in-game mesh used for baking.<br />
<br />
You should avoid changing the UVs after baking the normal map, because rotating or mirroring UVs after baking will cause the normal map not to match the [[#TB|tangent basis]] anymore, which will likely cause lighting problems. <br />
<br />
In 3ds Max, W is a third texture coordinate. It's used for 3D procedural textures and for storing vertex color in UV channels (you need 3 axes for RGB, so UVW can store vertex color). Bake problems can be avoided by moving any overlapping UVs to -1 on the W axis, with the same results as moving them 1 unit on the U or V axes. The tool Render To Texture will always bake whatever UVs are the highest along the W axis. However using W can be messy... it's generally hidden unless you purposefully look for it (bad for team work), doesn't get preserved on export to other apps, and high W values can prevent selecting and/or welding UVs. <br />
<br />
<span id="M"></span><span id="Mirroring"></span><br />
<br />
=== Mirroring ===<br />
Normal maps can be mirrored across a model to create symmetrical details, and save UV space, which allows more detail in the normal map since the texture pixels are smaller on the model. <br />
<br />
With [[#OSNM|object-space]] maps, mirroring requires [http://boards.polycount.net/showthread.php?t=53986 specific shader support]. For [[#TSNM|tangent-space]] maps, mirroring typically creates a shading seam, but this can be reduced or hidden altogether, depending on the method used.<br />
<br />
<span id="TMW"></span><br />
==== Typical Mirroring Workflow ====<br />
# Delete the mesh half that will be mirrored. <br />
# Arrange the UVs for the remaining model, filling the UV square.<br />
# Mirror the model to create a "whole" mesh, welding the mesh vertices along the seam. <br />
# Move the mirrored UVs exactly 1 unit (or any whole number) out of the 0-1 UV square.<br />
# Bake the normal map.<br />
<br />
Sometimes an artist will decide to delete half of a symmetrical model before baking. <br />
<br />
This is a mistake however because often the vertex normals along the hole will bend towards the hole a bit; there are no faces on the other side to average the normals with. This will create a strong lighting seam in the normal map. <br />
<br />
It's typically best to use the complete mirrored model to bake the normal map, not just the unique half. <br />
<br />
To prevent the mirrored UVs from causing overlaps or baking errors, move the mirrored [[#UVC|UVs]] out of the 0-1 UV space, so only one copy of the non-mirrored UVs is left within the 0-1 square.<br />
<br />
To avoid texel "leaks" between the UV shells, make sure there's enough [[#Edge_padding|Edge Padding]] around each shell, including along the edges of the normal map. None of the UV shells should be touching the edge of the 0-1 UV square, unless they're meant to tile with the other side of the map.<br />
<br />
<span id="CM"></span><br />
<br />
==== Center Mirroring ====<br />
If the mirror seam runs along the surface of a continuous mesh, like down the center of a human face for example, then it will probably create a lighting seam. <br />
<br />
In Epic Games' [http://www.unrealtechnology.com/technology.php Unreal Engine 3] (UE3) their symmetrical models commonly use centered mirroring. Epic uses materials that mix a [[DetailMap]] with the normal maps; these seem to scatter the diffuse/specular lighting and help minimize the obviousness of the mirror seams. For their [[Light Map]]ped models they use [http://udn.epicgames.com/Three/LightMapUnwrapping.html a technique] that can almost completely hide the mirror seam.<br />
<br />
[[image:Epic_MirroringCicada.jpg|frame|none| In UE3 a center mirror seam is reduced by using a detail normal map. <br> Image by "[http://epicgames.com Epic Games]"]]<br />
<br />
'''''[http://www.zbrushcentral.com/showpost.php?p=573108&postcount=28 GOW2 normal map seams], [http://utforums.epicgames.com/showthread.php?p=27166791#post27166791 UDK normal map seams]'''''<br />
<br />
<span id="OM"></span><br />
<br />
==== Offset Mirroring ====<br />
Offset mirroring is a method where you move the mirror seam off to one side of the model, so the seam doesn't run exactly down the center. For example with a character's head, the UV seam can go down along the side of the head in front of the ear. The UV shell for the nearest ear can then be mirrored to use the area on the other side of the head. <br />
<br />
This avoids the "Rorschach" effect and allows non-symmetrical details, but it still saves texture space because the two sides of the head can be mirrored (they're never seen at the same time anyhow).<br />
<br />
Offset mirroring doesn't get rid of the seam, but it does move it off to a place where it can either be less obvious, or where it can be hidden in a natural seam on the model.<br />
<br />
<span id="FCM"></span><br />
==== Flat Color Mirroring ====<br />
[http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] solves seams by painting a flat set of normals along the seam, using neutral blue (128,128,255). However it only works along horizontal or vertical UV seams, not across any angled UVs. It also removes any details along the mirror seam, creating blank areas. <br />
<br />
<span id="EM"></span><br />
==== Element Mirroring ====<br />
The mirror seam can be avoided completely when it doesn't run directly through any mesh. For example if there's a detached mesh element that runs down the center of the model, this can be uniquely mapped, while the meshes on either side can be mirrors of each other. Whenever the mirrored parts don't share any vertex normals with the non-mirrored parts, there won't be any seams. <br />
<br />
[[image:normalmap_mirrored-binocs-racer445.jpg|frame|none|The middle part (highlighted in red) uses unique non-mirrored UVs, allowing the mesh on the right to be mirrored without any seams. <br>Image by [http://http://racer445.com/ "racer445"]]]<br />
<br />
<span id="SGAHE"></span><br />
<br />
=== Smoothing Groups & Hard Edges ===<br />
Each vertex in a mesh has at least one vertex normal. Vertex normals are used to control the direction a triangle will be lit from; if the normal is facing the light the triangle will be fully lit, if facing away from the light the triangle won't be lit. <br />
<br />
Each vertex however can have more than one vertex normal. When two triangles have different vertex normals along their shared edge, this creates a shading seam, called a ''hard edge'' in most modeling tools. 3ds Max uses ''Smoothing Groups'' to create hard/soft edges, Maya uses ''Harden Edge'' and ''Soften Edge''. These tools create hard and soft edges by splitting and combining the vertex normals.<br />
<br />
[[image:BenMathis_SmoothingGroups_Excerpt.gif|frame|none|Hard edges occur where the vertices have multiple normals. <br>Image by [http://poopinmymouth.com Ben 'poopinmymouth' Mathis] ([http://poopinmymouth.com/process/tips/smoothing_groups.jpg tutorial here])]]<br />
<br />
When a mesh uses all soft normals (a single smoothing group) the lighting has to be interpolated across the extreme differences between the vertex normals. If your renderer doesn't support the same [[#TangentBasis|tangent basis]] that the baker uses, this can produce extreme shading differences across the model, which creates shading artifacts. It is generally best to reduce these extremes when you can because a mismatched renderer can only do so much to counteract it.<br />
<br />
Hard edges are usually best where the model already has a natural seam. For example, you can add a hard edge along the rim of a car's wheel well, to prevent the inside of the wheel well from distorting the shading for the outside of the car body. Mechanical models usually need hard edges where ever the surface bends more than about 45 degrees. <br />
<br />
For most meshes, the best results usually come from adding hard edges where ever there are UV seams. There are no hard rules however, you must experiment with different approaches to find what works best in your game.<br />
<br />
When you use object-space normal maps the vertex normal problem goes away since you're no longer relying on the crude vertex normals of the mesh. An object-space normal map completely ignores vertex normals. Object-space mapping allows you to use all soft edges and no bevels on the low-res mesh, without showing lighting errors.<br />
<br />
<span id="HEDAT"></span><br />
==== Hard Edge Discussions & Tutorials ====<br />
* [http://www.polycount.com/forum/showthread.php?p=2090450#post2090450 Maya MEL Script help needed (UV border edges)]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=73593 Normal Maps: Can Somone Explain This "Black Edge" issue]<br />
* [http://www.polycount.com/forum/showthread.php?t=73566 Normal Maps: Can someone explain normals, tangents and split UVs?]<br />
* [http://www.polycount.com/forum/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max]<br />
* [http://boards.polycount.net/showthread.php?t=68173 Why you should NOT trust 3ds Max's viewport normal-map display!]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/10503-xsi-normal-mapped-cube-looks-bad.html XSI - normal mapped cube looks bad]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/11924-weird-maya-normal-map-seam-artifact-problem-am-i-making-simple-mistake.html Weird Maya normal map seam/artifact problem]<br />
* [http://boards.polycount.net/showthread.php?p=1080600 Seams in Normals when Creating Tiling Environment Trims and other Tiles]<br />
* The tutorial [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing can affect the normal map.<br />
* The tutorial: [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] shows how smoothing affects raycasting.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses the breaking of normals and smoothing groups in general terms.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in the game, not the triangle count.<br />
* The Crysis documentation [http://doc.crymod.com/AssetCreation/PolyBumpReference.html PolyBump Reference] has a section towards the bottom that shows how smoothing affects their baked normal maps.<br />
* The polycount thread [http://boards.polycount.net/showthread.php?t=60694 Toying around with normal map approaches] has a great discussion of how best to use smoothing groups and bevels for better shading.<br />
<br />
<span id="UB"></span><br />
==== Using Bevels ====<br />
Bevels/chamfers generally improve the silhouette of the model, and can also help reflect specular highlights better. <br />
<br />
However bevels tend to produce long thin triangles, which slow down the in-game rendering of your model. Real-time renderers have trouble rendering long thin triangles because they create a lot of sub-pixel areas to render. <br />
<br />
Bevels also balloon the vertex count, which can increase the transform cost and memory usage. Hard edges increase the vertex count too, but not when the edge also shares a seam in UV space. For a good explanation of the vertex count issue, see [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly].<br />
<br />
Using hard edges with matching UV shells tends to give better performance and better cosmetic results than using bevels. However there are differing opinions on this, see the Polycount thread "[http://boards.polycount.net/showthread.php?t=71760 Maya transfer maps help]".<br />
<br />
<span id="EVN"></span><br />
==== Edited Vertex Normals ====<br />
If you use bevels the shading will be improved by editing the vertex normals so the larger flat surfaces have perpendicular normals. The vertex normals are then forced to blend across the smaller bevel faces, instead of across the larger faces. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66139 Superspecular soft edges tutorial chapter 1].<br />
<br />
[[image:oliverio_bevel_normals.gif|frame|none|Bending normals on bevelled models. <br>From the tutorial [http://deadlineproof.com/model-shading-techniques-soft-edge-superspecular/ Shading techniques Superspecular soft edges]<br>Image by [http://deadlineproof.com/ Paolo Oliverio]]]<br />
<br />
== Level of Detail Models ==<br />
See [http://www.polycount.com/forum/showthread.php?p=1216945#post1216945 Problem if you're using 3point-style normals with an LOD].<br />
<br />
<span id="MTHPM"></span><br />
<br />
== Modeling The High-Poly Mesh ==<br />
[[Subdivision Surface Modeling]] and [[DigitalSculpting]] are the techniques most often used for modeling a normal map. <br />
<br />
Some artists prefer to model the in-game mesh first, other artists prefer to model the high-res mesh first, and others start somewhere in the middle. The modeling order is ultimately a personal choice though, all three methods can produce excellent results:<br />
* Build the in-game model, then up-res it and sculpt it.<br />
* Build and sculpt a high resolution model, then build a new in-game model around that.<br />
* Build a basemesh model, up-res and sculpt it, then step down a few levels of detail and use that as a base for building a better in-game mesh.<br />
If the in-game mesh is started from one of the subdivision levels of the basemesh sculpt, various edge loops can be collapsed or new edges can be cut to add/remove detail as necessary.<br />
<br />
<span id="SE"></span><br />
=== Sloped Extrusions ===<br />
[[image:normal_slopes_hatred.jpg|frame|none|Extrusions on the high-poly model should be sloped to make a better normal map. <br>Image by [http://www.hatred.gameartisans.org/ Krzysztof "Hatred" Dolas].]]<br />
<br />
=== Floating Geometry ===<br />
[[image:FloatingGeo.jpg|frame|none|Normal map stores the direction the surface is facing rather than real depth information, thus allowing to save time using floating geometry. <br>To correctly bake AO with floating geo make it a separate object and turn off it's shadow casting. <br>Image by [http://artisaverb.info/ Andrew "d1ver" Maximov].]]<br />
<br />
See also [[3DTutorials/Modeling High-Low Poly Models for Next Gen Games|Modeling High/Low Poly Models for Next Gen Games]] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa]<br />
<br />
<span id="ET"></span><br />
<br />
=== Edge Thickness ===<br />
[[image:normal_edge_thickness.jpg|frame|none|When creating edges of the Highpoly, sometimes you'll need to make them rounded than in real life to <br>work better at the size they will be seen.<br>Image by [http://racer445.com/Evan "racer445" Herbert]]]<br />
<br />
<span id="MRF"></span><span id="MRRCB"></span><br />
<br />
=== mental ray Round Corners Bump ===<br />
The mental ray renderer offers an automatic bevel rendering effect called Round Corners Bump that can be baked into a normal map. This is available in 3ds Max, Maya, and XSI. See [http://boards.polycount.net/showthread.php?t=71995 Zero Effort Beveling for normal maps] - by [http://boards.polycount.net/member.php?u=31662 Robert "r_fletch_r" Fletcher].<br />
<br />
[http://jeffpatton.net/ Jeff Patton] posted about [http://jeffpatton.cgsociety.org/blog/archive/2007/10/ how to expose Round Corners Bump] in 3ds Max so you can use it in other materials.<br />
<br />
[http://cryrid.com/art/ Michael "cryrid" Taylor] posted a tutorial about how to use [http://cryrid.com/images/temp/XSI/zeroeffort_bevels.jpg Round Corners in XSI].<br />
<br />
XSI is able to bake a good normal map with it, but 3ds Max seems to bake it incorrectly, and Maya isn't able to bake the effect at all. Maybe Max might be able to bake it correctly, if the .mi shader is edited to use the correct coordinate space?<br />
<br />
<span id="Baking"></span><span id="B"></span><br />
== Baking ==<br />
The process of transferring normals from the high-res model to the in-game model is often called baking. The baking tool usually starts projecting a certain numerical distance out from the low-poly mesh, and sends rays inwards towards the high-poly mesh. When a ray intersects the high-poly mesh, it records the mesh's surface normal and saves it in the normal map.<br />
<br />
To get an understanding of how all the options affect your normal map, do some test bakes on simple meshes like boxes. They generate quickly so you can experiment with [[#UVCoordinates|UV mirroring]], [[#SGAHE|smoothing groups]], etc. This helps you learn the settings that really matter.<br />
* The tutorial [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] has more examples of ray-casting, plus how to get better results from the bake.<br />
<br />
Baking sub-sections:<br />
# [[#Anti-Aliasing|Anti-Aliasing]]<br />
# [[#Baking_Transparency|Baking Transparency]]<br />
# [[#Edge_Padding|Edge Padding]]<br />
# [[#High_Poly_Materials|High Poly Materials]]<br />
# [[#Reset_Transforms|Reset Transforms]]<br />
# [[#Solving_Intersections|Solving Intersections]]<br />
# [[#Solving_Pixel_Artifacts|Solving Pixel Artifacts]]<br />
# [[#Solving_Wavy_Lines|Solving Wavy Lines]]<br />
# [[#Triangulating|Triangulating]]<br />
# [[#Working_with_Cages|Working with Cages]]<br />
<br />
<span id="AA"></span><br />
=== Anti-Aliasing ===<br />
Turning on super-sampling or anti-aliasing (or whatever multi-ray casting is called in your normal map baking tool) will help to fix any jagged edges where the high-res model overlaps itself within the UV borders of the low-poly mesh, or wherever the background shows through holes in the mesh. Unfortunately this tends to render much much slower, and takes more memory.<br />
<br />
[[image:normalmap_aliasing_knak47.jpg|frame|none|A bake without anti-aliasing shows artifacts where the high-poly mesh has overlaps. <br>Image by [http://www.polycount.com/forum/member.php?u=35938 'knak47']]]<br />
<br />
One trick to speed this up is to render 2x the intended image size then scale the normal map down 1/2 in a paint program like Photoshop. The reduction's pixel resampling will add anti-aliasing for you in a very quick process. After scaling, make sure to re-normalize the map if your game doesn't do that already, because the un-normalized pixels in your normalmap may cause pixelly artifacts in your specular highlights. Re-normalizing can be done with [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA's normal map filter] for Photoshop.<br />
<br />
3ds Max's supersampling doesn't work nicely with edge padding, it produces dark streaks in the padded pixels. If so then turn off padding and re-do the padding later, either by re-baking without supersampling or by using a Photoshop filter like the one that comes with [[#3DTools|Xnormal]].<br />
<br />
=== Baking Transparency ===<br />
Sometimes you need to bake a normal map from an object that uses opacity maps, like a branch with opacity-mapped leaves. Unfortunately baking apps often completely ignore any transparency mapping on your high-poly mesh.<br />
<br />
{|class="wikitable"<br />
|[[image:JoeWilson_ivynormals_error.jpg]] <br />
|[[image:JoeWilson_ivynormals_rendered.jpg]]<br />
|-<br />
|3ds Max's RTT baker causes transparency errors.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|The lighting method bakes perfect transparency.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|}<br />
<br />
To solve this, render a Top view of the mesh. This only works if you're using a planar UV projection for your low-poly mesh and you're baking a tangent-space normal map.<br />
<br />
* Make sure the Top view matches the dimensions of the planar UV projection used by the low-poly mesh. It helps to use an orthographic camera for precise placement.<br />
* On the high-poly mesh either use a specific lighting setup or a use special material shader:<br />
* 1) The lighting setup is described in these tutorials:<br />
* * [http://www.bencloward.com/tutorials_normal_maps11.shtml Creating A Normal Map Right In Your 3D App] by [http://www.bencloward.com/ Ben Cloward]<br />
* *[http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy], Graphics Techniques Consultant, Xbox Content and Design Team<br />
* 2) The material shader does the same thing, but doesn't require lights.<br />
* * [http://www.scriptspot.com/3ds-max/normaltexmap NormalTexMap] scripted map for 3ds Max by [http://www.scriptspot.com/users/dave-locke Dave Locke].<br />
* * [http://www.footools.com/3dsmax_plugins.html InfoTexture] map plugin for 3ds Max by [http://www.footools.com John Burnett]<br />
<br />
[[image:BenCloward_NormalMapLighting.gif|frame|none|The lighting setup for top-down rendering. <br>Image by [http://www.bencloward.com Ben Cloward]]]<br />
<br />
<span id="EP"></span><br />
<br />
=== Edge Padding ===<br />
If a normal map doesn't have enough [[Edge_padding |Edge Padding]], this will create shading seams on the UV borders.<br />
<br />
=== High Poly Materials ===<br />
3ds Max will not bake a normal map properly if the high-res model has a mental ray Arch & Design material applied. If your normal map comes out mostly blank, either use a Standard material or none at all. For an example see the Polycount thread [http://www.polycount.com/forum/showthread.php?t=74792 Render to Texture >:O].<br />
<br />
<span id="RT"></span><br />
=== Reset Transforms ===<br />
Before baking, make sure your low-poly model's transforms have been reset. '''''This is very important!''''' Often during the modeling process a model will be rotated and scaled, but these compounded transforms can create a messy local "space" for the model, which in turn often creates rendering errors for normal maps. <br />
<br />
In 3ds Max, use the Reset Xforms utility then Collapse the Modifier Stack. In Maya use Freeze Transformation. In XSI use the Freeze button.<br />
<br />
<span id="SI"></span><br />
<br />
=== Solving Intersections ===<br />
The projection process often causes problems like misses, or overlaps, or intersections. It can be difficult generating a clean normal map in areas where the high-poly mesh intersects or nearly intersects itself, like in between the fingers of a hand. Setting the ray distance too large will make the baker pick the other finger as the source normal, while setting the ray distance too small will lead to problems at other places on the mesh where the distances between in-game mesh and high-poly mesh are greater.<br />
<br />
Fortunately there are several methods for solving these problems.<br />
<br />
# Change the shape of the cage. Manually edit points on the projection cage to help solve tight bits like the gaps between fingers.<br />
# Limit the projection to matching materials, or matching UVs.<br />
# Explode the meshes. See the polycount thread [http://boards.polycount.net/showthread.php?t=62921 Explode script needed (for baking purposes)].<br />
# Bake two or more times using different cage sizes, and combine them in Photoshop.<br />
<br />
<span id="SPA"></span><br />
<br />
=== Solving Pixel Artifacts ===<br />
[[image:filterMaps_artifact.jpg|frame|none|Random pixel artifacts in the bake. <br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
If you are using 3ds Max's ''Render To Texture'' to bake from one UV layout to another, you may see stray pixels scattered across the bake. This only happens if you are using a copy of the original mesh in the Projection, and that mesh is using a different UV channel than the original mesh.<br />
<br />
There are two solutions for this:<br />
<br />
* Add a Push modifier to the copied mesh, and set it to a low value like 0.01.<br />
- or -<br />
<br />
* Turn off ''Filter Maps'' in the render settings (Rendering menu > Render Setup > Renderer tab > uncheck Filter Maps). To prevent aliasing you may want to enable the Global Supersampler in Render Setup.<br />
<br />
See also [[#Anti-Aliasing]].<br />
<br />
<span id="SWL"></span><br />
<br />
=== Solving Wavy Lines ===<br />
When capturing from a cylindrical shape, often the differences between the low-poly mesh and the high-poly mesh will create a wavy edge in the normal map. There are a couple ways to avoid this:<br />
<br />
# The best way... create your lowpoly model with better supporting edges. See the Polycount threads [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?], [http://boards.polycount.net/showthread.php?t=55754 approach to techy stuff], [http://www.polycount.com/forum/showthread.php?t=72713 Any tips for normal mapping curved surface?].<br />
# Adjust the shape of the cage to influence the directions the rays will be cast. Beware... this work will have to be re-done every time you edit the lowpoly mesh, as the cage will be invalidated. At the bottom of [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm this page of his normal map tutorial], [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to do this in 3ds Max. Same method can be seen in the image below.<br />
# Subdivide the low-res mesh so it more closely matches the high-res mesh. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] has a [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa video tutorial] that shows how to do this in Maya.<br />
# Paint out the wavy line. Beware... this work will have to be re-done every time you re-bake the normal map. The [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
# Use a separate planar-projected mesh for the details that wrap around the barrel area, so the ray-casting is more even. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. For example to add tread around a tire, the tread can be baked from a tread model that is laid out flat, then that bake can layered onto the bake from the cylindrical tire mesh in a paint program.<br />
<br />
[[image:timothy_evison_normalmap_projections.jpg|frame|none|Adjusting the shape of the cage to remove distortion. <br>Image by [http://users.cybercity.dk/~dsl11905/resume/resume.html Timothy "tpe" Evison]]]<br />
<br />
<span id="TRI"></span><br />
<br />
=== Triangulating ===<br />
Before baking, it is usually best to triangulate the low-poly model, converting it from polygons into pure triangles. This prevents the vertex normals from being changed later on, which can create specular artifacts.<br />
<br />
[[image:triangulation_modo_ohare.jpg|frame|none| When quads are triangulated in [http://www.luxology.com/modo/ Modo], the internal edges are sometimes flipped, which causes shading differences.<br>Image by [http://www.farfarer.com/|James "Talon" O'Hare]]]<br />
<br />
<br />
Sometimes a baking tool or a mesh exporter/importer will re-triangulate the polygons. A quad polygon is actually treated as two triangles, and the internal edge between them is often switched diagonally during modeling operations. When the vertices of the quad are moved around in certain shapes, the software's algorithm for polygon models tries to keep the quad surface in a "rational" non-overlapping shape. It does this by switching the internal edge between its triangles.<br />
<br />
<br />
[[image:triangulation_spec_tychovii.jpg|frame|none| The specular highlight is affected by triangulation. Flip edges to fix skewing. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66651 Skewed Specular Highlight?] for pictures and more info.<br> Image by [http://robertkreps.com Robert "TychoVII" Kreps]]]<br />
<br />
<br />
<span id="WWC"></span><br />
<br />
=== Working with Cages ===<br />
''Cage'' has two meanings in the normal-mapping process: a low-poly base for [[subdivision surface modeling]] (usually called the [[DigitalSculpting#BM|basemesh]]), or a ray-casting mesh used for normal map baking. This section covers the ray-casting cage.<br />
<br />
Most normal map baking tools allow you to use a distance-based raycast. A ray is sent outwards along each vertex normal, then at the distance you set a ray is cast back inwards. Where ever that ray intersects the high poly mesh, it will sample the normals from it. <br />
<br />
{|class="wikitable"<br />
|[[Image:Normalmap_raycasting_1.jpg]] <br />
|[[Image:Normalmap_raycasting_2.jpg]]<br />
|-<br />
|Hard edges and a distance-based raycast (gray areas) cause ray misses (yellow) and ray overlaps (cyan).<br> Image by [http://www.mankua.com/ Diego Castaño]<br />
|The gray area shows that using all soft edges (or hard edges and a cage-based raycast) will avoid ray-casting errors from split normals.<br> Image by [http://www.mankua.com/ Diego Castaño] <br />
|}<br />
<br />
Unfortunately with a distance-based raycast, [[#SGAHE|split vertex normals]] will cause the bake to miss parts of the high-res mesh, causing errors and seams. <br />
<br />
Some software allows you to use ''cage mesh'' option instead, which basically inflates a copy of the low-poly mesh, then raycasts inwards from each vertex. This ballooned-out mesh is the cage.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
|<tablebgcolor="#ffaaaa">| <br />
|}<br />
<br />
In 3ds Max the cage controls both the distance and the direction of the raycasting. <br />
<br />
In Maya the cage only controls the distance; the ray direction matches the vertex normals (inverted).<br />
<br />
<span style="text-decoration: line-through"> This may have been fixed in the latest release...<<BR>><br />
In Xnormal the cage is split everywhere the model has [[#SGAHE|hard edges]], causing ray misses in the bake. You can fix the hard edge split problem but it involves an overly complex workflow. You must also repeat the whole process any time you change your mesh:</span><br />
# <s> Load the 3d viewer.</s><br />
# <s> Turn on the cage editing tools.</s><br />
# <s> Select all of the vertices.</s><br />
# <s> Weld all vertices.</s><br />
# <s> Expand the cage as you normally would.</s><br />
# <s> Save out your mesh using the Xnormal format.</s><br />
# <s> Make sure Xnormal is loading the correct mesh.</s><br />
<br />
<span id="P"></span><span id="Painting"></span><br />
<br />
== Painting ==<br />
Don't be afraid to edit normal maps in Photoshop. After all it is just a texture, so you can clone, blur, copy, blend all you want... as long as it looks good of course. Some understanding of [[#RGBChannels|the way colors work]] in normal maps will go a long way in helping you paint effectively.<br />
<br />
A normal map sampled from a high-poly mesh will nearly always be better than one sampled from a texture, since you're actually grabbing "proper" normals from an accurate, highly detailed surface. That means your normal map's pixels will basically be recreating the surface angles of your high-poly mesh, resulting in a very believable look.<br />
<br />
If you only convert an image into a normal-map, it can look very flat, and in some cases it can be completely wrong unless you're very careful about your value ranges. Most image conversion tools assume the input is a heightmap, where black is low and white is high. If you try to convert a diffuse texture that you've painted, the results are often very poor. Often the best results are obtained by baking the large and mid-level details from a high-poly mesh, and then combined with photo-sourced "fine detail" normals for surface details such as fabric weave, scratches and grain.<br />
<br />
Sometimes creating a high poly surface takes more time than your budget allows. For character or significant environment assets then that is the best route, but for less significant environment surfaces working from a heightmap-based texture will provide a good enough result for a much less commitment in time.<br />
<br />
* [http://crazybump.com/ CrazyBump] is a commercial normal map converter.<br />
* [http://www.renderingsystems.com/support/showthread.php?tid=3 ShaderMap] is a commercial normal map converter.<br />
* [http://www.pixplant.com/ PixPlant] is a commercial normal map converter.<br />
* [http://boards.polycount.net/showthread.php?t=68860 NJob] is a free normal map converter.<br />
* [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA normalmap filter for Photoshop] is a free normal map converter.<br />
* [http://xnormal.net Xnormal height-to-normals filter for Photoshop] is a free normal map converter.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm Normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
<br />
=== Flat Color ===<br />
The color (128,128,255) creates normals that are completely perpendicular to the polygon, as long as the vertex normals are also perpendicular. Remember a normal map's per-pixel normals create ''offsets'' from the vertex normals. If you want an area in the normal map to be flat, so it creates no offsets from the vertex normals, then use the color (128,128,255). <br />
<br />
This becomes especially obvious when [[#Mirroring|mirroring a normal map]] and using a shader with a reflection ingredient. Reflection tends to accentuate the angles between the normals, so any errors become much more apparent.<br />
<br />
[[image:normalmap_127seam.jpg|thumb|600px|none| Mirrored normal maps show a seam when (127,127,255) is used for the flat color; 128 is better.<br>Image by [http://www.ericchadwick.com Eric Chadwick]]]<br />
<br />
In a purely logical way, 127 seems like it would be the halfway point between 0 and 255. However 128 is the color that actually works in practice. When a test is done comparing (127,127,255) versus (128,128,255) it becomes obvious that 127 creates a slightly bent normal, and 128 creates a flat one.<br />
<br />
This is because most game pipelines use ''unsigned'' normal maps. For details see the Polycount forum thread [http://www.polycount.com/forum/showpost.php?p=771360&postcount=22 tutorial: fixing mirrored normal map seams].<br />
<br />
<span id="BNMT"></span><br />
<br />
=== Blending Normal Maps Together ===<br />
Blending normal maps together is a quick way to add high-frequency detail like wrinkles, cracks, and the like. Fine details can be painted as a height map, then it can be converted into a normal map using one of the normal map tools. Then this "details" normal map can be blended with a geometry-derived normal map using one of the methods below. <br />
<br />
Here is a comparison of four of the blending methods. Note that in these examples the default values were used for CrazyBump (Intensity 50, Strength 33, Strength 33), but the tool allows each layer's strength to be adjusted individually for stronger or milder results. Each of the normal maps below were [[#Renormalizing|re-normalized]] after blending.<br />
<br />
{|class="wikitable"<br />
|[[image:nrmlmap_blending_methods_Maps.png]]<br />
|[[image:nrmlmap_blending_methods_RTTNormalMapFX.png]]<br />
|-<br />
|The blended normal maps.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|Screenshot of the 3dsmax viewport, using the RTTNormalMap.fx shader.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|}<br />
<br />
The four blending methods used above:<br />
# [http://www.crazybump.com CrazyBump] by Ryan Clark blends normal maps together using calculations in 3D space rather than just in 2D. This does probably the best job at preserving details, and each layer's strength settings can be tweaked individually. <br />
# [http://www.rodgreen.com/?p=4 Combining Normal Maps in Photoshop] by Rod Green blends normal maps together using Linear Dodge mode for the positive values and Difference mode for the negative values, along with a Photoshop Action to simplify the process. It's free, but the results may be less accurate than CrazyBump.<br />
# [http://www.paultosca.com/makingofvarga.html Making of Varga] by [http://www.paultosca.com/ Paul "paultosca" Tosca] blends normal maps together using Overlay mode for the red and green channels and Multiply mode for the blue channel. This gives a slightly stronger bump than the Overlay-only method. [http://www.leocov.com/ Leo "chronic" Covarrubias] has a step-by-step tutorial for this method in [http://www.cgbootcamp.com/tutorials/2009/12/9/photoshop-combine-normal-maps.html CG Bootcamp Combine Normal Maps].<br />
# [[3DTutorials/Normal Map Deepening|Normal Map Deepening]] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to blend normal maps together using Overlay mode. [http://cgtextures.com/content.php?action=tutorial&name=normalmap CGTextures tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] also shows how to create normalmaps using multiple layers (Note: to work with the Overlay blend mode each layer's Output Level should be 128 instead of 255, you can use the Levels tool for this).<br />
<br />
The [http://boards.polycount.net/showthread.php?t=69615 Getting good height from Nvidia-filter normalizing grayscale height] thread on the Polycount forum has a discussion of different painting/blending options. Also see the [[#2DT|2D Tools]] section for painting and conversion tools.<br />
<br />
<span id="PCT"></span><br />
<br />
=== Pre-Created Templates ===<br />
A library of shapes can be developed and stored for later use, to save creation time for future normal maps. Things like screws, ports, pipes, and other doo-dads. These shapes can be stored as bitmaps with transparency so they can be layered into baked normal maps.<br />
<br />
* [http://www.beautifulrobot.com/?p=69 Creating & Using NormalMap "Widgets"] - by ''[http://www.beautifulrobot.com Steev "kobra" Kelly]''<<BR>> How to set up and render template objects.<br />
* [http://www.akramparvez.com/portfolio/scripts/normalmap-widget-for-3ds-max/ NormalMap Widget for 3ds Max] - by ''[http://www.akramparvez.com Akram Parvez]''<<BR>>A script to automate the setup and rendering process.<br />
* See the section [[#BT|Baking Transparency]] for more template-rendering tools and tutorials.<br />
<br />
<span id="RN"></span><span id="Renormalizing"></span><br />
=== Re-normalizing ===<br />
Re-normalizing means resetting the length of each normal in the map to 1.<br />
<br />
A normal mapping shader takes the three color channels of a normal map and combines them to create the direction and length of each pixel's normal. These normals are then used to apply the scene lighting to the mesh. However if you edit normal maps by hand or if you blend multiple normal maps together this can cause those lengths to change. Most shaders expect the length of the normals to always be 1 (normalized), but some are written to re-normalize the normal map dynamically (for example, 3ds Max's Hardware Shaders do re-normalize).<br />
<br />
If the normals in your normal map are not normalized, and your shader doesn't re-normalize them either, then you may see artifacts on the shaded surface... the specular highlight may speckle like crazy, the surface may get patches of odd shadowing, etc. To help you avoid this NVIDIA's normal map filter for Photoshop provides an easy way to re-normalize a map after editing; just use the '''Normalize Only''' option. [http://xnormal.net Xnormal] also comes with a Normalize filter for Photoshop.<br />
<br />
[[image:normalize_only.jpg|frame|none|The re-normalize option in the NVIDIA filter.<br>Image by [http://hirezstudios.com/ Scott Warren]]]<br />
<br />
Some shaders use [[#NormalMapCompression|compressed normal maps]]. Usually this means the blue channel is thrown away completely, so it's recalculated on-the-fly in the shader. However the shader has to re-normalize in order to recreate that data, so any custom normal lengths that were edited into the map will be ignored completely. <br />
<br />
<span id="AOIANM"></span><span id="AmbientOcclusionIntoANormalMap"></span><br />
<br />
=== Ambient Occlusion into a Normal Map ===<br />
If the shader doesn't re-normalize the normal map, an [[Ambient Occlusion Map]] can actually be baked into the normal map. This will shorten the normals in the crevices of the surface, causing the surface to receive less light there. This works with both diffuse and specular, or any other pass that uses the normal map, like reflection.<br />
<br />
However it's usually best to keep the AO as a separate map (or in an alpha channel) and multiply it against the ambient lighting only. This is usually done with a custom [[:Category:Shaders|shader]]. If you multiply it against the diffuse map or normal map then it also occludes diffuse lighting which can make the model look dirty. Ambient occlusion is best when it occludes ambient lighting only, for example a [[DiffuselyConvolvedCubeMap|diffusely convolved cubemap]].<br />
<br />
[[image:nrmlmap_ao.jpg|frame|none| AO can be baked into a normal map, shortening the normals (lower left model).<br>Model by [http://www.3dartisan.net/~kuman/ James Ku]]]<br />
<br />
To bake the AO into a normal map, adjust the levels of the AO layer first so the darks only go as low as 128 gray, then set the AO layer to Darken mode. This will shorten the normals in the normalmap, causing the surface to receive less light in the darker areas. <br />
<br />
This trick doesn't work with any shaders that re-normalize, like 3ds Max's Hardware Shaders. The shader must be altered to actually use the lengths of your custom normals; most shaders just assume all normals are 1 in length because this makes the shader code simpler. Also this trick will not work with most of the common [[#NormalMapCompression|normal map compression formats]], which often discard the blue channel and recalculate it in the shader, which requires re-normalization.<br />
<br />
<span id="BLE"></span><br />
<br />
=== Back Lighting Example ===<br />
You can customize normal maps for some interesting effects. If you invert the blue channel of a tangent-space map, the normals will be pointing to the opposite side of the surface, which can simulate backlighting.<br />
<br />
{|class="wikitable"<br />
|[[image:tree_front.jpg]]||[[image:tree_back.jpg]]<br />
|-<br />
|Tree simulating subsurface scattering (front view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|Tree simulating subsurface scattering (back view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|-<br />
|colspan="2"|[[image:tree_maps.jpg]]<br />
|-<br />
|colspan="2"|The maps used for the leaves. The 2nd diffuse was simply color-inverted, hue-shifted 180°, and saturated.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
The tree leaves use a shader than adds together two diffuse maps, one using a regular tangent-space normal map, the other using the same normal map but with the blue channel inverted. This causes the diffuse map using the regular normal map to only get lit on the side facing the light (front view), while the diffuse map using the inverted normal map only gets lit on the opposite side of the leaves (back view). The leaf geometry is 2-sided but uses the same shader on both sides, so the effect works no matter the lighting angle. As an added bonus, because the tree is self-shadowing the leaves in shadow do not receive direct lighting, which means their backsides do not show the inverted normal map, so the fake subsurface scatter effect only appears where the light directly hits the leaves. This wouldn't work for a whole forest because of the computational cost of self-shadowing and double normal maps, but could be useful for a single "star" asset, or if LODs switched the distant trees to a model that uses a cheaper shader.<br />
<br />
<span id="SAS"></span><br />
<br />
== Shaders and Seams ==<br />
You need to use the right kind of shader to avoid seeing seams where UV breaks occur. It must be written to use the same [[#TangentBasis|tangent basis]] that was used during baking. If the shader doesn't, the lighting will either be inconsistent across UV borders or it will show smoothing errors from the low-poly vertex normals.<br />
<br />
Xnormal generates accurate normals when displayed in Xnormal, and the SDK includes a method to write your own custom tangent space generator for the tool. <br />
<br />
<span id="3MS"></span><br />
=== 3ds Max Shaders ===<br />
The "Render To Texture" tool in 3ds Max 2011 and older generates [[#TSNM|tangent-space]] normal maps that render correctly in the offline renderer (scanline) but do not render correctly in the realtime viewport with the 3ds Max shaders. Max is using a different [[#TangentBasis|tangent basis]] for each. This is readily apparent when creating non-organic hard surface normalmaps; smoothing errors appear in the viewport that do not appear when rendered. <br />
<br />
The errors can be fixed by using "Render To Texture" to bake a [[#TSNM|tangent-space]] or [[#OSNM|object-space]] map, and using the free [http://www.3pointstudios.com/3pointshader_about.shtml "3Point Shader"] by Christoph '[[CrazyButcher]]' Kubisch and Per 'perna' Abrahamsen. The shader uses the same tangent basis as the baking tool, so it produces nearly flawless results. It also works with old bakes.<br />
<br />
You can get OK results in the Max viewport using a tangent-space map baked in Maya, loading it in a Standard material, and enabling "Show Hardware Map in Viewport". Another method is to use Render To Texture to bake an [[#OSNM|object-space]] map then use [[#CBS|Nspace]] to convert it into a tangent-space map then load that in a DirectX material and use the RTTNormalMap.fx shader. <br />
<br />
Autodesk is aware of these issues, and plans to address them in an upcoming release. See these links for more information:<br />
* Christoph "[[CrazyButcher]]" Kubisch and Per "perna" Abrahamsen designed a shader/modifier combination approach that fixes the viewport problem, see the Polycount forum post [http://boards.polycount.net/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max].<br />
* Jean-Francois "jfyelle" Yelle, Autodesk Media & Entertainment Technical Product Manager, has [http://boards.polycount.net/showthread.php?p=1115812#post1115812 this post]. <br />
* Ben Cloward posted [http://boards.polycount.net/showthread.php?p=1100270#post1100270 workarounds and FX code].<br />
* Christopher "cdiggins" Diggins, SDK writer for 3ds Max, shares some of the SDK code in his blog posts "[http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping How the 3ds Max Scanline Renderer Computes Tangent and Binormal Vectors for Normal Mapping]" and "[http://area.autodesk.com/blogs/chris/3ds_max_normal_map_baking_and_face_angle_weighting_the_plot_thickens 3ds Max Normal Map Baking and Face Angle Weighting: The Plot Thickens]".<br />
<br />
[[image:nmtest_uv-splits_thumb.jpg|thumb|600px|none|Comparison of map baking methods in Maya and Max, and Ben Cloward's custom FX code.<br>Image by [http://www.bencloward.com/ Ben Cloward] and [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
[[image:normalmapfix_3pointstudios_thumb.jpg|frame|none|3 Point Studios' normal map display fix for 3ds Max.<br>image by [http://www.3pointstudios.com 3 Point Studios]]]<br />
<br />
{|class="wikitable"<br />
|[[image:max2010_normalmap_workarounds.png|thumb|400px|none|]]<br />
|[[image:max2010_normalmap_compare.png|thumb|400px|none|]]<br />
|-<br />
|Viewport methods in 3ds Max 2010.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick] <br />
|More baking methods in 3ds Max 2010.<br> Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
<span id="3MENT"></span><br />
<br />
=== 3ds Max Edit Normals Trick ===<br />
After baking, if you add an Edit Normals modifier to your low-poly normalmapped model, this seems to "relax" the vertex normals for more accurate viewport shading. The modifier can be collapsed if desired.<br />
<br />
<span id="MS"></span><br />
=== Maya Shaders ===<br />
Maya seems to correctly generate normals to view in realtime, with the correct [[#TangentBasis|tangent basis]], with much less smoothing errors than 3ds Max. <br />
* [http://www.mentalwarp.com/~brice/shader.php BRDF shader] by [http://www.mentalwarp.com/~brice/ Brice Vandemoortele] and [http://www.kjapi.com/ Cedric Caillaud] (more info in [http://boards.polycount.net/showthread.php?t=49920 this Polycount thread]) '''Update:''' [http://boards.polycount.net/showthread.php?p=821862#post821862 New version here] with many updates, including object-space normal maps, relief mapping, self-shadowing, etc. Make sure you enable cgFX shaders in the Maya plugin manager, then you can create them in the same way you create a Lambert, Phong etc. Switch OFF high quality rendering in the viewports to see them correctly too.<br />
* If you want to use the software renderer, use mental ray instead of Maya's software renderer because mental ray correctly interprets tangent space normals. The Maya renderer treats the normal map as a grayscale bump map, giving nasty results. Mental ray supports Maya's Phong shader just fine (amongst others), although it won't recognise a gloss map plugged into the "cosine power" slot. The slider still works though, if you don't mind having a uniform value for gloss. Spec maps work fine though. Just use the same set up as you would for viewport rendering. You'll need to have your textures saved as TGAs or similar for mental ray to work though. - from [http://boards.polycount.net/member.php?u=14235 CheeseOnToast]<br />
<br />
<br />
<span id="NMC"></span><br />
<br />
== Normal Map Compression ==<br />
see; [[Normal Map Compression]]<br />
<br />
== Links ==<br />
<br />
=== Related Pages ===<br />
* [[Curvature map]]<br />
* [[DuDv map]]<br />
* [[Flow map]]<br />
* [[Normal map]]<br />
* [[Radiosity normal map]]<br />
* [[Vector displacement map]]<br />
<br />
<span id="3DT"></span> <span id="Tools"></span> <span id="3DTools"></span><br />
=== 3D Tools ===<br />
See [[:Category:Tools#A3D_Normal_Map_Software|Category:Tools#3D_Normal_Map_Software]]<br />
<br />
<span id="2DT"></span><span id="2DTools"></span><br />
=== 2D Tools ===<br />
See [[:Category:Tools#A2D_Normal_Map_Software|Category:Tools#2D_Normal_Map_Software]]<br />
<br />
<span id="T"></span><span id="Tutorials"></span><br />
=== Tutorials ===<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh tutorial for Max and Xnormal] by [http://www.exisinteractive.com/ PeterK] to prevent heavy distortions when baking with a cage, without the need to add extra supporting vertices.<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games] by [http://www.polycount.com/forum/member.php?u=56680 'SuperFranky']<br />
* [http://area.autodesk.com/userdata/fckdata/239955/The%20Generation%20and%20Display%20of%20Normal%20Maps%20in%203ds%20Max.pdf The Generation and Display of Normal Maps in 3ds Max] (500kb PDF) <<BR>> Excellent whitepaper from Autodesk about normal mapping in 3ds Max and other apps.<br />
* [http://www.katsbits.com/htm/tutorials/blender-baking-normal-maps-from-models.htm Renderbump and baking normal maps from high poly models using Blender 3D] by ''[http://www.katsbits.com/htm/about.htm "katsbits"]''<<BR>>Baking normal maps in Blender.<br />
* [http://udn.epicgames.com/Three/CreatingNormalMaps.html Techniques for Creating Normal Maps] in the Unreal Developer Network's [http://udn.epicgames.com/Three/WebHome.html Unreal Engine 3 section] contains advice from [http://www.epicgames.com/ Epic Games] artists on creating normal maps for UE3. The [http://udn.epicgames.com/Three/DesignWorkflow.html#Creating%20normal%20maps%20from%20meshes Design Workflow page] has a summary.<br />
* [http://www.iddevnet.com/quake4/ArtReference_CreatingModels#head-3400c230e92ff7d57424b2a68f6e0ea75dee4afa Creating Models in Quake 4] by [http://www.ravensoft.com/ Raven Software] is a comprehensive guide to creating Quake 4 characters.<br />
* [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing and UVs can affect normal maps in Doom 3.<br />
* [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] is an overview of modeling for normal maps.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses how smoothing groups and bevels affect the topology of the low-poly model.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in-game, not the triangle or poly count.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm Normal map workflow] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] demonstrates his normal mapping workflow in 3ds Max and Photoshop.<br />
* [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa This video tutorial] by [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] shows in Maya how to subdivide the low-poly mesh so it more closely matches the high-poly mesh, to help solve wavy lines in the bake.<br />
* [http://www.bencloward.com/tutorials_normal_maps1.shtml Normal Mapping Tutorial] by [http://www.bencloward.com/ Ben Cloward] is a comprehensive tutorial about the entire normal map creation process.<br />
* [http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy] shows how to use a special lighting setup to render normal maps (instead of baking them).<br />
* [http://cgtextures.com/content.php?action=tutorial&name=normalmap Tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] shows how to create deep normal maps using multiple layers. Note: to use Overlay blend mode properly, make sure to change each layer's Levels ''Output Level'' to 128 instead of 255.<br />
* [http://www.poopinmymouth.com/process/tips/normalmap_deepening.jpg Normalmap Deepening] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to adjust normal maps, and how to layer together painted and baked normal maps.<br />
* [http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] helps to solve seams along horizontal or vertical UV edges, but not across angled UVs.<br />
* [http://planetpixelemporium.com/tutorialpages/normal.html Cinema 4D and Normal Maps For Games] by [http://planetpixelemporium.com/index.php James Hastings-Trew] describes normal maps in plain language, with tips on creating them in Cinema 4D.<br />
* [http://forums.cgsociety.org/showthread.php?f=39&t=359082 3ds Max normal mapping overview] by [http://www.alan-noon.com/ Alan Noon] is a great thread on CGTalk about the normal mapping process.<br />
* [http://forums.cgsociety.org/showthread.php?f=46&t=373024 Hard Surface Texture Painting] by [http://stefan-morrell.cgsociety.org/gallery/ Stefan Morrell] is a good introduction to painting textures for metal surfaces.<br />
<br />
<span id="D"></span><span id="Discussion"></span><br />
<br />
=== Discussion ===<br />
[http://boards.polycount.net/showthread.php?p=820218 Discuss this page on the Polycount forums]. Suggestions welcome.<br />
<br />
Even though only one person has been editing this page so far, the information here was gathered from many different sources. We wish to thank all the contributors for their hard-earned knowledge. It is much appreciated!<br />
<br />
----<br />
[[Category:TextureTypes]] [[Category:Bump map]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Normal_mapNormal map2015-04-22T15:53:33Z<p>Dustinbrown: /* Common Swizzle Coordinates */</p>
<hr />
<div>== Out of Date ==<br />
The information on this page is a bit old, it needs to be updated. See these links for more current information:<br />
<br />
* [http://farfarer.com/resources.htm RNM Normal Map Combiner], by [http://www.farfarer.com/ James "Farfarer" O'Hare]<br />
* [http://vincentcallebaut.com/CombineNormal.html Combine Normal], by [http://vincentcallebaut.comVincent "Vincentt" Callebaut], [http://www.polycount.com/forum/showthread.php?t=131819 Combine normal maps script for Photoshop] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showpost.php?p=2226864&postcount=51 Earthquake on separating smoothing groups in the UV]<br />
* [http://www.polycount.com/forum/showpost.php?p=2225535&postcount=40 JedTheKrampus on offsetting Mirrored UVs]<br />
* [http://www.polycount.com/forum/showthread.php?t=148303 Of Bit Depths, Banding and Normal Maps]<br />
* [http://www.polycount.com/forum/showthread.php?t=147227 Skew you buddy! Making sense of skewed normal map details.]<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games]<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh Tutorial]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?]<br />
* [http://www.laurenscorijn.com/future-xoliulshader-support.html Future Xoliulshader support] = why Xoliulshader doesn't work properly in 3ds Max 2013/2014.<br />
<br />
== Synched Workflow ==<br />
To eliminate seams and shading artifacts, the model renderer and the normal map baking tool should use the same tangent basis.<br />
<br />
FBX model format can store tangents, and some renderers use this data to synch the incoming normal maps.<br />
<br />
{| class="wikitable sortable" style="color:grey;"<br />
|- <br />
! Renderer !! Normal map baker<br />
|-<br />
| 3ds Max || 3ds Max, Handplane, ?<br />
|-<br />
| Blender || ?<br />
|-<br />
| Creation Engine || Handplane, ?<br />
|-<br />
| CryEngine || ?<br />
|-<br />
| Knald || ?<br />
|-<br />
| Marmoset Toolbag || 3ds Max, Maya, Xnormal, ?<br />
|-<br />
| Maya || Handplane, Maya, ?<br />
|-<br />
| Source || Handplane, Maya ([http://www.polycount.com/forum/showpost.php?p=2224653&postcount=28]), ?<br />
|-<br />
| Starcraft II || Handplane, ?<br />
|-<br />
| Substance Designer || ?<br />
|-<br />
| Unity([http://www.polycount.com/forum/showpost.php?p=2224781&postcount=29], [http://www.polycount.com/forum/showthread.php?p=2194353#post2194353]) || Handplane, Xnormal (via Asset Store), ?<br />
|-<br />
| Unreal Engine 4 || Handplane, Xnormal([http://www.polycount.com/forum/showpost.php?p=2224402&postcount=20]), ? <br />
|-<br />
| Xnormal || Xnormal, ?<br />
|}<br />
<br />
----<br />
<br />
== What is a Normal Map? ==<br />
A Normal Map is usually used to fake high-res geometry detail when it's mapped onto a low-res mesh. The pixels of the normal map each store a ''normal'', a vector that describes the surface slope of the original high-res mesh at that point. The red, green, and blue channels of the normal map are used to control the direction of each pixel's normal. <br />
<br />
When a normal map is applied to a low-poly mesh, the texture pixels control the direction each of the pixels on the low-poly mesh will be facing in 3D space, creating the illusion of more surface detail or better curvature. However, the silhouette of the model doesn't change. <br />
<br />
<gallery mode="packed"><br />
Whatif_normalmap_mapped2.jpg|A model with a normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_low.jpg|The model without its normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_high.jpg|The high-resolution model used to create the normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
</gallery><br />
<br />
==Tangent-Space vs. Object-Space==<br />
<br />
Normal maps can be made in either of two basic flavors: tangent-space or object-space. World-space is basically the same as object-space, except it requires the model to remain in its original orientation, neither rotating nor deforming, so it's almost never used.<br />
<br />
===Tangent-space normal map===<br />
[[image:normalmap_tangentspace.jpg|frame|none|A tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Predominantly-blue colors. Object can rotate and deform. Good for deforming meshes, like characters, animals, flags, etc.<br />
<br />
Pros:<br />
* Maps can be reused easily, like on differently-shaped meshes.<br />
* Maps can be tiled and mirrored easily, though some games might not support mirroring very well.<br />
* Easier to overlay painted details.<br />
* Easier to use image compression.<br />
<br />
Cons:<br />
* More difficult to avoid smoothing problems from the low-poly vertex normals (see Smoothing Groups and Hard Edges).<br />
* Slightly slower performance than an object-space map (but not by much).<br />
<br />
===Object-space normal map===<br />
[[image:normalmap_worldspace.jpg|frame|none|An object-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Rainbow colors. Objects can rotate, but usually shouldn't be deformed, unless the shader has been modified to support deformation. Object-space is also called local-space or model-space. <br />
<br />
Pros:<br />
* Easier to generate high-quality curvature because it completely ignores the crude smoothing of the low-poly vertex normals.<br />
* Slightly better performance than a tangent-space map (but not by much).<br />
<br />
Cons:<br />
* Can't easily reuse maps, different mesh shapes require unique maps.<br />
* Difficult to tile properly, and mirroring requires specific shader support.<br />
* Harder to overlay painted details because the base colors vary across the surface of the mesh. Painted details must be converted into Object Space to be combined properly with the OS map.<br />
* They don't compress very well, since the blue channel can't be recreated in the shader like with tangent-space maps. Also the three color channels contain very different data which doesn't compress well, creating many artifacts. Using a half-resolution object-space map is one option. <br />
<br />
<br clear="all"/><br />
<br />
=== Converting Between Spaces ===<br />
Normal maps can be converted between object space and tangent space, in order to use them with different blending tools and shaders, which require one type or the other. <br />
<br />
Object space maps can also be converted to maps with different tangent bases, to better match the normal maps with the renderer and thus avoid lighting errors.<br />
<br />
* [http://www.handplane3d.com Handplane] by [http://www.alecmoody.com/ Alec Moody] is a tool that converts object space maps into a variety of tangent spaces: 3ds Max, Creation Engine, Maya, Source, Unity, Unreal, etc. See the Polycount Forum thread [http://www.polycount.com/forum/showthread.php?t=116899 Official handplane support thread - Now freeware!!].<br />
<br />
[[File:handplane_illus_1.jpg|frame|none|Handplane interface. <br>Image by [http://www.alecmoody.com/ Alec Moody].]]<br />
<br />
<br />
* [http://boards.polycount.net/showthread.php?p=1072599#post1072599 NSpace] by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] is a tool that converts an object-space normal map into a tangent-space map, which then works seamlessly in the 3ds Max viewport. He converts the map by using the same tangent basis that 3ds Max uses for its hardware shader. To see the results, load the converted map via the ''Normal Bump'' map and enable "Show Hardware Map in Viewport". [http://gameartist.nl/ Osman "osman" Tsjardiwal] created a GUI for NSpace, you can [http://boards.polycount.net/showthread.php?p=1075143#post1075143 download it here], just put it in the same folder as the NSpace exe and run it. <br />
<br />
[[File:NSpace_Gui_osman.png|frame|none|NSpace interface. <br>Image by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] and [http://gameartist.nl Osman "osman" Tsjardiwal].]]<br />
<br />
[http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson] said: "[8Monkey Labs has] a tool that lets you load up your reference mesh and object space map. Then load up your tangent normals, and adjust some sliders for things like tile and amount. We need to load up a mesh to know how to correctly orient the tangent normals or else things will come out upside down or reverse etc. It mostly works, but it tends to "bend" the resulting normals, so you gotta split the mesh up into some smoothing groups before you run it, and then I usually will just composite this "combo" texture over my orig map in Photoshop."<br />
<br />
<span id="RGBC"></span><span id="RGBChannels"></span><br />
<br />
== RGB Channels ==<br />
Shaders can use different techniques to render tangent-space normal maps, but the normal map directions are usually consistent within a game. Usually the red channel of a tangent-space normal map stores the X axis (pointing the normals predominantly leftwards or rightwards), the green channel stores the Y axis (pointing the normals predominantly upwards or downwards), and the blue channel stores the Z axis (pointing the normals outwards away from the surface).<br />
<br />
[[image:tangentspace_rgb.jpg|frame|none|The red, green, and blue channels of a tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you see lighting coming from the wrong angle when you're looking at your normal-mapped model, and the model is using a tangent-space normal map, the normal map shader might be expecting the red or green channel (or both) to point in the opposite direction. To fix this either change the shader, or simply invert the appropriate color channels in an image editor, so that the black pixels become white and the white pixels become black.<br />
<br />
Some shaders expect the color channels to be swapped or re-arranged to work with a particular [[#NormalMapCompression|compression format]]. For example the DXT5_nm format usually expects the X axis to be in the alpha channel, the Y axis to be in the green channel, and the red and blue channels to be empty.<br />
<br />
== Tangent Basis ==<br />
[[#TangentSpaceVsObjectSpace|Tangent-space]] normal maps use a special kind of vertex data called the ''tangent basis''. This is similar to UV coordinates except it provides directionality across the surface, it forms a surface-relative coordinate system for the per-pixel normals stored in the normal map. This coordinate system is required to light a normal mapped surface.<br />
<br />
Each vertex in the tangent basis is a combination of three things: the mesh vertex's normal (influenced by smoothing), the vertex's tangent (usually derived from the V texture coordinate), and the vertex's bitangent (derived in code, also called the binormal). These three vectors create an axis for each vertex, giving it a specific orientation in the tangent space. These axes are used to properly transform the incoming lighting from world space into tangent space, so your normal-mapped model will be lit correctly.<br />
<br />
Light rays are in world space, but the normals stored in the normal map are in tangent space. When the model is being rendered, the light rays must be converted from world space into tangent space, using the tangent basis to get there. At that point the incoming light rays are compared against the directions of the normals in the normal map, and this determines how much each pixel is going to be lit. Alternatively, instead of converting the light rays some shaders will convert the normals in the normal map from tangent space into world space. Then those world-space normals are compared against the light rays, and the model is lit appropriately. The method depends on who wrote the shader, but the end result is the same. Both methods require a tangent basis to transform the lighting.<br />
<br />
When a triangle's vertex normals are pointing straight out, and a pixel in the normal map is neutral blue (128,128,255) this means the pixel's normal will be pointing straight out from the surface of the low-poly mesh. When that pixel normal is tilted towards the left or the right in the tangent coordinate space, it will get either more or less red color, depending on whether the normal map is set to store the X axis as either a positive or a negative value. Same goes for when the normal is tilted up or down in tangent space, it will either get more or less green color. If the vertex normals aren't exactly perpendicular to the triangle, the normal map pixels will be tinted away from neutral blue as well.<br />
<br />
Unfortunately for artists, there are many different ways to calculate the tangent basis: [http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping 3ds Max], [http://download.autodesk.com/us/maya/2011help/index.html?url=./files/Appendix_A_Tangent_and_binormal_vectors.htm,topicNumber=d0e227193 Maya], [http://www.codesampler.com/dx9src/dx9src_4.htm#dx9_dot3_bump_mapping DirectX 9], [http://developer.nvidia.com/object/NVMeshMender.html NVMeshMender], [http://www.terathon.com/code/tangent.html Eric Lengyel], a custom solution, etc. This means a normal map baked in one application probably won't shade correctly in another. Artists must do some testing with different [[#T|baking tools]] to find which works best with their output. When the renderer (or game engine) renders your game model, [[#ShadersAndSeams|the shader]] must use the same tangent basis as the normal map baker, otherwise you'll get incorrect lighting, especially across the seams between UV shells.<br />
<br />
The [http://www.xnormal.net/ xNormal] SDK supports custom tangent basis methods. When a programmer uses it to implement their renderer's own tangent basis, artists can then use Xnormal to bake normal maps that will match their renderer perfectly.<br />
<br />
[[image:tangentseams.jpg|frame|none|When shared edges are at different angles in UV space, different colors will show up<br />
along the seam. The tangent basis uses these colors to light the model properly. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
When you look at a tangent-space normal map for a character, you typically see different colors along the UV seams. This is because the UV shells are often oriented at different angles on the mesh, a necessary evil when translating the 3D mesh into 2D textures. The body might be mapped with a vertical shell, and the arm mapped with a horizontal one. This requires the normals in the normal map to be twisted for the different orientations of those UV shells. The UVs are twisted, so the normals must be twisted in order to compensate. The tangent basis helps reorient (twist) the lighting as it comes into the surface's local space, so the lighting will then look uniform across the normal mapped mesh.<br />
<br />
When an artist tiles a tangent-space normal map across an arbitrary mesh, like a landscape, this tends to shade correctly because the mesh has a uniform direction in tangent space. If the mesh has discontinuous UV coordinates (UV seams), or the normal map has large directional gradients across it, the tangent space won't be uniform anymore so the surface will probably have shading seams.<br />
<br />
== Common Swizzle Coordinates ==<br />
3D Software capable of displaying tangent space normal maps will have a native required direction, or "handedness" for the RGB channels in a normal map, sometimes referred to as "Swizzle Coordinates," though [[#SAS|shaders]] can often be written to override this native handedness. You may hear developers refer to "flipping the green channel" in order to get a normal map to display correctly, and this simply indicates that when the normal map was baked, it was authored with the incorrect handedness in the green channel. Left/Down handedness is indicated with a negative (-), and right/up handedness is demarcated with a (+) positive.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
| '''Software''' <br />
| '''Red''' <br />
| '''Green''' <br />
| '''Blue''' <br />
|-<br />
|<#000000>| 3ds Max<br />
| X+<br />
| Y-<br />
| Z+ <br />
|-<br />
|<#000000>| Maya<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| [http://wiki.blender.org/index.php/Doc:2.6/Manual/Textures/Influence/Material/Bump_and_Normal Blender]<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| [https://docs.unrealengine.com/latest/INT/Engine/Content/Types/Textures/Properties/index.html Unreal Engine]<br />
| X+ <br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| [http://docs.cryengine.com/display/SDKDOC2/Normal+Maps CryENGINE]<br />
| X+<br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| [http://docs.unity3d.com/Manual/HOWTO-bumpmap.html Unity]<br />
| X+<br />
| Y+<br />
| Z+<br />
|-<br />
|<#000000>| [https://developer.valvesoftware.com/wiki/Bump_map Source]<br />
| X+<br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Toolbag<br />
| X+<br />
| Y+ <br />
| Z+<br />
|}<br />
<span id="MTLPM"></span><br />
<br />
== Modeling the Low-Poly Mesh ==<br />
The in-game mesh usually needs to be carefully optimized to create a good silhouette, define edge-loops for better deformation, and minimize extreme changes between the vertex normals for better shading (see [[#SmoothingGroupsAndHardEdges|Smoothing Groups & Hard Edges]]).<br />
<br />
In order to create an optimized in-game mesh including a good silhouette and loops for deforming in animation, you can start with the 2nd subdivision level of your [[DigitalSculpting|digital sculpt]], or in some cases with the base mesh itself. Then you can just collapse edge loops or cut in new edges to add/remove detail as necessary. Or you can [[DigitalSculpting#OART|re-toplogize]] from scratch if that works better for you.<br />
<br />
See [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts] on the Polycount forum.<br />
<br />
<span id="UVC"></span><span id="UVCoordinates"></span><br />
=== UV Coordinates ===<br />
Normal map baking tools only capture normals within the 0-1 UV square, any UV bits outside this area are ignored. <br />
<br />
Only one copy of the forward-facing UVs should remain in the 0-1 UV square at baking time. If the mesh uses overlapping UVs, this will likely cause artifacts to appear in the baked map, since the baker will try render each UV shell into the map. Before baking, it's best to move all the overlaps and mirrored bits outside the 0-1 square. <br />
<br />
[[image:Normalmap_uvcoord_offset.jpg|frame|none|The mirrored UVs (in red) are offset 1 unit before baking. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you move all the overlaps and mirrored bits exactly 1 UV unit (any whole number will do), then you can leave them there after the bake and they will still be mapped correctly. You can move them back if you want, it doesn't matter to most game engines. Be aware that ZBrush does use UV offsets to manage mesh visibility, however this usually doesn't matter because the ZBrush cage mesh is often a different mesh than the in-game mesh used for baking.<br />
<br />
You should avoid changing the UVs after baking the normal map, because rotating or mirroring UVs after baking will cause the normal map not to match the [[#TB|tangent basis]] anymore, which will likely cause lighting problems. <br />
<br />
In 3ds Max, W is a third texture coordinate. It's used for 3D procedural textures and for storing vertex color in UV channels (you need 3 axes for RGB, so UVW can store vertex color). Bake problems can be avoided by moving any overlapping UVs to -1 on the W axis, with the same results as moving them 1 unit on the U or V axes. The tool Render To Texture will always bake whatever UVs are the highest along the W axis. However using W can be messy... it's generally hidden unless you purposefully look for it (bad for team work), doesn't get preserved on export to other apps, and high W values can prevent selecting and/or welding UVs. <br />
<br />
<span id="M"></span><span id="Mirroring"></span><br />
<br />
=== Mirroring ===<br />
Normal maps can be mirrored across a model to create symmetrical details, and save UV space, which allows more detail in the normal map since the texture pixels are smaller on the model. <br />
<br />
With [[#OSNM|object-space]] maps, mirroring requires [http://boards.polycount.net/showthread.php?t=53986 specific shader support]. For [[#TSNM|tangent-space]] maps, mirroring typically creates a shading seam, but this can be reduced or hidden altogether, depending on the method used.<br />
<br />
<span id="TMW"></span><br />
==== Typical Mirroring Workflow ====<br />
# Delete the mesh half that will be mirrored. <br />
# Arrange the UVs for the remaining model, filling the UV square.<br />
# Mirror the model to create a "whole" mesh, welding the mesh vertices along the seam. <br />
# Move the mirrored UVs exactly 1 unit (or any whole number) out of the 0-1 UV square.<br />
# Bake the normal map.<br />
<br />
Sometimes an artist will decide to delete half of a symmetrical model before baking. <br />
<br />
This is a mistake however because often the vertex normals along the hole will bend towards the hole a bit; there are no faces on the other side to average the normals with. This will create a strong lighting seam in the normal map. <br />
<br />
It's typically best to use the complete mirrored model to bake the normal map, not just the unique half. <br />
<br />
To prevent the mirrored UVs from causing overlaps or baking errors, move the mirrored [[#UVC|UVs]] out of the 0-1 UV space, so only one copy of the non-mirrored UVs is left within the 0-1 square.<br />
<br />
To avoid texel "leaks" between the UV shells, make sure there's enough [[#Edge_padding|Edge Padding]] around each shell, including along the edges of the normal map. None of the UV shells should be touching the edge of the 0-1 UV square, unless they're meant to tile with the other side of the map.<br />
<br />
<span id="CM"></span><br />
<br />
==== Center Mirroring ====<br />
If the mirror seam runs along the surface of a continuous mesh, like down the center of a human face for example, then it will probably create a lighting seam. <br />
<br />
In Epic Games' [http://www.unrealtechnology.com/technology.php Unreal Engine 3] (UE3) their symmetrical models commonly use centered mirroring. Epic uses materials that mix a [[DetailMap]] with the normal maps; these seem to scatter the diffuse/specular lighting and help minimize the obviousness of the mirror seams. For their [[Light Map]]ped models they use [http://udn.epicgames.com/Three/LightMapUnwrapping.html a technique] that can almost completely hide the mirror seam.<br />
<br />
[[image:Epic_MirroringCicada.jpg|frame|none| In UE3 a center mirror seam is reduced by using a detail normal map. <br> Image by "[http://epicgames.com Epic Games]"]]<br />
<br />
'''''[http://www.zbrushcentral.com/showpost.php?p=573108&postcount=28 GOW2 normal map seams], [http://utforums.epicgames.com/showthread.php?p=27166791#post27166791 UDK normal map seams]'''''<br />
<br />
<span id="OM"></span><br />
<br />
==== Offset Mirroring ====<br />
Offset mirroring is a method where you move the mirror seam off to one side of the model, so the seam doesn't run exactly down the center. For example with a character's head, the UV seam can go down along the side of the head in front of the ear. The UV shell for the nearest ear can then be mirrored to use the area on the other side of the head. <br />
<br />
This avoids the "Rorschach" effect and allows non-symmetrical details, but it still saves texture space because the two sides of the head can be mirrored (they're never seen at the same time anyhow).<br />
<br />
Offset mirroring doesn't get rid of the seam, but it does move it off to a place where it can either be less obvious, or where it can be hidden in a natural seam on the model.<br />
<br />
<span id="FCM"></span><br />
==== Flat Color Mirroring ====<br />
[http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] solves seams by painting a flat set of normals along the seam, using neutral blue (128,128,255). However it only works along horizontal or vertical UV seams, not across any angled UVs. It also removes any details along the mirror seam, creating blank areas. <br />
<br />
<span id="EM"></span><br />
==== Element Mirroring ====<br />
The mirror seam can be avoided completely when it doesn't run directly through any mesh. For example if there's a detached mesh element that runs down the center of the model, this can be uniquely mapped, while the meshes on either side can be mirrors of each other. Whenever the mirrored parts don't share any vertex normals with the non-mirrored parts, there won't be any seams. <br />
<br />
[[image:normalmap_mirrored-binocs-racer445.jpg|frame|none|The middle part (highlighted in red) uses unique non-mirrored UVs, allowing the mesh on the right to be mirrored without any seams. <br>Image by [http://http://racer445.com/ "racer445"]]]<br />
<br />
<span id="SGAHE"></span><br />
<br />
=== Smoothing Groups & Hard Edges ===<br />
Each vertex in a mesh has at least one vertex normal. Vertex normals are used to control the direction a triangle will be lit from; if the normal is facing the light the triangle will be fully lit, if facing away from the light the triangle won't be lit. <br />
<br />
Each vertex however can have more than one vertex normal. When two triangles have different vertex normals along their shared edge, this creates a shading seam, called a ''hard edge'' in most modeling tools. 3ds Max uses ''Smoothing Groups'' to create hard/soft edges, Maya uses ''Harden Edge'' and ''Soften Edge''. These tools create hard and soft edges by splitting and combining the vertex normals.<br />
<br />
[[image:BenMathis_SmoothingGroups_Excerpt.gif|frame|none|Hard edges occur where the vertices have multiple normals. <br>Image by [http://poopinmymouth.com Ben 'poopinmymouth' Mathis] ([http://poopinmymouth.com/process/tips/smoothing_groups.jpg tutorial here])]]<br />
<br />
When a mesh uses all soft normals (a single smoothing group) the lighting has to be interpolated across the extreme differences between the vertex normals. If your renderer doesn't support the same [[#TangentBasis|tangent basis]] that the baker uses, this can produce extreme shading differences across the model, which creates shading artifacts. It is generally best to reduce these extremes when you can because a mismatched renderer can only do so much to counteract it.<br />
<br />
Hard edges are usually best where the model already has a natural seam. For example, you can add a hard edge along the rim of a car's wheel well, to prevent the inside of the wheel well from distorting the shading for the outside of the car body. Mechanical models usually need hard edges where ever the surface bends more than about 45 degrees. <br />
<br />
For most meshes, the best results usually come from adding hard edges where ever there are UV seams. There are no hard rules however, you must experiment with different approaches to find what works best in your game.<br />
<br />
When you use object-space normal maps the vertex normal problem goes away since you're no longer relying on the crude vertex normals of the mesh. An object-space normal map completely ignores vertex normals. Object-space mapping allows you to use all soft edges and no bevels on the low-res mesh, without showing lighting errors.<br />
<br />
<span id="HEDAT"></span><br />
==== Hard Edge Discussions & Tutorials ====<br />
* [http://www.polycount.com/forum/showthread.php?p=2090450#post2090450 Maya MEL Script help needed (UV border edges)]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=73593 Normal Maps: Can Somone Explain This "Black Edge" issue]<br />
* [http://www.polycount.com/forum/showthread.php?t=73566 Normal Maps: Can someone explain normals, tangents and split UVs?]<br />
* [http://www.polycount.com/forum/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max]<br />
* [http://boards.polycount.net/showthread.php?t=68173 Why you should NOT trust 3ds Max's viewport normal-map display!]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/10503-xsi-normal-mapped-cube-looks-bad.html XSI - normal mapped cube looks bad]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/11924-weird-maya-normal-map-seam-artifact-problem-am-i-making-simple-mistake.html Weird Maya normal map seam/artifact problem]<br />
* [http://boards.polycount.net/showthread.php?p=1080600 Seams in Normals when Creating Tiling Environment Trims and other Tiles]<br />
* The tutorial [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing can affect the normal map.<br />
* The tutorial: [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] shows how smoothing affects raycasting.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses the breaking of normals and smoothing groups in general terms.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in the game, not the triangle count.<br />
* The Crysis documentation [http://doc.crymod.com/AssetCreation/PolyBumpReference.html PolyBump Reference] has a section towards the bottom that shows how smoothing affects their baked normal maps.<br />
* The polycount thread [http://boards.polycount.net/showthread.php?t=60694 Toying around with normal map approaches] has a great discussion of how best to use smoothing groups and bevels for better shading.<br />
<br />
<span id="UB"></span><br />
==== Using Bevels ====<br />
Bevels/chamfers generally improve the silhouette of the model, and can also help reflect specular highlights better. <br />
<br />
However bevels tend to produce long thin triangles, which slow down the in-game rendering of your model. Real-time renderers have trouble rendering long thin triangles because they create a lot of sub-pixel areas to render. <br />
<br />
Bevels also balloon the vertex count, which can increase the transform cost and memory usage. Hard edges increase the vertex count too, but not when the edge also shares a seam in UV space. For a good explanation of the vertex count issue, see [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly].<br />
<br />
Using hard edges with matching UV shells tends to give better performance and better cosmetic results than using bevels. However there are differing opinions on this, see the Polycount thread "[http://boards.polycount.net/showthread.php?t=71760 Maya transfer maps help]".<br />
<br />
<span id="EVN"></span><br />
==== Edited Vertex Normals ====<br />
If you use bevels the shading will be improved by editing the vertex normals so the larger flat surfaces have perpendicular normals. The vertex normals are then forced to blend across the smaller bevel faces, instead of across the larger faces. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66139 Superspecular soft edges tutorial chapter 1].<br />
<br />
[[image:oliverio_bevel_normals.gif|frame|none|Bending normals on bevelled models. <br>From the tutorial [http://deadlineproof.com/model-shading-techniques-soft-edge-superspecular/ Shading techniques Superspecular soft edges]<br>Image by [http://deadlineproof.com/ Paolo Oliverio]]]<br />
<br />
== Level of Detail Models ==<br />
See [http://www.polycount.com/forum/showthread.php?p=1216945#post1216945 Problem if you're using 3point-style normals with an LOD].<br />
<br />
<span id="MTHPM"></span><br />
<br />
== Modeling The High-Poly Mesh ==<br />
[[Subdivision Surface Modeling]] and [[DigitalSculpting]] are the techniques most often used for modeling a normal map. <br />
<br />
Some artists prefer to model the in-game mesh first, other artists prefer to model the high-res mesh first, and others start somewhere in the middle. The modeling order is ultimately a personal choice though, all three methods can produce excellent results:<br />
* Build the in-game model, then up-res it and sculpt it.<br />
* Build and sculpt a high resolution model, then build a new in-game model around that.<br />
* Build a basemesh model, up-res and sculpt it, then step down a few levels of detail and use that as a base for building a better in-game mesh.<br />
If the in-game mesh is started from one of the subdivision levels of the basemesh sculpt, various edge loops can be collapsed or new edges can be cut to add/remove detail as necessary.<br />
<br />
<span id="SE"></span><br />
=== Sloped Extrusions ===<br />
[[image:normal_slopes_hatred.jpg|frame|none|Extrusions on the high-poly model should be sloped to make a better normal map. <br>Image by [http://www.hatred.gameartisans.org/ Krzysztof "Hatred" Dolas].]]<br />
<br />
=== Floating Geometry ===<br />
[[image:FloatingGeo.jpg|frame|none|Normal map stores the direction the surface is facing rather than real depth information, thus allowing to save time using floating geometry. <br>To correctly bake AO with floating geo make it a separate object and turn off it's shadow casting. <br>Image by [http://artisaverb.info/ Andrew "d1ver" Maximov].]]<br />
<br />
See also [[3DTutorials/Modeling High-Low Poly Models for Next Gen Games|Modeling High/Low Poly Models for Next Gen Games]] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa]<br />
<br />
<span id="ET"></span><br />
<br />
=== Edge Thickness ===<br />
[[image:normal_edge_thickness.jpg|frame|none|When creating edges of the Highpoly, sometimes you'll need to make them rounded than in real life to <br>work better at the size they will be seen.<br>Image by [http://racer445.com/Evan "racer445" Herbert]]]<br />
<br />
<span id="MRF"></span><span id="MRRCB"></span><br />
<br />
=== mental ray Round Corners Bump ===<br />
The mental ray renderer offers an automatic bevel rendering effect called Round Corners Bump that can be baked into a normal map. This is available in 3ds Max, Maya, and XSI. See [http://boards.polycount.net/showthread.php?t=71995 Zero Effort Beveling for normal maps] - by [http://boards.polycount.net/member.php?u=31662 Robert "r_fletch_r" Fletcher].<br />
<br />
[http://jeffpatton.net/ Jeff Patton] posted about [http://jeffpatton.cgsociety.org/blog/archive/2007/10/ how to expose Round Corners Bump] in 3ds Max so you can use it in other materials.<br />
<br />
[http://cryrid.com/art/ Michael "cryrid" Taylor] posted a tutorial about how to use [http://cryrid.com/images/temp/XSI/zeroeffort_bevels.jpg Round Corners in XSI].<br />
<br />
XSI is able to bake a good normal map with it, but 3ds Max seems to bake it incorrectly, and Maya isn't able to bake the effect at all. Maybe Max might be able to bake it correctly, if the .mi shader is edited to use the correct coordinate space?<br />
<br />
<span id="Baking"></span><span id="B"></span><br />
== Baking ==<br />
The process of transferring normals from the high-res model to the in-game model is often called baking. The baking tool usually starts projecting a certain numerical distance out from the low-poly mesh, and sends rays inwards towards the high-poly mesh. When a ray intersects the high-poly mesh, it records the mesh's surface normal and saves it in the normal map.<br />
<br />
To get an understanding of how all the options affect your normal map, do some test bakes on simple meshes like boxes. They generate quickly so you can experiment with [[#UVCoordinates|UV mirroring]], [[#SGAHE|smoothing groups]], etc. This helps you learn the settings that really matter.<br />
* The tutorial [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] has more examples of ray-casting, plus how to get better results from the bake.<br />
<br />
Baking sub-sections:<br />
# [[#Anti-Aliasing|Anti-Aliasing]]<br />
# [[#Baking_Transparency|Baking Transparency]]<br />
# [[#Edge_Padding|Edge Padding]]<br />
# [[#High_Poly_Materials|High Poly Materials]]<br />
# [[#Reset_Transforms|Reset Transforms]]<br />
# [[#Solving_Intersections|Solving Intersections]]<br />
# [[#Solving_Pixel_Artifacts|Solving Pixel Artifacts]]<br />
# [[#Solving_Wavy_Lines|Solving Wavy Lines]]<br />
# [[#Triangulating|Triangulating]]<br />
# [[#Working_with_Cages|Working with Cages]]<br />
<br />
<span id="AA"></span><br />
=== Anti-Aliasing ===<br />
Turning on super-sampling or anti-aliasing (or whatever multi-ray casting is called in your normal map baking tool) will help to fix any jagged edges where the high-res model overlaps itself within the UV borders of the low-poly mesh, or wherever the background shows through holes in the mesh. Unfortunately this tends to render much much slower, and takes more memory.<br />
<br />
[[image:normalmap_aliasing_knak47.jpg|frame|none|A bake without anti-aliasing shows artifacts where the high-poly mesh has overlaps. <br>Image by [http://www.polycount.com/forum/member.php?u=35938 'knak47']]]<br />
<br />
One trick to speed this up is to render 2x the intended image size then scale the normal map down 1/2 in a paint program like Photoshop. The reduction's pixel resampling will add anti-aliasing for you in a very quick process. After scaling, make sure to re-normalize the map if your game doesn't do that already, because the un-normalized pixels in your normalmap may cause pixelly artifacts in your specular highlights. Re-normalizing can be done with [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA's normal map filter] for Photoshop.<br />
<br />
3ds Max's supersampling doesn't work nicely with edge padding, it produces dark streaks in the padded pixels. If so then turn off padding and re-do the padding later, either by re-baking without supersampling or by using a Photoshop filter like the one that comes with [[#3DTools|Xnormal]].<br />
<br />
=== Baking Transparency ===<br />
Sometimes you need to bake a normal map from an object that uses opacity maps, like a branch with opacity-mapped leaves. Unfortunately baking apps often completely ignore any transparency mapping on your high-poly mesh.<br />
<br />
{|class="wikitable"<br />
|[[image:JoeWilson_ivynormals_error.jpg]] <br />
|[[image:JoeWilson_ivynormals_rendered.jpg]]<br />
|-<br />
|3ds Max's RTT baker causes transparency errors.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|The lighting method bakes perfect transparency.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|}<br />
<br />
To solve this, render a Top view of the mesh. This only works if you're using a planar UV projection for your low-poly mesh and you're baking a tangent-space normal map.<br />
<br />
* Make sure the Top view matches the dimensions of the planar UV projection used by the low-poly mesh. It helps to use an orthographic camera for precise placement.<br />
* On the high-poly mesh either use a specific lighting setup or a use special material shader:<br />
* 1) The lighting setup is described in these tutorials:<br />
* * [http://www.bencloward.com/tutorials_normal_maps11.shtml Creating A Normal Map Right In Your 3D App] by [http://www.bencloward.com/ Ben Cloward]<br />
* *[http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy], Graphics Techniques Consultant, Xbox Content and Design Team<br />
* 2) The material shader does the same thing, but doesn't require lights.<br />
* * [http://www.scriptspot.com/3ds-max/normaltexmap NormalTexMap] scripted map for 3ds Max by [http://www.scriptspot.com/users/dave-locke Dave Locke].<br />
* * [http://www.footools.com/3dsmax_plugins.html InfoTexture] map plugin for 3ds Max by [http://www.footools.com John Burnett]<br />
<br />
[[image:BenCloward_NormalMapLighting.gif|frame|none|The lighting setup for top-down rendering. <br>Image by [http://www.bencloward.com Ben Cloward]]]<br />
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<span id="EP"></span><br />
<br />
=== Edge Padding ===<br />
If a normal map doesn't have enough [[Edge_padding |Edge Padding]], this will create shading seams on the UV borders.<br />
<br />
=== High Poly Materials ===<br />
3ds Max will not bake a normal map properly if the high-res model has a mental ray Arch & Design material applied. If your normal map comes out mostly blank, either use a Standard material or none at all. For an example see the Polycount thread [http://www.polycount.com/forum/showthread.php?t=74792 Render to Texture >:O].<br />
<br />
<span id="RT"></span><br />
=== Reset Transforms ===<br />
Before baking, make sure your low-poly model's transforms have been reset. '''''This is very important!''''' Often during the modeling process a model will be rotated and scaled, but these compounded transforms can create a messy local "space" for the model, which in turn often creates rendering errors for normal maps. <br />
<br />
In 3ds Max, use the Reset Xforms utility then Collapse the Modifier Stack. In Maya use Freeze Transformation. In XSI use the Freeze button.<br />
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<span id="SI"></span><br />
<br />
=== Solving Intersections ===<br />
The projection process often causes problems like misses, or overlaps, or intersections. It can be difficult generating a clean normal map in areas where the high-poly mesh intersects or nearly intersects itself, like in between the fingers of a hand. Setting the ray distance too large will make the baker pick the other finger as the source normal, while setting the ray distance too small will lead to problems at other places on the mesh where the distances between in-game mesh and high-poly mesh are greater.<br />
<br />
Fortunately there are several methods for solving these problems.<br />
<br />
# Change the shape of the cage. Manually edit points on the projection cage to help solve tight bits like the gaps between fingers.<br />
# Limit the projection to matching materials, or matching UVs.<br />
# Explode the meshes. See the polycount thread [http://boards.polycount.net/showthread.php?t=62921 Explode script needed (for baking purposes)].<br />
# Bake two or more times using different cage sizes, and combine them in Photoshop.<br />
<br />
<span id="SPA"></span><br />
<br />
=== Solving Pixel Artifacts ===<br />
[[image:filterMaps_artifact.jpg|frame|none|Random pixel artifacts in the bake. <br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
If you are using 3ds Max's ''Render To Texture'' to bake from one UV layout to another, you may see stray pixels scattered across the bake. This only happens if you are using a copy of the original mesh in the Projection, and that mesh is using a different UV channel than the original mesh.<br />
<br />
There are two solutions for this:<br />
<br />
* Add a Push modifier to the copied mesh, and set it to a low value like 0.01.<br />
- or -<br />
<br />
* Turn off ''Filter Maps'' in the render settings (Rendering menu > Render Setup > Renderer tab > uncheck Filter Maps). To prevent aliasing you may want to enable the Global Supersampler in Render Setup.<br />
<br />
See also [[#Anti-Aliasing]].<br />
<br />
<span id="SWL"></span><br />
<br />
=== Solving Wavy Lines ===<br />
When capturing from a cylindrical shape, often the differences between the low-poly mesh and the high-poly mesh will create a wavy edge in the normal map. There are a couple ways to avoid this:<br />
<br />
# The best way... create your lowpoly model with better supporting edges. See the Polycount threads [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?], [http://boards.polycount.net/showthread.php?t=55754 approach to techy stuff], [http://www.polycount.com/forum/showthread.php?t=72713 Any tips for normal mapping curved surface?].<br />
# Adjust the shape of the cage to influence the directions the rays will be cast. Beware... this work will have to be re-done every time you edit the lowpoly mesh, as the cage will be invalidated. At the bottom of [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm this page of his normal map tutorial], [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to do this in 3ds Max. Same method can be seen in the image below.<br />
# Subdivide the low-res mesh so it more closely matches the high-res mesh. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] has a [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa video tutorial] that shows how to do this in Maya.<br />
# Paint out the wavy line. Beware... this work will have to be re-done every time you re-bake the normal map. The [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
# Use a separate planar-projected mesh for the details that wrap around the barrel area, so the ray-casting is more even. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. For example to add tread around a tire, the tread can be baked from a tread model that is laid out flat, then that bake can layered onto the bake from the cylindrical tire mesh in a paint program.<br />
<br />
[[image:timothy_evison_normalmap_projections.jpg|frame|none|Adjusting the shape of the cage to remove distortion. <br>Image by [http://users.cybercity.dk/~dsl11905/resume/resume.html Timothy "tpe" Evison]]]<br />
<br />
<span id="TRI"></span><br />
<br />
=== Triangulating ===<br />
Before baking, it is usually best to triangulate the low-poly model, converting it from polygons into pure triangles. This prevents the vertex normals from being changed later on, which can create specular artifacts.<br />
<br />
[[image:triangulation_modo_ohare.jpg|frame|none| When quads are triangulated in [http://www.luxology.com/modo/ Modo], the internal edges are sometimes flipped, which causes shading differences.<br>Image by [http://www.farfarer.com/|James "Talon" O'Hare]]]<br />
<br />
<br />
Sometimes a baking tool or a mesh exporter/importer will re-triangulate the polygons. A quad polygon is actually treated as two triangles, and the internal edge between them is often switched diagonally during modeling operations. When the vertices of the quad are moved around in certain shapes, the software's algorithm for polygon models tries to keep the quad surface in a "rational" non-overlapping shape. It does this by switching the internal edge between its triangles.<br />
<br />
<br />
[[image:triangulation_spec_tychovii.jpg|frame|none| The specular highlight is affected by triangulation. Flip edges to fix skewing. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66651 Skewed Specular Highlight?] for pictures and more info.<br> Image by [http://robertkreps.com Robert "TychoVII" Kreps]]]<br />
<br />
<br />
<span id="WWC"></span><br />
<br />
=== Working with Cages ===<br />
''Cage'' has two meanings in the normal-mapping process: a low-poly base for [[subdivision surface modeling]] (usually called the [[DigitalSculpting#BM|basemesh]]), or a ray-casting mesh used for normal map baking. This section covers the ray-casting cage.<br />
<br />
Most normal map baking tools allow you to use a distance-based raycast. A ray is sent outwards along each vertex normal, then at the distance you set a ray is cast back inwards. Where ever that ray intersects the high poly mesh, it will sample the normals from it. <br />
<br />
{|class="wikitable"<br />
|[[Image:Normalmap_raycasting_1.jpg]] <br />
|[[Image:Normalmap_raycasting_2.jpg]]<br />
|-<br />
|Hard edges and a distance-based raycast (gray areas) cause ray misses (yellow) and ray overlaps (cyan).<br> Image by [http://www.mankua.com/ Diego Castaño]<br />
|The gray area shows that using all soft edges (or hard edges and a cage-based raycast) will avoid ray-casting errors from split normals.<br> Image by [http://www.mankua.com/ Diego Castaño] <br />
|}<br />
<br />
Unfortunately with a distance-based raycast, [[#SGAHE|split vertex normals]] will cause the bake to miss parts of the high-res mesh, causing errors and seams. <br />
<br />
Some software allows you to use ''cage mesh'' option instead, which basically inflates a copy of the low-poly mesh, then raycasts inwards from each vertex. This ballooned-out mesh is the cage.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
|<tablebgcolor="#ffaaaa">| <br />
|}<br />
<br />
In 3ds Max the cage controls both the distance and the direction of the raycasting. <br />
<br />
In Maya the cage only controls the distance; the ray direction matches the vertex normals (inverted).<br />
<br />
<span style="text-decoration: line-through"> This may have been fixed in the latest release...<<BR>><br />
In Xnormal the cage is split everywhere the model has [[#SGAHE|hard edges]], causing ray misses in the bake. You can fix the hard edge split problem but it involves an overly complex workflow. You must also repeat the whole process any time you change your mesh:</span><br />
# <s> Load the 3d viewer.</s><br />
# <s> Turn on the cage editing tools.</s><br />
# <s> Select all of the vertices.</s><br />
# <s> Weld all vertices.</s><br />
# <s> Expand the cage as you normally would.</s><br />
# <s> Save out your mesh using the Xnormal format.</s><br />
# <s> Make sure Xnormal is loading the correct mesh.</s><br />
<br />
<span id="P"></span><span id="Painting"></span><br />
<br />
== Painting ==<br />
Don't be afraid to edit normal maps in Photoshop. After all it is just a texture, so you can clone, blur, copy, blend all you want... as long as it looks good of course. Some understanding of [[#RGBChannels|the way colors work]] in normal maps will go a long way in helping you paint effectively.<br />
<br />
A normal map sampled from a high-poly mesh will nearly always be better than one sampled from a texture, since you're actually grabbing "proper" normals from an accurate, highly detailed surface. That means your normal map's pixels will basically be recreating the surface angles of your high-poly mesh, resulting in a very believable look.<br />
<br />
If you only convert an image into a normal-map, it can look very flat, and in some cases it can be completely wrong unless you're very careful about your value ranges. Most image conversion tools assume the input is a heightmap, where black is low and white is high. If you try to convert a diffuse texture that you've painted, the results are often very poor. Often the best results are obtained by baking the large and mid-level details from a high-poly mesh, and then combined with photo-sourced "fine detail" normals for surface details such as fabric weave, scratches and grain.<br />
<br />
Sometimes creating a high poly surface takes more time than your budget allows. For character or significant environment assets then that is the best route, but for less significant environment surfaces working from a heightmap-based texture will provide a good enough result for a much less commitment in time.<br />
<br />
* [http://crazybump.com/ CrazyBump] is a commercial normal map converter.<br />
* [http://www.renderingsystems.com/support/showthread.php?tid=3 ShaderMap] is a commercial normal map converter.<br />
* [http://www.pixplant.com/ PixPlant] is a commercial normal map converter.<br />
* [http://boards.polycount.net/showthread.php?t=68860 NJob] is a free normal map converter.<br />
* [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA normalmap filter for Photoshop] is a free normal map converter.<br />
* [http://xnormal.net Xnormal height-to-normals filter for Photoshop] is a free normal map converter.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm Normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
<br />
=== Flat Color ===<br />
The color (128,128,255) creates normals that are completely perpendicular to the polygon, as long as the vertex normals are also perpendicular. Remember a normal map's per-pixel normals create ''offsets'' from the vertex normals. If you want an area in the normal map to be flat, so it creates no offsets from the vertex normals, then use the color (128,128,255). <br />
<br />
This becomes especially obvious when [[#Mirroring|mirroring a normal map]] and using a shader with a reflection ingredient. Reflection tends to accentuate the angles between the normals, so any errors become much more apparent.<br />
<br />
[[image:normalmap_127seam.jpg|thumb|600px|none| Mirrored normal maps show a seam when (127,127,255) is used for the flat color; 128 is better.<br>Image by [http://www.ericchadwick.com Eric Chadwick]]]<br />
<br />
In a purely logical way, 127 seems like it would be the halfway point between 0 and 255. However 128 is the color that actually works in practice. When a test is done comparing (127,127,255) versus (128,128,255) it becomes obvious that 127 creates a slightly bent normal, and 128 creates a flat one.<br />
<br />
This is because most game pipelines use ''unsigned'' normal maps. For details see the Polycount forum thread [http://www.polycount.com/forum/showpost.php?p=771360&postcount=22 tutorial: fixing mirrored normal map seams].<br />
<br />
<span id="BNMT"></span><br />
<br />
=== Blending Normal Maps Together ===<br />
Blending normal maps together is a quick way to add high-frequency detail like wrinkles, cracks, and the like. Fine details can be painted as a height map, then it can be converted into a normal map using one of the normal map tools. Then this "details" normal map can be blended with a geometry-derived normal map using one of the methods below. <br />
<br />
Here is a comparison of four of the blending methods. Note that in these examples the default values were used for CrazyBump (Intensity 50, Strength 33, Strength 33), but the tool allows each layer's strength to be adjusted individually for stronger or milder results. Each of the normal maps below were [[#Renormalizing|re-normalized]] after blending.<br />
<br />
{|class="wikitable"<br />
|[[image:nrmlmap_blending_methods_Maps.png]]<br />
|[[image:nrmlmap_blending_methods_RTTNormalMapFX.png]]<br />
|-<br />
|The blended normal maps.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|Screenshot of the 3dsmax viewport, using the RTTNormalMap.fx shader.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|}<br />
<br />
The four blending methods used above:<br />
# [http://www.crazybump.com CrazyBump] by Ryan Clark blends normal maps together using calculations in 3D space rather than just in 2D. This does probably the best job at preserving details, and each layer's strength settings can be tweaked individually. <br />
# [http://www.rodgreen.com/?p=4 Combining Normal Maps in Photoshop] by Rod Green blends normal maps together using Linear Dodge mode for the positive values and Difference mode for the negative values, along with a Photoshop Action to simplify the process. It's free, but the results may be less accurate than CrazyBump.<br />
# [http://www.paultosca.com/makingofvarga.html Making of Varga] by [http://www.paultosca.com/ Paul "paultosca" Tosca] blends normal maps together using Overlay mode for the red and green channels and Multiply mode for the blue channel. This gives a slightly stronger bump than the Overlay-only method. [http://www.leocov.com/ Leo "chronic" Covarrubias] has a step-by-step tutorial for this method in [http://www.cgbootcamp.com/tutorials/2009/12/9/photoshop-combine-normal-maps.html CG Bootcamp Combine Normal Maps].<br />
# [[3DTutorials/Normal Map Deepening|Normal Map Deepening]] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to blend normal maps together using Overlay mode. [http://cgtextures.com/content.php?action=tutorial&name=normalmap CGTextures tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] also shows how to create normalmaps using multiple layers (Note: to work with the Overlay blend mode each layer's Output Level should be 128 instead of 255, you can use the Levels tool for this).<br />
<br />
The [http://boards.polycount.net/showthread.php?t=69615 Getting good height from Nvidia-filter normalizing grayscale height] thread on the Polycount forum has a discussion of different painting/blending options. Also see the [[#2DT|2D Tools]] section for painting and conversion tools.<br />
<br />
<span id="PCT"></span><br />
<br />
=== Pre-Created Templates ===<br />
A library of shapes can be developed and stored for later use, to save creation time for future normal maps. Things like screws, ports, pipes, and other doo-dads. These shapes can be stored as bitmaps with transparency so they can be layered into baked normal maps.<br />
<br />
* [http://www.beautifulrobot.com/?p=69 Creating & Using NormalMap "Widgets"] - by ''[http://www.beautifulrobot.com Steev "kobra" Kelly]''<<BR>> How to set up and render template objects.<br />
* [http://www.akramparvez.com/portfolio/scripts/normalmap-widget-for-3ds-max/ NormalMap Widget for 3ds Max] - by ''[http://www.akramparvez.com Akram Parvez]''<<BR>>A script to automate the setup and rendering process.<br />
* See the section [[#BT|Baking Transparency]] for more template-rendering tools and tutorials.<br />
<br />
<span id="RN"></span><span id="Renormalizing"></span><br />
=== Re-normalizing ===<br />
Re-normalizing means resetting the length of each normal in the map to 1.<br />
<br />
A normal mapping shader takes the three color channels of a normal map and combines them to create the direction and length of each pixel's normal. These normals are then used to apply the scene lighting to the mesh. However if you edit normal maps by hand or if you blend multiple normal maps together this can cause those lengths to change. Most shaders expect the length of the normals to always be 1 (normalized), but some are written to re-normalize the normal map dynamically (for example, 3ds Max's Hardware Shaders do re-normalize).<br />
<br />
If the normals in your normal map are not normalized, and your shader doesn't re-normalize them either, then you may see artifacts on the shaded surface... the specular highlight may speckle like crazy, the surface may get patches of odd shadowing, etc. To help you avoid this NVIDIA's normal map filter for Photoshop provides an easy way to re-normalize a map after editing; just use the '''Normalize Only''' option. [http://xnormal.net Xnormal] also comes with a Normalize filter for Photoshop.<br />
<br />
[[image:normalize_only.jpg|frame|none|The re-normalize option in the NVIDIA filter.<br>Image by [http://hirezstudios.com/ Scott Warren]]]<br />
<br />
Some shaders use [[#NormalMapCompression|compressed normal maps]]. Usually this means the blue channel is thrown away completely, so it's recalculated on-the-fly in the shader. However the shader has to re-normalize in order to recreate that data, so any custom normal lengths that were edited into the map will be ignored completely. <br />
<br />
<span id="AOIANM"></span><span id="AmbientOcclusionIntoANormalMap"></span><br />
<br />
=== Ambient Occlusion into a Normal Map ===<br />
If the shader doesn't re-normalize the normal map, an [[Ambient Occlusion Map]] can actually be baked into the normal map. This will shorten the normals in the crevices of the surface, causing the surface to receive less light there. This works with both diffuse and specular, or any other pass that uses the normal map, like reflection.<br />
<br />
However it's usually best to keep the AO as a separate map (or in an alpha channel) and multiply it against the ambient lighting only. This is usually done with a custom [[:Category:Shaders|shader]]. If you multiply it against the diffuse map or normal map then it also occludes diffuse lighting which can make the model look dirty. Ambient occlusion is best when it occludes ambient lighting only, for example a [[DiffuselyConvolvedCubeMap|diffusely convolved cubemap]].<br />
<br />
[[image:nrmlmap_ao.jpg|frame|none| AO can be baked into a normal map, shortening the normals (lower left model).<br>Model by [http://www.3dartisan.net/~kuman/ James Ku]]]<br />
<br />
To bake the AO into a normal map, adjust the levels of the AO layer first so the darks only go as low as 128 gray, then set the AO layer to Darken mode. This will shorten the normals in the normalmap, causing the surface to receive less light in the darker areas. <br />
<br />
This trick doesn't work with any shaders that re-normalize, like 3ds Max's Hardware Shaders. The shader must be altered to actually use the lengths of your custom normals; most shaders just assume all normals are 1 in length because this makes the shader code simpler. Also this trick will not work with most of the common [[#NormalMapCompression|normal map compression formats]], which often discard the blue channel and recalculate it in the shader, which requires re-normalization.<br />
<br />
<span id="BLE"></span><br />
<br />
=== Back Lighting Example ===<br />
You can customize normal maps for some interesting effects. If you invert the blue channel of a tangent-space map, the normals will be pointing to the opposite side of the surface, which can simulate backlighting.<br />
<br />
{|class="wikitable"<br />
|[[image:tree_front.jpg]]||[[image:tree_back.jpg]]<br />
|-<br />
|Tree simulating subsurface scattering (front view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|Tree simulating subsurface scattering (back view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|-<br />
|colspan="2"|[[image:tree_maps.jpg]]<br />
|-<br />
|colspan="2"|The maps used for the leaves. The 2nd diffuse was simply color-inverted, hue-shifted 180°, and saturated.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
The tree leaves use a shader than adds together two diffuse maps, one using a regular tangent-space normal map, the other using the same normal map but with the blue channel inverted. This causes the diffuse map using the regular normal map to only get lit on the side facing the light (front view), while the diffuse map using the inverted normal map only gets lit on the opposite side of the leaves (back view). The leaf geometry is 2-sided but uses the same shader on both sides, so the effect works no matter the lighting angle. As an added bonus, because the tree is self-shadowing the leaves in shadow do not receive direct lighting, which means their backsides do not show the inverted normal map, so the fake subsurface scatter effect only appears where the light directly hits the leaves. This wouldn't work for a whole forest because of the computational cost of self-shadowing and double normal maps, but could be useful for a single "star" asset, or if LODs switched the distant trees to a model that uses a cheaper shader.<br />
<br />
<span id="SAS"></span><br />
<br />
== Shaders and Seams ==<br />
You need to use the right kind of shader to avoid seeing seams where UV breaks occur. It must be written to use the same [[#TangentBasis|tangent basis]] that was used during baking. If the shader doesn't, the lighting will either be inconsistent across UV borders or it will show smoothing errors from the low-poly vertex normals.<br />
<br />
Xnormal generates accurate normals when displayed in Xnormal, and the SDK includes a method to write your own custom tangent space generator for the tool. <br />
<br />
<span id="3MS"></span><br />
=== 3ds Max Shaders ===<br />
The "Render To Texture" tool in 3ds Max 2011 and older generates [[#TSNM|tangent-space]] normal maps that render correctly in the offline renderer (scanline) but do not render correctly in the realtime viewport with the 3ds Max shaders. Max is using a different [[#TangentBasis|tangent basis]] for each. This is readily apparent when creating non-organic hard surface normalmaps; smoothing errors appear in the viewport that do not appear when rendered. <br />
<br />
The errors can be fixed by using "Render To Texture" to bake a [[#TSNM|tangent-space]] or [[#OSNM|object-space]] map, and using the free [http://www.3pointstudios.com/3pointshader_about.shtml "3Point Shader"] by Christoph '[[CrazyButcher]]' Kubisch and Per 'perna' Abrahamsen. The shader uses the same tangent basis as the baking tool, so it produces nearly flawless results. It also works with old bakes.<br />
<br />
You can get OK results in the Max viewport using a tangent-space map baked in Maya, loading it in a Standard material, and enabling "Show Hardware Map in Viewport". Another method is to use Render To Texture to bake an [[#OSNM|object-space]] map then use [[#CBS|Nspace]] to convert it into a tangent-space map then load that in a DirectX material and use the RTTNormalMap.fx shader. <br />
<br />
Autodesk is aware of these issues, and plans to address them in an upcoming release. See these links for more information:<br />
* Christoph "[[CrazyButcher]]" Kubisch and Per "perna" Abrahamsen designed a shader/modifier combination approach that fixes the viewport problem, see the Polycount forum post [http://boards.polycount.net/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max].<br />
* Jean-Francois "jfyelle" Yelle, Autodesk Media & Entertainment Technical Product Manager, has [http://boards.polycount.net/showthread.php?p=1115812#post1115812 this post]. <br />
* Ben Cloward posted [http://boards.polycount.net/showthread.php?p=1100270#post1100270 workarounds and FX code].<br />
* Christopher "cdiggins" Diggins, SDK writer for 3ds Max, shares some of the SDK code in his blog posts "[http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping How the 3ds Max Scanline Renderer Computes Tangent and Binormal Vectors for Normal Mapping]" and "[http://area.autodesk.com/blogs/chris/3ds_max_normal_map_baking_and_face_angle_weighting_the_plot_thickens 3ds Max Normal Map Baking and Face Angle Weighting: The Plot Thickens]".<br />
<br />
[[image:nmtest_uv-splits_thumb.jpg|thumb|600px|none|Comparison of map baking methods in Maya and Max, and Ben Cloward's custom FX code.<br>Image by [http://www.bencloward.com/ Ben Cloward] and [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
[[image:normalmapfix_3pointstudios_thumb.jpg|frame|none|3 Point Studios' normal map display fix for 3ds Max.<br>image by [http://www.3pointstudios.com 3 Point Studios]]]<br />
<br />
{|class="wikitable"<br />
|[[image:max2010_normalmap_workarounds.png|thumb|400px|none|]]<br />
|[[image:max2010_normalmap_compare.png|thumb|400px|none|]]<br />
|-<br />
|Viewport methods in 3ds Max 2010.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick] <br />
|More baking methods in 3ds Max 2010.<br> Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
<span id="3MENT"></span><br />
<br />
=== 3ds Max Edit Normals Trick ===<br />
After baking, if you add an Edit Normals modifier to your low-poly normalmapped model, this seems to "relax" the vertex normals for more accurate viewport shading. The modifier can be collapsed if desired.<br />
<br />
<span id="MS"></span><br />
=== Maya Shaders ===<br />
Maya seems to correctly generate normals to view in realtime, with the correct [[#TangentBasis|tangent basis]], with much less smoothing errors than 3ds Max. <br />
* [http://www.mentalwarp.com/~brice/shader.php BRDF shader] by [http://www.mentalwarp.com/~brice/ Brice Vandemoortele] and [http://www.kjapi.com/ Cedric Caillaud] (more info in [http://boards.polycount.net/showthread.php?t=49920 this Polycount thread]) '''Update:''' [http://boards.polycount.net/showthread.php?p=821862#post821862 New version here] with many updates, including object-space normal maps, relief mapping, self-shadowing, etc. Make sure you enable cgFX shaders in the Maya plugin manager, then you can create them in the same way you create a Lambert, Phong etc. Switch OFF high quality rendering in the viewports to see them correctly too.<br />
* If you want to use the software renderer, use mental ray instead of Maya's software renderer because mental ray correctly interprets tangent space normals. The Maya renderer treats the normal map as a grayscale bump map, giving nasty results. Mental ray supports Maya's Phong shader just fine (amongst others), although it won't recognise a gloss map plugged into the "cosine power" slot. The slider still works though, if you don't mind having a uniform value for gloss. Spec maps work fine though. Just use the same set up as you would for viewport rendering. You'll need to have your textures saved as TGAs or similar for mental ray to work though. - from [http://boards.polycount.net/member.php?u=14235 CheeseOnToast]<br />
<br />
<br />
<span id="NMC"></span><br />
<br />
== Normal Map Compression ==<br />
see; [[Normal Map Compression]]<br />
<br />
== Links ==<br />
<br />
=== Related Pages ===<br />
* [[Curvature map]]<br />
* [[DuDv map]]<br />
* [[Flow map]]<br />
* [[Normal map]]<br />
* [[Radiosity normal map]]<br />
* [[Vector displacement map]]<br />
<br />
<span id="3DT"></span> <span id="Tools"></span> <span id="3DTools"></span><br />
=== 3D Tools ===<br />
See [[:Category:Tools#A3D_Normal_Map_Software|Category:Tools#3D_Normal_Map_Software]]<br />
<br />
<span id="2DT"></span><span id="2DTools"></span><br />
=== 2D Tools ===<br />
See [[:Category:Tools#A2D_Normal_Map_Software|Category:Tools#2D_Normal_Map_Software]]<br />
<br />
<span id="T"></span><span id="Tutorials"></span><br />
=== Tutorials ===<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh tutorial for Max and Xnormal] by [http://www.exisinteractive.com/ PeterK] to prevent heavy distortions when baking with a cage, without the need to add extra supporting vertices.<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games] by [http://www.polycount.com/forum/member.php?u=56680 'SuperFranky']<br />
* [http://area.autodesk.com/userdata/fckdata/239955/The%20Generation%20and%20Display%20of%20Normal%20Maps%20in%203ds%20Max.pdf The Generation and Display of Normal Maps in 3ds Max] (500kb PDF) <<BR>> Excellent whitepaper from Autodesk about normal mapping in 3ds Max and other apps.<br />
* [http://www.katsbits.com/htm/tutorials/blender-baking-normal-maps-from-models.htm Renderbump and baking normal maps from high poly models using Blender 3D] by ''[http://www.katsbits.com/htm/about.htm "katsbits"]''<<BR>>Baking normal maps in Blender.<br />
* [http://udn.epicgames.com/Three/CreatingNormalMaps.html Techniques for Creating Normal Maps] in the Unreal Developer Network's [http://udn.epicgames.com/Three/WebHome.html Unreal Engine 3 section] contains advice from [http://www.epicgames.com/ Epic Games] artists on creating normal maps for UE3. The [http://udn.epicgames.com/Three/DesignWorkflow.html#Creating%20normal%20maps%20from%20meshes Design Workflow page] has a summary.<br />
* [http://www.iddevnet.com/quake4/ArtReference_CreatingModels#head-3400c230e92ff7d57424b2a68f6e0ea75dee4afa Creating Models in Quake 4] by [http://www.ravensoft.com/ Raven Software] is a comprehensive guide to creating Quake 4 characters.<br />
* [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing and UVs can affect normal maps in Doom 3.<br />
* [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] is an overview of modeling for normal maps.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses how smoothing groups and bevels affect the topology of the low-poly model.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in-game, not the triangle or poly count.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm Normal map workflow] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] demonstrates his normal mapping workflow in 3ds Max and Photoshop.<br />
* [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa This video tutorial] by [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] shows in Maya how to subdivide the low-poly mesh so it more closely matches the high-poly mesh, to help solve wavy lines in the bake.<br />
* [http://www.bencloward.com/tutorials_normal_maps1.shtml Normal Mapping Tutorial] by [http://www.bencloward.com/ Ben Cloward] is a comprehensive tutorial about the entire normal map creation process.<br />
* [http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy] shows how to use a special lighting setup to render normal maps (instead of baking them).<br />
* [http://cgtextures.com/content.php?action=tutorial&name=normalmap Tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] shows how to create deep normal maps using multiple layers. Note: to use Overlay blend mode properly, make sure to change each layer's Levels ''Output Level'' to 128 instead of 255.<br />
* [http://www.poopinmymouth.com/process/tips/normalmap_deepening.jpg Normalmap Deepening] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to adjust normal maps, and how to layer together painted and baked normal maps.<br />
* [http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] helps to solve seams along horizontal or vertical UV edges, but not across angled UVs.<br />
* [http://planetpixelemporium.com/tutorialpages/normal.html Cinema 4D and Normal Maps For Games] by [http://planetpixelemporium.com/index.php James Hastings-Trew] describes normal maps in plain language, with tips on creating them in Cinema 4D.<br />
* [http://forums.cgsociety.org/showthread.php?f=39&t=359082 3ds Max normal mapping overview] by [http://www.alan-noon.com/ Alan Noon] is a great thread on CGTalk about the normal mapping process.<br />
* [http://forums.cgsociety.org/showthread.php?f=46&t=373024 Hard Surface Texture Painting] by [http://stefan-morrell.cgsociety.org/gallery/ Stefan Morrell] is a good introduction to painting textures for metal surfaces.<br />
<br />
<span id="D"></span><span id="Discussion"></span><br />
<br />
=== Discussion ===<br />
[http://boards.polycount.net/showthread.php?p=820218 Discuss this page on the Polycount forums]. Suggestions welcome.<br />
<br />
Even though only one person has been editing this page so far, the information here was gathered from many different sources. We wish to thank all the contributors for their hard-earned knowledge. It is much appreciated!<br />
<br />
----<br />
[[Category:TextureTypes]] [[Category:Bump map]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Normal_mapNormal map2015-04-22T15:46:33Z<p>Dustinbrown: /* Common Swizzle Coordinates */</p>
<hr />
<div>== Out of Date ==<br />
The information on this page is a bit old, it needs to be updated. See these links for more current information:<br />
<br />
* [http://farfarer.com/resources.htm RNM Normal Map Combiner], by [http://www.farfarer.com/ James "Farfarer" O'Hare]<br />
* [http://vincentcallebaut.com/CombineNormal.html Combine Normal], by [http://vincentcallebaut.comVincent "Vincentt" Callebaut], [http://www.polycount.com/forum/showthread.php?t=131819 Combine normal maps script for Photoshop] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showpost.php?p=2226864&postcount=51 Earthquake on separating smoothing groups in the UV]<br />
* [http://www.polycount.com/forum/showpost.php?p=2225535&postcount=40 JedTheKrampus on offsetting Mirrored UVs]<br />
* [http://www.polycount.com/forum/showthread.php?t=148303 Of Bit Depths, Banding and Normal Maps]<br />
* [http://www.polycount.com/forum/showthread.php?t=147227 Skew you buddy! Making sense of skewed normal map details.]<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games]<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh Tutorial]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?]<br />
* [http://www.laurenscorijn.com/future-xoliulshader-support.html Future Xoliulshader support] = why Xoliulshader doesn't work properly in 3ds Max 2013/2014.<br />
<br />
== Synched Workflow ==<br />
To eliminate seams and shading artifacts, the model renderer and the normal map baking tool should use the same tangent basis.<br />
<br />
FBX model format can store tangents, and some renderers use this data to synch the incoming normal maps.<br />
<br />
{| class="wikitable sortable" style="color:grey;"<br />
|- <br />
! Renderer !! Normal map baker<br />
|-<br />
| 3ds Max || 3ds Max, Handplane, ?<br />
|-<br />
| Blender || ?<br />
|-<br />
| Creation Engine || Handplane, ?<br />
|-<br />
| CryEngine || ?<br />
|-<br />
| Knald || ?<br />
|-<br />
| Marmoset Toolbag || 3ds Max, Maya, Xnormal, ?<br />
|-<br />
| Maya || Handplane, Maya, ?<br />
|-<br />
| Source || Handplane, Maya ([http://www.polycount.com/forum/showpost.php?p=2224653&postcount=28]), ?<br />
|-<br />
| Starcraft II || Handplane, ?<br />
|-<br />
| Substance Designer || ?<br />
|-<br />
| Unity([http://www.polycount.com/forum/showpost.php?p=2224781&postcount=29], [http://www.polycount.com/forum/showthread.php?p=2194353#post2194353]) || Handplane, Xnormal (via Asset Store), ?<br />
|-<br />
| Unreal Engine 4 || Handplane, Xnormal([http://www.polycount.com/forum/showpost.php?p=2224402&postcount=20]), ? <br />
|-<br />
| Xnormal || Xnormal, ?<br />
|}<br />
<br />
----<br />
<br />
== What is a Normal Map? ==<br />
A Normal Map is usually used to fake high-res geometry detail when it's mapped onto a low-res mesh. The pixels of the normal map each store a ''normal'', a vector that describes the surface slope of the original high-res mesh at that point. The red, green, and blue channels of the normal map are used to control the direction of each pixel's normal. <br />
<br />
When a normal map is applied to a low-poly mesh, the texture pixels control the direction each of the pixels on the low-poly mesh will be facing in 3D space, creating the illusion of more surface detail or better curvature. However, the silhouette of the model doesn't change. <br />
<br />
<gallery mode="packed"><br />
Whatif_normalmap_mapped2.jpg|A model with a normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_low.jpg|The model without its normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_high.jpg|The high-resolution model used to create the normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
</gallery><br />
<br />
==Tangent-Space vs. Object-Space==<br />
<br />
Normal maps can be made in either of two basic flavors: tangent-space or object-space. World-space is basically the same as object-space, except it requires the model to remain in its original orientation, neither rotating nor deforming, so it's almost never used.<br />
<br />
===Tangent-space normal map===<br />
[[image:normalmap_tangentspace.jpg|frame|none|A tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Predominantly-blue colors. Object can rotate and deform. Good for deforming meshes, like characters, animals, flags, etc.<br />
<br />
Pros:<br />
* Maps can be reused easily, like on differently-shaped meshes.<br />
* Maps can be tiled and mirrored easily, though some games might not support mirroring very well.<br />
* Easier to overlay painted details.<br />
* Easier to use image compression.<br />
<br />
Cons:<br />
* More difficult to avoid smoothing problems from the low-poly vertex normals (see Smoothing Groups and Hard Edges).<br />
* Slightly slower performance than an object-space map (but not by much).<br />
<br />
===Object-space normal map===<br />
[[image:normalmap_worldspace.jpg|frame|none|An object-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Rainbow colors. Objects can rotate, but usually shouldn't be deformed, unless the shader has been modified to support deformation. Object-space is also called local-space or model-space. <br />
<br />
Pros:<br />
* Easier to generate high-quality curvature because it completely ignores the crude smoothing of the low-poly vertex normals.<br />
* Slightly better performance than a tangent-space map (but not by much).<br />
<br />
Cons:<br />
* Can't easily reuse maps, different mesh shapes require unique maps.<br />
* Difficult to tile properly, and mirroring requires specific shader support.<br />
* Harder to overlay painted details because the base colors vary across the surface of the mesh. Painted details must be converted into Object Space to be combined properly with the OS map.<br />
* They don't compress very well, since the blue channel can't be recreated in the shader like with tangent-space maps. Also the three color channels contain very different data which doesn't compress well, creating many artifacts. Using a half-resolution object-space map is one option. <br />
<br />
<br clear="all"/><br />
<br />
=== Converting Between Spaces ===<br />
Normal maps can be converted between object space and tangent space, in order to use them with different blending tools and shaders, which require one type or the other. <br />
<br />
Object space maps can also be converted to maps with different tangent bases, to better match the normal maps with the renderer and thus avoid lighting errors.<br />
<br />
* [http://www.handplane3d.com Handplane] by [http://www.alecmoody.com/ Alec Moody] is a tool that converts object space maps into a variety of tangent spaces: 3ds Max, Creation Engine, Maya, Source, Unity, Unreal, etc. See the Polycount Forum thread [http://www.polycount.com/forum/showthread.php?t=116899 Official handplane support thread - Now freeware!!].<br />
<br />
[[File:handplane_illus_1.jpg|frame|none|Handplane interface. <br>Image by [http://www.alecmoody.com/ Alec Moody].]]<br />
<br />
<br />
* [http://boards.polycount.net/showthread.php?p=1072599#post1072599 NSpace] by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] is a tool that converts an object-space normal map into a tangent-space map, which then works seamlessly in the 3ds Max viewport. He converts the map by using the same tangent basis that 3ds Max uses for its hardware shader. To see the results, load the converted map via the ''Normal Bump'' map and enable "Show Hardware Map in Viewport". [http://gameartist.nl/ Osman "osman" Tsjardiwal] created a GUI for NSpace, you can [http://boards.polycount.net/showthread.php?p=1075143#post1075143 download it here], just put it in the same folder as the NSpace exe and run it. <br />
<br />
[[File:NSpace_Gui_osman.png|frame|none|NSpace interface. <br>Image by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] and [http://gameartist.nl Osman "osman" Tsjardiwal].]]<br />
<br />
[http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson] said: "[8Monkey Labs has] a tool that lets you load up your reference mesh and object space map. Then load up your tangent normals, and adjust some sliders for things like tile and amount. We need to load up a mesh to know how to correctly orient the tangent normals or else things will come out upside down or reverse etc. It mostly works, but it tends to "bend" the resulting normals, so you gotta split the mesh up into some smoothing groups before you run it, and then I usually will just composite this "combo" texture over my orig map in Photoshop."<br />
<br />
<span id="RGBC"></span><span id="RGBChannels"></span><br />
<br />
== RGB Channels ==<br />
Shaders can use different techniques to render tangent-space normal maps, but the normal map directions are usually consistent within a game. Usually the red channel of a tangent-space normal map stores the X axis (pointing the normals predominantly leftwards or rightwards), the green channel stores the Y axis (pointing the normals predominantly upwards or downwards), and the blue channel stores the Z axis (pointing the normals outwards away from the surface).<br />
<br />
[[image:tangentspace_rgb.jpg|frame|none|The red, green, and blue channels of a tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you see lighting coming from the wrong angle when you're looking at your normal-mapped model, and the model is using a tangent-space normal map, the normal map shader might be expecting the red or green channel (or both) to point in the opposite direction. To fix this either change the shader, or simply invert the appropriate color channels in an image editor, so that the black pixels become white and the white pixels become black.<br />
<br />
Some shaders expect the color channels to be swapped or re-arranged to work with a particular [[#NormalMapCompression|compression format]]. For example the DXT5_nm format usually expects the X axis to be in the alpha channel, the Y axis to be in the green channel, and the red and blue channels to be empty.<br />
<br />
== Tangent Basis ==<br />
[[#TangentSpaceVsObjectSpace|Tangent-space]] normal maps use a special kind of vertex data called the ''tangent basis''. This is similar to UV coordinates except it provides directionality across the surface, it forms a surface-relative coordinate system for the per-pixel normals stored in the normal map. This coordinate system is required to light a normal mapped surface.<br />
<br />
Each vertex in the tangent basis is a combination of three things: the mesh vertex's normal (influenced by smoothing), the vertex's tangent (usually derived from the V texture coordinate), and the vertex's bitangent (derived in code, also called the binormal). These three vectors create an axis for each vertex, giving it a specific orientation in the tangent space. These axes are used to properly transform the incoming lighting from world space into tangent space, so your normal-mapped model will be lit correctly.<br />
<br />
Light rays are in world space, but the normals stored in the normal map are in tangent space. When the model is being rendered, the light rays must be converted from world space into tangent space, using the tangent basis to get there. At that point the incoming light rays are compared against the directions of the normals in the normal map, and this determines how much each pixel is going to be lit. Alternatively, instead of converting the light rays some shaders will convert the normals in the normal map from tangent space into world space. Then those world-space normals are compared against the light rays, and the model is lit appropriately. The method depends on who wrote the shader, but the end result is the same. Both methods require a tangent basis to transform the lighting.<br />
<br />
When a triangle's vertex normals are pointing straight out, and a pixel in the normal map is neutral blue (128,128,255) this means the pixel's normal will be pointing straight out from the surface of the low-poly mesh. When that pixel normal is tilted towards the left or the right in the tangent coordinate space, it will get either more or less red color, depending on whether the normal map is set to store the X axis as either a positive or a negative value. Same goes for when the normal is tilted up or down in tangent space, it will either get more or less green color. If the vertex normals aren't exactly perpendicular to the triangle, the normal map pixels will be tinted away from neutral blue as well.<br />
<br />
Unfortunately for artists, there are many different ways to calculate the tangent basis: [http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping 3ds Max], [http://download.autodesk.com/us/maya/2011help/index.html?url=./files/Appendix_A_Tangent_and_binormal_vectors.htm,topicNumber=d0e227193 Maya], [http://www.codesampler.com/dx9src/dx9src_4.htm#dx9_dot3_bump_mapping DirectX 9], [http://developer.nvidia.com/object/NVMeshMender.html NVMeshMender], [http://www.terathon.com/code/tangent.html Eric Lengyel], a custom solution, etc. This means a normal map baked in one application probably won't shade correctly in another. Artists must do some testing with different [[#T|baking tools]] to find which works best with their output. When the renderer (or game engine) renders your game model, [[#ShadersAndSeams|the shader]] must use the same tangent basis as the normal map baker, otherwise you'll get incorrect lighting, especially across the seams between UV shells.<br />
<br />
The [http://www.xnormal.net/ xNormal] SDK supports custom tangent basis methods. When a programmer uses it to implement their renderer's own tangent basis, artists can then use Xnormal to bake normal maps that will match their renderer perfectly.<br />
<br />
[[image:tangentseams.jpg|frame|none|When shared edges are at different angles in UV space, different colors will show up<br />
along the seam. The tangent basis uses these colors to light the model properly. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
When you look at a tangent-space normal map for a character, you typically see different colors along the UV seams. This is because the UV shells are often oriented at different angles on the mesh, a necessary evil when translating the 3D mesh into 2D textures. The body might be mapped with a vertical shell, and the arm mapped with a horizontal one. This requires the normals in the normal map to be twisted for the different orientations of those UV shells. The UVs are twisted, so the normals must be twisted in order to compensate. The tangent basis helps reorient (twist) the lighting as it comes into the surface's local space, so the lighting will then look uniform across the normal mapped mesh.<br />
<br />
When an artist tiles a tangent-space normal map across an arbitrary mesh, like a landscape, this tends to shade correctly because the mesh has a uniform direction in tangent space. If the mesh has discontinuous UV coordinates (UV seams), or the normal map has large directional gradients across it, the tangent space won't be uniform anymore so the surface will probably have shading seams.<br />
<br />
== Common Swizzle Coordinates ==<br />
3D Software capable of displaying normal maps will have a native required direction, or "handedness" for the RGB channels in a normal map, sometimes referred to as "Swizzle Coordinates," though [[#SAS|shaders]] can often be written to override this native handedness. You may hear developers refer to "flipping the green channel" in order to get a normal map to display correctly, and this simply indicates that when the normal map was baked, it was authored with the incorrect handedness in the green channel. Left/Down handedness is indicated with a negative (-), and right/up handedness is demarcated with a (+) positive.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
| '''Software''' <br />
| '''Red''' <br />
| '''Green''' <br />
| '''Blue''' <br />
|-<br />
|<#000000>| 3ds Max<br />
| X+<br />
| Y-<br />
| Z+ <br />
|-<br />
|<#000000>| Maya<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| [http://wiki.blender.org/index.php/Doc:2.6/Manual/Textures/Influence/Material/Bump_and_Normal Blender]<br />
| X+<br />
| Y+<br />
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|<#000000>| [https://docs.unrealengine.com/latest/INT/Engine/Content/Types/Textures/Properties/index.html Unreal Engine]<br />
| X+ <br />
| Y-<br />
| Z+<br />
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|<#000000>| [http://docs.cryengine.com/display/SDKDOC2/Normal+Maps CryENGINE]<br />
| X+<br />
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|-<br />
|<#000000>| [http://docs.unity3d.com/Manual/HOWTO-bumpmap.html Unity]<br />
| X+<br />
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|-<br />
|<#000000>| [https://developer.valvesoftware.com/wiki/Bump_map Source]<br />
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|-<br />
|<#000000>| Toolbag<br />
| X+<br />
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<span id="MTLPM"></span><br />
<br />
== Modeling the Low-Poly Mesh ==<br />
The in-game mesh usually needs to be carefully optimized to create a good silhouette, define edge-loops for better deformation, and minimize extreme changes between the vertex normals for better shading (see [[#SmoothingGroupsAndHardEdges|Smoothing Groups & Hard Edges]]).<br />
<br />
In order to create an optimized in-game mesh including a good silhouette and loops for deforming in animation, you can start with the 2nd subdivision level of your [[DigitalSculpting|digital sculpt]], or in some cases with the base mesh itself. Then you can just collapse edge loops or cut in new edges to add/remove detail as necessary. Or you can [[DigitalSculpting#OART|re-toplogize]] from scratch if that works better for you.<br />
<br />
See [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts] on the Polycount forum.<br />
<br />
<span id="UVC"></span><span id="UVCoordinates"></span><br />
=== UV Coordinates ===<br />
Normal map baking tools only capture normals within the 0-1 UV square, any UV bits outside this area are ignored. <br />
<br />
Only one copy of the forward-facing UVs should remain in the 0-1 UV square at baking time. If the mesh uses overlapping UVs, this will likely cause artifacts to appear in the baked map, since the baker will try render each UV shell into the map. Before baking, it's best to move all the overlaps and mirrored bits outside the 0-1 square. <br />
<br />
[[image:Normalmap_uvcoord_offset.jpg|frame|none|The mirrored UVs (in red) are offset 1 unit before baking. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you move all the overlaps and mirrored bits exactly 1 UV unit (any whole number will do), then you can leave them there after the bake and they will still be mapped correctly. You can move them back if you want, it doesn't matter to most game engines. Be aware that ZBrush does use UV offsets to manage mesh visibility, however this usually doesn't matter because the ZBrush cage mesh is often a different mesh than the in-game mesh used for baking.<br />
<br />
You should avoid changing the UVs after baking the normal map, because rotating or mirroring UVs after baking will cause the normal map not to match the [[#TB|tangent basis]] anymore, which will likely cause lighting problems. <br />
<br />
In 3ds Max, W is a third texture coordinate. It's used for 3D procedural textures and for storing vertex color in UV channels (you need 3 axes for RGB, so UVW can store vertex color). Bake problems can be avoided by moving any overlapping UVs to -1 on the W axis, with the same results as moving them 1 unit on the U or V axes. The tool Render To Texture will always bake whatever UVs are the highest along the W axis. However using W can be messy... it's generally hidden unless you purposefully look for it (bad for team work), doesn't get preserved on export to other apps, and high W values can prevent selecting and/or welding UVs. <br />
<br />
<span id="M"></span><span id="Mirroring"></span><br />
<br />
=== Mirroring ===<br />
Normal maps can be mirrored across a model to create symmetrical details, and save UV space, which allows more detail in the normal map since the texture pixels are smaller on the model. <br />
<br />
With [[#OSNM|object-space]] maps, mirroring requires [http://boards.polycount.net/showthread.php?t=53986 specific shader support]. For [[#TSNM|tangent-space]] maps, mirroring typically creates a shading seam, but this can be reduced or hidden altogether, depending on the method used.<br />
<br />
<span id="TMW"></span><br />
==== Typical Mirroring Workflow ====<br />
# Delete the mesh half that will be mirrored. <br />
# Arrange the UVs for the remaining model, filling the UV square.<br />
# Mirror the model to create a "whole" mesh, welding the mesh vertices along the seam. <br />
# Move the mirrored UVs exactly 1 unit (or any whole number) out of the 0-1 UV square.<br />
# Bake the normal map.<br />
<br />
Sometimes an artist will decide to delete half of a symmetrical model before baking. <br />
<br />
This is a mistake however because often the vertex normals along the hole will bend towards the hole a bit; there are no faces on the other side to average the normals with. This will create a strong lighting seam in the normal map. <br />
<br />
It's typically best to use the complete mirrored model to bake the normal map, not just the unique half. <br />
<br />
To prevent the mirrored UVs from causing overlaps or baking errors, move the mirrored [[#UVC|UVs]] out of the 0-1 UV space, so only one copy of the non-mirrored UVs is left within the 0-1 square.<br />
<br />
To avoid texel "leaks" between the UV shells, make sure there's enough [[#Edge_padding|Edge Padding]] around each shell, including along the edges of the normal map. None of the UV shells should be touching the edge of the 0-1 UV square, unless they're meant to tile with the other side of the map.<br />
<br />
<span id="CM"></span><br />
<br />
==== Center Mirroring ====<br />
If the mirror seam runs along the surface of a continuous mesh, like down the center of a human face for example, then it will probably create a lighting seam. <br />
<br />
In Epic Games' [http://www.unrealtechnology.com/technology.php Unreal Engine 3] (UE3) their symmetrical models commonly use centered mirroring. Epic uses materials that mix a [[DetailMap]] with the normal maps; these seem to scatter the diffuse/specular lighting and help minimize the obviousness of the mirror seams. For their [[Light Map]]ped models they use [http://udn.epicgames.com/Three/LightMapUnwrapping.html a technique] that can almost completely hide the mirror seam.<br />
<br />
[[image:Epic_MirroringCicada.jpg|frame|none| In UE3 a center mirror seam is reduced by using a detail normal map. <br> Image by "[http://epicgames.com Epic Games]"]]<br />
<br />
'''''[http://www.zbrushcentral.com/showpost.php?p=573108&postcount=28 GOW2 normal map seams], [http://utforums.epicgames.com/showthread.php?p=27166791#post27166791 UDK normal map seams]'''''<br />
<br />
<span id="OM"></span><br />
<br />
==== Offset Mirroring ====<br />
Offset mirroring is a method where you move the mirror seam off to one side of the model, so the seam doesn't run exactly down the center. For example with a character's head, the UV seam can go down along the side of the head in front of the ear. The UV shell for the nearest ear can then be mirrored to use the area on the other side of the head. <br />
<br />
This avoids the "Rorschach" effect and allows non-symmetrical details, but it still saves texture space because the two sides of the head can be mirrored (they're never seen at the same time anyhow).<br />
<br />
Offset mirroring doesn't get rid of the seam, but it does move it off to a place where it can either be less obvious, or where it can be hidden in a natural seam on the model.<br />
<br />
<span id="FCM"></span><br />
==== Flat Color Mirroring ====<br />
[http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] solves seams by painting a flat set of normals along the seam, using neutral blue (128,128,255). However it only works along horizontal or vertical UV seams, not across any angled UVs. It also removes any details along the mirror seam, creating blank areas. <br />
<br />
<span id="EM"></span><br />
==== Element Mirroring ====<br />
The mirror seam can be avoided completely when it doesn't run directly through any mesh. For example if there's a detached mesh element that runs down the center of the model, this can be uniquely mapped, while the meshes on either side can be mirrors of each other. Whenever the mirrored parts don't share any vertex normals with the non-mirrored parts, there won't be any seams. <br />
<br />
[[image:normalmap_mirrored-binocs-racer445.jpg|frame|none|The middle part (highlighted in red) uses unique non-mirrored UVs, allowing the mesh on the right to be mirrored without any seams. <br>Image by [http://http://racer445.com/ "racer445"]]]<br />
<br />
<span id="SGAHE"></span><br />
<br />
=== Smoothing Groups & Hard Edges ===<br />
Each vertex in a mesh has at least one vertex normal. Vertex normals are used to control the direction a triangle will be lit from; if the normal is facing the light the triangle will be fully lit, if facing away from the light the triangle won't be lit. <br />
<br />
Each vertex however can have more than one vertex normal. When two triangles have different vertex normals along their shared edge, this creates a shading seam, called a ''hard edge'' in most modeling tools. 3ds Max uses ''Smoothing Groups'' to create hard/soft edges, Maya uses ''Harden Edge'' and ''Soften Edge''. These tools create hard and soft edges by splitting and combining the vertex normals.<br />
<br />
[[image:BenMathis_SmoothingGroups_Excerpt.gif|frame|none|Hard edges occur where the vertices have multiple normals. <br>Image by [http://poopinmymouth.com Ben 'poopinmymouth' Mathis] ([http://poopinmymouth.com/process/tips/smoothing_groups.jpg tutorial here])]]<br />
<br />
When a mesh uses all soft normals (a single smoothing group) the lighting has to be interpolated across the extreme differences between the vertex normals. If your renderer doesn't support the same [[#TangentBasis|tangent basis]] that the baker uses, this can produce extreme shading differences across the model, which creates shading artifacts. It is generally best to reduce these extremes when you can because a mismatched renderer can only do so much to counteract it.<br />
<br />
Hard edges are usually best where the model already has a natural seam. For example, you can add a hard edge along the rim of a car's wheel well, to prevent the inside of the wheel well from distorting the shading for the outside of the car body. Mechanical models usually need hard edges where ever the surface bends more than about 45 degrees. <br />
<br />
For most meshes, the best results usually come from adding hard edges where ever there are UV seams. There are no hard rules however, you must experiment with different approaches to find what works best in your game.<br />
<br />
When you use object-space normal maps the vertex normal problem goes away since you're no longer relying on the crude vertex normals of the mesh. An object-space normal map completely ignores vertex normals. Object-space mapping allows you to use all soft edges and no bevels on the low-res mesh, without showing lighting errors.<br />
<br />
<span id="HEDAT"></span><br />
==== Hard Edge Discussions & Tutorials ====<br />
* [http://www.polycount.com/forum/showthread.php?p=2090450#post2090450 Maya MEL Script help needed (UV border edges)]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=73593 Normal Maps: Can Somone Explain This "Black Edge" issue]<br />
* [http://www.polycount.com/forum/showthread.php?t=73566 Normal Maps: Can someone explain normals, tangents and split UVs?]<br />
* [http://www.polycount.com/forum/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max]<br />
* [http://boards.polycount.net/showthread.php?t=68173 Why you should NOT trust 3ds Max's viewport normal-map display!]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/10503-xsi-normal-mapped-cube-looks-bad.html XSI - normal mapped cube looks bad]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/11924-weird-maya-normal-map-seam-artifact-problem-am-i-making-simple-mistake.html Weird Maya normal map seam/artifact problem]<br />
* [http://boards.polycount.net/showthread.php?p=1080600 Seams in Normals when Creating Tiling Environment Trims and other Tiles]<br />
* The tutorial [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing can affect the normal map.<br />
* The tutorial: [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] shows how smoothing affects raycasting.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses the breaking of normals and smoothing groups in general terms.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in the game, not the triangle count.<br />
* The Crysis documentation [http://doc.crymod.com/AssetCreation/PolyBumpReference.html PolyBump Reference] has a section towards the bottom that shows how smoothing affects their baked normal maps.<br />
* The polycount thread [http://boards.polycount.net/showthread.php?t=60694 Toying around with normal map approaches] has a great discussion of how best to use smoothing groups and bevels for better shading.<br />
<br />
<span id="UB"></span><br />
==== Using Bevels ====<br />
Bevels/chamfers generally improve the silhouette of the model, and can also help reflect specular highlights better. <br />
<br />
However bevels tend to produce long thin triangles, which slow down the in-game rendering of your model. Real-time renderers have trouble rendering long thin triangles because they create a lot of sub-pixel areas to render. <br />
<br />
Bevels also balloon the vertex count, which can increase the transform cost and memory usage. Hard edges increase the vertex count too, but not when the edge also shares a seam in UV space. For a good explanation of the vertex count issue, see [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly].<br />
<br />
Using hard edges with matching UV shells tends to give better performance and better cosmetic results than using bevels. However there are differing opinions on this, see the Polycount thread "[http://boards.polycount.net/showthread.php?t=71760 Maya transfer maps help]".<br />
<br />
<span id="EVN"></span><br />
==== Edited Vertex Normals ====<br />
If you use bevels the shading will be improved by editing the vertex normals so the larger flat surfaces have perpendicular normals. The vertex normals are then forced to blend across the smaller bevel faces, instead of across the larger faces. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66139 Superspecular soft edges tutorial chapter 1].<br />
<br />
[[image:oliverio_bevel_normals.gif|frame|none|Bending normals on bevelled models. <br>From the tutorial [http://deadlineproof.com/model-shading-techniques-soft-edge-superspecular/ Shading techniques Superspecular soft edges]<br>Image by [http://deadlineproof.com/ Paolo Oliverio]]]<br />
<br />
== Level of Detail Models ==<br />
See [http://www.polycount.com/forum/showthread.php?p=1216945#post1216945 Problem if you're using 3point-style normals with an LOD].<br />
<br />
<span id="MTHPM"></span><br />
<br />
== Modeling The High-Poly Mesh ==<br />
[[Subdivision Surface Modeling]] and [[DigitalSculpting]] are the techniques most often used for modeling a normal map. <br />
<br />
Some artists prefer to model the in-game mesh first, other artists prefer to model the high-res mesh first, and others start somewhere in the middle. The modeling order is ultimately a personal choice though, all three methods can produce excellent results:<br />
* Build the in-game model, then up-res it and sculpt it.<br />
* Build and sculpt a high resolution model, then build a new in-game model around that.<br />
* Build a basemesh model, up-res and sculpt it, then step down a few levels of detail and use that as a base for building a better in-game mesh.<br />
If the in-game mesh is started from one of the subdivision levels of the basemesh sculpt, various edge loops can be collapsed or new edges can be cut to add/remove detail as necessary.<br />
<br />
<span id="SE"></span><br />
=== Sloped Extrusions ===<br />
[[image:normal_slopes_hatred.jpg|frame|none|Extrusions on the high-poly model should be sloped to make a better normal map. <br>Image by [http://www.hatred.gameartisans.org/ Krzysztof "Hatred" Dolas].]]<br />
<br />
=== Floating Geometry ===<br />
[[image:FloatingGeo.jpg|frame|none|Normal map stores the direction the surface is facing rather than real depth information, thus allowing to save time using floating geometry. <br>To correctly bake AO with floating geo make it a separate object and turn off it's shadow casting. <br>Image by [http://artisaverb.info/ Andrew "d1ver" Maximov].]]<br />
<br />
See also [[3DTutorials/Modeling High-Low Poly Models for Next Gen Games|Modeling High/Low Poly Models for Next Gen Games]] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa]<br />
<br />
<span id="ET"></span><br />
<br />
=== Edge Thickness ===<br />
[[image:normal_edge_thickness.jpg|frame|none|When creating edges of the Highpoly, sometimes you'll need to make them rounded than in real life to <br>work better at the size they will be seen.<br>Image by [http://racer445.com/Evan "racer445" Herbert]]]<br />
<br />
<span id="MRF"></span><span id="MRRCB"></span><br />
<br />
=== mental ray Round Corners Bump ===<br />
The mental ray renderer offers an automatic bevel rendering effect called Round Corners Bump that can be baked into a normal map. This is available in 3ds Max, Maya, and XSI. See [http://boards.polycount.net/showthread.php?t=71995 Zero Effort Beveling for normal maps] - by [http://boards.polycount.net/member.php?u=31662 Robert "r_fletch_r" Fletcher].<br />
<br />
[http://jeffpatton.net/ Jeff Patton] posted about [http://jeffpatton.cgsociety.org/blog/archive/2007/10/ how to expose Round Corners Bump] in 3ds Max so you can use it in other materials.<br />
<br />
[http://cryrid.com/art/ Michael "cryrid" Taylor] posted a tutorial about how to use [http://cryrid.com/images/temp/XSI/zeroeffort_bevels.jpg Round Corners in XSI].<br />
<br />
XSI is able to bake a good normal map with it, but 3ds Max seems to bake it incorrectly, and Maya isn't able to bake the effect at all. Maybe Max might be able to bake it correctly, if the .mi shader is edited to use the correct coordinate space?<br />
<br />
<span id="Baking"></span><span id="B"></span><br />
== Baking ==<br />
The process of transferring normals from the high-res model to the in-game model is often called baking. The baking tool usually starts projecting a certain numerical distance out from the low-poly mesh, and sends rays inwards towards the high-poly mesh. When a ray intersects the high-poly mesh, it records the mesh's surface normal and saves it in the normal map.<br />
<br />
To get an understanding of how all the options affect your normal map, do some test bakes on simple meshes like boxes. They generate quickly so you can experiment with [[#UVCoordinates|UV mirroring]], [[#SGAHE|smoothing groups]], etc. This helps you learn the settings that really matter.<br />
* The tutorial [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] has more examples of ray-casting, plus how to get better results from the bake.<br />
<br />
Baking sub-sections:<br />
# [[#Anti-Aliasing|Anti-Aliasing]]<br />
# [[#Baking_Transparency|Baking Transparency]]<br />
# [[#Edge_Padding|Edge Padding]]<br />
# [[#High_Poly_Materials|High Poly Materials]]<br />
# [[#Reset_Transforms|Reset Transforms]]<br />
# [[#Solving_Intersections|Solving Intersections]]<br />
# [[#Solving_Pixel_Artifacts|Solving Pixel Artifacts]]<br />
# [[#Solving_Wavy_Lines|Solving Wavy Lines]]<br />
# [[#Triangulating|Triangulating]]<br />
# [[#Working_with_Cages|Working with Cages]]<br />
<br />
<span id="AA"></span><br />
=== Anti-Aliasing ===<br />
Turning on super-sampling or anti-aliasing (or whatever multi-ray casting is called in your normal map baking tool) will help to fix any jagged edges where the high-res model overlaps itself within the UV borders of the low-poly mesh, or wherever the background shows through holes in the mesh. Unfortunately this tends to render much much slower, and takes more memory.<br />
<br />
[[image:normalmap_aliasing_knak47.jpg|frame|none|A bake without anti-aliasing shows artifacts where the high-poly mesh has overlaps. <br>Image by [http://www.polycount.com/forum/member.php?u=35938 'knak47']]]<br />
<br />
One trick to speed this up is to render 2x the intended image size then scale the normal map down 1/2 in a paint program like Photoshop. The reduction's pixel resampling will add anti-aliasing for you in a very quick process. After scaling, make sure to re-normalize the map if your game doesn't do that already, because the un-normalized pixels in your normalmap may cause pixelly artifacts in your specular highlights. Re-normalizing can be done with [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA's normal map filter] for Photoshop.<br />
<br />
3ds Max's supersampling doesn't work nicely with edge padding, it produces dark streaks in the padded pixels. If so then turn off padding and re-do the padding later, either by re-baking without supersampling or by using a Photoshop filter like the one that comes with [[#3DTools|Xnormal]].<br />
<br />
=== Baking Transparency ===<br />
Sometimes you need to bake a normal map from an object that uses opacity maps, like a branch with opacity-mapped leaves. Unfortunately baking apps often completely ignore any transparency mapping on your high-poly mesh.<br />
<br />
{|class="wikitable"<br />
|[[image:JoeWilson_ivynormals_error.jpg]] <br />
|[[image:JoeWilson_ivynormals_rendered.jpg]]<br />
|-<br />
|3ds Max's RTT baker causes transparency errors.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|The lighting method bakes perfect transparency.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|}<br />
<br />
To solve this, render a Top view of the mesh. This only works if you're using a planar UV projection for your low-poly mesh and you're baking a tangent-space normal map.<br />
<br />
* Make sure the Top view matches the dimensions of the planar UV projection used by the low-poly mesh. It helps to use an orthographic camera for precise placement.<br />
* On the high-poly mesh either use a specific lighting setup or a use special material shader:<br />
* 1) The lighting setup is described in these tutorials:<br />
* * [http://www.bencloward.com/tutorials_normal_maps11.shtml Creating A Normal Map Right In Your 3D App] by [http://www.bencloward.com/ Ben Cloward]<br />
* *[http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy], Graphics Techniques Consultant, Xbox Content and Design Team<br />
* 2) The material shader does the same thing, but doesn't require lights.<br />
* * [http://www.scriptspot.com/3ds-max/normaltexmap NormalTexMap] scripted map for 3ds Max by [http://www.scriptspot.com/users/dave-locke Dave Locke].<br />
* * [http://www.footools.com/3dsmax_plugins.html InfoTexture] map plugin for 3ds Max by [http://www.footools.com John Burnett]<br />
<br />
[[image:BenCloward_NormalMapLighting.gif|frame|none|The lighting setup for top-down rendering. <br>Image by [http://www.bencloward.com Ben Cloward]]]<br />
<br />
<span id="EP"></span><br />
<br />
=== Edge Padding ===<br />
If a normal map doesn't have enough [[Edge_padding |Edge Padding]], this will create shading seams on the UV borders.<br />
<br />
=== High Poly Materials ===<br />
3ds Max will not bake a normal map properly if the high-res model has a mental ray Arch & Design material applied. If your normal map comes out mostly blank, either use a Standard material or none at all. For an example see the Polycount thread [http://www.polycount.com/forum/showthread.php?t=74792 Render to Texture >:O].<br />
<br />
<span id="RT"></span><br />
=== Reset Transforms ===<br />
Before baking, make sure your low-poly model's transforms have been reset. '''''This is very important!''''' Often during the modeling process a model will be rotated and scaled, but these compounded transforms can create a messy local "space" for the model, which in turn often creates rendering errors for normal maps. <br />
<br />
In 3ds Max, use the Reset Xforms utility then Collapse the Modifier Stack. In Maya use Freeze Transformation. In XSI use the Freeze button.<br />
<br />
<span id="SI"></span><br />
<br />
=== Solving Intersections ===<br />
The projection process often causes problems like misses, or overlaps, or intersections. It can be difficult generating a clean normal map in areas where the high-poly mesh intersects or nearly intersects itself, like in between the fingers of a hand. Setting the ray distance too large will make the baker pick the other finger as the source normal, while setting the ray distance too small will lead to problems at other places on the mesh where the distances between in-game mesh and high-poly mesh are greater.<br />
<br />
Fortunately there are several methods for solving these problems.<br />
<br />
# Change the shape of the cage. Manually edit points on the projection cage to help solve tight bits like the gaps between fingers.<br />
# Limit the projection to matching materials, or matching UVs.<br />
# Explode the meshes. See the polycount thread [http://boards.polycount.net/showthread.php?t=62921 Explode script needed (for baking purposes)].<br />
# Bake two or more times using different cage sizes, and combine them in Photoshop.<br />
<br />
<span id="SPA"></span><br />
<br />
=== Solving Pixel Artifacts ===<br />
[[image:filterMaps_artifact.jpg|frame|none|Random pixel artifacts in the bake. <br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
If you are using 3ds Max's ''Render To Texture'' to bake from one UV layout to another, you may see stray pixels scattered across the bake. This only happens if you are using a copy of the original mesh in the Projection, and that mesh is using a different UV channel than the original mesh.<br />
<br />
There are two solutions for this:<br />
<br />
* Add a Push modifier to the copied mesh, and set it to a low value like 0.01.<br />
- or -<br />
<br />
* Turn off ''Filter Maps'' in the render settings (Rendering menu > Render Setup > Renderer tab > uncheck Filter Maps). To prevent aliasing you may want to enable the Global Supersampler in Render Setup.<br />
<br />
See also [[#Anti-Aliasing]].<br />
<br />
<span id="SWL"></span><br />
<br />
=== Solving Wavy Lines ===<br />
When capturing from a cylindrical shape, often the differences between the low-poly mesh and the high-poly mesh will create a wavy edge in the normal map. There are a couple ways to avoid this:<br />
<br />
# The best way... create your lowpoly model with better supporting edges. See the Polycount threads [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?], [http://boards.polycount.net/showthread.php?t=55754 approach to techy stuff], [http://www.polycount.com/forum/showthread.php?t=72713 Any tips for normal mapping curved surface?].<br />
# Adjust the shape of the cage to influence the directions the rays will be cast. Beware... this work will have to be re-done every time you edit the lowpoly mesh, as the cage will be invalidated. At the bottom of [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm this page of his normal map tutorial], [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to do this in 3ds Max. Same method can be seen in the image below.<br />
# Subdivide the low-res mesh so it more closely matches the high-res mesh. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] has a [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa video tutorial] that shows how to do this in Maya.<br />
# Paint out the wavy line. Beware... this work will have to be re-done every time you re-bake the normal map. The [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
# Use a separate planar-projected mesh for the details that wrap around the barrel area, so the ray-casting is more even. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. For example to add tread around a tire, the tread can be baked from a tread model that is laid out flat, then that bake can layered onto the bake from the cylindrical tire mesh in a paint program.<br />
<br />
[[image:timothy_evison_normalmap_projections.jpg|frame|none|Adjusting the shape of the cage to remove distortion. <br>Image by [http://users.cybercity.dk/~dsl11905/resume/resume.html Timothy "tpe" Evison]]]<br />
<br />
<span id="TRI"></span><br />
<br />
=== Triangulating ===<br />
Before baking, it is usually best to triangulate the low-poly model, converting it from polygons into pure triangles. This prevents the vertex normals from being changed later on, which can create specular artifacts.<br />
<br />
[[image:triangulation_modo_ohare.jpg|frame|none| When quads are triangulated in [http://www.luxology.com/modo/ Modo], the internal edges are sometimes flipped, which causes shading differences.<br>Image by [http://www.farfarer.com/|James "Talon" O'Hare]]]<br />
<br />
<br />
Sometimes a baking tool or a mesh exporter/importer will re-triangulate the polygons. A quad polygon is actually treated as two triangles, and the internal edge between them is often switched diagonally during modeling operations. When the vertices of the quad are moved around in certain shapes, the software's algorithm for polygon models tries to keep the quad surface in a "rational" non-overlapping shape. It does this by switching the internal edge between its triangles.<br />
<br />
<br />
[[image:triangulation_spec_tychovii.jpg|frame|none| The specular highlight is affected by triangulation. Flip edges to fix skewing. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66651 Skewed Specular Highlight?] for pictures and more info.<br> Image by [http://robertkreps.com Robert "TychoVII" Kreps]]]<br />
<br />
<br />
<span id="WWC"></span><br />
<br />
=== Working with Cages ===<br />
''Cage'' has two meanings in the normal-mapping process: a low-poly base for [[subdivision surface modeling]] (usually called the [[DigitalSculpting#BM|basemesh]]), or a ray-casting mesh used for normal map baking. This section covers the ray-casting cage.<br />
<br />
Most normal map baking tools allow you to use a distance-based raycast. A ray is sent outwards along each vertex normal, then at the distance you set a ray is cast back inwards. Where ever that ray intersects the high poly mesh, it will sample the normals from it. <br />
<br />
{|class="wikitable"<br />
|[[Image:Normalmap_raycasting_1.jpg]] <br />
|[[Image:Normalmap_raycasting_2.jpg]]<br />
|-<br />
|Hard edges and a distance-based raycast (gray areas) cause ray misses (yellow) and ray overlaps (cyan).<br> Image by [http://www.mankua.com/ Diego Castaño]<br />
|The gray area shows that using all soft edges (or hard edges and a cage-based raycast) will avoid ray-casting errors from split normals.<br> Image by [http://www.mankua.com/ Diego Castaño] <br />
|}<br />
<br />
Unfortunately with a distance-based raycast, [[#SGAHE|split vertex normals]] will cause the bake to miss parts of the high-res mesh, causing errors and seams. <br />
<br />
Some software allows you to use ''cage mesh'' option instead, which basically inflates a copy of the low-poly mesh, then raycasts inwards from each vertex. This ballooned-out mesh is the cage.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
|<tablebgcolor="#ffaaaa">| <br />
|}<br />
<br />
In 3ds Max the cage controls both the distance and the direction of the raycasting. <br />
<br />
In Maya the cage only controls the distance; the ray direction matches the vertex normals (inverted).<br />
<br />
<span style="text-decoration: line-through"> This may have been fixed in the latest release...<<BR>><br />
In Xnormal the cage is split everywhere the model has [[#SGAHE|hard edges]], causing ray misses in the bake. You can fix the hard edge split problem but it involves an overly complex workflow. You must also repeat the whole process any time you change your mesh:</span><br />
# <s> Load the 3d viewer.</s><br />
# <s> Turn on the cage editing tools.</s><br />
# <s> Select all of the vertices.</s><br />
# <s> Weld all vertices.</s><br />
# <s> Expand the cage as you normally would.</s><br />
# <s> Save out your mesh using the Xnormal format.</s><br />
# <s> Make sure Xnormal is loading the correct mesh.</s><br />
<br />
<span id="P"></span><span id="Painting"></span><br />
<br />
== Painting ==<br />
Don't be afraid to edit normal maps in Photoshop. After all it is just a texture, so you can clone, blur, copy, blend all you want... as long as it looks good of course. Some understanding of [[#RGBChannels|the way colors work]] in normal maps will go a long way in helping you paint effectively.<br />
<br />
A normal map sampled from a high-poly mesh will nearly always be better than one sampled from a texture, since you're actually grabbing "proper" normals from an accurate, highly detailed surface. That means your normal map's pixels will basically be recreating the surface angles of your high-poly mesh, resulting in a very believable look.<br />
<br />
If you only convert an image into a normal-map, it can look very flat, and in some cases it can be completely wrong unless you're very careful about your value ranges. Most image conversion tools assume the input is a heightmap, where black is low and white is high. If you try to convert a diffuse texture that you've painted, the results are often very poor. Often the best results are obtained by baking the large and mid-level details from a high-poly mesh, and then combined with photo-sourced "fine detail" normals for surface details such as fabric weave, scratches and grain.<br />
<br />
Sometimes creating a high poly surface takes more time than your budget allows. For character or significant environment assets then that is the best route, but for less significant environment surfaces working from a heightmap-based texture will provide a good enough result for a much less commitment in time.<br />
<br />
* [http://crazybump.com/ CrazyBump] is a commercial normal map converter.<br />
* [http://www.renderingsystems.com/support/showthread.php?tid=3 ShaderMap] is a commercial normal map converter.<br />
* [http://www.pixplant.com/ PixPlant] is a commercial normal map converter.<br />
* [http://boards.polycount.net/showthread.php?t=68860 NJob] is a free normal map converter.<br />
* [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA normalmap filter for Photoshop] is a free normal map converter.<br />
* [http://xnormal.net Xnormal height-to-normals filter for Photoshop] is a free normal map converter.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm Normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
<br />
=== Flat Color ===<br />
The color (128,128,255) creates normals that are completely perpendicular to the polygon, as long as the vertex normals are also perpendicular. Remember a normal map's per-pixel normals create ''offsets'' from the vertex normals. If you want an area in the normal map to be flat, so it creates no offsets from the vertex normals, then use the color (128,128,255). <br />
<br />
This becomes especially obvious when [[#Mirroring|mirroring a normal map]] and using a shader with a reflection ingredient. Reflection tends to accentuate the angles between the normals, so any errors become much more apparent.<br />
<br />
[[image:normalmap_127seam.jpg|thumb|600px|none| Mirrored normal maps show a seam when (127,127,255) is used for the flat color; 128 is better.<br>Image by [http://www.ericchadwick.com Eric Chadwick]]]<br />
<br />
In a purely logical way, 127 seems like it would be the halfway point between 0 and 255. However 128 is the color that actually works in practice. When a test is done comparing (127,127,255) versus (128,128,255) it becomes obvious that 127 creates a slightly bent normal, and 128 creates a flat one.<br />
<br />
This is because most game pipelines use ''unsigned'' normal maps. For details see the Polycount forum thread [http://www.polycount.com/forum/showpost.php?p=771360&postcount=22 tutorial: fixing mirrored normal map seams].<br />
<br />
<span id="BNMT"></span><br />
<br />
=== Blending Normal Maps Together ===<br />
Blending normal maps together is a quick way to add high-frequency detail like wrinkles, cracks, and the like. Fine details can be painted as a height map, then it can be converted into a normal map using one of the normal map tools. Then this "details" normal map can be blended with a geometry-derived normal map using one of the methods below. <br />
<br />
Here is a comparison of four of the blending methods. Note that in these examples the default values were used for CrazyBump (Intensity 50, Strength 33, Strength 33), but the tool allows each layer's strength to be adjusted individually for stronger or milder results. Each of the normal maps below were [[#Renormalizing|re-normalized]] after blending.<br />
<br />
{|class="wikitable"<br />
|[[image:nrmlmap_blending_methods_Maps.png]]<br />
|[[image:nrmlmap_blending_methods_RTTNormalMapFX.png]]<br />
|-<br />
|The blended normal maps.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|Screenshot of the 3dsmax viewport, using the RTTNormalMap.fx shader.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|}<br />
<br />
The four blending methods used above:<br />
# [http://www.crazybump.com CrazyBump] by Ryan Clark blends normal maps together using calculations in 3D space rather than just in 2D. This does probably the best job at preserving details, and each layer's strength settings can be tweaked individually. <br />
# [http://www.rodgreen.com/?p=4 Combining Normal Maps in Photoshop] by Rod Green blends normal maps together using Linear Dodge mode for the positive values and Difference mode for the negative values, along with a Photoshop Action to simplify the process. It's free, but the results may be less accurate than CrazyBump.<br />
# [http://www.paultosca.com/makingofvarga.html Making of Varga] by [http://www.paultosca.com/ Paul "paultosca" Tosca] blends normal maps together using Overlay mode for the red and green channels and Multiply mode for the blue channel. This gives a slightly stronger bump than the Overlay-only method. [http://www.leocov.com/ Leo "chronic" Covarrubias] has a step-by-step tutorial for this method in [http://www.cgbootcamp.com/tutorials/2009/12/9/photoshop-combine-normal-maps.html CG Bootcamp Combine Normal Maps].<br />
# [[3DTutorials/Normal Map Deepening|Normal Map Deepening]] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to blend normal maps together using Overlay mode. [http://cgtextures.com/content.php?action=tutorial&name=normalmap CGTextures tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] also shows how to create normalmaps using multiple layers (Note: to work with the Overlay blend mode each layer's Output Level should be 128 instead of 255, you can use the Levels tool for this).<br />
<br />
The [http://boards.polycount.net/showthread.php?t=69615 Getting good height from Nvidia-filter normalizing grayscale height] thread on the Polycount forum has a discussion of different painting/blending options. Also see the [[#2DT|2D Tools]] section for painting and conversion tools.<br />
<br />
<span id="PCT"></span><br />
<br />
=== Pre-Created Templates ===<br />
A library of shapes can be developed and stored for later use, to save creation time for future normal maps. Things like screws, ports, pipes, and other doo-dads. These shapes can be stored as bitmaps with transparency so they can be layered into baked normal maps.<br />
<br />
* [http://www.beautifulrobot.com/?p=69 Creating & Using NormalMap "Widgets"] - by ''[http://www.beautifulrobot.com Steev "kobra" Kelly]''<<BR>> How to set up and render template objects.<br />
* [http://www.akramparvez.com/portfolio/scripts/normalmap-widget-for-3ds-max/ NormalMap Widget for 3ds Max] - by ''[http://www.akramparvez.com Akram Parvez]''<<BR>>A script to automate the setup and rendering process.<br />
* See the section [[#BT|Baking Transparency]] for more template-rendering tools and tutorials.<br />
<br />
<span id="RN"></span><span id="Renormalizing"></span><br />
=== Re-normalizing ===<br />
Re-normalizing means resetting the length of each normal in the map to 1.<br />
<br />
A normal mapping shader takes the three color channels of a normal map and combines them to create the direction and length of each pixel's normal. These normals are then used to apply the scene lighting to the mesh. However if you edit normal maps by hand or if you blend multiple normal maps together this can cause those lengths to change. Most shaders expect the length of the normals to always be 1 (normalized), but some are written to re-normalize the normal map dynamically (for example, 3ds Max's Hardware Shaders do re-normalize).<br />
<br />
If the normals in your normal map are not normalized, and your shader doesn't re-normalize them either, then you may see artifacts on the shaded surface... the specular highlight may speckle like crazy, the surface may get patches of odd shadowing, etc. To help you avoid this NVIDIA's normal map filter for Photoshop provides an easy way to re-normalize a map after editing; just use the '''Normalize Only''' option. [http://xnormal.net Xnormal] also comes with a Normalize filter for Photoshop.<br />
<br />
[[image:normalize_only.jpg|frame|none|The re-normalize option in the NVIDIA filter.<br>Image by [http://hirezstudios.com/ Scott Warren]]]<br />
<br />
Some shaders use [[#NormalMapCompression|compressed normal maps]]. Usually this means the blue channel is thrown away completely, so it's recalculated on-the-fly in the shader. However the shader has to re-normalize in order to recreate that data, so any custom normal lengths that were edited into the map will be ignored completely. <br />
<br />
<span id="AOIANM"></span><span id="AmbientOcclusionIntoANormalMap"></span><br />
<br />
=== Ambient Occlusion into a Normal Map ===<br />
If the shader doesn't re-normalize the normal map, an [[Ambient Occlusion Map]] can actually be baked into the normal map. This will shorten the normals in the crevices of the surface, causing the surface to receive less light there. This works with both diffuse and specular, or any other pass that uses the normal map, like reflection.<br />
<br />
However it's usually best to keep the AO as a separate map (or in an alpha channel) and multiply it against the ambient lighting only. This is usually done with a custom [[:Category:Shaders|shader]]. If you multiply it against the diffuse map or normal map then it also occludes diffuse lighting which can make the model look dirty. Ambient occlusion is best when it occludes ambient lighting only, for example a [[DiffuselyConvolvedCubeMap|diffusely convolved cubemap]].<br />
<br />
[[image:nrmlmap_ao.jpg|frame|none| AO can be baked into a normal map, shortening the normals (lower left model).<br>Model by [http://www.3dartisan.net/~kuman/ James Ku]]]<br />
<br />
To bake the AO into a normal map, adjust the levels of the AO layer first so the darks only go as low as 128 gray, then set the AO layer to Darken mode. This will shorten the normals in the normalmap, causing the surface to receive less light in the darker areas. <br />
<br />
This trick doesn't work with any shaders that re-normalize, like 3ds Max's Hardware Shaders. The shader must be altered to actually use the lengths of your custom normals; most shaders just assume all normals are 1 in length because this makes the shader code simpler. Also this trick will not work with most of the common [[#NormalMapCompression|normal map compression formats]], which often discard the blue channel and recalculate it in the shader, which requires re-normalization.<br />
<br />
<span id="BLE"></span><br />
<br />
=== Back Lighting Example ===<br />
You can customize normal maps for some interesting effects. If you invert the blue channel of a tangent-space map, the normals will be pointing to the opposite side of the surface, which can simulate backlighting.<br />
<br />
{|class="wikitable"<br />
|[[image:tree_front.jpg]]||[[image:tree_back.jpg]]<br />
|-<br />
|Tree simulating subsurface scattering (front view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|Tree simulating subsurface scattering (back view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|-<br />
|colspan="2"|[[image:tree_maps.jpg]]<br />
|-<br />
|colspan="2"|The maps used for the leaves. The 2nd diffuse was simply color-inverted, hue-shifted 180°, and saturated.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
The tree leaves use a shader than adds together two diffuse maps, one using a regular tangent-space normal map, the other using the same normal map but with the blue channel inverted. This causes the diffuse map using the regular normal map to only get lit on the side facing the light (front view), while the diffuse map using the inverted normal map only gets lit on the opposite side of the leaves (back view). The leaf geometry is 2-sided but uses the same shader on both sides, so the effect works no matter the lighting angle. As an added bonus, because the tree is self-shadowing the leaves in shadow do not receive direct lighting, which means their backsides do not show the inverted normal map, so the fake subsurface scatter effect only appears where the light directly hits the leaves. This wouldn't work for a whole forest because of the computational cost of self-shadowing and double normal maps, but could be useful for a single "star" asset, or if LODs switched the distant trees to a model that uses a cheaper shader.<br />
<br />
<span id="SAS"></span><br />
<br />
== Shaders and Seams ==<br />
You need to use the right kind of shader to avoid seeing seams where UV breaks occur. It must be written to use the same [[#TangentBasis|tangent basis]] that was used during baking. If the shader doesn't, the lighting will either be inconsistent across UV borders or it will show smoothing errors from the low-poly vertex normals.<br />
<br />
Xnormal generates accurate normals when displayed in Xnormal, and the SDK includes a method to write your own custom tangent space generator for the tool. <br />
<br />
<span id="3MS"></span><br />
=== 3ds Max Shaders ===<br />
The "Render To Texture" tool in 3ds Max 2011 and older generates [[#TSNM|tangent-space]] normal maps that render correctly in the offline renderer (scanline) but do not render correctly in the realtime viewport with the 3ds Max shaders. Max is using a different [[#TangentBasis|tangent basis]] for each. This is readily apparent when creating non-organic hard surface normalmaps; smoothing errors appear in the viewport that do not appear when rendered. <br />
<br />
The errors can be fixed by using "Render To Texture" to bake a [[#TSNM|tangent-space]] or [[#OSNM|object-space]] map, and using the free [http://www.3pointstudios.com/3pointshader_about.shtml "3Point Shader"] by Christoph '[[CrazyButcher]]' Kubisch and Per 'perna' Abrahamsen. The shader uses the same tangent basis as the baking tool, so it produces nearly flawless results. It also works with old bakes.<br />
<br />
You can get OK results in the Max viewport using a tangent-space map baked in Maya, loading it in a Standard material, and enabling "Show Hardware Map in Viewport". Another method is to use Render To Texture to bake an [[#OSNM|object-space]] map then use [[#CBS|Nspace]] to convert it into a tangent-space map then load that in a DirectX material and use the RTTNormalMap.fx shader. <br />
<br />
Autodesk is aware of these issues, and plans to address them in an upcoming release. See these links for more information:<br />
* Christoph "[[CrazyButcher]]" Kubisch and Per "perna" Abrahamsen designed a shader/modifier combination approach that fixes the viewport problem, see the Polycount forum post [http://boards.polycount.net/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max].<br />
* Jean-Francois "jfyelle" Yelle, Autodesk Media & Entertainment Technical Product Manager, has [http://boards.polycount.net/showthread.php?p=1115812#post1115812 this post]. <br />
* Ben Cloward posted [http://boards.polycount.net/showthread.php?p=1100270#post1100270 workarounds and FX code].<br />
* Christopher "cdiggins" Diggins, SDK writer for 3ds Max, shares some of the SDK code in his blog posts "[http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping How the 3ds Max Scanline Renderer Computes Tangent and Binormal Vectors for Normal Mapping]" and "[http://area.autodesk.com/blogs/chris/3ds_max_normal_map_baking_and_face_angle_weighting_the_plot_thickens 3ds Max Normal Map Baking and Face Angle Weighting: The Plot Thickens]".<br />
<br />
[[image:nmtest_uv-splits_thumb.jpg|thumb|600px|none|Comparison of map baking methods in Maya and Max, and Ben Cloward's custom FX code.<br>Image by [http://www.bencloward.com/ Ben Cloward] and [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
[[image:normalmapfix_3pointstudios_thumb.jpg|frame|none|3 Point Studios' normal map display fix for 3ds Max.<br>image by [http://www.3pointstudios.com 3 Point Studios]]]<br />
<br />
{|class="wikitable"<br />
|[[image:max2010_normalmap_workarounds.png|thumb|400px|none|]]<br />
|[[image:max2010_normalmap_compare.png|thumb|400px|none|]]<br />
|-<br />
|Viewport methods in 3ds Max 2010.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick] <br />
|More baking methods in 3ds Max 2010.<br> Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
<span id="3MENT"></span><br />
<br />
=== 3ds Max Edit Normals Trick ===<br />
After baking, if you add an Edit Normals modifier to your low-poly normalmapped model, this seems to "relax" the vertex normals for more accurate viewport shading. The modifier can be collapsed if desired.<br />
<br />
<span id="MS"></span><br />
=== Maya Shaders ===<br />
Maya seems to correctly generate normals to view in realtime, with the correct [[#TangentBasis|tangent basis]], with much less smoothing errors than 3ds Max. <br />
* [http://www.mentalwarp.com/~brice/shader.php BRDF shader] by [http://www.mentalwarp.com/~brice/ Brice Vandemoortele] and [http://www.kjapi.com/ Cedric Caillaud] (more info in [http://boards.polycount.net/showthread.php?t=49920 this Polycount thread]) '''Update:''' [http://boards.polycount.net/showthread.php?p=821862#post821862 New version here] with many updates, including object-space normal maps, relief mapping, self-shadowing, etc. Make sure you enable cgFX shaders in the Maya plugin manager, then you can create them in the same way you create a Lambert, Phong etc. Switch OFF high quality rendering in the viewports to see them correctly too.<br />
* If you want to use the software renderer, use mental ray instead of Maya's software renderer because mental ray correctly interprets tangent space normals. The Maya renderer treats the normal map as a grayscale bump map, giving nasty results. Mental ray supports Maya's Phong shader just fine (amongst others), although it won't recognise a gloss map plugged into the "cosine power" slot. The slider still works though, if you don't mind having a uniform value for gloss. Spec maps work fine though. Just use the same set up as you would for viewport rendering. You'll need to have your textures saved as TGAs or similar for mental ray to work though. - from [http://boards.polycount.net/member.php?u=14235 CheeseOnToast]<br />
<br />
<br />
<span id="NMC"></span><br />
<br />
== Normal Map Compression ==<br />
see; [[Normal Map Compression]]<br />
<br />
== Links ==<br />
<br />
=== Related Pages ===<br />
* [[Curvature map]]<br />
* [[DuDv map]]<br />
* [[Flow map]]<br />
* [[Normal map]]<br />
* [[Radiosity normal map]]<br />
* [[Vector displacement map]]<br />
<br />
<span id="3DT"></span> <span id="Tools"></span> <span id="3DTools"></span><br />
=== 3D Tools ===<br />
See [[:Category:Tools#A3D_Normal_Map_Software|Category:Tools#3D_Normal_Map_Software]]<br />
<br />
<span id="2DT"></span><span id="2DTools"></span><br />
=== 2D Tools ===<br />
See [[:Category:Tools#A2D_Normal_Map_Software|Category:Tools#2D_Normal_Map_Software]]<br />
<br />
<span id="T"></span><span id="Tutorials"></span><br />
=== Tutorials ===<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh tutorial for Max and Xnormal] by [http://www.exisinteractive.com/ PeterK] to prevent heavy distortions when baking with a cage, without the need to add extra supporting vertices.<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games] by [http://www.polycount.com/forum/member.php?u=56680 'SuperFranky']<br />
* [http://area.autodesk.com/userdata/fckdata/239955/The%20Generation%20and%20Display%20of%20Normal%20Maps%20in%203ds%20Max.pdf The Generation and Display of Normal Maps in 3ds Max] (500kb PDF) <<BR>> Excellent whitepaper from Autodesk about normal mapping in 3ds Max and other apps.<br />
* [http://www.katsbits.com/htm/tutorials/blender-baking-normal-maps-from-models.htm Renderbump and baking normal maps from high poly models using Blender 3D] by ''[http://www.katsbits.com/htm/about.htm "katsbits"]''<<BR>>Baking normal maps in Blender.<br />
* [http://udn.epicgames.com/Three/CreatingNormalMaps.html Techniques for Creating Normal Maps] in the Unreal Developer Network's [http://udn.epicgames.com/Three/WebHome.html Unreal Engine 3 section] contains advice from [http://www.epicgames.com/ Epic Games] artists on creating normal maps for UE3. The [http://udn.epicgames.com/Three/DesignWorkflow.html#Creating%20normal%20maps%20from%20meshes Design Workflow page] has a summary.<br />
* [http://www.iddevnet.com/quake4/ArtReference_CreatingModels#head-3400c230e92ff7d57424b2a68f6e0ea75dee4afa Creating Models in Quake 4] by [http://www.ravensoft.com/ Raven Software] is a comprehensive guide to creating Quake 4 characters.<br />
* [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing and UVs can affect normal maps in Doom 3.<br />
* [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] is an overview of modeling for normal maps.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses how smoothing groups and bevels affect the topology of the low-poly model.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in-game, not the triangle or poly count.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm Normal map workflow] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] demonstrates his normal mapping workflow in 3ds Max and Photoshop.<br />
* [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa This video tutorial] by [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] shows in Maya how to subdivide the low-poly mesh so it more closely matches the high-poly mesh, to help solve wavy lines in the bake.<br />
* [http://www.bencloward.com/tutorials_normal_maps1.shtml Normal Mapping Tutorial] by [http://www.bencloward.com/ Ben Cloward] is a comprehensive tutorial about the entire normal map creation process.<br />
* [http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy] shows how to use a special lighting setup to render normal maps (instead of baking them).<br />
* [http://cgtextures.com/content.php?action=tutorial&name=normalmap Tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] shows how to create deep normal maps using multiple layers. Note: to use Overlay blend mode properly, make sure to change each layer's Levels ''Output Level'' to 128 instead of 255.<br />
* [http://www.poopinmymouth.com/process/tips/normalmap_deepening.jpg Normalmap Deepening] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to adjust normal maps, and how to layer together painted and baked normal maps.<br />
* [http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] helps to solve seams along horizontal or vertical UV edges, but not across angled UVs.<br />
* [http://planetpixelemporium.com/tutorialpages/normal.html Cinema 4D and Normal Maps For Games] by [http://planetpixelemporium.com/index.php James Hastings-Trew] describes normal maps in plain language, with tips on creating them in Cinema 4D.<br />
* [http://forums.cgsociety.org/showthread.php?f=39&t=359082 3ds Max normal mapping overview] by [http://www.alan-noon.com/ Alan Noon] is a great thread on CGTalk about the normal mapping process.<br />
* [http://forums.cgsociety.org/showthread.php?f=46&t=373024 Hard Surface Texture Painting] by [http://stefan-morrell.cgsociety.org/gallery/ Stefan Morrell] is a good introduction to painting textures for metal surfaces.<br />
<br />
<span id="D"></span><span id="Discussion"></span><br />
<br />
=== Discussion ===<br />
[http://boards.polycount.net/showthread.php?p=820218 Discuss this page on the Polycount forums]. Suggestions welcome.<br />
<br />
Even though only one person has been editing this page so far, the information here was gathered from many different sources. We wish to thank all the contributors for their hard-earned knowledge. It is much appreciated!<br />
<br />
----<br />
[[Category:TextureTypes]] [[Category:Bump map]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Normal_mapNormal map2015-04-22T15:44:25Z<p>Dustinbrown: /* Common Swizzle Coordinates */</p>
<hr />
<div>== Out of Date ==<br />
The information on this page is a bit old, it needs to be updated. See these links for more current information:<br />
<br />
* [http://farfarer.com/resources.htm RNM Normal Map Combiner], by [http://www.farfarer.com/ James "Farfarer" O'Hare]<br />
* [http://vincentcallebaut.com/CombineNormal.html Combine Normal], by [http://vincentcallebaut.comVincent "Vincentt" Callebaut], [http://www.polycount.com/forum/showthread.php?t=131819 Combine normal maps script for Photoshop] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showpost.php?p=2226864&postcount=51 Earthquake on separating smoothing groups in the UV]<br />
* [http://www.polycount.com/forum/showpost.php?p=2225535&postcount=40 JedTheKrampus on offsetting Mirrored UVs]<br />
* [http://www.polycount.com/forum/showthread.php?t=148303 Of Bit Depths, Banding and Normal Maps]<br />
* [http://www.polycount.com/forum/showthread.php?t=147227 Skew you buddy! Making sense of skewed normal map details.]<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games]<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh Tutorial]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?]<br />
* [http://www.laurenscorijn.com/future-xoliulshader-support.html Future Xoliulshader support] = why Xoliulshader doesn't work properly in 3ds Max 2013/2014.<br />
<br />
== Synched Workflow ==<br />
To eliminate seams and shading artifacts, the model renderer and the normal map baking tool should use the same tangent basis.<br />
<br />
FBX model format can store tangents, and some renderers use this data to synch the incoming normal maps.<br />
<br />
{| class="wikitable sortable" style="color:grey;"<br />
|- <br />
! Renderer !! Normal map baker<br />
|-<br />
| 3ds Max || 3ds Max, Handplane, ?<br />
|-<br />
| Blender || ?<br />
|-<br />
| Creation Engine || Handplane, ?<br />
|-<br />
| CryEngine || ?<br />
|-<br />
| Knald || ?<br />
|-<br />
| Marmoset Toolbag || 3ds Max, Maya, Xnormal, ?<br />
|-<br />
| Maya || Handplane, Maya, ?<br />
|-<br />
| Source || Handplane, Maya ([http://www.polycount.com/forum/showpost.php?p=2224653&postcount=28]), ?<br />
|-<br />
| Starcraft II || Handplane, ?<br />
|-<br />
| Substance Designer || ?<br />
|-<br />
| Unity([http://www.polycount.com/forum/showpost.php?p=2224781&postcount=29], [http://www.polycount.com/forum/showthread.php?p=2194353#post2194353]) || Handplane, Xnormal (via Asset Store), ?<br />
|-<br />
| Unreal Engine 4 || Handplane, Xnormal([http://www.polycount.com/forum/showpost.php?p=2224402&postcount=20]), ? <br />
|-<br />
| Xnormal || Xnormal, ?<br />
|}<br />
<br />
----<br />
<br />
== What is a Normal Map? ==<br />
A Normal Map is usually used to fake high-res geometry detail when it's mapped onto a low-res mesh. The pixels of the normal map each store a ''normal'', a vector that describes the surface slope of the original high-res mesh at that point. The red, green, and blue channels of the normal map are used to control the direction of each pixel's normal. <br />
<br />
When a normal map is applied to a low-poly mesh, the texture pixels control the direction each of the pixels on the low-poly mesh will be facing in 3D space, creating the illusion of more surface detail or better curvature. However, the silhouette of the model doesn't change. <br />
<br />
<gallery mode="packed"><br />
Whatif_normalmap_mapped2.jpg|A model with a normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_low.jpg|The model without its normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_high.jpg|The high-resolution model used to create the normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
</gallery><br />
<br />
==Tangent-Space vs. Object-Space==<br />
<br />
Normal maps can be made in either of two basic flavors: tangent-space or object-space. World-space is basically the same as object-space, except it requires the model to remain in its original orientation, neither rotating nor deforming, so it's almost never used.<br />
<br />
===Tangent-space normal map===<br />
[[image:normalmap_tangentspace.jpg|frame|none|A tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Predominantly-blue colors. Object can rotate and deform. Good for deforming meshes, like characters, animals, flags, etc.<br />
<br />
Pros:<br />
* Maps can be reused easily, like on differently-shaped meshes.<br />
* Maps can be tiled and mirrored easily, though some games might not support mirroring very well.<br />
* Easier to overlay painted details.<br />
* Easier to use image compression.<br />
<br />
Cons:<br />
* More difficult to avoid smoothing problems from the low-poly vertex normals (see Smoothing Groups and Hard Edges).<br />
* Slightly slower performance than an object-space map (but not by much).<br />
<br />
===Object-space normal map===<br />
[[image:normalmap_worldspace.jpg|frame|none|An object-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Rainbow colors. Objects can rotate, but usually shouldn't be deformed, unless the shader has been modified to support deformation. Object-space is also called local-space or model-space. <br />
<br />
Pros:<br />
* Easier to generate high-quality curvature because it completely ignores the crude smoothing of the low-poly vertex normals.<br />
* Slightly better performance than a tangent-space map (but not by much).<br />
<br />
Cons:<br />
* Can't easily reuse maps, different mesh shapes require unique maps.<br />
* Difficult to tile properly, and mirroring requires specific shader support.<br />
* Harder to overlay painted details because the base colors vary across the surface of the mesh. Painted details must be converted into Object Space to be combined properly with the OS map.<br />
* They don't compress very well, since the blue channel can't be recreated in the shader like with tangent-space maps. Also the three color channels contain very different data which doesn't compress well, creating many artifacts. Using a half-resolution object-space map is one option. <br />
<br />
<br clear="all"/><br />
<br />
=== Converting Between Spaces ===<br />
Normal maps can be converted between object space and tangent space, in order to use them with different blending tools and shaders, which require one type or the other. <br />
<br />
Object space maps can also be converted to maps with different tangent bases, to better match the normal maps with the renderer and thus avoid lighting errors.<br />
<br />
* [http://www.handplane3d.com Handplane] by [http://www.alecmoody.com/ Alec Moody] is a tool that converts object space maps into a variety of tangent spaces: 3ds Max, Creation Engine, Maya, Source, Unity, Unreal, etc. See the Polycount Forum thread [http://www.polycount.com/forum/showthread.php?t=116899 Official handplane support thread - Now freeware!!].<br />
<br />
[[File:handplane_illus_1.jpg|frame|none|Handplane interface. <br>Image by [http://www.alecmoody.com/ Alec Moody].]]<br />
<br />
<br />
* [http://boards.polycount.net/showthread.php?p=1072599#post1072599 NSpace] by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] is a tool that converts an object-space normal map into a tangent-space map, which then works seamlessly in the 3ds Max viewport. He converts the map by using the same tangent basis that 3ds Max uses for its hardware shader. To see the results, load the converted map via the ''Normal Bump'' map and enable "Show Hardware Map in Viewport". [http://gameartist.nl/ Osman "osman" Tsjardiwal] created a GUI for NSpace, you can [http://boards.polycount.net/showthread.php?p=1075143#post1075143 download it here], just put it in the same folder as the NSpace exe and run it. <br />
<br />
[[File:NSpace_Gui_osman.png|frame|none|NSpace interface. <br>Image by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] and [http://gameartist.nl Osman "osman" Tsjardiwal].]]<br />
<br />
[http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson] said: "[8Monkey Labs has] a tool that lets you load up your reference mesh and object space map. Then load up your tangent normals, and adjust some sliders for things like tile and amount. We need to load up a mesh to know how to correctly orient the tangent normals or else things will come out upside down or reverse etc. It mostly works, but it tends to "bend" the resulting normals, so you gotta split the mesh up into some smoothing groups before you run it, and then I usually will just composite this "combo" texture over my orig map in Photoshop."<br />
<br />
<span id="RGBC"></span><span id="RGBChannels"></span><br />
<br />
== RGB Channels ==<br />
Shaders can use different techniques to render tangent-space normal maps, but the normal map directions are usually consistent within a game. Usually the red channel of a tangent-space normal map stores the X axis (pointing the normals predominantly leftwards or rightwards), the green channel stores the Y axis (pointing the normals predominantly upwards or downwards), and the blue channel stores the Z axis (pointing the normals outwards away from the surface).<br />
<br />
[[image:tangentspace_rgb.jpg|frame|none|The red, green, and blue channels of a tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you see lighting coming from the wrong angle when you're looking at your normal-mapped model, and the model is using a tangent-space normal map, the normal map shader might be expecting the red or green channel (or both) to point in the opposite direction. To fix this either change the shader, or simply invert the appropriate color channels in an image editor, so that the black pixels become white and the white pixels become black.<br />
<br />
Some shaders expect the color channels to be swapped or re-arranged to work with a particular [[#NormalMapCompression|compression format]]. For example the DXT5_nm format usually expects the X axis to be in the alpha channel, the Y axis to be in the green channel, and the red and blue channels to be empty.<br />
<br />
== Tangent Basis ==<br />
[[#TangentSpaceVsObjectSpace|Tangent-space]] normal maps use a special kind of vertex data called the ''tangent basis''. This is similar to UV coordinates except it provides directionality across the surface, it forms a surface-relative coordinate system for the per-pixel normals stored in the normal map. This coordinate system is required to light a normal mapped surface.<br />
<br />
Each vertex in the tangent basis is a combination of three things: the mesh vertex's normal (influenced by smoothing), the vertex's tangent (usually derived from the V texture coordinate), and the vertex's bitangent (derived in code, also called the binormal). These three vectors create an axis for each vertex, giving it a specific orientation in the tangent space. These axes are used to properly transform the incoming lighting from world space into tangent space, so your normal-mapped model will be lit correctly.<br />
<br />
Light rays are in world space, but the normals stored in the normal map are in tangent space. When the model is being rendered, the light rays must be converted from world space into tangent space, using the tangent basis to get there. At that point the incoming light rays are compared against the directions of the normals in the normal map, and this determines how much each pixel is going to be lit. Alternatively, instead of converting the light rays some shaders will convert the normals in the normal map from tangent space into world space. Then those world-space normals are compared against the light rays, and the model is lit appropriately. The method depends on who wrote the shader, but the end result is the same. Both methods require a tangent basis to transform the lighting.<br />
<br />
When a triangle's vertex normals are pointing straight out, and a pixel in the normal map is neutral blue (128,128,255) this means the pixel's normal will be pointing straight out from the surface of the low-poly mesh. When that pixel normal is tilted towards the left or the right in the tangent coordinate space, it will get either more or less red color, depending on whether the normal map is set to store the X axis as either a positive or a negative value. Same goes for when the normal is tilted up or down in tangent space, it will either get more or less green color. If the vertex normals aren't exactly perpendicular to the triangle, the normal map pixels will be tinted away from neutral blue as well.<br />
<br />
Unfortunately for artists, there are many different ways to calculate the tangent basis: [http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping 3ds Max], [http://download.autodesk.com/us/maya/2011help/index.html?url=./files/Appendix_A_Tangent_and_binormal_vectors.htm,topicNumber=d0e227193 Maya], [http://www.codesampler.com/dx9src/dx9src_4.htm#dx9_dot3_bump_mapping DirectX 9], [http://developer.nvidia.com/object/NVMeshMender.html NVMeshMender], [http://www.terathon.com/code/tangent.html Eric Lengyel], a custom solution, etc. This means a normal map baked in one application probably won't shade correctly in another. Artists must do some testing with different [[#T|baking tools]] to find which works best with their output. When the renderer (or game engine) renders your game model, [[#ShadersAndSeams|the shader]] must use the same tangent basis as the normal map baker, otherwise you'll get incorrect lighting, especially across the seams between UV shells.<br />
<br />
The [http://www.xnormal.net/ xNormal] SDK supports custom tangent basis methods. When a programmer uses it to implement their renderer's own tangent basis, artists can then use Xnormal to bake normal maps that will match their renderer perfectly.<br />
<br />
[[image:tangentseams.jpg|frame|none|When shared edges are at different angles in UV space, different colors will show up<br />
along the seam. The tangent basis uses these colors to light the model properly. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
When you look at a tangent-space normal map for a character, you typically see different colors along the UV seams. This is because the UV shells are often oriented at different angles on the mesh, a necessary evil when translating the 3D mesh into 2D textures. The body might be mapped with a vertical shell, and the arm mapped with a horizontal one. This requires the normals in the normal map to be twisted for the different orientations of those UV shells. The UVs are twisted, so the normals must be twisted in order to compensate. The tangent basis helps reorient (twist) the lighting as it comes into the surface's local space, so the lighting will then look uniform across the normal mapped mesh.<br />
<br />
When an artist tiles a tangent-space normal map across an arbitrary mesh, like a landscape, this tends to shade correctly because the mesh has a uniform direction in tangent space. If the mesh has discontinuous UV coordinates (UV seams), or the normal map has large directional gradients across it, the tangent space won't be uniform anymore so the surface will probably have shading seams.<br />
<br />
== Common Swizzle Coordinates ==<br />
3D Software capable of displaying normal maps will have a native required direction, or "handedness" for the RGB channels in a normal map, sometimes referred to as "Swizzle Coordinates," though [[#SAS|shaders]] can often be written to override this native handedness. You may hear developers refer to "flipping the green channel" in order to get a normal map to display correctly, and this simply indicates that when the normal map was baked, it was authored with the incorrect handedness in the green channel. Left/Down handedness is indicated with a negative (-), and right/up handedness is demarcated with a (+) positive.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
| '''Software''' <br />
| '''Red''' <br />
| '''Green''' <br />
| '''Blue''' <br />
|-<br />
|<#000000>| Maya<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| 3ds Max<br />
| X+<br />
| Y-<br />
| Z+ <br />
|-<br />
|<#000000>| [http://wiki.blender.org/index.php/Doc:2.6/Manual/Textures/Influence/Material/Bump_and_Normal Blender]<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| [https://docs.unrealengine.com/latest/INT/Engine/Content/Types/Textures/Properties/index.html Unreal Engine]<br />
| X+ <br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| [https://docs.unrealengine.com/latest/INT/Engine/Content/Types/Textures/Properties/index.html CryENGINE]<br />
| <br />
| <br />
| <br />
|-<br />
|<#000000>| [http://docs.unity3d.com/Manual/HOWTO-bumpmap.html Unity]<br />
| X+<br />
| Y+<br />
| Z+<br />
|-<br />
|<#000000>| [https://developer.valvesoftware.com/wiki/Bump_map Source]<br />
| X+<br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Toolbag<br />
| X+<br />
| Y+ <br />
| Z+<br />
|}<br />
<span id="MTLPM"></span><br />
<br />
== Modeling the Low-Poly Mesh ==<br />
The in-game mesh usually needs to be carefully optimized to create a good silhouette, define edge-loops for better deformation, and minimize extreme changes between the vertex normals for better shading (see [[#SmoothingGroupsAndHardEdges|Smoothing Groups & Hard Edges]]).<br />
<br />
In order to create an optimized in-game mesh including a good silhouette and loops for deforming in animation, you can start with the 2nd subdivision level of your [[DigitalSculpting|digital sculpt]], or in some cases with the base mesh itself. Then you can just collapse edge loops or cut in new edges to add/remove detail as necessary. Or you can [[DigitalSculpting#OART|re-toplogize]] from scratch if that works better for you.<br />
<br />
See [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts] on the Polycount forum.<br />
<br />
<span id="UVC"></span><span id="UVCoordinates"></span><br />
=== UV Coordinates ===<br />
Normal map baking tools only capture normals within the 0-1 UV square, any UV bits outside this area are ignored. <br />
<br />
Only one copy of the forward-facing UVs should remain in the 0-1 UV square at baking time. If the mesh uses overlapping UVs, this will likely cause artifacts to appear in the baked map, since the baker will try render each UV shell into the map. Before baking, it's best to move all the overlaps and mirrored bits outside the 0-1 square. <br />
<br />
[[image:Normalmap_uvcoord_offset.jpg|frame|none|The mirrored UVs (in red) are offset 1 unit before baking. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you move all the overlaps and mirrored bits exactly 1 UV unit (any whole number will do), then you can leave them there after the bake and they will still be mapped correctly. You can move them back if you want, it doesn't matter to most game engines. Be aware that ZBrush does use UV offsets to manage mesh visibility, however this usually doesn't matter because the ZBrush cage mesh is often a different mesh than the in-game mesh used for baking.<br />
<br />
You should avoid changing the UVs after baking the normal map, because rotating or mirroring UVs after baking will cause the normal map not to match the [[#TB|tangent basis]] anymore, which will likely cause lighting problems. <br />
<br />
In 3ds Max, W is a third texture coordinate. It's used for 3D procedural textures and for storing vertex color in UV channels (you need 3 axes for RGB, so UVW can store vertex color). Bake problems can be avoided by moving any overlapping UVs to -1 on the W axis, with the same results as moving them 1 unit on the U or V axes. The tool Render To Texture will always bake whatever UVs are the highest along the W axis. However using W can be messy... it's generally hidden unless you purposefully look for it (bad for team work), doesn't get preserved on export to other apps, and high W values can prevent selecting and/or welding UVs. <br />
<br />
<span id="M"></span><span id="Mirroring"></span><br />
<br />
=== Mirroring ===<br />
Normal maps can be mirrored across a model to create symmetrical details, and save UV space, which allows more detail in the normal map since the texture pixels are smaller on the model. <br />
<br />
With [[#OSNM|object-space]] maps, mirroring requires [http://boards.polycount.net/showthread.php?t=53986 specific shader support]. For [[#TSNM|tangent-space]] maps, mirroring typically creates a shading seam, but this can be reduced or hidden altogether, depending on the method used.<br />
<br />
<span id="TMW"></span><br />
==== Typical Mirroring Workflow ====<br />
# Delete the mesh half that will be mirrored. <br />
# Arrange the UVs for the remaining model, filling the UV square.<br />
# Mirror the model to create a "whole" mesh, welding the mesh vertices along the seam. <br />
# Move the mirrored UVs exactly 1 unit (or any whole number) out of the 0-1 UV square.<br />
# Bake the normal map.<br />
<br />
Sometimes an artist will decide to delete half of a symmetrical model before baking. <br />
<br />
This is a mistake however because often the vertex normals along the hole will bend towards the hole a bit; there are no faces on the other side to average the normals with. This will create a strong lighting seam in the normal map. <br />
<br />
It's typically best to use the complete mirrored model to bake the normal map, not just the unique half. <br />
<br />
To prevent the mirrored UVs from causing overlaps or baking errors, move the mirrored [[#UVC|UVs]] out of the 0-1 UV space, so only one copy of the non-mirrored UVs is left within the 0-1 square.<br />
<br />
To avoid texel "leaks" between the UV shells, make sure there's enough [[#Edge_padding|Edge Padding]] around each shell, including along the edges of the normal map. None of the UV shells should be touching the edge of the 0-1 UV square, unless they're meant to tile with the other side of the map.<br />
<br />
<span id="CM"></span><br />
<br />
==== Center Mirroring ====<br />
If the mirror seam runs along the surface of a continuous mesh, like down the center of a human face for example, then it will probably create a lighting seam. <br />
<br />
In Epic Games' [http://www.unrealtechnology.com/technology.php Unreal Engine 3] (UE3) their symmetrical models commonly use centered mirroring. Epic uses materials that mix a [[DetailMap]] with the normal maps; these seem to scatter the diffuse/specular lighting and help minimize the obviousness of the mirror seams. For their [[Light Map]]ped models they use [http://udn.epicgames.com/Three/LightMapUnwrapping.html a technique] that can almost completely hide the mirror seam.<br />
<br />
[[image:Epic_MirroringCicada.jpg|frame|none| In UE3 a center mirror seam is reduced by using a detail normal map. <br> Image by "[http://epicgames.com Epic Games]"]]<br />
<br />
'''''[http://www.zbrushcentral.com/showpost.php?p=573108&postcount=28 GOW2 normal map seams], [http://utforums.epicgames.com/showthread.php?p=27166791#post27166791 UDK normal map seams]'''''<br />
<br />
<span id="OM"></span><br />
<br />
==== Offset Mirroring ====<br />
Offset mirroring is a method where you move the mirror seam off to one side of the model, so the seam doesn't run exactly down the center. For example with a character's head, the UV seam can go down along the side of the head in front of the ear. The UV shell for the nearest ear can then be mirrored to use the area on the other side of the head. <br />
<br />
This avoids the "Rorschach" effect and allows non-symmetrical details, but it still saves texture space because the two sides of the head can be mirrored (they're never seen at the same time anyhow).<br />
<br />
Offset mirroring doesn't get rid of the seam, but it does move it off to a place where it can either be less obvious, or where it can be hidden in a natural seam on the model.<br />
<br />
<span id="FCM"></span><br />
==== Flat Color Mirroring ====<br />
[http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] solves seams by painting a flat set of normals along the seam, using neutral blue (128,128,255). However it only works along horizontal or vertical UV seams, not across any angled UVs. It also removes any details along the mirror seam, creating blank areas. <br />
<br />
<span id="EM"></span><br />
==== Element Mirroring ====<br />
The mirror seam can be avoided completely when it doesn't run directly through any mesh. For example if there's a detached mesh element that runs down the center of the model, this can be uniquely mapped, while the meshes on either side can be mirrors of each other. Whenever the mirrored parts don't share any vertex normals with the non-mirrored parts, there won't be any seams. <br />
<br />
[[image:normalmap_mirrored-binocs-racer445.jpg|frame|none|The middle part (highlighted in red) uses unique non-mirrored UVs, allowing the mesh on the right to be mirrored without any seams. <br>Image by [http://http://racer445.com/ "racer445"]]]<br />
<br />
<span id="SGAHE"></span><br />
<br />
=== Smoothing Groups & Hard Edges ===<br />
Each vertex in a mesh has at least one vertex normal. Vertex normals are used to control the direction a triangle will be lit from; if the normal is facing the light the triangle will be fully lit, if facing away from the light the triangle won't be lit. <br />
<br />
Each vertex however can have more than one vertex normal. When two triangles have different vertex normals along their shared edge, this creates a shading seam, called a ''hard edge'' in most modeling tools. 3ds Max uses ''Smoothing Groups'' to create hard/soft edges, Maya uses ''Harden Edge'' and ''Soften Edge''. These tools create hard and soft edges by splitting and combining the vertex normals.<br />
<br />
[[image:BenMathis_SmoothingGroups_Excerpt.gif|frame|none|Hard edges occur where the vertices have multiple normals. <br>Image by [http://poopinmymouth.com Ben 'poopinmymouth' Mathis] ([http://poopinmymouth.com/process/tips/smoothing_groups.jpg tutorial here])]]<br />
<br />
When a mesh uses all soft normals (a single smoothing group) the lighting has to be interpolated across the extreme differences between the vertex normals. If your renderer doesn't support the same [[#TangentBasis|tangent basis]] that the baker uses, this can produce extreme shading differences across the model, which creates shading artifacts. It is generally best to reduce these extremes when you can because a mismatched renderer can only do so much to counteract it.<br />
<br />
Hard edges are usually best where the model already has a natural seam. For example, you can add a hard edge along the rim of a car's wheel well, to prevent the inside of the wheel well from distorting the shading for the outside of the car body. Mechanical models usually need hard edges where ever the surface bends more than about 45 degrees. <br />
<br />
For most meshes, the best results usually come from adding hard edges where ever there are UV seams. There are no hard rules however, you must experiment with different approaches to find what works best in your game.<br />
<br />
When you use object-space normal maps the vertex normal problem goes away since you're no longer relying on the crude vertex normals of the mesh. An object-space normal map completely ignores vertex normals. Object-space mapping allows you to use all soft edges and no bevels on the low-res mesh, without showing lighting errors.<br />
<br />
<span id="HEDAT"></span><br />
==== Hard Edge Discussions & Tutorials ====<br />
* [http://www.polycount.com/forum/showthread.php?p=2090450#post2090450 Maya MEL Script help needed (UV border edges)]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=73593 Normal Maps: Can Somone Explain This "Black Edge" issue]<br />
* [http://www.polycount.com/forum/showthread.php?t=73566 Normal Maps: Can someone explain normals, tangents and split UVs?]<br />
* [http://www.polycount.com/forum/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max]<br />
* [http://boards.polycount.net/showthread.php?t=68173 Why you should NOT trust 3ds Max's viewport normal-map display!]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/10503-xsi-normal-mapped-cube-looks-bad.html XSI - normal mapped cube looks bad]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/11924-weird-maya-normal-map-seam-artifact-problem-am-i-making-simple-mistake.html Weird Maya normal map seam/artifact problem]<br />
* [http://boards.polycount.net/showthread.php?p=1080600 Seams in Normals when Creating Tiling Environment Trims and other Tiles]<br />
* The tutorial [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing can affect the normal map.<br />
* The tutorial: [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] shows how smoothing affects raycasting.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses the breaking of normals and smoothing groups in general terms.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in the game, not the triangle count.<br />
* The Crysis documentation [http://doc.crymod.com/AssetCreation/PolyBumpReference.html PolyBump Reference] has a section towards the bottom that shows how smoothing affects their baked normal maps.<br />
* The polycount thread [http://boards.polycount.net/showthread.php?t=60694 Toying around with normal map approaches] has a great discussion of how best to use smoothing groups and bevels for better shading.<br />
<br />
<span id="UB"></span><br />
==== Using Bevels ====<br />
Bevels/chamfers generally improve the silhouette of the model, and can also help reflect specular highlights better. <br />
<br />
However bevels tend to produce long thin triangles, which slow down the in-game rendering of your model. Real-time renderers have trouble rendering long thin triangles because they create a lot of sub-pixel areas to render. <br />
<br />
Bevels also balloon the vertex count, which can increase the transform cost and memory usage. Hard edges increase the vertex count too, but not when the edge also shares a seam in UV space. For a good explanation of the vertex count issue, see [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly].<br />
<br />
Using hard edges with matching UV shells tends to give better performance and better cosmetic results than using bevels. However there are differing opinions on this, see the Polycount thread "[http://boards.polycount.net/showthread.php?t=71760 Maya transfer maps help]".<br />
<br />
<span id="EVN"></span><br />
==== Edited Vertex Normals ====<br />
If you use bevels the shading will be improved by editing the vertex normals so the larger flat surfaces have perpendicular normals. The vertex normals are then forced to blend across the smaller bevel faces, instead of across the larger faces. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66139 Superspecular soft edges tutorial chapter 1].<br />
<br />
[[image:oliverio_bevel_normals.gif|frame|none|Bending normals on bevelled models. <br>From the tutorial [http://deadlineproof.com/model-shading-techniques-soft-edge-superspecular/ Shading techniques Superspecular soft edges]<br>Image by [http://deadlineproof.com/ Paolo Oliverio]]]<br />
<br />
== Level of Detail Models ==<br />
See [http://www.polycount.com/forum/showthread.php?p=1216945#post1216945 Problem if you're using 3point-style normals with an LOD].<br />
<br />
<span id="MTHPM"></span><br />
<br />
== Modeling The High-Poly Mesh ==<br />
[[Subdivision Surface Modeling]] and [[DigitalSculpting]] are the techniques most often used for modeling a normal map. <br />
<br />
Some artists prefer to model the in-game mesh first, other artists prefer to model the high-res mesh first, and others start somewhere in the middle. The modeling order is ultimately a personal choice though, all three methods can produce excellent results:<br />
* Build the in-game model, then up-res it and sculpt it.<br />
* Build and sculpt a high resolution model, then build a new in-game model around that.<br />
* Build a basemesh model, up-res and sculpt it, then step down a few levels of detail and use that as a base for building a better in-game mesh.<br />
If the in-game mesh is started from one of the subdivision levels of the basemesh sculpt, various edge loops can be collapsed or new edges can be cut to add/remove detail as necessary.<br />
<br />
<span id="SE"></span><br />
=== Sloped Extrusions ===<br />
[[image:normal_slopes_hatred.jpg|frame|none|Extrusions on the high-poly model should be sloped to make a better normal map. <br>Image by [http://www.hatred.gameartisans.org/ Krzysztof "Hatred" Dolas].]]<br />
<br />
=== Floating Geometry ===<br />
[[image:FloatingGeo.jpg|frame|none|Normal map stores the direction the surface is facing rather than real depth information, thus allowing to save time using floating geometry. <br>To correctly bake AO with floating geo make it a separate object and turn off it's shadow casting. <br>Image by [http://artisaverb.info/ Andrew "d1ver" Maximov].]]<br />
<br />
See also [[3DTutorials/Modeling High-Low Poly Models for Next Gen Games|Modeling High/Low Poly Models for Next Gen Games]] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa]<br />
<br />
<span id="ET"></span><br />
<br />
=== Edge Thickness ===<br />
[[image:normal_edge_thickness.jpg|frame|none|When creating edges of the Highpoly, sometimes you'll need to make them rounded than in real life to <br>work better at the size they will be seen.<br>Image by [http://racer445.com/Evan "racer445" Herbert]]]<br />
<br />
<span id="MRF"></span><span id="MRRCB"></span><br />
<br />
=== mental ray Round Corners Bump ===<br />
The mental ray renderer offers an automatic bevel rendering effect called Round Corners Bump that can be baked into a normal map. This is available in 3ds Max, Maya, and XSI. See [http://boards.polycount.net/showthread.php?t=71995 Zero Effort Beveling for normal maps] - by [http://boards.polycount.net/member.php?u=31662 Robert "r_fletch_r" Fletcher].<br />
<br />
[http://jeffpatton.net/ Jeff Patton] posted about [http://jeffpatton.cgsociety.org/blog/archive/2007/10/ how to expose Round Corners Bump] in 3ds Max so you can use it in other materials.<br />
<br />
[http://cryrid.com/art/ Michael "cryrid" Taylor] posted a tutorial about how to use [http://cryrid.com/images/temp/XSI/zeroeffort_bevels.jpg Round Corners in XSI].<br />
<br />
XSI is able to bake a good normal map with it, but 3ds Max seems to bake it incorrectly, and Maya isn't able to bake the effect at all. Maybe Max might be able to bake it correctly, if the .mi shader is edited to use the correct coordinate space?<br />
<br />
<span id="Baking"></span><span id="B"></span><br />
== Baking ==<br />
The process of transferring normals from the high-res model to the in-game model is often called baking. The baking tool usually starts projecting a certain numerical distance out from the low-poly mesh, and sends rays inwards towards the high-poly mesh. When a ray intersects the high-poly mesh, it records the mesh's surface normal and saves it in the normal map.<br />
<br />
To get an understanding of how all the options affect your normal map, do some test bakes on simple meshes like boxes. They generate quickly so you can experiment with [[#UVCoordinates|UV mirroring]], [[#SGAHE|smoothing groups]], etc. This helps you learn the settings that really matter.<br />
* The tutorial [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] has more examples of ray-casting, plus how to get better results from the bake.<br />
<br />
Baking sub-sections:<br />
# [[#Anti-Aliasing|Anti-Aliasing]]<br />
# [[#Baking_Transparency|Baking Transparency]]<br />
# [[#Edge_Padding|Edge Padding]]<br />
# [[#High_Poly_Materials|High Poly Materials]]<br />
# [[#Reset_Transforms|Reset Transforms]]<br />
# [[#Solving_Intersections|Solving Intersections]]<br />
# [[#Solving_Pixel_Artifacts|Solving Pixel Artifacts]]<br />
# [[#Solving_Wavy_Lines|Solving Wavy Lines]]<br />
# [[#Triangulating|Triangulating]]<br />
# [[#Working_with_Cages|Working with Cages]]<br />
<br />
<span id="AA"></span><br />
=== Anti-Aliasing ===<br />
Turning on super-sampling or anti-aliasing (or whatever multi-ray casting is called in your normal map baking tool) will help to fix any jagged edges where the high-res model overlaps itself within the UV borders of the low-poly mesh, or wherever the background shows through holes in the mesh. Unfortunately this tends to render much much slower, and takes more memory.<br />
<br />
[[image:normalmap_aliasing_knak47.jpg|frame|none|A bake without anti-aliasing shows artifacts where the high-poly mesh has overlaps. <br>Image by [http://www.polycount.com/forum/member.php?u=35938 'knak47']]]<br />
<br />
One trick to speed this up is to render 2x the intended image size then scale the normal map down 1/2 in a paint program like Photoshop. The reduction's pixel resampling will add anti-aliasing for you in a very quick process. After scaling, make sure to re-normalize the map if your game doesn't do that already, because the un-normalized pixels in your normalmap may cause pixelly artifacts in your specular highlights. Re-normalizing can be done with [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA's normal map filter] for Photoshop.<br />
<br />
3ds Max's supersampling doesn't work nicely with edge padding, it produces dark streaks in the padded pixels. If so then turn off padding and re-do the padding later, either by re-baking without supersampling or by using a Photoshop filter like the one that comes with [[#3DTools|Xnormal]].<br />
<br />
=== Baking Transparency ===<br />
Sometimes you need to bake a normal map from an object that uses opacity maps, like a branch with opacity-mapped leaves. Unfortunately baking apps often completely ignore any transparency mapping on your high-poly mesh.<br />
<br />
{|class="wikitable"<br />
|[[image:JoeWilson_ivynormals_error.jpg]] <br />
|[[image:JoeWilson_ivynormals_rendered.jpg]]<br />
|-<br />
|3ds Max's RTT baker causes transparency errors.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|The lighting method bakes perfect transparency.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|}<br />
<br />
To solve this, render a Top view of the mesh. This only works if you're using a planar UV projection for your low-poly mesh and you're baking a tangent-space normal map.<br />
<br />
* Make sure the Top view matches the dimensions of the planar UV projection used by the low-poly mesh. It helps to use an orthographic camera for precise placement.<br />
* On the high-poly mesh either use a specific lighting setup or a use special material shader:<br />
* 1) The lighting setup is described in these tutorials:<br />
* * [http://www.bencloward.com/tutorials_normal_maps11.shtml Creating A Normal Map Right In Your 3D App] by [http://www.bencloward.com/ Ben Cloward]<br />
* *[http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy], Graphics Techniques Consultant, Xbox Content and Design Team<br />
* 2) The material shader does the same thing, but doesn't require lights.<br />
* * [http://www.scriptspot.com/3ds-max/normaltexmap NormalTexMap] scripted map for 3ds Max by [http://www.scriptspot.com/users/dave-locke Dave Locke].<br />
* * [http://www.footools.com/3dsmax_plugins.html InfoTexture] map plugin for 3ds Max by [http://www.footools.com John Burnett]<br />
<br />
[[image:BenCloward_NormalMapLighting.gif|frame|none|The lighting setup for top-down rendering. <br>Image by [http://www.bencloward.com Ben Cloward]]]<br />
<br />
<span id="EP"></span><br />
<br />
=== Edge Padding ===<br />
If a normal map doesn't have enough [[Edge_padding |Edge Padding]], this will create shading seams on the UV borders.<br />
<br />
=== High Poly Materials ===<br />
3ds Max will not bake a normal map properly if the high-res model has a mental ray Arch & Design material applied. If your normal map comes out mostly blank, either use a Standard material or none at all. For an example see the Polycount thread [http://www.polycount.com/forum/showthread.php?t=74792 Render to Texture >:O].<br />
<br />
<span id="RT"></span><br />
=== Reset Transforms ===<br />
Before baking, make sure your low-poly model's transforms have been reset. '''''This is very important!''''' Often during the modeling process a model will be rotated and scaled, but these compounded transforms can create a messy local "space" for the model, which in turn often creates rendering errors for normal maps. <br />
<br />
In 3ds Max, use the Reset Xforms utility then Collapse the Modifier Stack. In Maya use Freeze Transformation. In XSI use the Freeze button.<br />
<br />
<span id="SI"></span><br />
<br />
=== Solving Intersections ===<br />
The projection process often causes problems like misses, or overlaps, or intersections. It can be difficult generating a clean normal map in areas where the high-poly mesh intersects or nearly intersects itself, like in between the fingers of a hand. Setting the ray distance too large will make the baker pick the other finger as the source normal, while setting the ray distance too small will lead to problems at other places on the mesh where the distances between in-game mesh and high-poly mesh are greater.<br />
<br />
Fortunately there are several methods for solving these problems.<br />
<br />
# Change the shape of the cage. Manually edit points on the projection cage to help solve tight bits like the gaps between fingers.<br />
# Limit the projection to matching materials, or matching UVs.<br />
# Explode the meshes. See the polycount thread [http://boards.polycount.net/showthread.php?t=62921 Explode script needed (for baking purposes)].<br />
# Bake two or more times using different cage sizes, and combine them in Photoshop.<br />
<br />
<span id="SPA"></span><br />
<br />
=== Solving Pixel Artifacts ===<br />
[[image:filterMaps_artifact.jpg|frame|none|Random pixel artifacts in the bake. <br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
If you are using 3ds Max's ''Render To Texture'' to bake from one UV layout to another, you may see stray pixels scattered across the bake. This only happens if you are using a copy of the original mesh in the Projection, and that mesh is using a different UV channel than the original mesh.<br />
<br />
There are two solutions for this:<br />
<br />
* Add a Push modifier to the copied mesh, and set it to a low value like 0.01.<br />
- or -<br />
<br />
* Turn off ''Filter Maps'' in the render settings (Rendering menu > Render Setup > Renderer tab > uncheck Filter Maps). To prevent aliasing you may want to enable the Global Supersampler in Render Setup.<br />
<br />
See also [[#Anti-Aliasing]].<br />
<br />
<span id="SWL"></span><br />
<br />
=== Solving Wavy Lines ===<br />
When capturing from a cylindrical shape, often the differences between the low-poly mesh and the high-poly mesh will create a wavy edge in the normal map. There are a couple ways to avoid this:<br />
<br />
# The best way... create your lowpoly model with better supporting edges. See the Polycount threads [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?], [http://boards.polycount.net/showthread.php?t=55754 approach to techy stuff], [http://www.polycount.com/forum/showthread.php?t=72713 Any tips for normal mapping curved surface?].<br />
# Adjust the shape of the cage to influence the directions the rays will be cast. Beware... this work will have to be re-done every time you edit the lowpoly mesh, as the cage will be invalidated. At the bottom of [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm this page of his normal map tutorial], [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to do this in 3ds Max. Same method can be seen in the image below.<br />
# Subdivide the low-res mesh so it more closely matches the high-res mesh. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] has a [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa video tutorial] that shows how to do this in Maya.<br />
# Paint out the wavy line. Beware... this work will have to be re-done every time you re-bake the normal map. The [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
# Use a separate planar-projected mesh for the details that wrap around the barrel area, so the ray-casting is more even. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. For example to add tread around a tire, the tread can be baked from a tread model that is laid out flat, then that bake can layered onto the bake from the cylindrical tire mesh in a paint program.<br />
<br />
[[image:timothy_evison_normalmap_projections.jpg|frame|none|Adjusting the shape of the cage to remove distortion. <br>Image by [http://users.cybercity.dk/~dsl11905/resume/resume.html Timothy "tpe" Evison]]]<br />
<br />
<span id="TRI"></span><br />
<br />
=== Triangulating ===<br />
Before baking, it is usually best to triangulate the low-poly model, converting it from polygons into pure triangles. This prevents the vertex normals from being changed later on, which can create specular artifacts.<br />
<br />
[[image:triangulation_modo_ohare.jpg|frame|none| When quads are triangulated in [http://www.luxology.com/modo/ Modo], the internal edges are sometimes flipped, which causes shading differences.<br>Image by [http://www.farfarer.com/|James "Talon" O'Hare]]]<br />
<br />
<br />
Sometimes a baking tool or a mesh exporter/importer will re-triangulate the polygons. A quad polygon is actually treated as two triangles, and the internal edge between them is often switched diagonally during modeling operations. When the vertices of the quad are moved around in certain shapes, the software's algorithm for polygon models tries to keep the quad surface in a "rational" non-overlapping shape. It does this by switching the internal edge between its triangles.<br />
<br />
<br />
[[image:triangulation_spec_tychovii.jpg|frame|none| The specular highlight is affected by triangulation. Flip edges to fix skewing. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66651 Skewed Specular Highlight?] for pictures and more info.<br> Image by [http://robertkreps.com Robert "TychoVII" Kreps]]]<br />
<br />
<br />
<span id="WWC"></span><br />
<br />
=== Working with Cages ===<br />
''Cage'' has two meanings in the normal-mapping process: a low-poly base for [[subdivision surface modeling]] (usually called the [[DigitalSculpting#BM|basemesh]]), or a ray-casting mesh used for normal map baking. This section covers the ray-casting cage.<br />
<br />
Most normal map baking tools allow you to use a distance-based raycast. A ray is sent outwards along each vertex normal, then at the distance you set a ray is cast back inwards. Where ever that ray intersects the high poly mesh, it will sample the normals from it. <br />
<br />
{|class="wikitable"<br />
|[[Image:Normalmap_raycasting_1.jpg]] <br />
|[[Image:Normalmap_raycasting_2.jpg]]<br />
|-<br />
|Hard edges and a distance-based raycast (gray areas) cause ray misses (yellow) and ray overlaps (cyan).<br> Image by [http://www.mankua.com/ Diego Castaño]<br />
|The gray area shows that using all soft edges (or hard edges and a cage-based raycast) will avoid ray-casting errors from split normals.<br> Image by [http://www.mankua.com/ Diego Castaño] <br />
|}<br />
<br />
Unfortunately with a distance-based raycast, [[#SGAHE|split vertex normals]] will cause the bake to miss parts of the high-res mesh, causing errors and seams. <br />
<br />
Some software allows you to use ''cage mesh'' option instead, which basically inflates a copy of the low-poly mesh, then raycasts inwards from each vertex. This ballooned-out mesh is the cage.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
|<tablebgcolor="#ffaaaa">| <br />
|}<br />
<br />
In 3ds Max the cage controls both the distance and the direction of the raycasting. <br />
<br />
In Maya the cage only controls the distance; the ray direction matches the vertex normals (inverted).<br />
<br />
<span style="text-decoration: line-through"> This may have been fixed in the latest release...<<BR>><br />
In Xnormal the cage is split everywhere the model has [[#SGAHE|hard edges]], causing ray misses in the bake. You can fix the hard edge split problem but it involves an overly complex workflow. You must also repeat the whole process any time you change your mesh:</span><br />
# <s> Load the 3d viewer.</s><br />
# <s> Turn on the cage editing tools.</s><br />
# <s> Select all of the vertices.</s><br />
# <s> Weld all vertices.</s><br />
# <s> Expand the cage as you normally would.</s><br />
# <s> Save out your mesh using the Xnormal format.</s><br />
# <s> Make sure Xnormal is loading the correct mesh.</s><br />
<br />
<span id="P"></span><span id="Painting"></span><br />
<br />
== Painting ==<br />
Don't be afraid to edit normal maps in Photoshop. After all it is just a texture, so you can clone, blur, copy, blend all you want... as long as it looks good of course. Some understanding of [[#RGBChannels|the way colors work]] in normal maps will go a long way in helping you paint effectively.<br />
<br />
A normal map sampled from a high-poly mesh will nearly always be better than one sampled from a texture, since you're actually grabbing "proper" normals from an accurate, highly detailed surface. That means your normal map's pixels will basically be recreating the surface angles of your high-poly mesh, resulting in a very believable look.<br />
<br />
If you only convert an image into a normal-map, it can look very flat, and in some cases it can be completely wrong unless you're very careful about your value ranges. Most image conversion tools assume the input is a heightmap, where black is low and white is high. If you try to convert a diffuse texture that you've painted, the results are often very poor. Often the best results are obtained by baking the large and mid-level details from a high-poly mesh, and then combined with photo-sourced "fine detail" normals for surface details such as fabric weave, scratches and grain.<br />
<br />
Sometimes creating a high poly surface takes more time than your budget allows. For character or significant environment assets then that is the best route, but for less significant environment surfaces working from a heightmap-based texture will provide a good enough result for a much less commitment in time.<br />
<br />
* [http://crazybump.com/ CrazyBump] is a commercial normal map converter.<br />
* [http://www.renderingsystems.com/support/showthread.php?tid=3 ShaderMap] is a commercial normal map converter.<br />
* [http://www.pixplant.com/ PixPlant] is a commercial normal map converter.<br />
* [http://boards.polycount.net/showthread.php?t=68860 NJob] is a free normal map converter.<br />
* [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA normalmap filter for Photoshop] is a free normal map converter.<br />
* [http://xnormal.net Xnormal height-to-normals filter for Photoshop] is a free normal map converter.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm Normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
<br />
=== Flat Color ===<br />
The color (128,128,255) creates normals that are completely perpendicular to the polygon, as long as the vertex normals are also perpendicular. Remember a normal map's per-pixel normals create ''offsets'' from the vertex normals. If you want an area in the normal map to be flat, so it creates no offsets from the vertex normals, then use the color (128,128,255). <br />
<br />
This becomes especially obvious when [[#Mirroring|mirroring a normal map]] and using a shader with a reflection ingredient. Reflection tends to accentuate the angles between the normals, so any errors become much more apparent.<br />
<br />
[[image:normalmap_127seam.jpg|thumb|600px|none| Mirrored normal maps show a seam when (127,127,255) is used for the flat color; 128 is better.<br>Image by [http://www.ericchadwick.com Eric Chadwick]]]<br />
<br />
In a purely logical way, 127 seems like it would be the halfway point between 0 and 255. However 128 is the color that actually works in practice. When a test is done comparing (127,127,255) versus (128,128,255) it becomes obvious that 127 creates a slightly bent normal, and 128 creates a flat one.<br />
<br />
This is because most game pipelines use ''unsigned'' normal maps. For details see the Polycount forum thread [http://www.polycount.com/forum/showpost.php?p=771360&postcount=22 tutorial: fixing mirrored normal map seams].<br />
<br />
<span id="BNMT"></span><br />
<br />
=== Blending Normal Maps Together ===<br />
Blending normal maps together is a quick way to add high-frequency detail like wrinkles, cracks, and the like. Fine details can be painted as a height map, then it can be converted into a normal map using one of the normal map tools. Then this "details" normal map can be blended with a geometry-derived normal map using one of the methods below. <br />
<br />
Here is a comparison of four of the blending methods. Note that in these examples the default values were used for CrazyBump (Intensity 50, Strength 33, Strength 33), but the tool allows each layer's strength to be adjusted individually for stronger or milder results. Each of the normal maps below were [[#Renormalizing|re-normalized]] after blending.<br />
<br />
{|class="wikitable"<br />
|[[image:nrmlmap_blending_methods_Maps.png]]<br />
|[[image:nrmlmap_blending_methods_RTTNormalMapFX.png]]<br />
|-<br />
|The blended normal maps.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|Screenshot of the 3dsmax viewport, using the RTTNormalMap.fx shader.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|}<br />
<br />
The four blending methods used above:<br />
# [http://www.crazybump.com CrazyBump] by Ryan Clark blends normal maps together using calculations in 3D space rather than just in 2D. This does probably the best job at preserving details, and each layer's strength settings can be tweaked individually. <br />
# [http://www.rodgreen.com/?p=4 Combining Normal Maps in Photoshop] by Rod Green blends normal maps together using Linear Dodge mode for the positive values and Difference mode for the negative values, along with a Photoshop Action to simplify the process. It's free, but the results may be less accurate than CrazyBump.<br />
# [http://www.paultosca.com/makingofvarga.html Making of Varga] by [http://www.paultosca.com/ Paul "paultosca" Tosca] blends normal maps together using Overlay mode for the red and green channels and Multiply mode for the blue channel. This gives a slightly stronger bump than the Overlay-only method. [http://www.leocov.com/ Leo "chronic" Covarrubias] has a step-by-step tutorial for this method in [http://www.cgbootcamp.com/tutorials/2009/12/9/photoshop-combine-normal-maps.html CG Bootcamp Combine Normal Maps].<br />
# [[3DTutorials/Normal Map Deepening|Normal Map Deepening]] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to blend normal maps together using Overlay mode. [http://cgtextures.com/content.php?action=tutorial&name=normalmap CGTextures tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] also shows how to create normalmaps using multiple layers (Note: to work with the Overlay blend mode each layer's Output Level should be 128 instead of 255, you can use the Levels tool for this).<br />
<br />
The [http://boards.polycount.net/showthread.php?t=69615 Getting good height from Nvidia-filter normalizing grayscale height] thread on the Polycount forum has a discussion of different painting/blending options. Also see the [[#2DT|2D Tools]] section for painting and conversion tools.<br />
<br />
<span id="PCT"></span><br />
<br />
=== Pre-Created Templates ===<br />
A library of shapes can be developed and stored for later use, to save creation time for future normal maps. Things like screws, ports, pipes, and other doo-dads. These shapes can be stored as bitmaps with transparency so they can be layered into baked normal maps.<br />
<br />
* [http://www.beautifulrobot.com/?p=69 Creating & Using NormalMap "Widgets"] - by ''[http://www.beautifulrobot.com Steev "kobra" Kelly]''<<BR>> How to set up and render template objects.<br />
* [http://www.akramparvez.com/portfolio/scripts/normalmap-widget-for-3ds-max/ NormalMap Widget for 3ds Max] - by ''[http://www.akramparvez.com Akram Parvez]''<<BR>>A script to automate the setup and rendering process.<br />
* See the section [[#BT|Baking Transparency]] for more template-rendering tools and tutorials.<br />
<br />
<span id="RN"></span><span id="Renormalizing"></span><br />
=== Re-normalizing ===<br />
Re-normalizing means resetting the length of each normal in the map to 1.<br />
<br />
A normal mapping shader takes the three color channels of a normal map and combines them to create the direction and length of each pixel's normal. These normals are then used to apply the scene lighting to the mesh. However if you edit normal maps by hand or if you blend multiple normal maps together this can cause those lengths to change. Most shaders expect the length of the normals to always be 1 (normalized), but some are written to re-normalize the normal map dynamically (for example, 3ds Max's Hardware Shaders do re-normalize).<br />
<br />
If the normals in your normal map are not normalized, and your shader doesn't re-normalize them either, then you may see artifacts on the shaded surface... the specular highlight may speckle like crazy, the surface may get patches of odd shadowing, etc. To help you avoid this NVIDIA's normal map filter for Photoshop provides an easy way to re-normalize a map after editing; just use the '''Normalize Only''' option. [http://xnormal.net Xnormal] also comes with a Normalize filter for Photoshop.<br />
<br />
[[image:normalize_only.jpg|frame|none|The re-normalize option in the NVIDIA filter.<br>Image by [http://hirezstudios.com/ Scott Warren]]]<br />
<br />
Some shaders use [[#NormalMapCompression|compressed normal maps]]. Usually this means the blue channel is thrown away completely, so it's recalculated on-the-fly in the shader. However the shader has to re-normalize in order to recreate that data, so any custom normal lengths that were edited into the map will be ignored completely. <br />
<br />
<span id="AOIANM"></span><span id="AmbientOcclusionIntoANormalMap"></span><br />
<br />
=== Ambient Occlusion into a Normal Map ===<br />
If the shader doesn't re-normalize the normal map, an [[Ambient Occlusion Map]] can actually be baked into the normal map. This will shorten the normals in the crevices of the surface, causing the surface to receive less light there. This works with both diffuse and specular, or any other pass that uses the normal map, like reflection.<br />
<br />
However it's usually best to keep the AO as a separate map (or in an alpha channel) and multiply it against the ambient lighting only. This is usually done with a custom [[:Category:Shaders|shader]]. If you multiply it against the diffuse map or normal map then it also occludes diffuse lighting which can make the model look dirty. Ambient occlusion is best when it occludes ambient lighting only, for example a [[DiffuselyConvolvedCubeMap|diffusely convolved cubemap]].<br />
<br />
[[image:nrmlmap_ao.jpg|frame|none| AO can be baked into a normal map, shortening the normals (lower left model).<br>Model by [http://www.3dartisan.net/~kuman/ James Ku]]]<br />
<br />
To bake the AO into a normal map, adjust the levels of the AO layer first so the darks only go as low as 128 gray, then set the AO layer to Darken mode. This will shorten the normals in the normalmap, causing the surface to receive less light in the darker areas. <br />
<br />
This trick doesn't work with any shaders that re-normalize, like 3ds Max's Hardware Shaders. The shader must be altered to actually use the lengths of your custom normals; most shaders just assume all normals are 1 in length because this makes the shader code simpler. Also this trick will not work with most of the common [[#NormalMapCompression|normal map compression formats]], which often discard the blue channel and recalculate it in the shader, which requires re-normalization.<br />
<br />
<span id="BLE"></span><br />
<br />
=== Back Lighting Example ===<br />
You can customize normal maps for some interesting effects. If you invert the blue channel of a tangent-space map, the normals will be pointing to the opposite side of the surface, which can simulate backlighting.<br />
<br />
{|class="wikitable"<br />
|[[image:tree_front.jpg]]||[[image:tree_back.jpg]]<br />
|-<br />
|Tree simulating subsurface scattering (front view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|Tree simulating subsurface scattering (back view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|-<br />
|colspan="2"|[[image:tree_maps.jpg]]<br />
|-<br />
|colspan="2"|The maps used for the leaves. The 2nd diffuse was simply color-inverted, hue-shifted 180°, and saturated.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
The tree leaves use a shader than adds together two diffuse maps, one using a regular tangent-space normal map, the other using the same normal map but with the blue channel inverted. This causes the diffuse map using the regular normal map to only get lit on the side facing the light (front view), while the diffuse map using the inverted normal map only gets lit on the opposite side of the leaves (back view). The leaf geometry is 2-sided but uses the same shader on both sides, so the effect works no matter the lighting angle. As an added bonus, because the tree is self-shadowing the leaves in shadow do not receive direct lighting, which means their backsides do not show the inverted normal map, so the fake subsurface scatter effect only appears where the light directly hits the leaves. This wouldn't work for a whole forest because of the computational cost of self-shadowing and double normal maps, but could be useful for a single "star" asset, or if LODs switched the distant trees to a model that uses a cheaper shader.<br />
<br />
<span id="SAS"></span><br />
<br />
== Shaders and Seams ==<br />
You need to use the right kind of shader to avoid seeing seams where UV breaks occur. It must be written to use the same [[#TangentBasis|tangent basis]] that was used during baking. If the shader doesn't, the lighting will either be inconsistent across UV borders or it will show smoothing errors from the low-poly vertex normals.<br />
<br />
Xnormal generates accurate normals when displayed in Xnormal, and the SDK includes a method to write your own custom tangent space generator for the tool. <br />
<br />
<span id="3MS"></span><br />
=== 3ds Max Shaders ===<br />
The "Render To Texture" tool in 3ds Max 2011 and older generates [[#TSNM|tangent-space]] normal maps that render correctly in the offline renderer (scanline) but do not render correctly in the realtime viewport with the 3ds Max shaders. Max is using a different [[#TangentBasis|tangent basis]] for each. This is readily apparent when creating non-organic hard surface normalmaps; smoothing errors appear in the viewport that do not appear when rendered. <br />
<br />
The errors can be fixed by using "Render To Texture" to bake a [[#TSNM|tangent-space]] or [[#OSNM|object-space]] map, and using the free [http://www.3pointstudios.com/3pointshader_about.shtml "3Point Shader"] by Christoph '[[CrazyButcher]]' Kubisch and Per 'perna' Abrahamsen. The shader uses the same tangent basis as the baking tool, so it produces nearly flawless results. It also works with old bakes.<br />
<br />
You can get OK results in the Max viewport using a tangent-space map baked in Maya, loading it in a Standard material, and enabling "Show Hardware Map in Viewport". Another method is to use Render To Texture to bake an [[#OSNM|object-space]] map then use [[#CBS|Nspace]] to convert it into a tangent-space map then load that in a DirectX material and use the RTTNormalMap.fx shader. <br />
<br />
Autodesk is aware of these issues, and plans to address them in an upcoming release. See these links for more information:<br />
* Christoph "[[CrazyButcher]]" Kubisch and Per "perna" Abrahamsen designed a shader/modifier combination approach that fixes the viewport problem, see the Polycount forum post [http://boards.polycount.net/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max].<br />
* Jean-Francois "jfyelle" Yelle, Autodesk Media & Entertainment Technical Product Manager, has [http://boards.polycount.net/showthread.php?p=1115812#post1115812 this post]. <br />
* Ben Cloward posted [http://boards.polycount.net/showthread.php?p=1100270#post1100270 workarounds and FX code].<br />
* Christopher "cdiggins" Diggins, SDK writer for 3ds Max, shares some of the SDK code in his blog posts "[http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping How the 3ds Max Scanline Renderer Computes Tangent and Binormal Vectors for Normal Mapping]" and "[http://area.autodesk.com/blogs/chris/3ds_max_normal_map_baking_and_face_angle_weighting_the_plot_thickens 3ds Max Normal Map Baking and Face Angle Weighting: The Plot Thickens]".<br />
<br />
[[image:nmtest_uv-splits_thumb.jpg|thumb|600px|none|Comparison of map baking methods in Maya and Max, and Ben Cloward's custom FX code.<br>Image by [http://www.bencloward.com/ Ben Cloward] and [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
[[image:normalmapfix_3pointstudios_thumb.jpg|frame|none|3 Point Studios' normal map display fix for 3ds Max.<br>image by [http://www.3pointstudios.com 3 Point Studios]]]<br />
<br />
{|class="wikitable"<br />
|[[image:max2010_normalmap_workarounds.png|thumb|400px|none|]]<br />
|[[image:max2010_normalmap_compare.png|thumb|400px|none|]]<br />
|-<br />
|Viewport methods in 3ds Max 2010.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick] <br />
|More baking methods in 3ds Max 2010.<br> Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
<span id="3MENT"></span><br />
<br />
=== 3ds Max Edit Normals Trick ===<br />
After baking, if you add an Edit Normals modifier to your low-poly normalmapped model, this seems to "relax" the vertex normals for more accurate viewport shading. The modifier can be collapsed if desired.<br />
<br />
<span id="MS"></span><br />
=== Maya Shaders ===<br />
Maya seems to correctly generate normals to view in realtime, with the correct [[#TangentBasis|tangent basis]], with much less smoothing errors than 3ds Max. <br />
* [http://www.mentalwarp.com/~brice/shader.php BRDF shader] by [http://www.mentalwarp.com/~brice/ Brice Vandemoortele] and [http://www.kjapi.com/ Cedric Caillaud] (more info in [http://boards.polycount.net/showthread.php?t=49920 this Polycount thread]) '''Update:''' [http://boards.polycount.net/showthread.php?p=821862#post821862 New version here] with many updates, including object-space normal maps, relief mapping, self-shadowing, etc. Make sure you enable cgFX shaders in the Maya plugin manager, then you can create them in the same way you create a Lambert, Phong etc. Switch OFF high quality rendering in the viewports to see them correctly too.<br />
* If you want to use the software renderer, use mental ray instead of Maya's software renderer because mental ray correctly interprets tangent space normals. The Maya renderer treats the normal map as a grayscale bump map, giving nasty results. Mental ray supports Maya's Phong shader just fine (amongst others), although it won't recognise a gloss map plugged into the "cosine power" slot. The slider still works though, if you don't mind having a uniform value for gloss. Spec maps work fine though. Just use the same set up as you would for viewport rendering. You'll need to have your textures saved as TGAs or similar for mental ray to work though. - from [http://boards.polycount.net/member.php?u=14235 CheeseOnToast]<br />
<br />
<br />
<span id="NMC"></span><br />
<br />
== Normal Map Compression ==<br />
see; [[Normal Map Compression]]<br />
<br />
== Links ==<br />
<br />
=== Related Pages ===<br />
* [[Curvature map]]<br />
* [[DuDv map]]<br />
* [[Flow map]]<br />
* [[Normal map]]<br />
* [[Radiosity normal map]]<br />
* [[Vector displacement map]]<br />
<br />
<span id="3DT"></span> <span id="Tools"></span> <span id="3DTools"></span><br />
=== 3D Tools ===<br />
See [[:Category:Tools#A3D_Normal_Map_Software|Category:Tools#3D_Normal_Map_Software]]<br />
<br />
<span id="2DT"></span><span id="2DTools"></span><br />
=== 2D Tools ===<br />
See [[:Category:Tools#A2D_Normal_Map_Software|Category:Tools#2D_Normal_Map_Software]]<br />
<br />
<span id="T"></span><span id="Tutorials"></span><br />
=== Tutorials ===<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh tutorial for Max and Xnormal] by [http://www.exisinteractive.com/ PeterK] to prevent heavy distortions when baking with a cage, without the need to add extra supporting vertices.<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games] by [http://www.polycount.com/forum/member.php?u=56680 'SuperFranky']<br />
* [http://area.autodesk.com/userdata/fckdata/239955/The%20Generation%20and%20Display%20of%20Normal%20Maps%20in%203ds%20Max.pdf The Generation and Display of Normal Maps in 3ds Max] (500kb PDF) <<BR>> Excellent whitepaper from Autodesk about normal mapping in 3ds Max and other apps.<br />
* [http://www.katsbits.com/htm/tutorials/blender-baking-normal-maps-from-models.htm Renderbump and baking normal maps from high poly models using Blender 3D] by ''[http://www.katsbits.com/htm/about.htm "katsbits"]''<<BR>>Baking normal maps in Blender.<br />
* [http://udn.epicgames.com/Three/CreatingNormalMaps.html Techniques for Creating Normal Maps] in the Unreal Developer Network's [http://udn.epicgames.com/Three/WebHome.html Unreal Engine 3 section] contains advice from [http://www.epicgames.com/ Epic Games] artists on creating normal maps for UE3. The [http://udn.epicgames.com/Three/DesignWorkflow.html#Creating%20normal%20maps%20from%20meshes Design Workflow page] has a summary.<br />
* [http://www.iddevnet.com/quake4/ArtReference_CreatingModels#head-3400c230e92ff7d57424b2a68f6e0ea75dee4afa Creating Models in Quake 4] by [http://www.ravensoft.com/ Raven Software] is a comprehensive guide to creating Quake 4 characters.<br />
* [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing and UVs can affect normal maps in Doom 3.<br />
* [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] is an overview of modeling for normal maps.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses how smoothing groups and bevels affect the topology of the low-poly model.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in-game, not the triangle or poly count.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm Normal map workflow] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] demonstrates his normal mapping workflow in 3ds Max and Photoshop.<br />
* [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa This video tutorial] by [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] shows in Maya how to subdivide the low-poly mesh so it more closely matches the high-poly mesh, to help solve wavy lines in the bake.<br />
* [http://www.bencloward.com/tutorials_normal_maps1.shtml Normal Mapping Tutorial] by [http://www.bencloward.com/ Ben Cloward] is a comprehensive tutorial about the entire normal map creation process.<br />
* [http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy] shows how to use a special lighting setup to render normal maps (instead of baking them).<br />
* [http://cgtextures.com/content.php?action=tutorial&name=normalmap Tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] shows how to create deep normal maps using multiple layers. Note: to use Overlay blend mode properly, make sure to change each layer's Levels ''Output Level'' to 128 instead of 255.<br />
* [http://www.poopinmymouth.com/process/tips/normalmap_deepening.jpg Normalmap Deepening] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to adjust normal maps, and how to layer together painted and baked normal maps.<br />
* [http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] helps to solve seams along horizontal or vertical UV edges, but not across angled UVs.<br />
* [http://planetpixelemporium.com/tutorialpages/normal.html Cinema 4D and Normal Maps For Games] by [http://planetpixelemporium.com/index.php James Hastings-Trew] describes normal maps in plain language, with tips on creating them in Cinema 4D.<br />
* [http://forums.cgsociety.org/showthread.php?f=39&t=359082 3ds Max normal mapping overview] by [http://www.alan-noon.com/ Alan Noon] is a great thread on CGTalk about the normal mapping process.<br />
* [http://forums.cgsociety.org/showthread.php?f=46&t=373024 Hard Surface Texture Painting] by [http://stefan-morrell.cgsociety.org/gallery/ Stefan Morrell] is a good introduction to painting textures for metal surfaces.<br />
<br />
<span id="D"></span><span id="Discussion"></span><br />
<br />
=== Discussion ===<br />
[http://boards.polycount.net/showthread.php?p=820218 Discuss this page on the Polycount forums]. Suggestions welcome.<br />
<br />
Even though only one person has been editing this page so far, the information here was gathered from many different sources. We wish to thank all the contributors for their hard-earned knowledge. It is much appreciated!<br />
<br />
----<br />
[[Category:TextureTypes]] [[Category:Bump map]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Normal_mapNormal map2015-04-22T15:18:24Z<p>Dustinbrown: /* Common Swizzle Coordinates */</p>
<hr />
<div>== Out of Date ==<br />
The information on this page is a bit old, it needs to be updated. See these links for more current information:<br />
<br />
* [http://farfarer.com/resources.htm RNM Normal Map Combiner], by [http://www.farfarer.com/ James "Farfarer" O'Hare]<br />
* [http://vincentcallebaut.com/CombineNormal.html Combine Normal], by [http://vincentcallebaut.comVincent "Vincentt" Callebaut], [http://www.polycount.com/forum/showthread.php?t=131819 Combine normal maps script for Photoshop] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showpost.php?p=2226864&postcount=51 Earthquake on separating smoothing groups in the UV]<br />
* [http://www.polycount.com/forum/showpost.php?p=2225535&postcount=40 JedTheKrampus on offsetting Mirrored UVs]<br />
* [http://www.polycount.com/forum/showthread.php?t=148303 Of Bit Depths, Banding and Normal Maps]<br />
* [http://www.polycount.com/forum/showthread.php?t=147227 Skew you buddy! Making sense of skewed normal map details.]<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games]<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh Tutorial]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?]<br />
* [http://www.laurenscorijn.com/future-xoliulshader-support.html Future Xoliulshader support] = why Xoliulshader doesn't work properly in 3ds Max 2013/2014.<br />
<br />
== Synched Workflow ==<br />
To eliminate seams and shading artifacts, the model renderer and the normal map baking tool should use the same tangent basis.<br />
<br />
FBX model format can store tangents, and some renderers use this data to synch the incoming normal maps.<br />
<br />
{| class="wikitable sortable" style="color:grey;"<br />
|- <br />
! Renderer !! Normal map baker<br />
|-<br />
| 3ds Max || 3ds Max, Handplane, ?<br />
|-<br />
| Blender || ?<br />
|-<br />
| Creation Engine || Handplane, ?<br />
|-<br />
| CryEngine || ?<br />
|-<br />
| Knald || ?<br />
|-<br />
| Marmoset Toolbag || 3ds Max, Maya, Xnormal, ?<br />
|-<br />
| Maya || Handplane, Maya, ?<br />
|-<br />
| Source || Handplane, Maya ([http://www.polycount.com/forum/showpost.php?p=2224653&postcount=28]), ?<br />
|-<br />
| Starcraft II || Handplane, ?<br />
|-<br />
| Substance Designer || ?<br />
|-<br />
| Unity([http://www.polycount.com/forum/showpost.php?p=2224781&postcount=29], [http://www.polycount.com/forum/showthread.php?p=2194353#post2194353]) || Handplane, Xnormal (via Asset Store), ?<br />
|-<br />
| Unreal Engine 4 || Handplane, Xnormal([http://www.polycount.com/forum/showpost.php?p=2224402&postcount=20]), ? <br />
|-<br />
| Xnormal || Xnormal, ?<br />
|}<br />
<br />
----<br />
<br />
== What is a Normal Map? ==<br />
A Normal Map is usually used to fake high-res geometry detail when it's mapped onto a low-res mesh. The pixels of the normal map each store a ''normal'', a vector that describes the surface slope of the original high-res mesh at that point. The red, green, and blue channels of the normal map are used to control the direction of each pixel's normal. <br />
<br />
When a normal map is applied to a low-poly mesh, the texture pixels control the direction each of the pixels on the low-poly mesh will be facing in 3D space, creating the illusion of more surface detail or better curvature. However, the silhouette of the model doesn't change. <br />
<br />
<gallery mode="packed"><br />
Whatif_normalmap_mapped2.jpg|A model with a normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_low.jpg|The model without its normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_high.jpg|The high-resolution model used to create the normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
</gallery><br />
<br />
==Tangent-Space vs. Object-Space==<br />
<br />
Normal maps can be made in either of two basic flavors: tangent-space or object-space. World-space is basically the same as object-space, except it requires the model to remain in its original orientation, neither rotating nor deforming, so it's almost never used.<br />
<br />
===Tangent-space normal map===<br />
[[image:normalmap_tangentspace.jpg|frame|none|A tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Predominantly-blue colors. Object can rotate and deform. Good for deforming meshes, like characters, animals, flags, etc.<br />
<br />
Pros:<br />
* Maps can be reused easily, like on differently-shaped meshes.<br />
* Maps can be tiled and mirrored easily, though some games might not support mirroring very well.<br />
* Easier to overlay painted details.<br />
* Easier to use image compression.<br />
<br />
Cons:<br />
* More difficult to avoid smoothing problems from the low-poly vertex normals (see Smoothing Groups and Hard Edges).<br />
* Slightly slower performance than an object-space map (but not by much).<br />
<br />
===Object-space normal map===<br />
[[image:normalmap_worldspace.jpg|frame|none|An object-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Rainbow colors. Objects can rotate, but usually shouldn't be deformed, unless the shader has been modified to support deformation. Object-space is also called local-space or model-space. <br />
<br />
Pros:<br />
* Easier to generate high-quality curvature because it completely ignores the crude smoothing of the low-poly vertex normals.<br />
* Slightly better performance than a tangent-space map (but not by much).<br />
<br />
Cons:<br />
* Can't easily reuse maps, different mesh shapes require unique maps.<br />
* Difficult to tile properly, and mirroring requires specific shader support.<br />
* Harder to overlay painted details because the base colors vary across the surface of the mesh. Painted details must be converted into Object Space to be combined properly with the OS map.<br />
* They don't compress very well, since the blue channel can't be recreated in the shader like with tangent-space maps. Also the three color channels contain very different data which doesn't compress well, creating many artifacts. Using a half-resolution object-space map is one option. <br />
<br />
<br clear="all"/><br />
<br />
=== Converting Between Spaces ===<br />
Normal maps can be converted between object space and tangent space, in order to use them with different blending tools and shaders, which require one type or the other. <br />
<br />
Object space maps can also be converted to maps with different tangent bases, to better match the normal maps with the renderer and thus avoid lighting errors.<br />
<br />
* [http://www.handplane3d.com Handplane] by [http://www.alecmoody.com/ Alec Moody] is a tool that converts object space maps into a variety of tangent spaces: 3ds Max, Creation Engine, Maya, Source, Unity, Unreal, etc. See the Polycount Forum thread [http://www.polycount.com/forum/showthread.php?t=116899 Official handplane support thread - Now freeware!!].<br />
<br />
[[File:handplane_illus_1.jpg|frame|none|Handplane interface. <br>Image by [http://www.alecmoody.com/ Alec Moody].]]<br />
<br />
<br />
* [http://boards.polycount.net/showthread.php?p=1072599#post1072599 NSpace] by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] is a tool that converts an object-space normal map into a tangent-space map, which then works seamlessly in the 3ds Max viewport. He converts the map by using the same tangent basis that 3ds Max uses for its hardware shader. To see the results, load the converted map via the ''Normal Bump'' map and enable "Show Hardware Map in Viewport". [http://gameartist.nl/ Osman "osman" Tsjardiwal] created a GUI for NSpace, you can [http://boards.polycount.net/showthread.php?p=1075143#post1075143 download it here], just put it in the same folder as the NSpace exe and run it. <br />
<br />
[[File:NSpace_Gui_osman.png|frame|none|NSpace interface. <br>Image by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] and [http://gameartist.nl Osman "osman" Tsjardiwal].]]<br />
<br />
[http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson] said: "[8Monkey Labs has] a tool that lets you load up your reference mesh and object space map. Then load up your tangent normals, and adjust some sliders for things like tile and amount. We need to load up a mesh to know how to correctly orient the tangent normals or else things will come out upside down or reverse etc. It mostly works, but it tends to "bend" the resulting normals, so you gotta split the mesh up into some smoothing groups before you run it, and then I usually will just composite this "combo" texture over my orig map in Photoshop."<br />
<br />
<span id="RGBC"></span><span id="RGBChannels"></span><br />
<br />
== RGB Channels ==<br />
Shaders can use different techniques to render tangent-space normal maps, but the normal map directions are usually consistent within a game. Usually the red channel of a tangent-space normal map stores the X axis (pointing the normals predominantly leftwards or rightwards), the green channel stores the Y axis (pointing the normals predominantly upwards or downwards), and the blue channel stores the Z axis (pointing the normals outwards away from the surface).<br />
<br />
[[image:tangentspace_rgb.jpg|frame|none|The red, green, and blue channels of a tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you see lighting coming from the wrong angle when you're looking at your normal-mapped model, and the model is using a tangent-space normal map, the normal map shader might be expecting the red or green channel (or both) to point in the opposite direction. To fix this either change the shader, or simply invert the appropriate color channels in an image editor, so that the black pixels become white and the white pixels become black.<br />
<br />
Some shaders expect the color channels to be swapped or re-arranged to work with a particular [[#NormalMapCompression|compression format]]. For example the DXT5_nm format usually expects the X axis to be in the alpha channel, the Y axis to be in the green channel, and the red and blue channels to be empty.<br />
<br />
== Tangent Basis ==<br />
[[#TangentSpaceVsObjectSpace|Tangent-space]] normal maps use a special kind of vertex data called the ''tangent basis''. This is similar to UV coordinates except it provides directionality across the surface, it forms a surface-relative coordinate system for the per-pixel normals stored in the normal map. This coordinate system is required to light a normal mapped surface.<br />
<br />
Each vertex in the tangent basis is a combination of three things: the mesh vertex's normal (influenced by smoothing), the vertex's tangent (usually derived from the V texture coordinate), and the vertex's bitangent (derived in code, also called the binormal). These three vectors create an axis for each vertex, giving it a specific orientation in the tangent space. These axes are used to properly transform the incoming lighting from world space into tangent space, so your normal-mapped model will be lit correctly.<br />
<br />
Light rays are in world space, but the normals stored in the normal map are in tangent space. When the model is being rendered, the light rays must be converted from world space into tangent space, using the tangent basis to get there. At that point the incoming light rays are compared against the directions of the normals in the normal map, and this determines how much each pixel is going to be lit. Alternatively, instead of converting the light rays some shaders will convert the normals in the normal map from tangent space into world space. Then those world-space normals are compared against the light rays, and the model is lit appropriately. The method depends on who wrote the shader, but the end result is the same. Both methods require a tangent basis to transform the lighting.<br />
<br />
When a triangle's vertex normals are pointing straight out, and a pixel in the normal map is neutral blue (128,128,255) this means the pixel's normal will be pointing straight out from the surface of the low-poly mesh. When that pixel normal is tilted towards the left or the right in the tangent coordinate space, it will get either more or less red color, depending on whether the normal map is set to store the X axis as either a positive or a negative value. Same goes for when the normal is tilted up or down in tangent space, it will either get more or less green color. If the vertex normals aren't exactly perpendicular to the triangle, the normal map pixels will be tinted away from neutral blue as well.<br />
<br />
Unfortunately for artists, there are many different ways to calculate the tangent basis: [http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping 3ds Max], [http://download.autodesk.com/us/maya/2011help/index.html?url=./files/Appendix_A_Tangent_and_binormal_vectors.htm,topicNumber=d0e227193 Maya], [http://www.codesampler.com/dx9src/dx9src_4.htm#dx9_dot3_bump_mapping DirectX 9], [http://developer.nvidia.com/object/NVMeshMender.html NVMeshMender], [http://www.terathon.com/code/tangent.html Eric Lengyel], a custom solution, etc. This means a normal map baked in one application probably won't shade correctly in another. Artists must do some testing with different [[#T|baking tools]] to find which works best with their output. When the renderer (or game engine) renders your game model, [[#ShadersAndSeams|the shader]] must use the same tangent basis as the normal map baker, otherwise you'll get incorrect lighting, especially across the seams between UV shells.<br />
<br />
The [http://www.xnormal.net/ xNormal] SDK supports custom tangent basis methods. When a programmer uses it to implement their renderer's own tangent basis, artists can then use Xnormal to bake normal maps that will match their renderer perfectly.<br />
<br />
[[image:tangentseams.jpg|frame|none|When shared edges are at different angles in UV space, different colors will show up<br />
along the seam. The tangent basis uses these colors to light the model properly. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
When you look at a tangent-space normal map for a character, you typically see different colors along the UV seams. This is because the UV shells are often oriented at different angles on the mesh, a necessary evil when translating the 3D mesh into 2D textures. The body might be mapped with a vertical shell, and the arm mapped with a horizontal one. This requires the normals in the normal map to be twisted for the different orientations of those UV shells. The UVs are twisted, so the normals must be twisted in order to compensate. The tangent basis helps reorient (twist) the lighting as it comes into the surface's local space, so the lighting will then look uniform across the normal mapped mesh.<br />
<br />
When an artist tiles a tangent-space normal map across an arbitrary mesh, like a landscape, this tends to shade correctly because the mesh has a uniform direction in tangent space. If the mesh has discontinuous UV coordinates (UV seams), or the normal map has large directional gradients across it, the tangent space won't be uniform anymore so the surface will probably have shading seams.<br />
<br />
== Common Swizzle Coordinates ==<br />
3D Software capable of displaying normal maps will have a native required direction, or "handedness" for the RGB channels in a normal map, sometimes referred to as "Swizzle Coordinates," though [[#SAS|shaders]] can often be written to override this native handedness. You may hear developers refer to "flipping the green channel" in order to get a normal map to display correctly, and this simply indicates that when the normal map was baked, it was authored with the incorrect handedness in the green channel. Left/Down handedness is indicated with a negative (-), and right/up handedness is demarcated with a (+) positive.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
| '''Software''' <br />
| '''Red''' <br />
| '''Green''' <br />
| '''Blue''' <br />
|-<br />
|<#000000>| Maya<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| 3ds Max<br />
| X+<br />
| Y-<br />
| Z+ <br />
|-<br />
|<#000000>| [https://docs.unrealengine.com/latest/INT/Engine/Content/Types/Textures/Properties/index.html Unreal Engine]<br />
| X+ <br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Unity<br />
| X+<br />
| Y+<br />
| Z+<br />
|-<br />
|<#000000>| [https://developer.valvesoftware.com/wiki/Bump_map Source]<br />
| X+<br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Toolbag<br />
| X+<br />
| Y+ <br />
| Z+<br />
|}<br />
<span id="MTLPM"></span><br />
<br />
== Modeling the Low-Poly Mesh ==<br />
The in-game mesh usually needs to be carefully optimized to create a good silhouette, define edge-loops for better deformation, and minimize extreme changes between the vertex normals for better shading (see [[#SmoothingGroupsAndHardEdges|Smoothing Groups & Hard Edges]]).<br />
<br />
In order to create an optimized in-game mesh including a good silhouette and loops for deforming in animation, you can start with the 2nd subdivision level of your [[DigitalSculpting|digital sculpt]], or in some cases with the base mesh itself. Then you can just collapse edge loops or cut in new edges to add/remove detail as necessary. Or you can [[DigitalSculpting#OART|re-toplogize]] from scratch if that works better for you.<br />
<br />
See [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts] on the Polycount forum.<br />
<br />
<span id="UVC"></span><span id="UVCoordinates"></span><br />
=== UV Coordinates ===<br />
Normal map baking tools only capture normals within the 0-1 UV square, any UV bits outside this area are ignored. <br />
<br />
Only one copy of the forward-facing UVs should remain in the 0-1 UV square at baking time. If the mesh uses overlapping UVs, this will likely cause artifacts to appear in the baked map, since the baker will try render each UV shell into the map. Before baking, it's best to move all the overlaps and mirrored bits outside the 0-1 square. <br />
<br />
[[image:Normalmap_uvcoord_offset.jpg|frame|none|The mirrored UVs (in red) are offset 1 unit before baking. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you move all the overlaps and mirrored bits exactly 1 UV unit (any whole number will do), then you can leave them there after the bake and they will still be mapped correctly. You can move them back if you want, it doesn't matter to most game engines. Be aware that ZBrush does use UV offsets to manage mesh visibility, however this usually doesn't matter because the ZBrush cage mesh is often a different mesh than the in-game mesh used for baking.<br />
<br />
You should avoid changing the UVs after baking the normal map, because rotating or mirroring UVs after baking will cause the normal map not to match the [[#TB|tangent basis]] anymore, which will likely cause lighting problems. <br />
<br />
In 3ds Max, W is a third texture coordinate. It's used for 3D procedural textures and for storing vertex color in UV channels (you need 3 axes for RGB, so UVW can store vertex color). Bake problems can be avoided by moving any overlapping UVs to -1 on the W axis, with the same results as moving them 1 unit on the U or V axes. The tool Render To Texture will always bake whatever UVs are the highest along the W axis. However using W can be messy... it's generally hidden unless you purposefully look for it (bad for team work), doesn't get preserved on export to other apps, and high W values can prevent selecting and/or welding UVs. <br />
<br />
<span id="M"></span><span id="Mirroring"></span><br />
<br />
=== Mirroring ===<br />
Normal maps can be mirrored across a model to create symmetrical details, and save UV space, which allows more detail in the normal map since the texture pixels are smaller on the model. <br />
<br />
With [[#OSNM|object-space]] maps, mirroring requires [http://boards.polycount.net/showthread.php?t=53986 specific shader support]. For [[#TSNM|tangent-space]] maps, mirroring typically creates a shading seam, but this can be reduced or hidden altogether, depending on the method used.<br />
<br />
<span id="TMW"></span><br />
==== Typical Mirroring Workflow ====<br />
# Delete the mesh half that will be mirrored. <br />
# Arrange the UVs for the remaining model, filling the UV square.<br />
# Mirror the model to create a "whole" mesh, welding the mesh vertices along the seam. <br />
# Move the mirrored UVs exactly 1 unit (or any whole number) out of the 0-1 UV square.<br />
# Bake the normal map.<br />
<br />
Sometimes an artist will decide to delete half of a symmetrical model before baking. <br />
<br />
This is a mistake however because often the vertex normals along the hole will bend towards the hole a bit; there are no faces on the other side to average the normals with. This will create a strong lighting seam in the normal map. <br />
<br />
It's typically best to use the complete mirrored model to bake the normal map, not just the unique half. <br />
<br />
To prevent the mirrored UVs from causing overlaps or baking errors, move the mirrored [[#UVC|UVs]] out of the 0-1 UV space, so only one copy of the non-mirrored UVs is left within the 0-1 square.<br />
<br />
To avoid texel "leaks" between the UV shells, make sure there's enough [[#Edge_padding|Edge Padding]] around each shell, including along the edges of the normal map. None of the UV shells should be touching the edge of the 0-1 UV square, unless they're meant to tile with the other side of the map.<br />
<br />
<span id="CM"></span><br />
<br />
==== Center Mirroring ====<br />
If the mirror seam runs along the surface of a continuous mesh, like down the center of a human face for example, then it will probably create a lighting seam. <br />
<br />
In Epic Games' [http://www.unrealtechnology.com/technology.php Unreal Engine 3] (UE3) their symmetrical models commonly use centered mirroring. Epic uses materials that mix a [[DetailMap]] with the normal maps; these seem to scatter the diffuse/specular lighting and help minimize the obviousness of the mirror seams. For their [[Light Map]]ped models they use [http://udn.epicgames.com/Three/LightMapUnwrapping.html a technique] that can almost completely hide the mirror seam.<br />
<br />
[[image:Epic_MirroringCicada.jpg|frame|none| In UE3 a center mirror seam is reduced by using a detail normal map. <br> Image by "[http://epicgames.com Epic Games]"]]<br />
<br />
'''''[http://www.zbrushcentral.com/showpost.php?p=573108&postcount=28 GOW2 normal map seams], [http://utforums.epicgames.com/showthread.php?p=27166791#post27166791 UDK normal map seams]'''''<br />
<br />
<span id="OM"></span><br />
<br />
==== Offset Mirroring ====<br />
Offset mirroring is a method where you move the mirror seam off to one side of the model, so the seam doesn't run exactly down the center. For example with a character's head, the UV seam can go down along the side of the head in front of the ear. The UV shell for the nearest ear can then be mirrored to use the area on the other side of the head. <br />
<br />
This avoids the "Rorschach" effect and allows non-symmetrical details, but it still saves texture space because the two sides of the head can be mirrored (they're never seen at the same time anyhow).<br />
<br />
Offset mirroring doesn't get rid of the seam, but it does move it off to a place where it can either be less obvious, or where it can be hidden in a natural seam on the model.<br />
<br />
<span id="FCM"></span><br />
==== Flat Color Mirroring ====<br />
[http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] solves seams by painting a flat set of normals along the seam, using neutral blue (128,128,255). However it only works along horizontal or vertical UV seams, not across any angled UVs. It also removes any details along the mirror seam, creating blank areas. <br />
<br />
<span id="EM"></span><br />
==== Element Mirroring ====<br />
The mirror seam can be avoided completely when it doesn't run directly through any mesh. For example if there's a detached mesh element that runs down the center of the model, this can be uniquely mapped, while the meshes on either side can be mirrors of each other. Whenever the mirrored parts don't share any vertex normals with the non-mirrored parts, there won't be any seams. <br />
<br />
[[image:normalmap_mirrored-binocs-racer445.jpg|frame|none|The middle part (highlighted in red) uses unique non-mirrored UVs, allowing the mesh on the right to be mirrored without any seams. <br>Image by [http://http://racer445.com/ "racer445"]]]<br />
<br />
<span id="SGAHE"></span><br />
<br />
=== Smoothing Groups & Hard Edges ===<br />
Each vertex in a mesh has at least one vertex normal. Vertex normals are used to control the direction a triangle will be lit from; if the normal is facing the light the triangle will be fully lit, if facing away from the light the triangle won't be lit. <br />
<br />
Each vertex however can have more than one vertex normal. When two triangles have different vertex normals along their shared edge, this creates a shading seam, called a ''hard edge'' in most modeling tools. 3ds Max uses ''Smoothing Groups'' to create hard/soft edges, Maya uses ''Harden Edge'' and ''Soften Edge''. These tools create hard and soft edges by splitting and combining the vertex normals.<br />
<br />
[[image:BenMathis_SmoothingGroups_Excerpt.gif|frame|none|Hard edges occur where the vertices have multiple normals. <br>Image by [http://poopinmymouth.com Ben 'poopinmymouth' Mathis] ([http://poopinmymouth.com/process/tips/smoothing_groups.jpg tutorial here])]]<br />
<br />
When a mesh uses all soft normals (a single smoothing group) the lighting has to be interpolated across the extreme differences between the vertex normals. If your renderer doesn't support the same [[#TangentBasis|tangent basis]] that the baker uses, this can produce extreme shading differences across the model, which creates shading artifacts. It is generally best to reduce these extremes when you can because a mismatched renderer can only do so much to counteract it.<br />
<br />
Hard edges are usually best where the model already has a natural seam. For example, you can add a hard edge along the rim of a car's wheel well, to prevent the inside of the wheel well from distorting the shading for the outside of the car body. Mechanical models usually need hard edges where ever the surface bends more than about 45 degrees. <br />
<br />
For most meshes, the best results usually come from adding hard edges where ever there are UV seams. There are no hard rules however, you must experiment with different approaches to find what works best in your game.<br />
<br />
When you use object-space normal maps the vertex normal problem goes away since you're no longer relying on the crude vertex normals of the mesh. An object-space normal map completely ignores vertex normals. Object-space mapping allows you to use all soft edges and no bevels on the low-res mesh, without showing lighting errors.<br />
<br />
<span id="HEDAT"></span><br />
==== Hard Edge Discussions & Tutorials ====<br />
* [http://www.polycount.com/forum/showthread.php?p=2090450#post2090450 Maya MEL Script help needed (UV border edges)]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=73593 Normal Maps: Can Somone Explain This "Black Edge" issue]<br />
* [http://www.polycount.com/forum/showthread.php?t=73566 Normal Maps: Can someone explain normals, tangents and split UVs?]<br />
* [http://www.polycount.com/forum/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max]<br />
* [http://boards.polycount.net/showthread.php?t=68173 Why you should NOT trust 3ds Max's viewport normal-map display!]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/10503-xsi-normal-mapped-cube-looks-bad.html XSI - normal mapped cube looks bad]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/11924-weird-maya-normal-map-seam-artifact-problem-am-i-making-simple-mistake.html Weird Maya normal map seam/artifact problem]<br />
* [http://boards.polycount.net/showthread.php?p=1080600 Seams in Normals when Creating Tiling Environment Trims and other Tiles]<br />
* The tutorial [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing can affect the normal map.<br />
* The tutorial: [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] shows how smoothing affects raycasting.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses the breaking of normals and smoothing groups in general terms.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in the game, not the triangle count.<br />
* The Crysis documentation [http://doc.crymod.com/AssetCreation/PolyBumpReference.html PolyBump Reference] has a section towards the bottom that shows how smoothing affects their baked normal maps.<br />
* The polycount thread [http://boards.polycount.net/showthread.php?t=60694 Toying around with normal map approaches] has a great discussion of how best to use smoothing groups and bevels for better shading.<br />
<br />
<span id="UB"></span><br />
==== Using Bevels ====<br />
Bevels/chamfers generally improve the silhouette of the model, and can also help reflect specular highlights better. <br />
<br />
However bevels tend to produce long thin triangles, which slow down the in-game rendering of your model. Real-time renderers have trouble rendering long thin triangles because they create a lot of sub-pixel areas to render. <br />
<br />
Bevels also balloon the vertex count, which can increase the transform cost and memory usage. Hard edges increase the vertex count too, but not when the edge also shares a seam in UV space. For a good explanation of the vertex count issue, see [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly].<br />
<br />
Using hard edges with matching UV shells tends to give better performance and better cosmetic results than using bevels. However there are differing opinions on this, see the Polycount thread "[http://boards.polycount.net/showthread.php?t=71760 Maya transfer maps help]".<br />
<br />
<span id="EVN"></span><br />
==== Edited Vertex Normals ====<br />
If you use bevels the shading will be improved by editing the vertex normals so the larger flat surfaces have perpendicular normals. The vertex normals are then forced to blend across the smaller bevel faces, instead of across the larger faces. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66139 Superspecular soft edges tutorial chapter 1].<br />
<br />
[[image:oliverio_bevel_normals.gif|frame|none|Bending normals on bevelled models. <br>From the tutorial [http://deadlineproof.com/model-shading-techniques-soft-edge-superspecular/ Shading techniques Superspecular soft edges]<br>Image by [http://deadlineproof.com/ Paolo Oliverio]]]<br />
<br />
== Level of Detail Models ==<br />
See [http://www.polycount.com/forum/showthread.php?p=1216945#post1216945 Problem if you're using 3point-style normals with an LOD].<br />
<br />
<span id="MTHPM"></span><br />
<br />
== Modeling The High-Poly Mesh ==<br />
[[Subdivision Surface Modeling]] and [[DigitalSculpting]] are the techniques most often used for modeling a normal map. <br />
<br />
Some artists prefer to model the in-game mesh first, other artists prefer to model the high-res mesh first, and others start somewhere in the middle. The modeling order is ultimately a personal choice though, all three methods can produce excellent results:<br />
* Build the in-game model, then up-res it and sculpt it.<br />
* Build and sculpt a high resolution model, then build a new in-game model around that.<br />
* Build a basemesh model, up-res and sculpt it, then step down a few levels of detail and use that as a base for building a better in-game mesh.<br />
If the in-game mesh is started from one of the subdivision levels of the basemesh sculpt, various edge loops can be collapsed or new edges can be cut to add/remove detail as necessary.<br />
<br />
<span id="SE"></span><br />
=== Sloped Extrusions ===<br />
[[image:normal_slopes_hatred.jpg|frame|none|Extrusions on the high-poly model should be sloped to make a better normal map. <br>Image by [http://www.hatred.gameartisans.org/ Krzysztof "Hatred" Dolas].]]<br />
<br />
=== Floating Geometry ===<br />
[[image:FloatingGeo.jpg|frame|none|Normal map stores the direction the surface is facing rather than real depth information, thus allowing to save time using floating geometry. <br>To correctly bake AO with floating geo make it a separate object and turn off it's shadow casting. <br>Image by [http://artisaverb.info/ Andrew "d1ver" Maximov].]]<br />
<br />
See also [[3DTutorials/Modeling High-Low Poly Models for Next Gen Games|Modeling High/Low Poly Models for Next Gen Games]] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa]<br />
<br />
<span id="ET"></span><br />
<br />
=== Edge Thickness ===<br />
[[image:normal_edge_thickness.jpg|frame|none|When creating edges of the Highpoly, sometimes you'll need to make them rounded than in real life to <br>work better at the size they will be seen.<br>Image by [http://racer445.com/Evan "racer445" Herbert]]]<br />
<br />
<span id="MRF"></span><span id="MRRCB"></span><br />
<br />
=== mental ray Round Corners Bump ===<br />
The mental ray renderer offers an automatic bevel rendering effect called Round Corners Bump that can be baked into a normal map. This is available in 3ds Max, Maya, and XSI. See [http://boards.polycount.net/showthread.php?t=71995 Zero Effort Beveling for normal maps] - by [http://boards.polycount.net/member.php?u=31662 Robert "r_fletch_r" Fletcher].<br />
<br />
[http://jeffpatton.net/ Jeff Patton] posted about [http://jeffpatton.cgsociety.org/blog/archive/2007/10/ how to expose Round Corners Bump] in 3ds Max so you can use it in other materials.<br />
<br />
[http://cryrid.com/art/ Michael "cryrid" Taylor] posted a tutorial about how to use [http://cryrid.com/images/temp/XSI/zeroeffort_bevels.jpg Round Corners in XSI].<br />
<br />
XSI is able to bake a good normal map with it, but 3ds Max seems to bake it incorrectly, and Maya isn't able to bake the effect at all. Maybe Max might be able to bake it correctly, if the .mi shader is edited to use the correct coordinate space?<br />
<br />
<span id="Baking"></span><span id="B"></span><br />
== Baking ==<br />
The process of transferring normals from the high-res model to the in-game model is often called baking. The baking tool usually starts projecting a certain numerical distance out from the low-poly mesh, and sends rays inwards towards the high-poly mesh. When a ray intersects the high-poly mesh, it records the mesh's surface normal and saves it in the normal map.<br />
<br />
To get an understanding of how all the options affect your normal map, do some test bakes on simple meshes like boxes. They generate quickly so you can experiment with [[#UVCoordinates|UV mirroring]], [[#SGAHE|smoothing groups]], etc. This helps you learn the settings that really matter.<br />
* The tutorial [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] has more examples of ray-casting, plus how to get better results from the bake.<br />
<br />
Baking sub-sections:<br />
# [[#Anti-Aliasing|Anti-Aliasing]]<br />
# [[#Baking_Transparency|Baking Transparency]]<br />
# [[#Edge_Padding|Edge Padding]]<br />
# [[#High_Poly_Materials|High Poly Materials]]<br />
# [[#Reset_Transforms|Reset Transforms]]<br />
# [[#Solving_Intersections|Solving Intersections]]<br />
# [[#Solving_Pixel_Artifacts|Solving Pixel Artifacts]]<br />
# [[#Solving_Wavy_Lines|Solving Wavy Lines]]<br />
# [[#Triangulating|Triangulating]]<br />
# [[#Working_with_Cages|Working with Cages]]<br />
<br />
<span id="AA"></span><br />
=== Anti-Aliasing ===<br />
Turning on super-sampling or anti-aliasing (or whatever multi-ray casting is called in your normal map baking tool) will help to fix any jagged edges where the high-res model overlaps itself within the UV borders of the low-poly mesh, or wherever the background shows through holes in the mesh. Unfortunately this tends to render much much slower, and takes more memory.<br />
<br />
[[image:normalmap_aliasing_knak47.jpg|frame|none|A bake without anti-aliasing shows artifacts where the high-poly mesh has overlaps. <br>Image by [http://www.polycount.com/forum/member.php?u=35938 'knak47']]]<br />
<br />
One trick to speed this up is to render 2x the intended image size then scale the normal map down 1/2 in a paint program like Photoshop. The reduction's pixel resampling will add anti-aliasing for you in a very quick process. After scaling, make sure to re-normalize the map if your game doesn't do that already, because the un-normalized pixels in your normalmap may cause pixelly artifacts in your specular highlights. Re-normalizing can be done with [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA's normal map filter] for Photoshop.<br />
<br />
3ds Max's supersampling doesn't work nicely with edge padding, it produces dark streaks in the padded pixels. If so then turn off padding and re-do the padding later, either by re-baking without supersampling or by using a Photoshop filter like the one that comes with [[#3DTools|Xnormal]].<br />
<br />
=== Baking Transparency ===<br />
Sometimes you need to bake a normal map from an object that uses opacity maps, like a branch with opacity-mapped leaves. Unfortunately baking apps often completely ignore any transparency mapping on your high-poly mesh.<br />
<br />
{|class="wikitable"<br />
|[[image:JoeWilson_ivynormals_error.jpg]] <br />
|[[image:JoeWilson_ivynormals_rendered.jpg]]<br />
|-<br />
|3ds Max's RTT baker causes transparency errors.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|The lighting method bakes perfect transparency.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|}<br />
<br />
To solve this, render a Top view of the mesh. This only works if you're using a planar UV projection for your low-poly mesh and you're baking a tangent-space normal map.<br />
<br />
* Make sure the Top view matches the dimensions of the planar UV projection used by the low-poly mesh. It helps to use an orthographic camera for precise placement.<br />
* On the high-poly mesh either use a specific lighting setup or a use special material shader:<br />
* 1) The lighting setup is described in these tutorials:<br />
* * [http://www.bencloward.com/tutorials_normal_maps11.shtml Creating A Normal Map Right In Your 3D App] by [http://www.bencloward.com/ Ben Cloward]<br />
* *[http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy], Graphics Techniques Consultant, Xbox Content and Design Team<br />
* 2) The material shader does the same thing, but doesn't require lights.<br />
* * [http://www.scriptspot.com/3ds-max/normaltexmap NormalTexMap] scripted map for 3ds Max by [http://www.scriptspot.com/users/dave-locke Dave Locke].<br />
* * [http://www.footools.com/3dsmax_plugins.html InfoTexture] map plugin for 3ds Max by [http://www.footools.com John Burnett]<br />
<br />
[[image:BenCloward_NormalMapLighting.gif|frame|none|The lighting setup for top-down rendering. <br>Image by [http://www.bencloward.com Ben Cloward]]]<br />
<br />
<span id="EP"></span><br />
<br />
=== Edge Padding ===<br />
If a normal map doesn't have enough [[Edge_padding |Edge Padding]], this will create shading seams on the UV borders.<br />
<br />
=== High Poly Materials ===<br />
3ds Max will not bake a normal map properly if the high-res model has a mental ray Arch & Design material applied. If your normal map comes out mostly blank, either use a Standard material or none at all. For an example see the Polycount thread [http://www.polycount.com/forum/showthread.php?t=74792 Render to Texture >:O].<br />
<br />
<span id="RT"></span><br />
=== Reset Transforms ===<br />
Before baking, make sure your low-poly model's transforms have been reset. '''''This is very important!''''' Often during the modeling process a model will be rotated and scaled, but these compounded transforms can create a messy local "space" for the model, which in turn often creates rendering errors for normal maps. <br />
<br />
In 3ds Max, use the Reset Xforms utility then Collapse the Modifier Stack. In Maya use Freeze Transformation. In XSI use the Freeze button.<br />
<br />
<span id="SI"></span><br />
<br />
=== Solving Intersections ===<br />
The projection process often causes problems like misses, or overlaps, or intersections. It can be difficult generating a clean normal map in areas where the high-poly mesh intersects or nearly intersects itself, like in between the fingers of a hand. Setting the ray distance too large will make the baker pick the other finger as the source normal, while setting the ray distance too small will lead to problems at other places on the mesh where the distances between in-game mesh and high-poly mesh are greater.<br />
<br />
Fortunately there are several methods for solving these problems.<br />
<br />
# Change the shape of the cage. Manually edit points on the projection cage to help solve tight bits like the gaps between fingers.<br />
# Limit the projection to matching materials, or matching UVs.<br />
# Explode the meshes. See the polycount thread [http://boards.polycount.net/showthread.php?t=62921 Explode script needed (for baking purposes)].<br />
# Bake two or more times using different cage sizes, and combine them in Photoshop.<br />
<br />
<span id="SPA"></span><br />
<br />
=== Solving Pixel Artifacts ===<br />
[[image:filterMaps_artifact.jpg|frame|none|Random pixel artifacts in the bake. <br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
If you are using 3ds Max's ''Render To Texture'' to bake from one UV layout to another, you may see stray pixels scattered across the bake. This only happens if you are using a copy of the original mesh in the Projection, and that mesh is using a different UV channel than the original mesh.<br />
<br />
There are two solutions for this:<br />
<br />
* Add a Push modifier to the copied mesh, and set it to a low value like 0.01.<br />
- or -<br />
<br />
* Turn off ''Filter Maps'' in the render settings (Rendering menu > Render Setup > Renderer tab > uncheck Filter Maps). To prevent aliasing you may want to enable the Global Supersampler in Render Setup.<br />
<br />
See also [[#Anti-Aliasing]].<br />
<br />
<span id="SWL"></span><br />
<br />
=== Solving Wavy Lines ===<br />
When capturing from a cylindrical shape, often the differences between the low-poly mesh and the high-poly mesh will create a wavy edge in the normal map. There are a couple ways to avoid this:<br />
<br />
# The best way... create your lowpoly model with better supporting edges. See the Polycount threads [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?], [http://boards.polycount.net/showthread.php?t=55754 approach to techy stuff], [http://www.polycount.com/forum/showthread.php?t=72713 Any tips for normal mapping curved surface?].<br />
# Adjust the shape of the cage to influence the directions the rays will be cast. Beware... this work will have to be re-done every time you edit the lowpoly mesh, as the cage will be invalidated. At the bottom of [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm this page of his normal map tutorial], [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to do this in 3ds Max. Same method can be seen in the image below.<br />
# Subdivide the low-res mesh so it more closely matches the high-res mesh. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] has a [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa video tutorial] that shows how to do this in Maya.<br />
# Paint out the wavy line. Beware... this work will have to be re-done every time you re-bake the normal map. The [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
# Use a separate planar-projected mesh for the details that wrap around the barrel area, so the ray-casting is more even. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. For example to add tread around a tire, the tread can be baked from a tread model that is laid out flat, then that bake can layered onto the bake from the cylindrical tire mesh in a paint program.<br />
<br />
[[image:timothy_evison_normalmap_projections.jpg|frame|none|Adjusting the shape of the cage to remove distortion. <br>Image by [http://users.cybercity.dk/~dsl11905/resume/resume.html Timothy "tpe" Evison]]]<br />
<br />
<span id="TRI"></span><br />
<br />
=== Triangulating ===<br />
Before baking, it is usually best to triangulate the low-poly model, converting it from polygons into pure triangles. This prevents the vertex normals from being changed later on, which can create specular artifacts.<br />
<br />
[[image:triangulation_modo_ohare.jpg|frame|none| When quads are triangulated in [http://www.luxology.com/modo/ Modo], the internal edges are sometimes flipped, which causes shading differences.<br>Image by [http://www.farfarer.com/|James "Talon" O'Hare]]]<br />
<br />
<br />
Sometimes a baking tool or a mesh exporter/importer will re-triangulate the polygons. A quad polygon is actually treated as two triangles, and the internal edge between them is often switched diagonally during modeling operations. When the vertices of the quad are moved around in certain shapes, the software's algorithm for polygon models tries to keep the quad surface in a "rational" non-overlapping shape. It does this by switching the internal edge between its triangles.<br />
<br />
<br />
[[image:triangulation_spec_tychovii.jpg|frame|none| The specular highlight is affected by triangulation. Flip edges to fix skewing. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66651 Skewed Specular Highlight?] for pictures and more info.<br> Image by [http://robertkreps.com Robert "TychoVII" Kreps]]]<br />
<br />
<br />
<span id="WWC"></span><br />
<br />
=== Working with Cages ===<br />
''Cage'' has two meanings in the normal-mapping process: a low-poly base for [[subdivision surface modeling]] (usually called the [[DigitalSculpting#BM|basemesh]]), or a ray-casting mesh used for normal map baking. This section covers the ray-casting cage.<br />
<br />
Most normal map baking tools allow you to use a distance-based raycast. A ray is sent outwards along each vertex normal, then at the distance you set a ray is cast back inwards. Where ever that ray intersects the high poly mesh, it will sample the normals from it. <br />
<br />
{|class="wikitable"<br />
|[[Image:Normalmap_raycasting_1.jpg]] <br />
|[[Image:Normalmap_raycasting_2.jpg]]<br />
|-<br />
|Hard edges and a distance-based raycast (gray areas) cause ray misses (yellow) and ray overlaps (cyan).<br> Image by [http://www.mankua.com/ Diego Castaño]<br />
|The gray area shows that using all soft edges (or hard edges and a cage-based raycast) will avoid ray-casting errors from split normals.<br> Image by [http://www.mankua.com/ Diego Castaño] <br />
|}<br />
<br />
Unfortunately with a distance-based raycast, [[#SGAHE|split vertex normals]] will cause the bake to miss parts of the high-res mesh, causing errors and seams. <br />
<br />
Some software allows you to use ''cage mesh'' option instead, which basically inflates a copy of the low-poly mesh, then raycasts inwards from each vertex. This ballooned-out mesh is the cage.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
|<tablebgcolor="#ffaaaa">| <br />
|}<br />
<br />
In 3ds Max the cage controls both the distance and the direction of the raycasting. <br />
<br />
In Maya the cage only controls the distance; the ray direction matches the vertex normals (inverted).<br />
<br />
<span style="text-decoration: line-through"> This may have been fixed in the latest release...<<BR>><br />
In Xnormal the cage is split everywhere the model has [[#SGAHE|hard edges]], causing ray misses in the bake. You can fix the hard edge split problem but it involves an overly complex workflow. You must also repeat the whole process any time you change your mesh:</span><br />
# <s> Load the 3d viewer.</s><br />
# <s> Turn on the cage editing tools.</s><br />
# <s> Select all of the vertices.</s><br />
# <s> Weld all vertices.</s><br />
# <s> Expand the cage as you normally would.</s><br />
# <s> Save out your mesh using the Xnormal format.</s><br />
# <s> Make sure Xnormal is loading the correct mesh.</s><br />
<br />
<span id="P"></span><span id="Painting"></span><br />
<br />
== Painting ==<br />
Don't be afraid to edit normal maps in Photoshop. After all it is just a texture, so you can clone, blur, copy, blend all you want... as long as it looks good of course. Some understanding of [[#RGBChannels|the way colors work]] in normal maps will go a long way in helping you paint effectively.<br />
<br />
A normal map sampled from a high-poly mesh will nearly always be better than one sampled from a texture, since you're actually grabbing "proper" normals from an accurate, highly detailed surface. That means your normal map's pixels will basically be recreating the surface angles of your high-poly mesh, resulting in a very believable look.<br />
<br />
If you only convert an image into a normal-map, it can look very flat, and in some cases it can be completely wrong unless you're very careful about your value ranges. Most image conversion tools assume the input is a heightmap, where black is low and white is high. If you try to convert a diffuse texture that you've painted, the results are often very poor. Often the best results are obtained by baking the large and mid-level details from a high-poly mesh, and then combined with photo-sourced "fine detail" normals for surface details such as fabric weave, scratches and grain.<br />
<br />
Sometimes creating a high poly surface takes more time than your budget allows. For character or significant environment assets then that is the best route, but for less significant environment surfaces working from a heightmap-based texture will provide a good enough result for a much less commitment in time.<br />
<br />
* [http://crazybump.com/ CrazyBump] is a commercial normal map converter.<br />
* [http://www.renderingsystems.com/support/showthread.php?tid=3 ShaderMap] is a commercial normal map converter.<br />
* [http://www.pixplant.com/ PixPlant] is a commercial normal map converter.<br />
* [http://boards.polycount.net/showthread.php?t=68860 NJob] is a free normal map converter.<br />
* [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA normalmap filter for Photoshop] is a free normal map converter.<br />
* [http://xnormal.net Xnormal height-to-normals filter for Photoshop] is a free normal map converter.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm Normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
<br />
=== Flat Color ===<br />
The color (128,128,255) creates normals that are completely perpendicular to the polygon, as long as the vertex normals are also perpendicular. Remember a normal map's per-pixel normals create ''offsets'' from the vertex normals. If you want an area in the normal map to be flat, so it creates no offsets from the vertex normals, then use the color (128,128,255). <br />
<br />
This becomes especially obvious when [[#Mirroring|mirroring a normal map]] and using a shader with a reflection ingredient. Reflection tends to accentuate the angles between the normals, so any errors become much more apparent.<br />
<br />
[[image:normalmap_127seam.jpg|thumb|600px|none| Mirrored normal maps show a seam when (127,127,255) is used for the flat color; 128 is better.<br>Image by [http://www.ericchadwick.com Eric Chadwick]]]<br />
<br />
In a purely logical way, 127 seems like it would be the halfway point between 0 and 255. However 128 is the color that actually works in practice. When a test is done comparing (127,127,255) versus (128,128,255) it becomes obvious that 127 creates a slightly bent normal, and 128 creates a flat one.<br />
<br />
This is because most game pipelines use ''unsigned'' normal maps. For details see the Polycount forum thread [http://www.polycount.com/forum/showpost.php?p=771360&postcount=22 tutorial: fixing mirrored normal map seams].<br />
<br />
<span id="BNMT"></span><br />
<br />
=== Blending Normal Maps Together ===<br />
Blending normal maps together is a quick way to add high-frequency detail like wrinkles, cracks, and the like. Fine details can be painted as a height map, then it can be converted into a normal map using one of the normal map tools. Then this "details" normal map can be blended with a geometry-derived normal map using one of the methods below. <br />
<br />
Here is a comparison of four of the blending methods. Note that in these examples the default values were used for CrazyBump (Intensity 50, Strength 33, Strength 33), but the tool allows each layer's strength to be adjusted individually for stronger or milder results. Each of the normal maps below were [[#Renormalizing|re-normalized]] after blending.<br />
<br />
{|class="wikitable"<br />
|[[image:nrmlmap_blending_methods_Maps.png]]<br />
|[[image:nrmlmap_blending_methods_RTTNormalMapFX.png]]<br />
|-<br />
|The blended normal maps.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|Screenshot of the 3dsmax viewport, using the RTTNormalMap.fx shader.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|}<br />
<br />
The four blending methods used above:<br />
# [http://www.crazybump.com CrazyBump] by Ryan Clark blends normal maps together using calculations in 3D space rather than just in 2D. This does probably the best job at preserving details, and each layer's strength settings can be tweaked individually. <br />
# [http://www.rodgreen.com/?p=4 Combining Normal Maps in Photoshop] by Rod Green blends normal maps together using Linear Dodge mode for the positive values and Difference mode for the negative values, along with a Photoshop Action to simplify the process. It's free, but the results may be less accurate than CrazyBump.<br />
# [http://www.paultosca.com/makingofvarga.html Making of Varga] by [http://www.paultosca.com/ Paul "paultosca" Tosca] blends normal maps together using Overlay mode for the red and green channels and Multiply mode for the blue channel. This gives a slightly stronger bump than the Overlay-only method. [http://www.leocov.com/ Leo "chronic" Covarrubias] has a step-by-step tutorial for this method in [http://www.cgbootcamp.com/tutorials/2009/12/9/photoshop-combine-normal-maps.html CG Bootcamp Combine Normal Maps].<br />
# [[3DTutorials/Normal Map Deepening|Normal Map Deepening]] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to blend normal maps together using Overlay mode. [http://cgtextures.com/content.php?action=tutorial&name=normalmap CGTextures tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] also shows how to create normalmaps using multiple layers (Note: to work with the Overlay blend mode each layer's Output Level should be 128 instead of 255, you can use the Levels tool for this).<br />
<br />
The [http://boards.polycount.net/showthread.php?t=69615 Getting good height from Nvidia-filter normalizing grayscale height] thread on the Polycount forum has a discussion of different painting/blending options. Also see the [[#2DT|2D Tools]] section for painting and conversion tools.<br />
<br />
<span id="PCT"></span><br />
<br />
=== Pre-Created Templates ===<br />
A library of shapes can be developed and stored for later use, to save creation time for future normal maps. Things like screws, ports, pipes, and other doo-dads. These shapes can be stored as bitmaps with transparency so they can be layered into baked normal maps.<br />
<br />
* [http://www.beautifulrobot.com/?p=69 Creating & Using NormalMap "Widgets"] - by ''[http://www.beautifulrobot.com Steev "kobra" Kelly]''<<BR>> How to set up and render template objects.<br />
* [http://www.akramparvez.com/portfolio/scripts/normalmap-widget-for-3ds-max/ NormalMap Widget for 3ds Max] - by ''[http://www.akramparvez.com Akram Parvez]''<<BR>>A script to automate the setup and rendering process.<br />
* See the section [[#BT|Baking Transparency]] for more template-rendering tools and tutorials.<br />
<br />
<span id="RN"></span><span id="Renormalizing"></span><br />
=== Re-normalizing ===<br />
Re-normalizing means resetting the length of each normal in the map to 1.<br />
<br />
A normal mapping shader takes the three color channels of a normal map and combines them to create the direction and length of each pixel's normal. These normals are then used to apply the scene lighting to the mesh. However if you edit normal maps by hand or if you blend multiple normal maps together this can cause those lengths to change. Most shaders expect the length of the normals to always be 1 (normalized), but some are written to re-normalize the normal map dynamically (for example, 3ds Max's Hardware Shaders do re-normalize).<br />
<br />
If the normals in your normal map are not normalized, and your shader doesn't re-normalize them either, then you may see artifacts on the shaded surface... the specular highlight may speckle like crazy, the surface may get patches of odd shadowing, etc. To help you avoid this NVIDIA's normal map filter for Photoshop provides an easy way to re-normalize a map after editing; just use the '''Normalize Only''' option. [http://xnormal.net Xnormal] also comes with a Normalize filter for Photoshop.<br />
<br />
[[image:normalize_only.jpg|frame|none|The re-normalize option in the NVIDIA filter.<br>Image by [http://hirezstudios.com/ Scott Warren]]]<br />
<br />
Some shaders use [[#NormalMapCompression|compressed normal maps]]. Usually this means the blue channel is thrown away completely, so it's recalculated on-the-fly in the shader. However the shader has to re-normalize in order to recreate that data, so any custom normal lengths that were edited into the map will be ignored completely. <br />
<br />
<span id="AOIANM"></span><span id="AmbientOcclusionIntoANormalMap"></span><br />
<br />
=== Ambient Occlusion into a Normal Map ===<br />
If the shader doesn't re-normalize the normal map, an [[Ambient Occlusion Map]] can actually be baked into the normal map. This will shorten the normals in the crevices of the surface, causing the surface to receive less light there. This works with both diffuse and specular, or any other pass that uses the normal map, like reflection.<br />
<br />
However it's usually best to keep the AO as a separate map (or in an alpha channel) and multiply it against the ambient lighting only. This is usually done with a custom [[:Category:Shaders|shader]]. If you multiply it against the diffuse map or normal map then it also occludes diffuse lighting which can make the model look dirty. Ambient occlusion is best when it occludes ambient lighting only, for example a [[DiffuselyConvolvedCubeMap|diffusely convolved cubemap]].<br />
<br />
[[image:nrmlmap_ao.jpg|frame|none| AO can be baked into a normal map, shortening the normals (lower left model).<br>Model by [http://www.3dartisan.net/~kuman/ James Ku]]]<br />
<br />
To bake the AO into a normal map, adjust the levels of the AO layer first so the darks only go as low as 128 gray, then set the AO layer to Darken mode. This will shorten the normals in the normalmap, causing the surface to receive less light in the darker areas. <br />
<br />
This trick doesn't work with any shaders that re-normalize, like 3ds Max's Hardware Shaders. The shader must be altered to actually use the lengths of your custom normals; most shaders just assume all normals are 1 in length because this makes the shader code simpler. Also this trick will not work with most of the common [[#NormalMapCompression|normal map compression formats]], which often discard the blue channel and recalculate it in the shader, which requires re-normalization.<br />
<br />
<span id="BLE"></span><br />
<br />
=== Back Lighting Example ===<br />
You can customize normal maps for some interesting effects. If you invert the blue channel of a tangent-space map, the normals will be pointing to the opposite side of the surface, which can simulate backlighting.<br />
<br />
{|class="wikitable"<br />
|[[image:tree_front.jpg]]||[[image:tree_back.jpg]]<br />
|-<br />
|Tree simulating subsurface scattering (front view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|Tree simulating subsurface scattering (back view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|-<br />
|colspan="2"|[[image:tree_maps.jpg]]<br />
|-<br />
|colspan="2"|The maps used for the leaves. The 2nd diffuse was simply color-inverted, hue-shifted 180°, and saturated.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
The tree leaves use a shader than adds together two diffuse maps, one using a regular tangent-space normal map, the other using the same normal map but with the blue channel inverted. This causes the diffuse map using the regular normal map to only get lit on the side facing the light (front view), while the diffuse map using the inverted normal map only gets lit on the opposite side of the leaves (back view). The leaf geometry is 2-sided but uses the same shader on both sides, so the effect works no matter the lighting angle. As an added bonus, because the tree is self-shadowing the leaves in shadow do not receive direct lighting, which means their backsides do not show the inverted normal map, so the fake subsurface scatter effect only appears where the light directly hits the leaves. This wouldn't work for a whole forest because of the computational cost of self-shadowing and double normal maps, but could be useful for a single "star" asset, or if LODs switched the distant trees to a model that uses a cheaper shader.<br />
<br />
<span id="SAS"></span><br />
<br />
== Shaders and Seams ==<br />
You need to use the right kind of shader to avoid seeing seams where UV breaks occur. It must be written to use the same [[#TangentBasis|tangent basis]] that was used during baking. If the shader doesn't, the lighting will either be inconsistent across UV borders or it will show smoothing errors from the low-poly vertex normals.<br />
<br />
Xnormal generates accurate normals when displayed in Xnormal, and the SDK includes a method to write your own custom tangent space generator for the tool. <br />
<br />
<span id="3MS"></span><br />
=== 3ds Max Shaders ===<br />
The "Render To Texture" tool in 3ds Max 2011 and older generates [[#TSNM|tangent-space]] normal maps that render correctly in the offline renderer (scanline) but do not render correctly in the realtime viewport with the 3ds Max shaders. Max is using a different [[#TangentBasis|tangent basis]] for each. This is readily apparent when creating non-organic hard surface normalmaps; smoothing errors appear in the viewport that do not appear when rendered. <br />
<br />
The errors can be fixed by using "Render To Texture" to bake a [[#TSNM|tangent-space]] or [[#OSNM|object-space]] map, and using the free [http://www.3pointstudios.com/3pointshader_about.shtml "3Point Shader"] by Christoph '[[CrazyButcher]]' Kubisch and Per 'perna' Abrahamsen. The shader uses the same tangent basis as the baking tool, so it produces nearly flawless results. It also works with old bakes.<br />
<br />
You can get OK results in the Max viewport using a tangent-space map baked in Maya, loading it in a Standard material, and enabling "Show Hardware Map in Viewport". Another method is to use Render To Texture to bake an [[#OSNM|object-space]] map then use [[#CBS|Nspace]] to convert it into a tangent-space map then load that in a DirectX material and use the RTTNormalMap.fx shader. <br />
<br />
Autodesk is aware of these issues, and plans to address them in an upcoming release. See these links for more information:<br />
* Christoph "[[CrazyButcher]]" Kubisch and Per "perna" Abrahamsen designed a shader/modifier combination approach that fixes the viewport problem, see the Polycount forum post [http://boards.polycount.net/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max].<br />
* Jean-Francois "jfyelle" Yelle, Autodesk Media & Entertainment Technical Product Manager, has [http://boards.polycount.net/showthread.php?p=1115812#post1115812 this post]. <br />
* Ben Cloward posted [http://boards.polycount.net/showthread.php?p=1100270#post1100270 workarounds and FX code].<br />
* Christopher "cdiggins" Diggins, SDK writer for 3ds Max, shares some of the SDK code in his blog posts "[http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping How the 3ds Max Scanline Renderer Computes Tangent and Binormal Vectors for Normal Mapping]" and "[http://area.autodesk.com/blogs/chris/3ds_max_normal_map_baking_and_face_angle_weighting_the_plot_thickens 3ds Max Normal Map Baking and Face Angle Weighting: The Plot Thickens]".<br />
<br />
[[image:nmtest_uv-splits_thumb.jpg|thumb|600px|none|Comparison of map baking methods in Maya and Max, and Ben Cloward's custom FX code.<br>Image by [http://www.bencloward.com/ Ben Cloward] and [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
[[image:normalmapfix_3pointstudios_thumb.jpg|frame|none|3 Point Studios' normal map display fix for 3ds Max.<br>image by [http://www.3pointstudios.com 3 Point Studios]]]<br />
<br />
{|class="wikitable"<br />
|[[image:max2010_normalmap_workarounds.png|thumb|400px|none|]]<br />
|[[image:max2010_normalmap_compare.png|thumb|400px|none|]]<br />
|-<br />
|Viewport methods in 3ds Max 2010.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick] <br />
|More baking methods in 3ds Max 2010.<br> Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
<span id="3MENT"></span><br />
<br />
=== 3ds Max Edit Normals Trick ===<br />
After baking, if you add an Edit Normals modifier to your low-poly normalmapped model, this seems to "relax" the vertex normals for more accurate viewport shading. The modifier can be collapsed if desired.<br />
<br />
<span id="MS"></span><br />
=== Maya Shaders ===<br />
Maya seems to correctly generate normals to view in realtime, with the correct [[#TangentBasis|tangent basis]], with much less smoothing errors than 3ds Max. <br />
* [http://www.mentalwarp.com/~brice/shader.php BRDF shader] by [http://www.mentalwarp.com/~brice/ Brice Vandemoortele] and [http://www.kjapi.com/ Cedric Caillaud] (more info in [http://boards.polycount.net/showthread.php?t=49920 this Polycount thread]) '''Update:''' [http://boards.polycount.net/showthread.php?p=821862#post821862 New version here] with many updates, including object-space normal maps, relief mapping, self-shadowing, etc. Make sure you enable cgFX shaders in the Maya plugin manager, then you can create them in the same way you create a Lambert, Phong etc. Switch OFF high quality rendering in the viewports to see them correctly too.<br />
* If you want to use the software renderer, use mental ray instead of Maya's software renderer because mental ray correctly interprets tangent space normals. The Maya renderer treats the normal map as a grayscale bump map, giving nasty results. Mental ray supports Maya's Phong shader just fine (amongst others), although it won't recognise a gloss map plugged into the "cosine power" slot. The slider still works though, if you don't mind having a uniform value for gloss. Spec maps work fine though. Just use the same set up as you would for viewport rendering. You'll need to have your textures saved as TGAs or similar for mental ray to work though. - from [http://boards.polycount.net/member.php?u=14235 CheeseOnToast]<br />
<br />
<br />
<span id="NMC"></span><br />
<br />
== Normal Map Compression ==<br />
see; [[Normal Map Compression]]<br />
<br />
== Links ==<br />
<br />
=== Related Pages ===<br />
* [[Curvature map]]<br />
* [[DuDv map]]<br />
* [[Flow map]]<br />
* [[Normal map]]<br />
* [[Radiosity normal map]]<br />
* [[Vector displacement map]]<br />
<br />
<span id="3DT"></span> <span id="Tools"></span> <span id="3DTools"></span><br />
=== 3D Tools ===<br />
See [[:Category:Tools#A3D_Normal_Map_Software|Category:Tools#3D_Normal_Map_Software]]<br />
<br />
<span id="2DT"></span><span id="2DTools"></span><br />
=== 2D Tools ===<br />
See [[:Category:Tools#A2D_Normal_Map_Software|Category:Tools#2D_Normal_Map_Software]]<br />
<br />
<span id="T"></span><span id="Tutorials"></span><br />
=== Tutorials ===<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh tutorial for Max and Xnormal] by [http://www.exisinteractive.com/ PeterK] to prevent heavy distortions when baking with a cage, without the need to add extra supporting vertices.<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games] by [http://www.polycount.com/forum/member.php?u=56680 'SuperFranky']<br />
* [http://area.autodesk.com/userdata/fckdata/239955/The%20Generation%20and%20Display%20of%20Normal%20Maps%20in%203ds%20Max.pdf The Generation and Display of Normal Maps in 3ds Max] (500kb PDF) <<BR>> Excellent whitepaper from Autodesk about normal mapping in 3ds Max and other apps.<br />
* [http://www.katsbits.com/htm/tutorials/blender-baking-normal-maps-from-models.htm Renderbump and baking normal maps from high poly models using Blender 3D] by ''[http://www.katsbits.com/htm/about.htm "katsbits"]''<<BR>>Baking normal maps in Blender.<br />
* [http://udn.epicgames.com/Three/CreatingNormalMaps.html Techniques for Creating Normal Maps] in the Unreal Developer Network's [http://udn.epicgames.com/Three/WebHome.html Unreal Engine 3 section] contains advice from [http://www.epicgames.com/ Epic Games] artists on creating normal maps for UE3. The [http://udn.epicgames.com/Three/DesignWorkflow.html#Creating%20normal%20maps%20from%20meshes Design Workflow page] has a summary.<br />
* [http://www.iddevnet.com/quake4/ArtReference_CreatingModels#head-3400c230e92ff7d57424b2a68f6e0ea75dee4afa Creating Models in Quake 4] by [http://www.ravensoft.com/ Raven Software] is a comprehensive guide to creating Quake 4 characters.<br />
* [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing and UVs can affect normal maps in Doom 3.<br />
* [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] is an overview of modeling for normal maps.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses how smoothing groups and bevels affect the topology of the low-poly model.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in-game, not the triangle or poly count.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm Normal map workflow] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] demonstrates his normal mapping workflow in 3ds Max and Photoshop.<br />
* [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa This video tutorial] by [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] shows in Maya how to subdivide the low-poly mesh so it more closely matches the high-poly mesh, to help solve wavy lines in the bake.<br />
* [http://www.bencloward.com/tutorials_normal_maps1.shtml Normal Mapping Tutorial] by [http://www.bencloward.com/ Ben Cloward] is a comprehensive tutorial about the entire normal map creation process.<br />
* [http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy] shows how to use a special lighting setup to render normal maps (instead of baking them).<br />
* [http://cgtextures.com/content.php?action=tutorial&name=normalmap Tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] shows how to create deep normal maps using multiple layers. Note: to use Overlay blend mode properly, make sure to change each layer's Levels ''Output Level'' to 128 instead of 255.<br />
* [http://www.poopinmymouth.com/process/tips/normalmap_deepening.jpg Normalmap Deepening] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to adjust normal maps, and how to layer together painted and baked normal maps.<br />
* [http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] helps to solve seams along horizontal or vertical UV edges, but not across angled UVs.<br />
* [http://planetpixelemporium.com/tutorialpages/normal.html Cinema 4D and Normal Maps For Games] by [http://planetpixelemporium.com/index.php James Hastings-Trew] describes normal maps in plain language, with tips on creating them in Cinema 4D.<br />
* [http://forums.cgsociety.org/showthread.php?f=39&t=359082 3ds Max normal mapping overview] by [http://www.alan-noon.com/ Alan Noon] is a great thread on CGTalk about the normal mapping process.<br />
* [http://forums.cgsociety.org/showthread.php?f=46&t=373024 Hard Surface Texture Painting] by [http://stefan-morrell.cgsociety.org/gallery/ Stefan Morrell] is a good introduction to painting textures for metal surfaces.<br />
<br />
<span id="D"></span><span id="Discussion"></span><br />
<br />
=== Discussion ===<br />
[http://boards.polycount.net/showthread.php?p=820218 Discuss this page on the Polycount forums]. Suggestions welcome.<br />
<br />
Even though only one person has been editing this page so far, the information here was gathered from many different sources. We wish to thank all the contributors for their hard-earned knowledge. It is much appreciated!<br />
<br />
----<br />
[[Category:TextureTypes]] [[Category:Bump map]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Normal_mapNormal map2015-04-22T15:01:55Z<p>Dustinbrown: /* Common Swizzle Coordinates */</p>
<hr />
<div>== Out of Date ==<br />
The information on this page is a bit old, it needs to be updated. See these links for more current information:<br />
<br />
* [http://farfarer.com/resources.htm RNM Normal Map Combiner], by [http://www.farfarer.com/ James "Farfarer" O'Hare]<br />
* [http://vincentcallebaut.com/CombineNormal.html Combine Normal], by [http://vincentcallebaut.comVincent "Vincentt" Callebaut], [http://www.polycount.com/forum/showthread.php?t=131819 Combine normal maps script for Photoshop] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showpost.php?p=2226864&postcount=51 Earthquake on separating smoothing groups in the UV]<br />
* [http://www.polycount.com/forum/showpost.php?p=2225535&postcount=40 JedTheKrampus on offsetting Mirrored UVs]<br />
* [http://www.polycount.com/forum/showthread.php?t=148303 Of Bit Depths, Banding and Normal Maps]<br />
* [http://www.polycount.com/forum/showthread.php?t=147227 Skew you buddy! Making sense of skewed normal map details.]<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games]<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh Tutorial]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?]<br />
* [http://www.laurenscorijn.com/future-xoliulshader-support.html Future Xoliulshader support] = why Xoliulshader doesn't work properly in 3ds Max 2013/2014.<br />
<br />
== Synched Workflow ==<br />
To eliminate seams and shading artifacts, the model renderer and the normal map baking tool should use the same tangent basis.<br />
<br />
FBX model format can store tangents, and some renderers use this data to synch the incoming normal maps.<br />
<br />
{| class="wikitable sortable" style="color:grey;"<br />
|- <br />
! Renderer !! Normal map baker<br />
|-<br />
| 3ds Max || 3ds Max, Handplane, ?<br />
|-<br />
| Blender || ?<br />
|-<br />
| Creation Engine || Handplane, ?<br />
|-<br />
| CryEngine || ?<br />
|-<br />
| Knald || ?<br />
|-<br />
| Marmoset Toolbag || 3ds Max, Maya, Xnormal, ?<br />
|-<br />
| Maya || Handplane, Maya, ?<br />
|-<br />
| Source || Handplane, Maya ([http://www.polycount.com/forum/showpost.php?p=2224653&postcount=28]), ?<br />
|-<br />
| Starcraft II || Handplane, ?<br />
|-<br />
| Substance Designer || ?<br />
|-<br />
| Unity([http://www.polycount.com/forum/showpost.php?p=2224781&postcount=29], [http://www.polycount.com/forum/showthread.php?p=2194353#post2194353]) || Handplane, Xnormal (via Asset Store), ?<br />
|-<br />
| Unreal Engine 4 || Handplane, Xnormal([http://www.polycount.com/forum/showpost.php?p=2224402&postcount=20]), ? <br />
|-<br />
| Xnormal || Xnormal, ?<br />
|}<br />
<br />
----<br />
<br />
== What is a Normal Map? ==<br />
A Normal Map is usually used to fake high-res geometry detail when it's mapped onto a low-res mesh. The pixels of the normal map each store a ''normal'', a vector that describes the surface slope of the original high-res mesh at that point. The red, green, and blue channels of the normal map are used to control the direction of each pixel's normal. <br />
<br />
When a normal map is applied to a low-poly mesh, the texture pixels control the direction each of the pixels on the low-poly mesh will be facing in 3D space, creating the illusion of more surface detail or better curvature. However, the silhouette of the model doesn't change. <br />
<br />
<gallery mode="packed"><br />
Whatif_normalmap_mapped2.jpg|A model with a normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_low.jpg|The model without its normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_high.jpg|The high-resolution model used to create the normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
</gallery><br />
<br />
==Tangent-Space vs. Object-Space==<br />
<br />
Normal maps can be made in either of two basic flavors: tangent-space or object-space. World-space is basically the same as object-space, except it requires the model to remain in its original orientation, neither rotating nor deforming, so it's almost never used.<br />
<br />
===Tangent-space normal map===<br />
[[image:normalmap_tangentspace.jpg|frame|none|A tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Predominantly-blue colors. Object can rotate and deform. Good for deforming meshes, like characters, animals, flags, etc.<br />
<br />
Pros:<br />
* Maps can be reused easily, like on differently-shaped meshes.<br />
* Maps can be tiled and mirrored easily, though some games might not support mirroring very well.<br />
* Easier to overlay painted details.<br />
* Easier to use image compression.<br />
<br />
Cons:<br />
* More difficult to avoid smoothing problems from the low-poly vertex normals (see Smoothing Groups and Hard Edges).<br />
* Slightly slower performance than an object-space map (but not by much).<br />
<br />
===Object-space normal map===<br />
[[image:normalmap_worldspace.jpg|frame|none|An object-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Rainbow colors. Objects can rotate, but usually shouldn't be deformed, unless the shader has been modified to support deformation. Object-space is also called local-space or model-space. <br />
<br />
Pros:<br />
* Easier to generate high-quality curvature because it completely ignores the crude smoothing of the low-poly vertex normals.<br />
* Slightly better performance than a tangent-space map (but not by much).<br />
<br />
Cons:<br />
* Can't easily reuse maps, different mesh shapes require unique maps.<br />
* Difficult to tile properly, and mirroring requires specific shader support.<br />
* Harder to overlay painted details because the base colors vary across the surface of the mesh. Painted details must be converted into Object Space to be combined properly with the OS map.<br />
* They don't compress very well, since the blue channel can't be recreated in the shader like with tangent-space maps. Also the three color channels contain very different data which doesn't compress well, creating many artifacts. Using a half-resolution object-space map is one option. <br />
<br />
<br clear="all"/><br />
<br />
=== Converting Between Spaces ===<br />
Normal maps can be converted between object space and tangent space, in order to use them with different blending tools and shaders, which require one type or the other. <br />
<br />
Object space maps can also be converted to maps with different tangent bases, to better match the normal maps with the renderer and thus avoid lighting errors.<br />
<br />
* [http://www.handplane3d.com Handplane] by [http://www.alecmoody.com/ Alec Moody] is a tool that converts object space maps into a variety of tangent spaces: 3ds Max, Creation Engine, Maya, Source, Unity, Unreal, etc. See the Polycount Forum thread [http://www.polycount.com/forum/showthread.php?t=116899 Official handplane support thread - Now freeware!!].<br />
<br />
[[File:handplane_illus_1.jpg|frame|none|Handplane interface. <br>Image by [http://www.alecmoody.com/ Alec Moody].]]<br />
<br />
<br />
* [http://boards.polycount.net/showthread.php?p=1072599#post1072599 NSpace] by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] is a tool that converts an object-space normal map into a tangent-space map, which then works seamlessly in the 3ds Max viewport. He converts the map by using the same tangent basis that 3ds Max uses for its hardware shader. To see the results, load the converted map via the ''Normal Bump'' map and enable "Show Hardware Map in Viewport". [http://gameartist.nl/ Osman "osman" Tsjardiwal] created a GUI for NSpace, you can [http://boards.polycount.net/showthread.php?p=1075143#post1075143 download it here], just put it in the same folder as the NSpace exe and run it. <br />
<br />
[[File:NSpace_Gui_osman.png|frame|none|NSpace interface. <br>Image by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] and [http://gameartist.nl Osman "osman" Tsjardiwal].]]<br />
<br />
[http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson] said: "[8Monkey Labs has] a tool that lets you load up your reference mesh and object space map. Then load up your tangent normals, and adjust some sliders for things like tile and amount. We need to load up a mesh to know how to correctly orient the tangent normals or else things will come out upside down or reverse etc. It mostly works, but it tends to "bend" the resulting normals, so you gotta split the mesh up into some smoothing groups before you run it, and then I usually will just composite this "combo" texture over my orig map in Photoshop."<br />
<br />
<span id="RGBC"></span><span id="RGBChannels"></span><br />
<br />
== RGB Channels ==<br />
Shaders can use different techniques to render tangent-space normal maps, but the normal map directions are usually consistent within a game. Usually the red channel of a tangent-space normal map stores the X axis (pointing the normals predominantly leftwards or rightwards), the green channel stores the Y axis (pointing the normals predominantly upwards or downwards), and the blue channel stores the Z axis (pointing the normals outwards away from the surface).<br />
<br />
[[image:tangentspace_rgb.jpg|frame|none|The red, green, and blue channels of a tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you see lighting coming from the wrong angle when you're looking at your normal-mapped model, and the model is using a tangent-space normal map, the normal map shader might be expecting the red or green channel (or both) to point in the opposite direction. To fix this either change the shader, or simply invert the appropriate color channels in an image editor, so that the black pixels become white and the white pixels become black.<br />
<br />
Some shaders expect the color channels to be swapped or re-arranged to work with a particular [[#NormalMapCompression|compression format]]. For example the DXT5_nm format usually expects the X axis to be in the alpha channel, the Y axis to be in the green channel, and the red and blue channels to be empty.<br />
<br />
== Tangent Basis ==<br />
[[#TangentSpaceVsObjectSpace|Tangent-space]] normal maps use a special kind of vertex data called the ''tangent basis''. This is similar to UV coordinates except it provides directionality across the surface, it forms a surface-relative coordinate system for the per-pixel normals stored in the normal map. This coordinate system is required to light a normal mapped surface.<br />
<br />
Each vertex in the tangent basis is a combination of three things: the mesh vertex's normal (influenced by smoothing), the vertex's tangent (usually derived from the V texture coordinate), and the vertex's bitangent (derived in code, also called the binormal). These three vectors create an axis for each vertex, giving it a specific orientation in the tangent space. These axes are used to properly transform the incoming lighting from world space into tangent space, so your normal-mapped model will be lit correctly.<br />
<br />
Light rays are in world space, but the normals stored in the normal map are in tangent space. When the model is being rendered, the light rays must be converted from world space into tangent space, using the tangent basis to get there. At that point the incoming light rays are compared against the directions of the normals in the normal map, and this determines how much each pixel is going to be lit. Alternatively, instead of converting the light rays some shaders will convert the normals in the normal map from tangent space into world space. Then those world-space normals are compared against the light rays, and the model is lit appropriately. The method depends on who wrote the shader, but the end result is the same. Both methods require a tangent basis to transform the lighting.<br />
<br />
When a triangle's vertex normals are pointing straight out, and a pixel in the normal map is neutral blue (128,128,255) this means the pixel's normal will be pointing straight out from the surface of the low-poly mesh. When that pixel normal is tilted towards the left or the right in the tangent coordinate space, it will get either more or less red color, depending on whether the normal map is set to store the X axis as either a positive or a negative value. Same goes for when the normal is tilted up or down in tangent space, it will either get more or less green color. If the vertex normals aren't exactly perpendicular to the triangle, the normal map pixels will be tinted away from neutral blue as well.<br />
<br />
Unfortunately for artists, there are many different ways to calculate the tangent basis: [http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping 3ds Max], [http://download.autodesk.com/us/maya/2011help/index.html?url=./files/Appendix_A_Tangent_and_binormal_vectors.htm,topicNumber=d0e227193 Maya], [http://www.codesampler.com/dx9src/dx9src_4.htm#dx9_dot3_bump_mapping DirectX 9], [http://developer.nvidia.com/object/NVMeshMender.html NVMeshMender], [http://www.terathon.com/code/tangent.html Eric Lengyel], a custom solution, etc. This means a normal map baked in one application probably won't shade correctly in another. Artists must do some testing with different [[#T|baking tools]] to find which works best with their output. When the renderer (or game engine) renders your game model, [[#ShadersAndSeams|the shader]] must use the same tangent basis as the normal map baker, otherwise you'll get incorrect lighting, especially across the seams between UV shells.<br />
<br />
The [http://www.xnormal.net/ xNormal] SDK supports custom tangent basis methods. When a programmer uses it to implement their renderer's own tangent basis, artists can then use Xnormal to bake normal maps that will match their renderer perfectly.<br />
<br />
[[image:tangentseams.jpg|frame|none|When shared edges are at different angles in UV space, different colors will show up<br />
along the seam. The tangent basis uses these colors to light the model properly. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
When you look at a tangent-space normal map for a character, you typically see different colors along the UV seams. This is because the UV shells are often oriented at different angles on the mesh, a necessary evil when translating the 3D mesh into 2D textures. The body might be mapped with a vertical shell, and the arm mapped with a horizontal one. This requires the normals in the normal map to be twisted for the different orientations of those UV shells. The UVs are twisted, so the normals must be twisted in order to compensate. The tangent basis helps reorient (twist) the lighting as it comes into the surface's local space, so the lighting will then look uniform across the normal mapped mesh.<br />
<br />
When an artist tiles a tangent-space normal map across an arbitrary mesh, like a landscape, this tends to shade correctly because the mesh has a uniform direction in tangent space. If the mesh has discontinuous UV coordinates (UV seams), or the normal map has large directional gradients across it, the tangent space won't be uniform anymore so the surface will probably have shading seams.<br />
<br />
== Common Swizzle Coordinates ==<br />
3D Software capable of displaying normal maps will have a native required direction, or "handedness" for the RGB channels in a normal map, sometimes referred to as "Swizzle Coordinates," though [[#SAS|shaders]] can often be written to override this native handedness. You may hear developers refer to "flipping the green channel" in order to get a normal map to display correctly, and this simply indicates that when the normal map was baked, it was authored with the incorrect handedness in the green channel.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
| '''Software''' <br />
| '''Red''' <br />
| '''Green''' <br />
| '''Blue''' <br />
|-<br />
|<#000000>| Maya<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| 3ds Max<br />
| X+<br />
| Y-<br />
| Z+ <br />
|-<br />
|<#000000>| Unreal Engine<br />
| X+ <br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Unity<br />
| X+<br />
| Y+<br />
| Z+<br />
|-<br />
|<#000000>| [https://developer.valvesoftware.com/wiki/Bump_map Source]<br />
| X+<br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Toolbag<br />
| X+<br />
| Y+ <br />
| Z+<br />
|}<br />
<span id="MTLPM"></span><br />
<br />
== Modeling the Low-Poly Mesh ==<br />
The in-game mesh usually needs to be carefully optimized to create a good silhouette, define edge-loops for better deformation, and minimize extreme changes between the vertex normals for better shading (see [[#SmoothingGroupsAndHardEdges|Smoothing Groups & Hard Edges]]).<br />
<br />
In order to create an optimized in-game mesh including a good silhouette and loops for deforming in animation, you can start with the 2nd subdivision level of your [[DigitalSculpting|digital sculpt]], or in some cases with the base mesh itself. Then you can just collapse edge loops or cut in new edges to add/remove detail as necessary. Or you can [[DigitalSculpting#OART|re-toplogize]] from scratch if that works better for you.<br />
<br />
See [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts] on the Polycount forum.<br />
<br />
<span id="UVC"></span><span id="UVCoordinates"></span><br />
=== UV Coordinates ===<br />
Normal map baking tools only capture normals within the 0-1 UV square, any UV bits outside this area are ignored. <br />
<br />
Only one copy of the forward-facing UVs should remain in the 0-1 UV square at baking time. If the mesh uses overlapping UVs, this will likely cause artifacts to appear in the baked map, since the baker will try render each UV shell into the map. Before baking, it's best to move all the overlaps and mirrored bits outside the 0-1 square. <br />
<br />
[[image:Normalmap_uvcoord_offset.jpg|frame|none|The mirrored UVs (in red) are offset 1 unit before baking. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you move all the overlaps and mirrored bits exactly 1 UV unit (any whole number will do), then you can leave them there after the bake and they will still be mapped correctly. You can move them back if you want, it doesn't matter to most game engines. Be aware that ZBrush does use UV offsets to manage mesh visibility, however this usually doesn't matter because the ZBrush cage mesh is often a different mesh than the in-game mesh used for baking.<br />
<br />
You should avoid changing the UVs after baking the normal map, because rotating or mirroring UVs after baking will cause the normal map not to match the [[#TB|tangent basis]] anymore, which will likely cause lighting problems. <br />
<br />
In 3ds Max, W is a third texture coordinate. It's used for 3D procedural textures and for storing vertex color in UV channels (you need 3 axes for RGB, so UVW can store vertex color). Bake problems can be avoided by moving any overlapping UVs to -1 on the W axis, with the same results as moving them 1 unit on the U or V axes. The tool Render To Texture will always bake whatever UVs are the highest along the W axis. However using W can be messy... it's generally hidden unless you purposefully look for it (bad for team work), doesn't get preserved on export to other apps, and high W values can prevent selecting and/or welding UVs. <br />
<br />
<span id="M"></span><span id="Mirroring"></span><br />
<br />
=== Mirroring ===<br />
Normal maps can be mirrored across a model to create symmetrical details, and save UV space, which allows more detail in the normal map since the texture pixels are smaller on the model. <br />
<br />
With [[#OSNM|object-space]] maps, mirroring requires [http://boards.polycount.net/showthread.php?t=53986 specific shader support]. For [[#TSNM|tangent-space]] maps, mirroring typically creates a shading seam, but this can be reduced or hidden altogether, depending on the method used.<br />
<br />
<span id="TMW"></span><br />
==== Typical Mirroring Workflow ====<br />
# Delete the mesh half that will be mirrored. <br />
# Arrange the UVs for the remaining model, filling the UV square.<br />
# Mirror the model to create a "whole" mesh, welding the mesh vertices along the seam. <br />
# Move the mirrored UVs exactly 1 unit (or any whole number) out of the 0-1 UV square.<br />
# Bake the normal map.<br />
<br />
Sometimes an artist will decide to delete half of a symmetrical model before baking. <br />
<br />
This is a mistake however because often the vertex normals along the hole will bend towards the hole a bit; there are no faces on the other side to average the normals with. This will create a strong lighting seam in the normal map. <br />
<br />
It's typically best to use the complete mirrored model to bake the normal map, not just the unique half. <br />
<br />
To prevent the mirrored UVs from causing overlaps or baking errors, move the mirrored [[#UVC|UVs]] out of the 0-1 UV space, so only one copy of the non-mirrored UVs is left within the 0-1 square.<br />
<br />
To avoid texel "leaks" between the UV shells, make sure there's enough [[#Edge_padding|Edge Padding]] around each shell, including along the edges of the normal map. None of the UV shells should be touching the edge of the 0-1 UV square, unless they're meant to tile with the other side of the map.<br />
<br />
<span id="CM"></span><br />
<br />
==== Center Mirroring ====<br />
If the mirror seam runs along the surface of a continuous mesh, like down the center of a human face for example, then it will probably create a lighting seam. <br />
<br />
In Epic Games' [http://www.unrealtechnology.com/technology.php Unreal Engine 3] (UE3) their symmetrical models commonly use centered mirroring. Epic uses materials that mix a [[DetailMap]] with the normal maps; these seem to scatter the diffuse/specular lighting and help minimize the obviousness of the mirror seams. For their [[Light Map]]ped models they use [http://udn.epicgames.com/Three/LightMapUnwrapping.html a technique] that can almost completely hide the mirror seam.<br />
<br />
[[image:Epic_MirroringCicada.jpg|frame|none| In UE3 a center mirror seam is reduced by using a detail normal map. <br> Image by "[http://epicgames.com Epic Games]"]]<br />
<br />
'''''[http://www.zbrushcentral.com/showpost.php?p=573108&postcount=28 GOW2 normal map seams], [http://utforums.epicgames.com/showthread.php?p=27166791#post27166791 UDK normal map seams]'''''<br />
<br />
<span id="OM"></span><br />
<br />
==== Offset Mirroring ====<br />
Offset mirroring is a method where you move the mirror seam off to one side of the model, so the seam doesn't run exactly down the center. For example with a character's head, the UV seam can go down along the side of the head in front of the ear. The UV shell for the nearest ear can then be mirrored to use the area on the other side of the head. <br />
<br />
This avoids the "Rorschach" effect and allows non-symmetrical details, but it still saves texture space because the two sides of the head can be mirrored (they're never seen at the same time anyhow).<br />
<br />
Offset mirroring doesn't get rid of the seam, but it does move it off to a place where it can either be less obvious, or where it can be hidden in a natural seam on the model.<br />
<br />
<span id="FCM"></span><br />
==== Flat Color Mirroring ====<br />
[http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] solves seams by painting a flat set of normals along the seam, using neutral blue (128,128,255). However it only works along horizontal or vertical UV seams, not across any angled UVs. It also removes any details along the mirror seam, creating blank areas. <br />
<br />
<span id="EM"></span><br />
==== Element Mirroring ====<br />
The mirror seam can be avoided completely when it doesn't run directly through any mesh. For example if there's a detached mesh element that runs down the center of the model, this can be uniquely mapped, while the meshes on either side can be mirrors of each other. Whenever the mirrored parts don't share any vertex normals with the non-mirrored parts, there won't be any seams. <br />
<br />
[[image:normalmap_mirrored-binocs-racer445.jpg|frame|none|The middle part (highlighted in red) uses unique non-mirrored UVs, allowing the mesh on the right to be mirrored without any seams. <br>Image by [http://http://racer445.com/ "racer445"]]]<br />
<br />
<span id="SGAHE"></span><br />
<br />
=== Smoothing Groups & Hard Edges ===<br />
Each vertex in a mesh has at least one vertex normal. Vertex normals are used to control the direction a triangle will be lit from; if the normal is facing the light the triangle will be fully lit, if facing away from the light the triangle won't be lit. <br />
<br />
Each vertex however can have more than one vertex normal. When two triangles have different vertex normals along their shared edge, this creates a shading seam, called a ''hard edge'' in most modeling tools. 3ds Max uses ''Smoothing Groups'' to create hard/soft edges, Maya uses ''Harden Edge'' and ''Soften Edge''. These tools create hard and soft edges by splitting and combining the vertex normals.<br />
<br />
[[image:BenMathis_SmoothingGroups_Excerpt.gif|frame|none|Hard edges occur where the vertices have multiple normals. <br>Image by [http://poopinmymouth.com Ben 'poopinmymouth' Mathis] ([http://poopinmymouth.com/process/tips/smoothing_groups.jpg tutorial here])]]<br />
<br />
When a mesh uses all soft normals (a single smoothing group) the lighting has to be interpolated across the extreme differences between the vertex normals. If your renderer doesn't support the same [[#TangentBasis|tangent basis]] that the baker uses, this can produce extreme shading differences across the model, which creates shading artifacts. It is generally best to reduce these extremes when you can because a mismatched renderer can only do so much to counteract it.<br />
<br />
Hard edges are usually best where the model already has a natural seam. For example, you can add a hard edge along the rim of a car's wheel well, to prevent the inside of the wheel well from distorting the shading for the outside of the car body. Mechanical models usually need hard edges where ever the surface bends more than about 45 degrees. <br />
<br />
For most meshes, the best results usually come from adding hard edges where ever there are UV seams. There are no hard rules however, you must experiment with different approaches to find what works best in your game.<br />
<br />
When you use object-space normal maps the vertex normal problem goes away since you're no longer relying on the crude vertex normals of the mesh. An object-space normal map completely ignores vertex normals. Object-space mapping allows you to use all soft edges and no bevels on the low-res mesh, without showing lighting errors.<br />
<br />
<span id="HEDAT"></span><br />
==== Hard Edge Discussions & Tutorials ====<br />
* [http://www.polycount.com/forum/showthread.php?p=2090450#post2090450 Maya MEL Script help needed (UV border edges)]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=73593 Normal Maps: Can Somone Explain This "Black Edge" issue]<br />
* [http://www.polycount.com/forum/showthread.php?t=73566 Normal Maps: Can someone explain normals, tangents and split UVs?]<br />
* [http://www.polycount.com/forum/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max]<br />
* [http://boards.polycount.net/showthread.php?t=68173 Why you should NOT trust 3ds Max's viewport normal-map display!]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/10503-xsi-normal-mapped-cube-looks-bad.html XSI - normal mapped cube looks bad]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/11924-weird-maya-normal-map-seam-artifact-problem-am-i-making-simple-mistake.html Weird Maya normal map seam/artifact problem]<br />
* [http://boards.polycount.net/showthread.php?p=1080600 Seams in Normals when Creating Tiling Environment Trims and other Tiles]<br />
* The tutorial [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing can affect the normal map.<br />
* The tutorial: [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] shows how smoothing affects raycasting.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses the breaking of normals and smoothing groups in general terms.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in the game, not the triangle count.<br />
* The Crysis documentation [http://doc.crymod.com/AssetCreation/PolyBumpReference.html PolyBump Reference] has a section towards the bottom that shows how smoothing affects their baked normal maps.<br />
* The polycount thread [http://boards.polycount.net/showthread.php?t=60694 Toying around with normal map approaches] has a great discussion of how best to use smoothing groups and bevels for better shading.<br />
<br />
<span id="UB"></span><br />
==== Using Bevels ====<br />
Bevels/chamfers generally improve the silhouette of the model, and can also help reflect specular highlights better. <br />
<br />
However bevels tend to produce long thin triangles, which slow down the in-game rendering of your model. Real-time renderers have trouble rendering long thin triangles because they create a lot of sub-pixel areas to render. <br />
<br />
Bevels also balloon the vertex count, which can increase the transform cost and memory usage. Hard edges increase the vertex count too, but not when the edge also shares a seam in UV space. For a good explanation of the vertex count issue, see [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly].<br />
<br />
Using hard edges with matching UV shells tends to give better performance and better cosmetic results than using bevels. However there are differing opinions on this, see the Polycount thread "[http://boards.polycount.net/showthread.php?t=71760 Maya transfer maps help]".<br />
<br />
<span id="EVN"></span><br />
==== Edited Vertex Normals ====<br />
If you use bevels the shading will be improved by editing the vertex normals so the larger flat surfaces have perpendicular normals. The vertex normals are then forced to blend across the smaller bevel faces, instead of across the larger faces. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66139 Superspecular soft edges tutorial chapter 1].<br />
<br />
[[image:oliverio_bevel_normals.gif|frame|none|Bending normals on bevelled models. <br>From the tutorial [http://deadlineproof.com/model-shading-techniques-soft-edge-superspecular/ Shading techniques Superspecular soft edges]<br>Image by [http://deadlineproof.com/ Paolo Oliverio]]]<br />
<br />
== Level of Detail Models ==<br />
See [http://www.polycount.com/forum/showthread.php?p=1216945#post1216945 Problem if you're using 3point-style normals with an LOD].<br />
<br />
<span id="MTHPM"></span><br />
<br />
== Modeling The High-Poly Mesh ==<br />
[[Subdivision Surface Modeling]] and [[DigitalSculpting]] are the techniques most often used for modeling a normal map. <br />
<br />
Some artists prefer to model the in-game mesh first, other artists prefer to model the high-res mesh first, and others start somewhere in the middle. The modeling order is ultimately a personal choice though, all three methods can produce excellent results:<br />
* Build the in-game model, then up-res it and sculpt it.<br />
* Build and sculpt a high resolution model, then build a new in-game model around that.<br />
* Build a basemesh model, up-res and sculpt it, then step down a few levels of detail and use that as a base for building a better in-game mesh.<br />
If the in-game mesh is started from one of the subdivision levels of the basemesh sculpt, various edge loops can be collapsed or new edges can be cut to add/remove detail as necessary.<br />
<br />
<span id="SE"></span><br />
=== Sloped Extrusions ===<br />
[[image:normal_slopes_hatred.jpg|frame|none|Extrusions on the high-poly model should be sloped to make a better normal map. <br>Image by [http://www.hatred.gameartisans.org/ Krzysztof "Hatred" Dolas].]]<br />
<br />
=== Floating Geometry ===<br />
[[image:FloatingGeo.jpg|frame|none|Normal map stores the direction the surface is facing rather than real depth information, thus allowing to save time using floating geometry. <br>To correctly bake AO with floating geo make it a separate object and turn off it's shadow casting. <br>Image by [http://artisaverb.info/ Andrew "d1ver" Maximov].]]<br />
<br />
See also [[3DTutorials/Modeling High-Low Poly Models for Next Gen Games|Modeling High/Low Poly Models for Next Gen Games]] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa]<br />
<br />
<span id="ET"></span><br />
<br />
=== Edge Thickness ===<br />
[[image:normal_edge_thickness.jpg|frame|none|When creating edges of the Highpoly, sometimes you'll need to make them rounded than in real life to <br>work better at the size they will be seen.<br>Image by [http://racer445.com/Evan "racer445" Herbert]]]<br />
<br />
<span id="MRF"></span><span id="MRRCB"></span><br />
<br />
=== mental ray Round Corners Bump ===<br />
The mental ray renderer offers an automatic bevel rendering effect called Round Corners Bump that can be baked into a normal map. This is available in 3ds Max, Maya, and XSI. See [http://boards.polycount.net/showthread.php?t=71995 Zero Effort Beveling for normal maps] - by [http://boards.polycount.net/member.php?u=31662 Robert "r_fletch_r" Fletcher].<br />
<br />
[http://jeffpatton.net/ Jeff Patton] posted about [http://jeffpatton.cgsociety.org/blog/archive/2007/10/ how to expose Round Corners Bump] in 3ds Max so you can use it in other materials.<br />
<br />
[http://cryrid.com/art/ Michael "cryrid" Taylor] posted a tutorial about how to use [http://cryrid.com/images/temp/XSI/zeroeffort_bevels.jpg Round Corners in XSI].<br />
<br />
XSI is able to bake a good normal map with it, but 3ds Max seems to bake it incorrectly, and Maya isn't able to bake the effect at all. Maybe Max might be able to bake it correctly, if the .mi shader is edited to use the correct coordinate space?<br />
<br />
<span id="Baking"></span><span id="B"></span><br />
== Baking ==<br />
The process of transferring normals from the high-res model to the in-game model is often called baking. The baking tool usually starts projecting a certain numerical distance out from the low-poly mesh, and sends rays inwards towards the high-poly mesh. When a ray intersects the high-poly mesh, it records the mesh's surface normal and saves it in the normal map.<br />
<br />
To get an understanding of how all the options affect your normal map, do some test bakes on simple meshes like boxes. They generate quickly so you can experiment with [[#UVCoordinates|UV mirroring]], [[#SGAHE|smoothing groups]], etc. This helps you learn the settings that really matter.<br />
* The tutorial [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] has more examples of ray-casting, plus how to get better results from the bake.<br />
<br />
Baking sub-sections:<br />
# [[#Anti-Aliasing|Anti-Aliasing]]<br />
# [[#Baking_Transparency|Baking Transparency]]<br />
# [[#Edge_Padding|Edge Padding]]<br />
# [[#High_Poly_Materials|High Poly Materials]]<br />
# [[#Reset_Transforms|Reset Transforms]]<br />
# [[#Solving_Intersections|Solving Intersections]]<br />
# [[#Solving_Pixel_Artifacts|Solving Pixel Artifacts]]<br />
# [[#Solving_Wavy_Lines|Solving Wavy Lines]]<br />
# [[#Triangulating|Triangulating]]<br />
# [[#Working_with_Cages|Working with Cages]]<br />
<br />
<span id="AA"></span><br />
=== Anti-Aliasing ===<br />
Turning on super-sampling or anti-aliasing (or whatever multi-ray casting is called in your normal map baking tool) will help to fix any jagged edges where the high-res model overlaps itself within the UV borders of the low-poly mesh, or wherever the background shows through holes in the mesh. Unfortunately this tends to render much much slower, and takes more memory.<br />
<br />
[[image:normalmap_aliasing_knak47.jpg|frame|none|A bake without anti-aliasing shows artifacts where the high-poly mesh has overlaps. <br>Image by [http://www.polycount.com/forum/member.php?u=35938 'knak47']]]<br />
<br />
One trick to speed this up is to render 2x the intended image size then scale the normal map down 1/2 in a paint program like Photoshop. The reduction's pixel resampling will add anti-aliasing for you in a very quick process. After scaling, make sure to re-normalize the map if your game doesn't do that already, because the un-normalized pixels in your normalmap may cause pixelly artifacts in your specular highlights. Re-normalizing can be done with [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA's normal map filter] for Photoshop.<br />
<br />
3ds Max's supersampling doesn't work nicely with edge padding, it produces dark streaks in the padded pixels. If so then turn off padding and re-do the padding later, either by re-baking without supersampling or by using a Photoshop filter like the one that comes with [[#3DTools|Xnormal]].<br />
<br />
=== Baking Transparency ===<br />
Sometimes you need to bake a normal map from an object that uses opacity maps, like a branch with opacity-mapped leaves. Unfortunately baking apps often completely ignore any transparency mapping on your high-poly mesh.<br />
<br />
{|class="wikitable"<br />
|[[image:JoeWilson_ivynormals_error.jpg]] <br />
|[[image:JoeWilson_ivynormals_rendered.jpg]]<br />
|-<br />
|3ds Max's RTT baker causes transparency errors.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|The lighting method bakes perfect transparency.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|}<br />
<br />
To solve this, render a Top view of the mesh. This only works if you're using a planar UV projection for your low-poly mesh and you're baking a tangent-space normal map.<br />
<br />
* Make sure the Top view matches the dimensions of the planar UV projection used by the low-poly mesh. It helps to use an orthographic camera for precise placement.<br />
* On the high-poly mesh either use a specific lighting setup or a use special material shader:<br />
* 1) The lighting setup is described in these tutorials:<br />
* * [http://www.bencloward.com/tutorials_normal_maps11.shtml Creating A Normal Map Right In Your 3D App] by [http://www.bencloward.com/ Ben Cloward]<br />
* *[http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy], Graphics Techniques Consultant, Xbox Content and Design Team<br />
* 2) The material shader does the same thing, but doesn't require lights.<br />
* * [http://www.scriptspot.com/3ds-max/normaltexmap NormalTexMap] scripted map for 3ds Max by [http://www.scriptspot.com/users/dave-locke Dave Locke].<br />
* * [http://www.footools.com/3dsmax_plugins.html InfoTexture] map plugin for 3ds Max by [http://www.footools.com John Burnett]<br />
<br />
[[image:BenCloward_NormalMapLighting.gif|frame|none|The lighting setup for top-down rendering. <br>Image by [http://www.bencloward.com Ben Cloward]]]<br />
<br />
<span id="EP"></span><br />
<br />
=== Edge Padding ===<br />
If a normal map doesn't have enough [[Edge_padding |Edge Padding]], this will create shading seams on the UV borders.<br />
<br />
=== High Poly Materials ===<br />
3ds Max will not bake a normal map properly if the high-res model has a mental ray Arch & Design material applied. If your normal map comes out mostly blank, either use a Standard material or none at all. For an example see the Polycount thread [http://www.polycount.com/forum/showthread.php?t=74792 Render to Texture >:O].<br />
<br />
<span id="RT"></span><br />
=== Reset Transforms ===<br />
Before baking, make sure your low-poly model's transforms have been reset. '''''This is very important!''''' Often during the modeling process a model will be rotated and scaled, but these compounded transforms can create a messy local "space" for the model, which in turn often creates rendering errors for normal maps. <br />
<br />
In 3ds Max, use the Reset Xforms utility then Collapse the Modifier Stack. In Maya use Freeze Transformation. In XSI use the Freeze button.<br />
<br />
<span id="SI"></span><br />
<br />
=== Solving Intersections ===<br />
The projection process often causes problems like misses, or overlaps, or intersections. It can be difficult generating a clean normal map in areas where the high-poly mesh intersects or nearly intersects itself, like in between the fingers of a hand. Setting the ray distance too large will make the baker pick the other finger as the source normal, while setting the ray distance too small will lead to problems at other places on the mesh where the distances between in-game mesh and high-poly mesh are greater.<br />
<br />
Fortunately there are several methods for solving these problems.<br />
<br />
# Change the shape of the cage. Manually edit points on the projection cage to help solve tight bits like the gaps between fingers.<br />
# Limit the projection to matching materials, or matching UVs.<br />
# Explode the meshes. See the polycount thread [http://boards.polycount.net/showthread.php?t=62921 Explode script needed (for baking purposes)].<br />
# Bake two or more times using different cage sizes, and combine them in Photoshop.<br />
<br />
<span id="SPA"></span><br />
<br />
=== Solving Pixel Artifacts ===<br />
[[image:filterMaps_artifact.jpg|frame|none|Random pixel artifacts in the bake. <br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
If you are using 3ds Max's ''Render To Texture'' to bake from one UV layout to another, you may see stray pixels scattered across the bake. This only happens if you are using a copy of the original mesh in the Projection, and that mesh is using a different UV channel than the original mesh.<br />
<br />
There are two solutions for this:<br />
<br />
* Add a Push modifier to the copied mesh, and set it to a low value like 0.01.<br />
- or -<br />
<br />
* Turn off ''Filter Maps'' in the render settings (Rendering menu > Render Setup > Renderer tab > uncheck Filter Maps). To prevent aliasing you may want to enable the Global Supersampler in Render Setup.<br />
<br />
See also [[#Anti-Aliasing]].<br />
<br />
<span id="SWL"></span><br />
<br />
=== Solving Wavy Lines ===<br />
When capturing from a cylindrical shape, often the differences between the low-poly mesh and the high-poly mesh will create a wavy edge in the normal map. There are a couple ways to avoid this:<br />
<br />
# The best way... create your lowpoly model with better supporting edges. See the Polycount threads [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?], [http://boards.polycount.net/showthread.php?t=55754 approach to techy stuff], [http://www.polycount.com/forum/showthread.php?t=72713 Any tips for normal mapping curved surface?].<br />
# Adjust the shape of the cage to influence the directions the rays will be cast. Beware... this work will have to be re-done every time you edit the lowpoly mesh, as the cage will be invalidated. At the bottom of [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm this page of his normal map tutorial], [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to do this in 3ds Max. Same method can be seen in the image below.<br />
# Subdivide the low-res mesh so it more closely matches the high-res mesh. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] has a [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa video tutorial] that shows how to do this in Maya.<br />
# Paint out the wavy line. Beware... this work will have to be re-done every time you re-bake the normal map. The [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
# Use a separate planar-projected mesh for the details that wrap around the barrel area, so the ray-casting is more even. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. For example to add tread around a tire, the tread can be baked from a tread model that is laid out flat, then that bake can layered onto the bake from the cylindrical tire mesh in a paint program.<br />
<br />
[[image:timothy_evison_normalmap_projections.jpg|frame|none|Adjusting the shape of the cage to remove distortion. <br>Image by [http://users.cybercity.dk/~dsl11905/resume/resume.html Timothy "tpe" Evison]]]<br />
<br />
<span id="TRI"></span><br />
<br />
=== Triangulating ===<br />
Before baking, it is usually best to triangulate the low-poly model, converting it from polygons into pure triangles. This prevents the vertex normals from being changed later on, which can create specular artifacts.<br />
<br />
[[image:triangulation_modo_ohare.jpg|frame|none| When quads are triangulated in [http://www.luxology.com/modo/ Modo], the internal edges are sometimes flipped, which causes shading differences.<br>Image by [http://www.farfarer.com/|James "Talon" O'Hare]]]<br />
<br />
<br />
Sometimes a baking tool or a mesh exporter/importer will re-triangulate the polygons. A quad polygon is actually treated as two triangles, and the internal edge between them is often switched diagonally during modeling operations. When the vertices of the quad are moved around in certain shapes, the software's algorithm for polygon models tries to keep the quad surface in a "rational" non-overlapping shape. It does this by switching the internal edge between its triangles.<br />
<br />
<br />
[[image:triangulation_spec_tychovii.jpg|frame|none| The specular highlight is affected by triangulation. Flip edges to fix skewing. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66651 Skewed Specular Highlight?] for pictures and more info.<br> Image by [http://robertkreps.com Robert "TychoVII" Kreps]]]<br />
<br />
<br />
<span id="WWC"></span><br />
<br />
=== Working with Cages ===<br />
''Cage'' has two meanings in the normal-mapping process: a low-poly base for [[subdivision surface modeling]] (usually called the [[DigitalSculpting#BM|basemesh]]), or a ray-casting mesh used for normal map baking. This section covers the ray-casting cage.<br />
<br />
Most normal map baking tools allow you to use a distance-based raycast. A ray is sent outwards along each vertex normal, then at the distance you set a ray is cast back inwards. Where ever that ray intersects the high poly mesh, it will sample the normals from it. <br />
<br />
{|class="wikitable"<br />
|[[Image:Normalmap_raycasting_1.jpg]] <br />
|[[Image:Normalmap_raycasting_2.jpg]]<br />
|-<br />
|Hard edges and a distance-based raycast (gray areas) cause ray misses (yellow) and ray overlaps (cyan).<br> Image by [http://www.mankua.com/ Diego Castaño]<br />
|The gray area shows that using all soft edges (or hard edges and a cage-based raycast) will avoid ray-casting errors from split normals.<br> Image by [http://www.mankua.com/ Diego Castaño] <br />
|}<br />
<br />
Unfortunately with a distance-based raycast, [[#SGAHE|split vertex normals]] will cause the bake to miss parts of the high-res mesh, causing errors and seams. <br />
<br />
Some software allows you to use ''cage mesh'' option instead, which basically inflates a copy of the low-poly mesh, then raycasts inwards from each vertex. This ballooned-out mesh is the cage.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
|<tablebgcolor="#ffaaaa">| <br />
|}<br />
<br />
In 3ds Max the cage controls both the distance and the direction of the raycasting. <br />
<br />
In Maya the cage only controls the distance; the ray direction matches the vertex normals (inverted).<br />
<br />
<span style="text-decoration: line-through"> This may have been fixed in the latest release...<<BR>><br />
In Xnormal the cage is split everywhere the model has [[#SGAHE|hard edges]], causing ray misses in the bake. You can fix the hard edge split problem but it involves an overly complex workflow. You must also repeat the whole process any time you change your mesh:</span><br />
# <s> Load the 3d viewer.</s><br />
# <s> Turn on the cage editing tools.</s><br />
# <s> Select all of the vertices.</s><br />
# <s> Weld all vertices.</s><br />
# <s> Expand the cage as you normally would.</s><br />
# <s> Save out your mesh using the Xnormal format.</s><br />
# <s> Make sure Xnormal is loading the correct mesh.</s><br />
<br />
<span id="P"></span><span id="Painting"></span><br />
<br />
== Painting ==<br />
Don't be afraid to edit normal maps in Photoshop. After all it is just a texture, so you can clone, blur, copy, blend all you want... as long as it looks good of course. Some understanding of [[#RGBChannels|the way colors work]] in normal maps will go a long way in helping you paint effectively.<br />
<br />
A normal map sampled from a high-poly mesh will nearly always be better than one sampled from a texture, since you're actually grabbing "proper" normals from an accurate, highly detailed surface. That means your normal map's pixels will basically be recreating the surface angles of your high-poly mesh, resulting in a very believable look.<br />
<br />
If you only convert an image into a normal-map, it can look very flat, and in some cases it can be completely wrong unless you're very careful about your value ranges. Most image conversion tools assume the input is a heightmap, where black is low and white is high. If you try to convert a diffuse texture that you've painted, the results are often very poor. Often the best results are obtained by baking the large and mid-level details from a high-poly mesh, and then combined with photo-sourced "fine detail" normals for surface details such as fabric weave, scratches and grain.<br />
<br />
Sometimes creating a high poly surface takes more time than your budget allows. For character or significant environment assets then that is the best route, but for less significant environment surfaces working from a heightmap-based texture will provide a good enough result for a much less commitment in time.<br />
<br />
* [http://crazybump.com/ CrazyBump] is a commercial normal map converter.<br />
* [http://www.renderingsystems.com/support/showthread.php?tid=3 ShaderMap] is a commercial normal map converter.<br />
* [http://www.pixplant.com/ PixPlant] is a commercial normal map converter.<br />
* [http://boards.polycount.net/showthread.php?t=68860 NJob] is a free normal map converter.<br />
* [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA normalmap filter for Photoshop] is a free normal map converter.<br />
* [http://xnormal.net Xnormal height-to-normals filter for Photoshop] is a free normal map converter.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm Normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
<br />
=== Flat Color ===<br />
The color (128,128,255) creates normals that are completely perpendicular to the polygon, as long as the vertex normals are also perpendicular. Remember a normal map's per-pixel normals create ''offsets'' from the vertex normals. If you want an area in the normal map to be flat, so it creates no offsets from the vertex normals, then use the color (128,128,255). <br />
<br />
This becomes especially obvious when [[#Mirroring|mirroring a normal map]] and using a shader with a reflection ingredient. Reflection tends to accentuate the angles between the normals, so any errors become much more apparent.<br />
<br />
[[image:normalmap_127seam.jpg|thumb|600px|none| Mirrored normal maps show a seam when (127,127,255) is used for the flat color; 128 is better.<br>Image by [http://www.ericchadwick.com Eric Chadwick]]]<br />
<br />
In a purely logical way, 127 seems like it would be the halfway point between 0 and 255. However 128 is the color that actually works in practice. When a test is done comparing (127,127,255) versus (128,128,255) it becomes obvious that 127 creates a slightly bent normal, and 128 creates a flat one.<br />
<br />
This is because most game pipelines use ''unsigned'' normal maps. For details see the Polycount forum thread [http://www.polycount.com/forum/showpost.php?p=771360&postcount=22 tutorial: fixing mirrored normal map seams].<br />
<br />
<span id="BNMT"></span><br />
<br />
=== Blending Normal Maps Together ===<br />
Blending normal maps together is a quick way to add high-frequency detail like wrinkles, cracks, and the like. Fine details can be painted as a height map, then it can be converted into a normal map using one of the normal map tools. Then this "details" normal map can be blended with a geometry-derived normal map using one of the methods below. <br />
<br />
Here is a comparison of four of the blending methods. Note that in these examples the default values were used for CrazyBump (Intensity 50, Strength 33, Strength 33), but the tool allows each layer's strength to be adjusted individually for stronger or milder results. Each of the normal maps below were [[#Renormalizing|re-normalized]] after blending.<br />
<br />
{|class="wikitable"<br />
|[[image:nrmlmap_blending_methods_Maps.png]]<br />
|[[image:nrmlmap_blending_methods_RTTNormalMapFX.png]]<br />
|-<br />
|The blended normal maps.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|Screenshot of the 3dsmax viewport, using the RTTNormalMap.fx shader.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|}<br />
<br />
The four blending methods used above:<br />
# [http://www.crazybump.com CrazyBump] by Ryan Clark blends normal maps together using calculations in 3D space rather than just in 2D. This does probably the best job at preserving details, and each layer's strength settings can be tweaked individually. <br />
# [http://www.rodgreen.com/?p=4 Combining Normal Maps in Photoshop] by Rod Green blends normal maps together using Linear Dodge mode for the positive values and Difference mode for the negative values, along with a Photoshop Action to simplify the process. It's free, but the results may be less accurate than CrazyBump.<br />
# [http://www.paultosca.com/makingofvarga.html Making of Varga] by [http://www.paultosca.com/ Paul "paultosca" Tosca] blends normal maps together using Overlay mode for the red and green channels and Multiply mode for the blue channel. This gives a slightly stronger bump than the Overlay-only method. [http://www.leocov.com/ Leo "chronic" Covarrubias] has a step-by-step tutorial for this method in [http://www.cgbootcamp.com/tutorials/2009/12/9/photoshop-combine-normal-maps.html CG Bootcamp Combine Normal Maps].<br />
# [[3DTutorials/Normal Map Deepening|Normal Map Deepening]] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to blend normal maps together using Overlay mode. [http://cgtextures.com/content.php?action=tutorial&name=normalmap CGTextures tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] also shows how to create normalmaps using multiple layers (Note: to work with the Overlay blend mode each layer's Output Level should be 128 instead of 255, you can use the Levels tool for this).<br />
<br />
The [http://boards.polycount.net/showthread.php?t=69615 Getting good height from Nvidia-filter normalizing grayscale height] thread on the Polycount forum has a discussion of different painting/blending options. Also see the [[#2DT|2D Tools]] section for painting and conversion tools.<br />
<br />
<span id="PCT"></span><br />
<br />
=== Pre-Created Templates ===<br />
A library of shapes can be developed and stored for later use, to save creation time for future normal maps. Things like screws, ports, pipes, and other doo-dads. These shapes can be stored as bitmaps with transparency so they can be layered into baked normal maps.<br />
<br />
* [http://www.beautifulrobot.com/?p=69 Creating & Using NormalMap "Widgets"] - by ''[http://www.beautifulrobot.com Steev "kobra" Kelly]''<<BR>> How to set up and render template objects.<br />
* [http://www.akramparvez.com/portfolio/scripts/normalmap-widget-for-3ds-max/ NormalMap Widget for 3ds Max] - by ''[http://www.akramparvez.com Akram Parvez]''<<BR>>A script to automate the setup and rendering process.<br />
* See the section [[#BT|Baking Transparency]] for more template-rendering tools and tutorials.<br />
<br />
<span id="RN"></span><span id="Renormalizing"></span><br />
=== Re-normalizing ===<br />
Re-normalizing means resetting the length of each normal in the map to 1.<br />
<br />
A normal mapping shader takes the three color channels of a normal map and combines them to create the direction and length of each pixel's normal. These normals are then used to apply the scene lighting to the mesh. However if you edit normal maps by hand or if you blend multiple normal maps together this can cause those lengths to change. Most shaders expect the length of the normals to always be 1 (normalized), but some are written to re-normalize the normal map dynamically (for example, 3ds Max's Hardware Shaders do re-normalize).<br />
<br />
If the normals in your normal map are not normalized, and your shader doesn't re-normalize them either, then you may see artifacts on the shaded surface... the specular highlight may speckle like crazy, the surface may get patches of odd shadowing, etc. To help you avoid this NVIDIA's normal map filter for Photoshop provides an easy way to re-normalize a map after editing; just use the '''Normalize Only''' option. [http://xnormal.net Xnormal] also comes with a Normalize filter for Photoshop.<br />
<br />
[[image:normalize_only.jpg|frame|none|The re-normalize option in the NVIDIA filter.<br>Image by [http://hirezstudios.com/ Scott Warren]]]<br />
<br />
Some shaders use [[#NormalMapCompression|compressed normal maps]]. Usually this means the blue channel is thrown away completely, so it's recalculated on-the-fly in the shader. However the shader has to re-normalize in order to recreate that data, so any custom normal lengths that were edited into the map will be ignored completely. <br />
<br />
<span id="AOIANM"></span><span id="AmbientOcclusionIntoANormalMap"></span><br />
<br />
=== Ambient Occlusion into a Normal Map ===<br />
If the shader doesn't re-normalize the normal map, an [[Ambient Occlusion Map]] can actually be baked into the normal map. This will shorten the normals in the crevices of the surface, causing the surface to receive less light there. This works with both diffuse and specular, or any other pass that uses the normal map, like reflection.<br />
<br />
However it's usually best to keep the AO as a separate map (or in an alpha channel) and multiply it against the ambient lighting only. This is usually done with a custom [[:Category:Shaders|shader]]. If you multiply it against the diffuse map or normal map then it also occludes diffuse lighting which can make the model look dirty. Ambient occlusion is best when it occludes ambient lighting only, for example a [[DiffuselyConvolvedCubeMap|diffusely convolved cubemap]].<br />
<br />
[[image:nrmlmap_ao.jpg|frame|none| AO can be baked into a normal map, shortening the normals (lower left model).<br>Model by [http://www.3dartisan.net/~kuman/ James Ku]]]<br />
<br />
To bake the AO into a normal map, adjust the levels of the AO layer first so the darks only go as low as 128 gray, then set the AO layer to Darken mode. This will shorten the normals in the normalmap, causing the surface to receive less light in the darker areas. <br />
<br />
This trick doesn't work with any shaders that re-normalize, like 3ds Max's Hardware Shaders. The shader must be altered to actually use the lengths of your custom normals; most shaders just assume all normals are 1 in length because this makes the shader code simpler. Also this trick will not work with most of the common [[#NormalMapCompression|normal map compression formats]], which often discard the blue channel and recalculate it in the shader, which requires re-normalization.<br />
<br />
<span id="BLE"></span><br />
<br />
=== Back Lighting Example ===<br />
You can customize normal maps for some interesting effects. If you invert the blue channel of a tangent-space map, the normals will be pointing to the opposite side of the surface, which can simulate backlighting.<br />
<br />
{|class="wikitable"<br />
|[[image:tree_front.jpg]]||[[image:tree_back.jpg]]<br />
|-<br />
|Tree simulating subsurface scattering (front view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|Tree simulating subsurface scattering (back view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|-<br />
|colspan="2"|[[image:tree_maps.jpg]]<br />
|-<br />
|colspan="2"|The maps used for the leaves. The 2nd diffuse was simply color-inverted, hue-shifted 180°, and saturated.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
The tree leaves use a shader than adds together two diffuse maps, one using a regular tangent-space normal map, the other using the same normal map but with the blue channel inverted. This causes the diffuse map using the regular normal map to only get lit on the side facing the light (front view), while the diffuse map using the inverted normal map only gets lit on the opposite side of the leaves (back view). The leaf geometry is 2-sided but uses the same shader on both sides, so the effect works no matter the lighting angle. As an added bonus, because the tree is self-shadowing the leaves in shadow do not receive direct lighting, which means their backsides do not show the inverted normal map, so the fake subsurface scatter effect only appears where the light directly hits the leaves. This wouldn't work for a whole forest because of the computational cost of self-shadowing and double normal maps, but could be useful for a single "star" asset, or if LODs switched the distant trees to a model that uses a cheaper shader.<br />
<br />
<span id="SAS"></span><br />
<br />
== Shaders and Seams ==<br />
You need to use the right kind of shader to avoid seeing seams where UV breaks occur. It must be written to use the same [[#TangentBasis|tangent basis]] that was used during baking. If the shader doesn't, the lighting will either be inconsistent across UV borders or it will show smoothing errors from the low-poly vertex normals.<br />
<br />
Xnormal generates accurate normals when displayed in Xnormal, and the SDK includes a method to write your own custom tangent space generator for the tool. <br />
<br />
<span id="3MS"></span><br />
=== 3ds Max Shaders ===<br />
The "Render To Texture" tool in 3ds Max 2011 and older generates [[#TSNM|tangent-space]] normal maps that render correctly in the offline renderer (scanline) but do not render correctly in the realtime viewport with the 3ds Max shaders. Max is using a different [[#TangentBasis|tangent basis]] for each. This is readily apparent when creating non-organic hard surface normalmaps; smoothing errors appear in the viewport that do not appear when rendered. <br />
<br />
The errors can be fixed by using "Render To Texture" to bake a [[#TSNM|tangent-space]] or [[#OSNM|object-space]] map, and using the free [http://www.3pointstudios.com/3pointshader_about.shtml "3Point Shader"] by Christoph '[[CrazyButcher]]' Kubisch and Per 'perna' Abrahamsen. The shader uses the same tangent basis as the baking tool, so it produces nearly flawless results. It also works with old bakes.<br />
<br />
You can get OK results in the Max viewport using a tangent-space map baked in Maya, loading it in a Standard material, and enabling "Show Hardware Map in Viewport". Another method is to use Render To Texture to bake an [[#OSNM|object-space]] map then use [[#CBS|Nspace]] to convert it into a tangent-space map then load that in a DirectX material and use the RTTNormalMap.fx shader. <br />
<br />
Autodesk is aware of these issues, and plans to address them in an upcoming release. See these links for more information:<br />
* Christoph "[[CrazyButcher]]" Kubisch and Per "perna" Abrahamsen designed a shader/modifier combination approach that fixes the viewport problem, see the Polycount forum post [http://boards.polycount.net/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max].<br />
* Jean-Francois "jfyelle" Yelle, Autodesk Media & Entertainment Technical Product Manager, has [http://boards.polycount.net/showthread.php?p=1115812#post1115812 this post]. <br />
* Ben Cloward posted [http://boards.polycount.net/showthread.php?p=1100270#post1100270 workarounds and FX code].<br />
* Christopher "cdiggins" Diggins, SDK writer for 3ds Max, shares some of the SDK code in his blog posts "[http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping How the 3ds Max Scanline Renderer Computes Tangent and Binormal Vectors for Normal Mapping]" and "[http://area.autodesk.com/blogs/chris/3ds_max_normal_map_baking_and_face_angle_weighting_the_plot_thickens 3ds Max Normal Map Baking and Face Angle Weighting: The Plot Thickens]".<br />
<br />
[[image:nmtest_uv-splits_thumb.jpg|thumb|600px|none|Comparison of map baking methods in Maya and Max, and Ben Cloward's custom FX code.<br>Image by [http://www.bencloward.com/ Ben Cloward] and [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
[[image:normalmapfix_3pointstudios_thumb.jpg|frame|none|3 Point Studios' normal map display fix for 3ds Max.<br>image by [http://www.3pointstudios.com 3 Point Studios]]]<br />
<br />
{|class="wikitable"<br />
|[[image:max2010_normalmap_workarounds.png|thumb|400px|none|]]<br />
|[[image:max2010_normalmap_compare.png|thumb|400px|none|]]<br />
|-<br />
|Viewport methods in 3ds Max 2010.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick] <br />
|More baking methods in 3ds Max 2010.<br> Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
<span id="3MENT"></span><br />
<br />
=== 3ds Max Edit Normals Trick ===<br />
After baking, if you add an Edit Normals modifier to your low-poly normalmapped model, this seems to "relax" the vertex normals for more accurate viewport shading. The modifier can be collapsed if desired.<br />
<br />
<span id="MS"></span><br />
=== Maya Shaders ===<br />
Maya seems to correctly generate normals to view in realtime, with the correct [[#TangentBasis|tangent basis]], with much less smoothing errors than 3ds Max. <br />
* [http://www.mentalwarp.com/~brice/shader.php BRDF shader] by [http://www.mentalwarp.com/~brice/ Brice Vandemoortele] and [http://www.kjapi.com/ Cedric Caillaud] (more info in [http://boards.polycount.net/showthread.php?t=49920 this Polycount thread]) '''Update:''' [http://boards.polycount.net/showthread.php?p=821862#post821862 New version here] with many updates, including object-space normal maps, relief mapping, self-shadowing, etc. Make sure you enable cgFX shaders in the Maya plugin manager, then you can create them in the same way you create a Lambert, Phong etc. Switch OFF high quality rendering in the viewports to see them correctly too.<br />
* If you want to use the software renderer, use mental ray instead of Maya's software renderer because mental ray correctly interprets tangent space normals. The Maya renderer treats the normal map as a grayscale bump map, giving nasty results. Mental ray supports Maya's Phong shader just fine (amongst others), although it won't recognise a gloss map plugged into the "cosine power" slot. The slider still works though, if you don't mind having a uniform value for gloss. Spec maps work fine though. Just use the same set up as you would for viewport rendering. You'll need to have your textures saved as TGAs or similar for mental ray to work though. - from [http://boards.polycount.net/member.php?u=14235 CheeseOnToast]<br />
<br />
<br />
<span id="NMC"></span><br />
<br />
== Normal Map Compression ==<br />
see; [[Normal Map Compression]]<br />
<br />
== Links ==<br />
<br />
=== Related Pages ===<br />
* [[Curvature map]]<br />
* [[DuDv map]]<br />
* [[Flow map]]<br />
* [[Normal map]]<br />
* [[Radiosity normal map]]<br />
* [[Vector displacement map]]<br />
<br />
<span id="3DT"></span> <span id="Tools"></span> <span id="3DTools"></span><br />
=== 3D Tools ===<br />
See [[:Category:Tools#A3D_Normal_Map_Software|Category:Tools#3D_Normal_Map_Software]]<br />
<br />
<span id="2DT"></span><span id="2DTools"></span><br />
=== 2D Tools ===<br />
See [[:Category:Tools#A2D_Normal_Map_Software|Category:Tools#2D_Normal_Map_Software]]<br />
<br />
<span id="T"></span><span id="Tutorials"></span><br />
=== Tutorials ===<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh tutorial for Max and Xnormal] by [http://www.exisinteractive.com/ PeterK] to prevent heavy distortions when baking with a cage, without the need to add extra supporting vertices.<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games] by [http://www.polycount.com/forum/member.php?u=56680 'SuperFranky']<br />
* [http://area.autodesk.com/userdata/fckdata/239955/The%20Generation%20and%20Display%20of%20Normal%20Maps%20in%203ds%20Max.pdf The Generation and Display of Normal Maps in 3ds Max] (500kb PDF) <<BR>> Excellent whitepaper from Autodesk about normal mapping in 3ds Max and other apps.<br />
* [http://www.katsbits.com/htm/tutorials/blender-baking-normal-maps-from-models.htm Renderbump and baking normal maps from high poly models using Blender 3D] by ''[http://www.katsbits.com/htm/about.htm "katsbits"]''<<BR>>Baking normal maps in Blender.<br />
* [http://udn.epicgames.com/Three/CreatingNormalMaps.html Techniques for Creating Normal Maps] in the Unreal Developer Network's [http://udn.epicgames.com/Three/WebHome.html Unreal Engine 3 section] contains advice from [http://www.epicgames.com/ Epic Games] artists on creating normal maps for UE3. The [http://udn.epicgames.com/Three/DesignWorkflow.html#Creating%20normal%20maps%20from%20meshes Design Workflow page] has a summary.<br />
* [http://www.iddevnet.com/quake4/ArtReference_CreatingModels#head-3400c230e92ff7d57424b2a68f6e0ea75dee4afa Creating Models in Quake 4] by [http://www.ravensoft.com/ Raven Software] is a comprehensive guide to creating Quake 4 characters.<br />
* [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing and UVs can affect normal maps in Doom 3.<br />
* [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] is an overview of modeling for normal maps.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses how smoothing groups and bevels affect the topology of the low-poly model.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in-game, not the triangle or poly count.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm Normal map workflow] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] demonstrates his normal mapping workflow in 3ds Max and Photoshop.<br />
* [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa This video tutorial] by [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] shows in Maya how to subdivide the low-poly mesh so it more closely matches the high-poly mesh, to help solve wavy lines in the bake.<br />
* [http://www.bencloward.com/tutorials_normal_maps1.shtml Normal Mapping Tutorial] by [http://www.bencloward.com/ Ben Cloward] is a comprehensive tutorial about the entire normal map creation process.<br />
* [http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy] shows how to use a special lighting setup to render normal maps (instead of baking them).<br />
* [http://cgtextures.com/content.php?action=tutorial&name=normalmap Tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] shows how to create deep normal maps using multiple layers. Note: to use Overlay blend mode properly, make sure to change each layer's Levels ''Output Level'' to 128 instead of 255.<br />
* [http://www.poopinmymouth.com/process/tips/normalmap_deepening.jpg Normalmap Deepening] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to adjust normal maps, and how to layer together painted and baked normal maps.<br />
* [http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] helps to solve seams along horizontal or vertical UV edges, but not across angled UVs.<br />
* [http://planetpixelemporium.com/tutorialpages/normal.html Cinema 4D and Normal Maps For Games] by [http://planetpixelemporium.com/index.php James Hastings-Trew] describes normal maps in plain language, with tips on creating them in Cinema 4D.<br />
* [http://forums.cgsociety.org/showthread.php?f=39&t=359082 3ds Max normal mapping overview] by [http://www.alan-noon.com/ Alan Noon] is a great thread on CGTalk about the normal mapping process.<br />
* [http://forums.cgsociety.org/showthread.php?f=46&t=373024 Hard Surface Texture Painting] by [http://stefan-morrell.cgsociety.org/gallery/ Stefan Morrell] is a good introduction to painting textures for metal surfaces.<br />
<br />
<span id="D"></span><span id="Discussion"></span><br />
<br />
=== Discussion ===<br />
[http://boards.polycount.net/showthread.php?p=820218 Discuss this page on the Polycount forums]. Suggestions welcome.<br />
<br />
Even though only one person has been editing this page so far, the information here was gathered from many different sources. We wish to thank all the contributors for their hard-earned knowledge. It is much appreciated!<br />
<br />
----<br />
[[Category:TextureTypes]] [[Category:Bump map]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Normal_mapNormal map2015-04-22T15:01:34Z<p>Dustinbrown: /* Common Swizzle Coordinates */</p>
<hr />
<div>== Out of Date ==<br />
The information on this page is a bit old, it needs to be updated. See these links for more current information:<br />
<br />
* [http://farfarer.com/resources.htm RNM Normal Map Combiner], by [http://www.farfarer.com/ James "Farfarer" O'Hare]<br />
* [http://vincentcallebaut.com/CombineNormal.html Combine Normal], by [http://vincentcallebaut.comVincent "Vincentt" Callebaut], [http://www.polycount.com/forum/showthread.php?t=131819 Combine normal maps script for Photoshop] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showpost.php?p=2226864&postcount=51 Earthquake on separating smoothing groups in the UV]<br />
* [http://www.polycount.com/forum/showpost.php?p=2225535&postcount=40 JedTheKrampus on offsetting Mirrored UVs]<br />
* [http://www.polycount.com/forum/showthread.php?t=148303 Of Bit Depths, Banding and Normal Maps]<br />
* [http://www.polycount.com/forum/showthread.php?t=147227 Skew you buddy! Making sense of skewed normal map details.]<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games]<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh Tutorial]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?]<br />
* [http://www.laurenscorijn.com/future-xoliulshader-support.html Future Xoliulshader support] = why Xoliulshader doesn't work properly in 3ds Max 2013/2014.<br />
<br />
== Synched Workflow ==<br />
To eliminate seams and shading artifacts, the model renderer and the normal map baking tool should use the same tangent basis.<br />
<br />
FBX model format can store tangents, and some renderers use this data to synch the incoming normal maps.<br />
<br />
{| class="wikitable sortable" style="color:grey;"<br />
|- <br />
! Renderer !! Normal map baker<br />
|-<br />
| 3ds Max || 3ds Max, Handplane, ?<br />
|-<br />
| Blender || ?<br />
|-<br />
| Creation Engine || Handplane, ?<br />
|-<br />
| CryEngine || ?<br />
|-<br />
| Knald || ?<br />
|-<br />
| Marmoset Toolbag || 3ds Max, Maya, Xnormal, ?<br />
|-<br />
| Maya || Handplane, Maya, ?<br />
|-<br />
| Source || Handplane, Maya ([http://www.polycount.com/forum/showpost.php?p=2224653&postcount=28]), ?<br />
|-<br />
| Starcraft II || Handplane, ?<br />
|-<br />
| Substance Designer || ?<br />
|-<br />
| Unity([http://www.polycount.com/forum/showpost.php?p=2224781&postcount=29], [http://www.polycount.com/forum/showthread.php?p=2194353#post2194353]) || Handplane, Xnormal (via Asset Store), ?<br />
|-<br />
| Unreal Engine 4 || Handplane, Xnormal([http://www.polycount.com/forum/showpost.php?p=2224402&postcount=20]), ? <br />
|-<br />
| Xnormal || Xnormal, ?<br />
|}<br />
<br />
----<br />
<br />
== What is a Normal Map? ==<br />
A Normal Map is usually used to fake high-res geometry detail when it's mapped onto a low-res mesh. The pixels of the normal map each store a ''normal'', a vector that describes the surface slope of the original high-res mesh at that point. The red, green, and blue channels of the normal map are used to control the direction of each pixel's normal. <br />
<br />
When a normal map is applied to a low-poly mesh, the texture pixels control the direction each of the pixels on the low-poly mesh will be facing in 3D space, creating the illusion of more surface detail or better curvature. However, the silhouette of the model doesn't change. <br />
<br />
<gallery mode="packed"><br />
Whatif_normalmap_mapped2.jpg|A model with a normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_low.jpg|The model without its normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_high.jpg|The high-resolution model used to create the normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
</gallery><br />
<br />
==Tangent-Space vs. Object-Space==<br />
<br />
Normal maps can be made in either of two basic flavors: tangent-space or object-space. World-space is basically the same as object-space, except it requires the model to remain in its original orientation, neither rotating nor deforming, so it's almost never used.<br />
<br />
===Tangent-space normal map===<br />
[[image:normalmap_tangentspace.jpg|frame|none|A tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Predominantly-blue colors. Object can rotate and deform. Good for deforming meshes, like characters, animals, flags, etc.<br />
<br />
Pros:<br />
* Maps can be reused easily, like on differently-shaped meshes.<br />
* Maps can be tiled and mirrored easily, though some games might not support mirroring very well.<br />
* Easier to overlay painted details.<br />
* Easier to use image compression.<br />
<br />
Cons:<br />
* More difficult to avoid smoothing problems from the low-poly vertex normals (see Smoothing Groups and Hard Edges).<br />
* Slightly slower performance than an object-space map (but not by much).<br />
<br />
===Object-space normal map===<br />
[[image:normalmap_worldspace.jpg|frame|none|An object-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Rainbow colors. Objects can rotate, but usually shouldn't be deformed, unless the shader has been modified to support deformation. Object-space is also called local-space or model-space. <br />
<br />
Pros:<br />
* Easier to generate high-quality curvature because it completely ignores the crude smoothing of the low-poly vertex normals.<br />
* Slightly better performance than a tangent-space map (but not by much).<br />
<br />
Cons:<br />
* Can't easily reuse maps, different mesh shapes require unique maps.<br />
* Difficult to tile properly, and mirroring requires specific shader support.<br />
* Harder to overlay painted details because the base colors vary across the surface of the mesh. Painted details must be converted into Object Space to be combined properly with the OS map.<br />
* They don't compress very well, since the blue channel can't be recreated in the shader like with tangent-space maps. Also the three color channels contain very different data which doesn't compress well, creating many artifacts. Using a half-resolution object-space map is one option. <br />
<br />
<br clear="all"/><br />
<br />
=== Converting Between Spaces ===<br />
Normal maps can be converted between object space and tangent space, in order to use them with different blending tools and shaders, which require one type or the other. <br />
<br />
Object space maps can also be converted to maps with different tangent bases, to better match the normal maps with the renderer and thus avoid lighting errors.<br />
<br />
* [http://www.handplane3d.com Handplane] by [http://www.alecmoody.com/ Alec Moody] is a tool that converts object space maps into a variety of tangent spaces: 3ds Max, Creation Engine, Maya, Source, Unity, Unreal, etc. See the Polycount Forum thread [http://www.polycount.com/forum/showthread.php?t=116899 Official handplane support thread - Now freeware!!].<br />
<br />
[[File:handplane_illus_1.jpg|frame|none|Handplane interface. <br>Image by [http://www.alecmoody.com/ Alec Moody].]]<br />
<br />
<br />
* [http://boards.polycount.net/showthread.php?p=1072599#post1072599 NSpace] by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] is a tool that converts an object-space normal map into a tangent-space map, which then works seamlessly in the 3ds Max viewport. He converts the map by using the same tangent basis that 3ds Max uses for its hardware shader. To see the results, load the converted map via the ''Normal Bump'' map and enable "Show Hardware Map in Viewport". [http://gameartist.nl/ Osman "osman" Tsjardiwal] created a GUI for NSpace, you can [http://boards.polycount.net/showthread.php?p=1075143#post1075143 download it here], just put it in the same folder as the NSpace exe and run it. <br />
<br />
[[File:NSpace_Gui_osman.png|frame|none|NSpace interface. <br>Image by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] and [http://gameartist.nl Osman "osman" Tsjardiwal].]]<br />
<br />
[http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson] said: "[8Monkey Labs has] a tool that lets you load up your reference mesh and object space map. Then load up your tangent normals, and adjust some sliders for things like tile and amount. We need to load up a mesh to know how to correctly orient the tangent normals or else things will come out upside down or reverse etc. It mostly works, but it tends to "bend" the resulting normals, so you gotta split the mesh up into some smoothing groups before you run it, and then I usually will just composite this "combo" texture over my orig map in Photoshop."<br />
<br />
<span id="RGBC"></span><span id="RGBChannels"></span><br />
<br />
== RGB Channels ==<br />
Shaders can use different techniques to render tangent-space normal maps, but the normal map directions are usually consistent within a game. Usually the red channel of a tangent-space normal map stores the X axis (pointing the normals predominantly leftwards or rightwards), the green channel stores the Y axis (pointing the normals predominantly upwards or downwards), and the blue channel stores the Z axis (pointing the normals outwards away from the surface).<br />
<br />
[[image:tangentspace_rgb.jpg|frame|none|The red, green, and blue channels of a tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you see lighting coming from the wrong angle when you're looking at your normal-mapped model, and the model is using a tangent-space normal map, the normal map shader might be expecting the red or green channel (or both) to point in the opposite direction. To fix this either change the shader, or simply invert the appropriate color channels in an image editor, so that the black pixels become white and the white pixels become black.<br />
<br />
Some shaders expect the color channels to be swapped or re-arranged to work with a particular [[#NormalMapCompression|compression format]]. For example the DXT5_nm format usually expects the X axis to be in the alpha channel, the Y axis to be in the green channel, and the red and blue channels to be empty.<br />
<br />
== Tangent Basis ==<br />
[[#TangentSpaceVsObjectSpace|Tangent-space]] normal maps use a special kind of vertex data called the ''tangent basis''. This is similar to UV coordinates except it provides directionality across the surface, it forms a surface-relative coordinate system for the per-pixel normals stored in the normal map. This coordinate system is required to light a normal mapped surface.<br />
<br />
Each vertex in the tangent basis is a combination of three things: the mesh vertex's normal (influenced by smoothing), the vertex's tangent (usually derived from the V texture coordinate), and the vertex's bitangent (derived in code, also called the binormal). These three vectors create an axis for each vertex, giving it a specific orientation in the tangent space. These axes are used to properly transform the incoming lighting from world space into tangent space, so your normal-mapped model will be lit correctly.<br />
<br />
Light rays are in world space, but the normals stored in the normal map are in tangent space. When the model is being rendered, the light rays must be converted from world space into tangent space, using the tangent basis to get there. At that point the incoming light rays are compared against the directions of the normals in the normal map, and this determines how much each pixel is going to be lit. Alternatively, instead of converting the light rays some shaders will convert the normals in the normal map from tangent space into world space. Then those world-space normals are compared against the light rays, and the model is lit appropriately. The method depends on who wrote the shader, but the end result is the same. Both methods require a tangent basis to transform the lighting.<br />
<br />
When a triangle's vertex normals are pointing straight out, and a pixel in the normal map is neutral blue (128,128,255) this means the pixel's normal will be pointing straight out from the surface of the low-poly mesh. When that pixel normal is tilted towards the left or the right in the tangent coordinate space, it will get either more or less red color, depending on whether the normal map is set to store the X axis as either a positive or a negative value. Same goes for when the normal is tilted up or down in tangent space, it will either get more or less green color. If the vertex normals aren't exactly perpendicular to the triangle, the normal map pixels will be tinted away from neutral blue as well.<br />
<br />
Unfortunately for artists, there are many different ways to calculate the tangent basis: [http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping 3ds Max], [http://download.autodesk.com/us/maya/2011help/index.html?url=./files/Appendix_A_Tangent_and_binormal_vectors.htm,topicNumber=d0e227193 Maya], [http://www.codesampler.com/dx9src/dx9src_4.htm#dx9_dot3_bump_mapping DirectX 9], [http://developer.nvidia.com/object/NVMeshMender.html NVMeshMender], [http://www.terathon.com/code/tangent.html Eric Lengyel], a custom solution, etc. This means a normal map baked in one application probably won't shade correctly in another. Artists must do some testing with different [[#T|baking tools]] to find which works best with their output. When the renderer (or game engine) renders your game model, [[#ShadersAndSeams|the shader]] must use the same tangent basis as the normal map baker, otherwise you'll get incorrect lighting, especially across the seams between UV shells.<br />
<br />
The [http://www.xnormal.net/ xNormal] SDK supports custom tangent basis methods. When a programmer uses it to implement their renderer's own tangent basis, artists can then use Xnormal to bake normal maps that will match their renderer perfectly.<br />
<br />
[[image:tangentseams.jpg|frame|none|When shared edges are at different angles in UV space, different colors will show up<br />
along the seam. The tangent basis uses these colors to light the model properly. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
When you look at a tangent-space normal map for a character, you typically see different colors along the UV seams. This is because the UV shells are often oriented at different angles on the mesh, a necessary evil when translating the 3D mesh into 2D textures. The body might be mapped with a vertical shell, and the arm mapped with a horizontal one. This requires the normals in the normal map to be twisted for the different orientations of those UV shells. The UVs are twisted, so the normals must be twisted in order to compensate. The tangent basis helps reorient (twist) the lighting as it comes into the surface's local space, so the lighting will then look uniform across the normal mapped mesh.<br />
<br />
When an artist tiles a tangent-space normal map across an arbitrary mesh, like a landscape, this tends to shade correctly because the mesh has a uniform direction in tangent space. If the mesh has discontinuous UV coordinates (UV seams), or the normal map has large directional gradients across it, the tangent space won't be uniform anymore so the surface will probably have shading seams.<br />
<br />
== Common Swizzle Coordinates ==<br />
3D Software capable of displaying normal maps will have a native required direction, or "handedness" for the RGB channels in a normal map, sometimes referred to as "Swizzle Coordinates," though [[#SAS|shaders]] can often be written to override this native handedness. You may hear developers refer to "flipping the green channel" in order to get a normal map to display correctly, and this simply indicates that when the normal map was baked, it was authored with the incorrect handedness in the green channel.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
| '''Software''' <br />
| '''Red''' <br />
| '''Green''' <br />
| '''Blue''' <br />
|-<br />
|<#000000>| Maya<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| 3ds Max<br />
| X+<br />
| Y-<br />
| Z+ <br />
|-<br />
|<#000000>| Unreal Engine<br />
| X+ <br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Unity<br />
| X+<br />
| Y+<br />
| Z+<br />
|-<br />
|<#000000>| [https://developer.valvesoftware.com/wiki/Bump_map Source]<br />
| X+<br />
| Y-<br />
| Z+<br />
|<#000000>| Toolbag<br />
| X+<br />
| Y+ <br />
| Z+<br />
|}<br />
<span id="MTLPM"></span><br />
<br />
== Modeling the Low-Poly Mesh ==<br />
The in-game mesh usually needs to be carefully optimized to create a good silhouette, define edge-loops for better deformation, and minimize extreme changes between the vertex normals for better shading (see [[#SmoothingGroupsAndHardEdges|Smoothing Groups & Hard Edges]]).<br />
<br />
In order to create an optimized in-game mesh including a good silhouette and loops for deforming in animation, you can start with the 2nd subdivision level of your [[DigitalSculpting|digital sculpt]], or in some cases with the base mesh itself. Then you can just collapse edge loops or cut in new edges to add/remove detail as necessary. Or you can [[DigitalSculpting#OART|re-toplogize]] from scratch if that works better for you.<br />
<br />
See [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts] on the Polycount forum.<br />
<br />
<span id="UVC"></span><span id="UVCoordinates"></span><br />
=== UV Coordinates ===<br />
Normal map baking tools only capture normals within the 0-1 UV square, any UV bits outside this area are ignored. <br />
<br />
Only one copy of the forward-facing UVs should remain in the 0-1 UV square at baking time. If the mesh uses overlapping UVs, this will likely cause artifacts to appear in the baked map, since the baker will try render each UV shell into the map. Before baking, it's best to move all the overlaps and mirrored bits outside the 0-1 square. <br />
<br />
[[image:Normalmap_uvcoord_offset.jpg|frame|none|The mirrored UVs (in red) are offset 1 unit before baking. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you move all the overlaps and mirrored bits exactly 1 UV unit (any whole number will do), then you can leave them there after the bake and they will still be mapped correctly. You can move them back if you want, it doesn't matter to most game engines. Be aware that ZBrush does use UV offsets to manage mesh visibility, however this usually doesn't matter because the ZBrush cage mesh is often a different mesh than the in-game mesh used for baking.<br />
<br />
You should avoid changing the UVs after baking the normal map, because rotating or mirroring UVs after baking will cause the normal map not to match the [[#TB|tangent basis]] anymore, which will likely cause lighting problems. <br />
<br />
In 3ds Max, W is a third texture coordinate. It's used for 3D procedural textures and for storing vertex color in UV channels (you need 3 axes for RGB, so UVW can store vertex color). Bake problems can be avoided by moving any overlapping UVs to -1 on the W axis, with the same results as moving them 1 unit on the U or V axes. The tool Render To Texture will always bake whatever UVs are the highest along the W axis. However using W can be messy... it's generally hidden unless you purposefully look for it (bad for team work), doesn't get preserved on export to other apps, and high W values can prevent selecting and/or welding UVs. <br />
<br />
<span id="M"></span><span id="Mirroring"></span><br />
<br />
=== Mirroring ===<br />
Normal maps can be mirrored across a model to create symmetrical details, and save UV space, which allows more detail in the normal map since the texture pixels are smaller on the model. <br />
<br />
With [[#OSNM|object-space]] maps, mirroring requires [http://boards.polycount.net/showthread.php?t=53986 specific shader support]. For [[#TSNM|tangent-space]] maps, mirroring typically creates a shading seam, but this can be reduced or hidden altogether, depending on the method used.<br />
<br />
<span id="TMW"></span><br />
==== Typical Mirroring Workflow ====<br />
# Delete the mesh half that will be mirrored. <br />
# Arrange the UVs for the remaining model, filling the UV square.<br />
# Mirror the model to create a "whole" mesh, welding the mesh vertices along the seam. <br />
# Move the mirrored UVs exactly 1 unit (or any whole number) out of the 0-1 UV square.<br />
# Bake the normal map.<br />
<br />
Sometimes an artist will decide to delete half of a symmetrical model before baking. <br />
<br />
This is a mistake however because often the vertex normals along the hole will bend towards the hole a bit; there are no faces on the other side to average the normals with. This will create a strong lighting seam in the normal map. <br />
<br />
It's typically best to use the complete mirrored model to bake the normal map, not just the unique half. <br />
<br />
To prevent the mirrored UVs from causing overlaps or baking errors, move the mirrored [[#UVC|UVs]] out of the 0-1 UV space, so only one copy of the non-mirrored UVs is left within the 0-1 square.<br />
<br />
To avoid texel "leaks" between the UV shells, make sure there's enough [[#Edge_padding|Edge Padding]] around each shell, including along the edges of the normal map. None of the UV shells should be touching the edge of the 0-1 UV square, unless they're meant to tile with the other side of the map.<br />
<br />
<span id="CM"></span><br />
<br />
==== Center Mirroring ====<br />
If the mirror seam runs along the surface of a continuous mesh, like down the center of a human face for example, then it will probably create a lighting seam. <br />
<br />
In Epic Games' [http://www.unrealtechnology.com/technology.php Unreal Engine 3] (UE3) their symmetrical models commonly use centered mirroring. Epic uses materials that mix a [[DetailMap]] with the normal maps; these seem to scatter the diffuse/specular lighting and help minimize the obviousness of the mirror seams. For their [[Light Map]]ped models they use [http://udn.epicgames.com/Three/LightMapUnwrapping.html a technique] that can almost completely hide the mirror seam.<br />
<br />
[[image:Epic_MirroringCicada.jpg|frame|none| In UE3 a center mirror seam is reduced by using a detail normal map. <br> Image by "[http://epicgames.com Epic Games]"]]<br />
<br />
'''''[http://www.zbrushcentral.com/showpost.php?p=573108&postcount=28 GOW2 normal map seams], [http://utforums.epicgames.com/showthread.php?p=27166791#post27166791 UDK normal map seams]'''''<br />
<br />
<span id="OM"></span><br />
<br />
==== Offset Mirroring ====<br />
Offset mirroring is a method where you move the mirror seam off to one side of the model, so the seam doesn't run exactly down the center. For example with a character's head, the UV seam can go down along the side of the head in front of the ear. The UV shell for the nearest ear can then be mirrored to use the area on the other side of the head. <br />
<br />
This avoids the "Rorschach" effect and allows non-symmetrical details, but it still saves texture space because the two sides of the head can be mirrored (they're never seen at the same time anyhow).<br />
<br />
Offset mirroring doesn't get rid of the seam, but it does move it off to a place where it can either be less obvious, or where it can be hidden in a natural seam on the model.<br />
<br />
<span id="FCM"></span><br />
==== Flat Color Mirroring ====<br />
[http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] solves seams by painting a flat set of normals along the seam, using neutral blue (128,128,255). However it only works along horizontal or vertical UV seams, not across any angled UVs. It also removes any details along the mirror seam, creating blank areas. <br />
<br />
<span id="EM"></span><br />
==== Element Mirroring ====<br />
The mirror seam can be avoided completely when it doesn't run directly through any mesh. For example if there's a detached mesh element that runs down the center of the model, this can be uniquely mapped, while the meshes on either side can be mirrors of each other. Whenever the mirrored parts don't share any vertex normals with the non-mirrored parts, there won't be any seams. <br />
<br />
[[image:normalmap_mirrored-binocs-racer445.jpg|frame|none|The middle part (highlighted in red) uses unique non-mirrored UVs, allowing the mesh on the right to be mirrored without any seams. <br>Image by [http://http://racer445.com/ "racer445"]]]<br />
<br />
<span id="SGAHE"></span><br />
<br />
=== Smoothing Groups & Hard Edges ===<br />
Each vertex in a mesh has at least one vertex normal. Vertex normals are used to control the direction a triangle will be lit from; if the normal is facing the light the triangle will be fully lit, if facing away from the light the triangle won't be lit. <br />
<br />
Each vertex however can have more than one vertex normal. When two triangles have different vertex normals along their shared edge, this creates a shading seam, called a ''hard edge'' in most modeling tools. 3ds Max uses ''Smoothing Groups'' to create hard/soft edges, Maya uses ''Harden Edge'' and ''Soften Edge''. These tools create hard and soft edges by splitting and combining the vertex normals.<br />
<br />
[[image:BenMathis_SmoothingGroups_Excerpt.gif|frame|none|Hard edges occur where the vertices have multiple normals. <br>Image by [http://poopinmymouth.com Ben 'poopinmymouth' Mathis] ([http://poopinmymouth.com/process/tips/smoothing_groups.jpg tutorial here])]]<br />
<br />
When a mesh uses all soft normals (a single smoothing group) the lighting has to be interpolated across the extreme differences between the vertex normals. If your renderer doesn't support the same [[#TangentBasis|tangent basis]] that the baker uses, this can produce extreme shading differences across the model, which creates shading artifacts. It is generally best to reduce these extremes when you can because a mismatched renderer can only do so much to counteract it.<br />
<br />
Hard edges are usually best where the model already has a natural seam. For example, you can add a hard edge along the rim of a car's wheel well, to prevent the inside of the wheel well from distorting the shading for the outside of the car body. Mechanical models usually need hard edges where ever the surface bends more than about 45 degrees. <br />
<br />
For most meshes, the best results usually come from adding hard edges where ever there are UV seams. There are no hard rules however, you must experiment with different approaches to find what works best in your game.<br />
<br />
When you use object-space normal maps the vertex normal problem goes away since you're no longer relying on the crude vertex normals of the mesh. An object-space normal map completely ignores vertex normals. Object-space mapping allows you to use all soft edges and no bevels on the low-res mesh, without showing lighting errors.<br />
<br />
<span id="HEDAT"></span><br />
==== Hard Edge Discussions & Tutorials ====<br />
* [http://www.polycount.com/forum/showthread.php?p=2090450#post2090450 Maya MEL Script help needed (UV border edges)]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=73593 Normal Maps: Can Somone Explain This "Black Edge" issue]<br />
* [http://www.polycount.com/forum/showthread.php?t=73566 Normal Maps: Can someone explain normals, tangents and split UVs?]<br />
* [http://www.polycount.com/forum/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max]<br />
* [http://boards.polycount.net/showthread.php?t=68173 Why you should NOT trust 3ds Max's viewport normal-map display!]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/10503-xsi-normal-mapped-cube-looks-bad.html XSI - normal mapped cube looks bad]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/11924-weird-maya-normal-map-seam-artifact-problem-am-i-making-simple-mistake.html Weird Maya normal map seam/artifact problem]<br />
* [http://boards.polycount.net/showthread.php?p=1080600 Seams in Normals when Creating Tiling Environment Trims and other Tiles]<br />
* The tutorial [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing can affect the normal map.<br />
* The tutorial: [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] shows how smoothing affects raycasting.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses the breaking of normals and smoothing groups in general terms.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in the game, not the triangle count.<br />
* The Crysis documentation [http://doc.crymod.com/AssetCreation/PolyBumpReference.html PolyBump Reference] has a section towards the bottom that shows how smoothing affects their baked normal maps.<br />
* The polycount thread [http://boards.polycount.net/showthread.php?t=60694 Toying around with normal map approaches] has a great discussion of how best to use smoothing groups and bevels for better shading.<br />
<br />
<span id="UB"></span><br />
==== Using Bevels ====<br />
Bevels/chamfers generally improve the silhouette of the model, and can also help reflect specular highlights better. <br />
<br />
However bevels tend to produce long thin triangles, which slow down the in-game rendering of your model. Real-time renderers have trouble rendering long thin triangles because they create a lot of sub-pixel areas to render. <br />
<br />
Bevels also balloon the vertex count, which can increase the transform cost and memory usage. Hard edges increase the vertex count too, but not when the edge also shares a seam in UV space. For a good explanation of the vertex count issue, see [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly].<br />
<br />
Using hard edges with matching UV shells tends to give better performance and better cosmetic results than using bevels. However there are differing opinions on this, see the Polycount thread "[http://boards.polycount.net/showthread.php?t=71760 Maya transfer maps help]".<br />
<br />
<span id="EVN"></span><br />
==== Edited Vertex Normals ====<br />
If you use bevels the shading will be improved by editing the vertex normals so the larger flat surfaces have perpendicular normals. The vertex normals are then forced to blend across the smaller bevel faces, instead of across the larger faces. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66139 Superspecular soft edges tutorial chapter 1].<br />
<br />
[[image:oliverio_bevel_normals.gif|frame|none|Bending normals on bevelled models. <br>From the tutorial [http://deadlineproof.com/model-shading-techniques-soft-edge-superspecular/ Shading techniques Superspecular soft edges]<br>Image by [http://deadlineproof.com/ Paolo Oliverio]]]<br />
<br />
== Level of Detail Models ==<br />
See [http://www.polycount.com/forum/showthread.php?p=1216945#post1216945 Problem if you're using 3point-style normals with an LOD].<br />
<br />
<span id="MTHPM"></span><br />
<br />
== Modeling The High-Poly Mesh ==<br />
[[Subdivision Surface Modeling]] and [[DigitalSculpting]] are the techniques most often used for modeling a normal map. <br />
<br />
Some artists prefer to model the in-game mesh first, other artists prefer to model the high-res mesh first, and others start somewhere in the middle. The modeling order is ultimately a personal choice though, all three methods can produce excellent results:<br />
* Build the in-game model, then up-res it and sculpt it.<br />
* Build and sculpt a high resolution model, then build a new in-game model around that.<br />
* Build a basemesh model, up-res and sculpt it, then step down a few levels of detail and use that as a base for building a better in-game mesh.<br />
If the in-game mesh is started from one of the subdivision levels of the basemesh sculpt, various edge loops can be collapsed or new edges can be cut to add/remove detail as necessary.<br />
<br />
<span id="SE"></span><br />
=== Sloped Extrusions ===<br />
[[image:normal_slopes_hatred.jpg|frame|none|Extrusions on the high-poly model should be sloped to make a better normal map. <br>Image by [http://www.hatred.gameartisans.org/ Krzysztof "Hatred" Dolas].]]<br />
<br />
=== Floating Geometry ===<br />
[[image:FloatingGeo.jpg|frame|none|Normal map stores the direction the surface is facing rather than real depth information, thus allowing to save time using floating geometry. <br>To correctly bake AO with floating geo make it a separate object and turn off it's shadow casting. <br>Image by [http://artisaverb.info/ Andrew "d1ver" Maximov].]]<br />
<br />
See also [[3DTutorials/Modeling High-Low Poly Models for Next Gen Games|Modeling High/Low Poly Models for Next Gen Games]] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa]<br />
<br />
<span id="ET"></span><br />
<br />
=== Edge Thickness ===<br />
[[image:normal_edge_thickness.jpg|frame|none|When creating edges of the Highpoly, sometimes you'll need to make them rounded than in real life to <br>work better at the size they will be seen.<br>Image by [http://racer445.com/Evan "racer445" Herbert]]]<br />
<br />
<span id="MRF"></span><span id="MRRCB"></span><br />
<br />
=== mental ray Round Corners Bump ===<br />
The mental ray renderer offers an automatic bevel rendering effect called Round Corners Bump that can be baked into a normal map. This is available in 3ds Max, Maya, and XSI. See [http://boards.polycount.net/showthread.php?t=71995 Zero Effort Beveling for normal maps] - by [http://boards.polycount.net/member.php?u=31662 Robert "r_fletch_r" Fletcher].<br />
<br />
[http://jeffpatton.net/ Jeff Patton] posted about [http://jeffpatton.cgsociety.org/blog/archive/2007/10/ how to expose Round Corners Bump] in 3ds Max so you can use it in other materials.<br />
<br />
[http://cryrid.com/art/ Michael "cryrid" Taylor] posted a tutorial about how to use [http://cryrid.com/images/temp/XSI/zeroeffort_bevels.jpg Round Corners in XSI].<br />
<br />
XSI is able to bake a good normal map with it, but 3ds Max seems to bake it incorrectly, and Maya isn't able to bake the effect at all. Maybe Max might be able to bake it correctly, if the .mi shader is edited to use the correct coordinate space?<br />
<br />
<span id="Baking"></span><span id="B"></span><br />
== Baking ==<br />
The process of transferring normals from the high-res model to the in-game model is often called baking. The baking tool usually starts projecting a certain numerical distance out from the low-poly mesh, and sends rays inwards towards the high-poly mesh. When a ray intersects the high-poly mesh, it records the mesh's surface normal and saves it in the normal map.<br />
<br />
To get an understanding of how all the options affect your normal map, do some test bakes on simple meshes like boxes. They generate quickly so you can experiment with [[#UVCoordinates|UV mirroring]], [[#SGAHE|smoothing groups]], etc. This helps you learn the settings that really matter.<br />
* The tutorial [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] has more examples of ray-casting, plus how to get better results from the bake.<br />
<br />
Baking sub-sections:<br />
# [[#Anti-Aliasing|Anti-Aliasing]]<br />
# [[#Baking_Transparency|Baking Transparency]]<br />
# [[#Edge_Padding|Edge Padding]]<br />
# [[#High_Poly_Materials|High Poly Materials]]<br />
# [[#Reset_Transforms|Reset Transforms]]<br />
# [[#Solving_Intersections|Solving Intersections]]<br />
# [[#Solving_Pixel_Artifacts|Solving Pixel Artifacts]]<br />
# [[#Solving_Wavy_Lines|Solving Wavy Lines]]<br />
# [[#Triangulating|Triangulating]]<br />
# [[#Working_with_Cages|Working with Cages]]<br />
<br />
<span id="AA"></span><br />
=== Anti-Aliasing ===<br />
Turning on super-sampling or anti-aliasing (or whatever multi-ray casting is called in your normal map baking tool) will help to fix any jagged edges where the high-res model overlaps itself within the UV borders of the low-poly mesh, or wherever the background shows through holes in the mesh. Unfortunately this tends to render much much slower, and takes more memory.<br />
<br />
[[image:normalmap_aliasing_knak47.jpg|frame|none|A bake without anti-aliasing shows artifacts where the high-poly mesh has overlaps. <br>Image by [http://www.polycount.com/forum/member.php?u=35938 'knak47']]]<br />
<br />
One trick to speed this up is to render 2x the intended image size then scale the normal map down 1/2 in a paint program like Photoshop. The reduction's pixel resampling will add anti-aliasing for you in a very quick process. After scaling, make sure to re-normalize the map if your game doesn't do that already, because the un-normalized pixels in your normalmap may cause pixelly artifacts in your specular highlights. Re-normalizing can be done with [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA's normal map filter] for Photoshop.<br />
<br />
3ds Max's supersampling doesn't work nicely with edge padding, it produces dark streaks in the padded pixels. If so then turn off padding and re-do the padding later, either by re-baking without supersampling or by using a Photoshop filter like the one that comes with [[#3DTools|Xnormal]].<br />
<br />
=== Baking Transparency ===<br />
Sometimes you need to bake a normal map from an object that uses opacity maps, like a branch with opacity-mapped leaves. Unfortunately baking apps often completely ignore any transparency mapping on your high-poly mesh.<br />
<br />
{|class="wikitable"<br />
|[[image:JoeWilson_ivynormals_error.jpg]] <br />
|[[image:JoeWilson_ivynormals_rendered.jpg]]<br />
|-<br />
|3ds Max's RTT baker causes transparency errors.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|The lighting method bakes perfect transparency.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|}<br />
<br />
To solve this, render a Top view of the mesh. This only works if you're using a planar UV projection for your low-poly mesh and you're baking a tangent-space normal map.<br />
<br />
* Make sure the Top view matches the dimensions of the planar UV projection used by the low-poly mesh. It helps to use an orthographic camera for precise placement.<br />
* On the high-poly mesh either use a specific lighting setup or a use special material shader:<br />
* 1) The lighting setup is described in these tutorials:<br />
* * [http://www.bencloward.com/tutorials_normal_maps11.shtml Creating A Normal Map Right In Your 3D App] by [http://www.bencloward.com/ Ben Cloward]<br />
* *[http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy], Graphics Techniques Consultant, Xbox Content and Design Team<br />
* 2) The material shader does the same thing, but doesn't require lights.<br />
* * [http://www.scriptspot.com/3ds-max/normaltexmap NormalTexMap] scripted map for 3ds Max by [http://www.scriptspot.com/users/dave-locke Dave Locke].<br />
* * [http://www.footools.com/3dsmax_plugins.html InfoTexture] map plugin for 3ds Max by [http://www.footools.com John Burnett]<br />
<br />
[[image:BenCloward_NormalMapLighting.gif|frame|none|The lighting setup for top-down rendering. <br>Image by [http://www.bencloward.com Ben Cloward]]]<br />
<br />
<span id="EP"></span><br />
<br />
=== Edge Padding ===<br />
If a normal map doesn't have enough [[Edge_padding |Edge Padding]], this will create shading seams on the UV borders.<br />
<br />
=== High Poly Materials ===<br />
3ds Max will not bake a normal map properly if the high-res model has a mental ray Arch & Design material applied. If your normal map comes out mostly blank, either use a Standard material or none at all. For an example see the Polycount thread [http://www.polycount.com/forum/showthread.php?t=74792 Render to Texture >:O].<br />
<br />
<span id="RT"></span><br />
=== Reset Transforms ===<br />
Before baking, make sure your low-poly model's transforms have been reset. '''''This is very important!''''' Often during the modeling process a model will be rotated and scaled, but these compounded transforms can create a messy local "space" for the model, which in turn often creates rendering errors for normal maps. <br />
<br />
In 3ds Max, use the Reset Xforms utility then Collapse the Modifier Stack. In Maya use Freeze Transformation. In XSI use the Freeze button.<br />
<br />
<span id="SI"></span><br />
<br />
=== Solving Intersections ===<br />
The projection process often causes problems like misses, or overlaps, or intersections. It can be difficult generating a clean normal map in areas where the high-poly mesh intersects or nearly intersects itself, like in between the fingers of a hand. Setting the ray distance too large will make the baker pick the other finger as the source normal, while setting the ray distance too small will lead to problems at other places on the mesh where the distances between in-game mesh and high-poly mesh are greater.<br />
<br />
Fortunately there are several methods for solving these problems.<br />
<br />
# Change the shape of the cage. Manually edit points on the projection cage to help solve tight bits like the gaps between fingers.<br />
# Limit the projection to matching materials, or matching UVs.<br />
# Explode the meshes. See the polycount thread [http://boards.polycount.net/showthread.php?t=62921 Explode script needed (for baking purposes)].<br />
# Bake two or more times using different cage sizes, and combine them in Photoshop.<br />
<br />
<span id="SPA"></span><br />
<br />
=== Solving Pixel Artifacts ===<br />
[[image:filterMaps_artifact.jpg|frame|none|Random pixel artifacts in the bake. <br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
If you are using 3ds Max's ''Render To Texture'' to bake from one UV layout to another, you may see stray pixels scattered across the bake. This only happens if you are using a copy of the original mesh in the Projection, and that mesh is using a different UV channel than the original mesh.<br />
<br />
There are two solutions for this:<br />
<br />
* Add a Push modifier to the copied mesh, and set it to a low value like 0.01.<br />
- or -<br />
<br />
* Turn off ''Filter Maps'' in the render settings (Rendering menu > Render Setup > Renderer tab > uncheck Filter Maps). To prevent aliasing you may want to enable the Global Supersampler in Render Setup.<br />
<br />
See also [[#Anti-Aliasing]].<br />
<br />
<span id="SWL"></span><br />
<br />
=== Solving Wavy Lines ===<br />
When capturing from a cylindrical shape, often the differences between the low-poly mesh and the high-poly mesh will create a wavy edge in the normal map. There are a couple ways to avoid this:<br />
<br />
# The best way... create your lowpoly model with better supporting edges. See the Polycount threads [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?], [http://boards.polycount.net/showthread.php?t=55754 approach to techy stuff], [http://www.polycount.com/forum/showthread.php?t=72713 Any tips for normal mapping curved surface?].<br />
# Adjust the shape of the cage to influence the directions the rays will be cast. Beware... this work will have to be re-done every time you edit the lowpoly mesh, as the cage will be invalidated. At the bottom of [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm this page of his normal map tutorial], [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to do this in 3ds Max. Same method can be seen in the image below.<br />
# Subdivide the low-res mesh so it more closely matches the high-res mesh. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] has a [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa video tutorial] that shows how to do this in Maya.<br />
# Paint out the wavy line. Beware... this work will have to be re-done every time you re-bake the normal map. The [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
# Use a separate planar-projected mesh for the details that wrap around the barrel area, so the ray-casting is more even. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. For example to add tread around a tire, the tread can be baked from a tread model that is laid out flat, then that bake can layered onto the bake from the cylindrical tire mesh in a paint program.<br />
<br />
[[image:timothy_evison_normalmap_projections.jpg|frame|none|Adjusting the shape of the cage to remove distortion. <br>Image by [http://users.cybercity.dk/~dsl11905/resume/resume.html Timothy "tpe" Evison]]]<br />
<br />
<span id="TRI"></span><br />
<br />
=== Triangulating ===<br />
Before baking, it is usually best to triangulate the low-poly model, converting it from polygons into pure triangles. This prevents the vertex normals from being changed later on, which can create specular artifacts.<br />
<br />
[[image:triangulation_modo_ohare.jpg|frame|none| When quads are triangulated in [http://www.luxology.com/modo/ Modo], the internal edges are sometimes flipped, which causes shading differences.<br>Image by [http://www.farfarer.com/|James "Talon" O'Hare]]]<br />
<br />
<br />
Sometimes a baking tool or a mesh exporter/importer will re-triangulate the polygons. A quad polygon is actually treated as two triangles, and the internal edge between them is often switched diagonally during modeling operations. When the vertices of the quad are moved around in certain shapes, the software's algorithm for polygon models tries to keep the quad surface in a "rational" non-overlapping shape. It does this by switching the internal edge between its triangles.<br />
<br />
<br />
[[image:triangulation_spec_tychovii.jpg|frame|none| The specular highlight is affected by triangulation. Flip edges to fix skewing. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66651 Skewed Specular Highlight?] for pictures and more info.<br> Image by [http://robertkreps.com Robert "TychoVII" Kreps]]]<br />
<br />
<br />
<span id="WWC"></span><br />
<br />
=== Working with Cages ===<br />
''Cage'' has two meanings in the normal-mapping process: a low-poly base for [[subdivision surface modeling]] (usually called the [[DigitalSculpting#BM|basemesh]]), or a ray-casting mesh used for normal map baking. This section covers the ray-casting cage.<br />
<br />
Most normal map baking tools allow you to use a distance-based raycast. A ray is sent outwards along each vertex normal, then at the distance you set a ray is cast back inwards. Where ever that ray intersects the high poly mesh, it will sample the normals from it. <br />
<br />
{|class="wikitable"<br />
|[[Image:Normalmap_raycasting_1.jpg]] <br />
|[[Image:Normalmap_raycasting_2.jpg]]<br />
|-<br />
|Hard edges and a distance-based raycast (gray areas) cause ray misses (yellow) and ray overlaps (cyan).<br> Image by [http://www.mankua.com/ Diego Castaño]<br />
|The gray area shows that using all soft edges (or hard edges and a cage-based raycast) will avoid ray-casting errors from split normals.<br> Image by [http://www.mankua.com/ Diego Castaño] <br />
|}<br />
<br />
Unfortunately with a distance-based raycast, [[#SGAHE|split vertex normals]] will cause the bake to miss parts of the high-res mesh, causing errors and seams. <br />
<br />
Some software allows you to use ''cage mesh'' option instead, which basically inflates a copy of the low-poly mesh, then raycasts inwards from each vertex. This ballooned-out mesh is the cage.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
|<tablebgcolor="#ffaaaa">| <br />
|}<br />
<br />
In 3ds Max the cage controls both the distance and the direction of the raycasting. <br />
<br />
In Maya the cage only controls the distance; the ray direction matches the vertex normals (inverted).<br />
<br />
<span style="text-decoration: line-through"> This may have been fixed in the latest release...<<BR>><br />
In Xnormal the cage is split everywhere the model has [[#SGAHE|hard edges]], causing ray misses in the bake. You can fix the hard edge split problem but it involves an overly complex workflow. You must also repeat the whole process any time you change your mesh:</span><br />
# <s> Load the 3d viewer.</s><br />
# <s> Turn on the cage editing tools.</s><br />
# <s> Select all of the vertices.</s><br />
# <s> Weld all vertices.</s><br />
# <s> Expand the cage as you normally would.</s><br />
# <s> Save out your mesh using the Xnormal format.</s><br />
# <s> Make sure Xnormal is loading the correct mesh.</s><br />
<br />
<span id="P"></span><span id="Painting"></span><br />
<br />
== Painting ==<br />
Don't be afraid to edit normal maps in Photoshop. After all it is just a texture, so you can clone, blur, copy, blend all you want... as long as it looks good of course. Some understanding of [[#RGBChannels|the way colors work]] in normal maps will go a long way in helping you paint effectively.<br />
<br />
A normal map sampled from a high-poly mesh will nearly always be better than one sampled from a texture, since you're actually grabbing "proper" normals from an accurate, highly detailed surface. That means your normal map's pixels will basically be recreating the surface angles of your high-poly mesh, resulting in a very believable look.<br />
<br />
If you only convert an image into a normal-map, it can look very flat, and in some cases it can be completely wrong unless you're very careful about your value ranges. Most image conversion tools assume the input is a heightmap, where black is low and white is high. If you try to convert a diffuse texture that you've painted, the results are often very poor. Often the best results are obtained by baking the large and mid-level details from a high-poly mesh, and then combined with photo-sourced "fine detail" normals for surface details such as fabric weave, scratches and grain.<br />
<br />
Sometimes creating a high poly surface takes more time than your budget allows. For character or significant environment assets then that is the best route, but for less significant environment surfaces working from a heightmap-based texture will provide a good enough result for a much less commitment in time.<br />
<br />
* [http://crazybump.com/ CrazyBump] is a commercial normal map converter.<br />
* [http://www.renderingsystems.com/support/showthread.php?tid=3 ShaderMap] is a commercial normal map converter.<br />
* [http://www.pixplant.com/ PixPlant] is a commercial normal map converter.<br />
* [http://boards.polycount.net/showthread.php?t=68860 NJob] is a free normal map converter.<br />
* [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA normalmap filter for Photoshop] is a free normal map converter.<br />
* [http://xnormal.net Xnormal height-to-normals filter for Photoshop] is a free normal map converter.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm Normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
<br />
=== Flat Color ===<br />
The color (128,128,255) creates normals that are completely perpendicular to the polygon, as long as the vertex normals are also perpendicular. Remember a normal map's per-pixel normals create ''offsets'' from the vertex normals. If you want an area in the normal map to be flat, so it creates no offsets from the vertex normals, then use the color (128,128,255). <br />
<br />
This becomes especially obvious when [[#Mirroring|mirroring a normal map]] and using a shader with a reflection ingredient. Reflection tends to accentuate the angles between the normals, so any errors become much more apparent.<br />
<br />
[[image:normalmap_127seam.jpg|thumb|600px|none| Mirrored normal maps show a seam when (127,127,255) is used for the flat color; 128 is better.<br>Image by [http://www.ericchadwick.com Eric Chadwick]]]<br />
<br />
In a purely logical way, 127 seems like it would be the halfway point between 0 and 255. However 128 is the color that actually works in practice. When a test is done comparing (127,127,255) versus (128,128,255) it becomes obvious that 127 creates a slightly bent normal, and 128 creates a flat one.<br />
<br />
This is because most game pipelines use ''unsigned'' normal maps. For details see the Polycount forum thread [http://www.polycount.com/forum/showpost.php?p=771360&postcount=22 tutorial: fixing mirrored normal map seams].<br />
<br />
<span id="BNMT"></span><br />
<br />
=== Blending Normal Maps Together ===<br />
Blending normal maps together is a quick way to add high-frequency detail like wrinkles, cracks, and the like. Fine details can be painted as a height map, then it can be converted into a normal map using one of the normal map tools. Then this "details" normal map can be blended with a geometry-derived normal map using one of the methods below. <br />
<br />
Here is a comparison of four of the blending methods. Note that in these examples the default values were used for CrazyBump (Intensity 50, Strength 33, Strength 33), but the tool allows each layer's strength to be adjusted individually for stronger or milder results. Each of the normal maps below were [[#Renormalizing|re-normalized]] after blending.<br />
<br />
{|class="wikitable"<br />
|[[image:nrmlmap_blending_methods_Maps.png]]<br />
|[[image:nrmlmap_blending_methods_RTTNormalMapFX.png]]<br />
|-<br />
|The blended normal maps.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|Screenshot of the 3dsmax viewport, using the RTTNormalMap.fx shader.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|}<br />
<br />
The four blending methods used above:<br />
# [http://www.crazybump.com CrazyBump] by Ryan Clark blends normal maps together using calculations in 3D space rather than just in 2D. This does probably the best job at preserving details, and each layer's strength settings can be tweaked individually. <br />
# [http://www.rodgreen.com/?p=4 Combining Normal Maps in Photoshop] by Rod Green blends normal maps together using Linear Dodge mode for the positive values and Difference mode for the negative values, along with a Photoshop Action to simplify the process. It's free, but the results may be less accurate than CrazyBump.<br />
# [http://www.paultosca.com/makingofvarga.html Making of Varga] by [http://www.paultosca.com/ Paul "paultosca" Tosca] blends normal maps together using Overlay mode for the red and green channels and Multiply mode for the blue channel. This gives a slightly stronger bump than the Overlay-only method. [http://www.leocov.com/ Leo "chronic" Covarrubias] has a step-by-step tutorial for this method in [http://www.cgbootcamp.com/tutorials/2009/12/9/photoshop-combine-normal-maps.html CG Bootcamp Combine Normal Maps].<br />
# [[3DTutorials/Normal Map Deepening|Normal Map Deepening]] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to blend normal maps together using Overlay mode. [http://cgtextures.com/content.php?action=tutorial&name=normalmap CGTextures tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] also shows how to create normalmaps using multiple layers (Note: to work with the Overlay blend mode each layer's Output Level should be 128 instead of 255, you can use the Levels tool for this).<br />
<br />
The [http://boards.polycount.net/showthread.php?t=69615 Getting good height from Nvidia-filter normalizing grayscale height] thread on the Polycount forum has a discussion of different painting/blending options. Also see the [[#2DT|2D Tools]] section for painting and conversion tools.<br />
<br />
<span id="PCT"></span><br />
<br />
=== Pre-Created Templates ===<br />
A library of shapes can be developed and stored for later use, to save creation time for future normal maps. Things like screws, ports, pipes, and other doo-dads. These shapes can be stored as bitmaps with transparency so they can be layered into baked normal maps.<br />
<br />
* [http://www.beautifulrobot.com/?p=69 Creating & Using NormalMap "Widgets"] - by ''[http://www.beautifulrobot.com Steev "kobra" Kelly]''<<BR>> How to set up and render template objects.<br />
* [http://www.akramparvez.com/portfolio/scripts/normalmap-widget-for-3ds-max/ NormalMap Widget for 3ds Max] - by ''[http://www.akramparvez.com Akram Parvez]''<<BR>>A script to automate the setup and rendering process.<br />
* See the section [[#BT|Baking Transparency]] for more template-rendering tools and tutorials.<br />
<br />
<span id="RN"></span><span id="Renormalizing"></span><br />
=== Re-normalizing ===<br />
Re-normalizing means resetting the length of each normal in the map to 1.<br />
<br />
A normal mapping shader takes the three color channels of a normal map and combines them to create the direction and length of each pixel's normal. These normals are then used to apply the scene lighting to the mesh. However if you edit normal maps by hand or if you blend multiple normal maps together this can cause those lengths to change. Most shaders expect the length of the normals to always be 1 (normalized), but some are written to re-normalize the normal map dynamically (for example, 3ds Max's Hardware Shaders do re-normalize).<br />
<br />
If the normals in your normal map are not normalized, and your shader doesn't re-normalize them either, then you may see artifacts on the shaded surface... the specular highlight may speckle like crazy, the surface may get patches of odd shadowing, etc. To help you avoid this NVIDIA's normal map filter for Photoshop provides an easy way to re-normalize a map after editing; just use the '''Normalize Only''' option. [http://xnormal.net Xnormal] also comes with a Normalize filter for Photoshop.<br />
<br />
[[image:normalize_only.jpg|frame|none|The re-normalize option in the NVIDIA filter.<br>Image by [http://hirezstudios.com/ Scott Warren]]]<br />
<br />
Some shaders use [[#NormalMapCompression|compressed normal maps]]. Usually this means the blue channel is thrown away completely, so it's recalculated on-the-fly in the shader. However the shader has to re-normalize in order to recreate that data, so any custom normal lengths that were edited into the map will be ignored completely. <br />
<br />
<span id="AOIANM"></span><span id="AmbientOcclusionIntoANormalMap"></span><br />
<br />
=== Ambient Occlusion into a Normal Map ===<br />
If the shader doesn't re-normalize the normal map, an [[Ambient Occlusion Map]] can actually be baked into the normal map. This will shorten the normals in the crevices of the surface, causing the surface to receive less light there. This works with both diffuse and specular, or any other pass that uses the normal map, like reflection.<br />
<br />
However it's usually best to keep the AO as a separate map (or in an alpha channel) and multiply it against the ambient lighting only. This is usually done with a custom [[:Category:Shaders|shader]]. If you multiply it against the diffuse map or normal map then it also occludes diffuse lighting which can make the model look dirty. Ambient occlusion is best when it occludes ambient lighting only, for example a [[DiffuselyConvolvedCubeMap|diffusely convolved cubemap]].<br />
<br />
[[image:nrmlmap_ao.jpg|frame|none| AO can be baked into a normal map, shortening the normals (lower left model).<br>Model by [http://www.3dartisan.net/~kuman/ James Ku]]]<br />
<br />
To bake the AO into a normal map, adjust the levels of the AO layer first so the darks only go as low as 128 gray, then set the AO layer to Darken mode. This will shorten the normals in the normalmap, causing the surface to receive less light in the darker areas. <br />
<br />
This trick doesn't work with any shaders that re-normalize, like 3ds Max's Hardware Shaders. The shader must be altered to actually use the lengths of your custom normals; most shaders just assume all normals are 1 in length because this makes the shader code simpler. Also this trick will not work with most of the common [[#NormalMapCompression|normal map compression formats]], which often discard the blue channel and recalculate it in the shader, which requires re-normalization.<br />
<br />
<span id="BLE"></span><br />
<br />
=== Back Lighting Example ===<br />
You can customize normal maps for some interesting effects. If you invert the blue channel of a tangent-space map, the normals will be pointing to the opposite side of the surface, which can simulate backlighting.<br />
<br />
{|class="wikitable"<br />
|[[image:tree_front.jpg]]||[[image:tree_back.jpg]]<br />
|-<br />
|Tree simulating subsurface scattering (front view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|Tree simulating subsurface scattering (back view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|-<br />
|colspan="2"|[[image:tree_maps.jpg]]<br />
|-<br />
|colspan="2"|The maps used for the leaves. The 2nd diffuse was simply color-inverted, hue-shifted 180°, and saturated.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
The tree leaves use a shader than adds together two diffuse maps, one using a regular tangent-space normal map, the other using the same normal map but with the blue channel inverted. This causes the diffuse map using the regular normal map to only get lit on the side facing the light (front view), while the diffuse map using the inverted normal map only gets lit on the opposite side of the leaves (back view). The leaf geometry is 2-sided but uses the same shader on both sides, so the effect works no matter the lighting angle. As an added bonus, because the tree is self-shadowing the leaves in shadow do not receive direct lighting, which means their backsides do not show the inverted normal map, so the fake subsurface scatter effect only appears where the light directly hits the leaves. This wouldn't work for a whole forest because of the computational cost of self-shadowing and double normal maps, but could be useful for a single "star" asset, or if LODs switched the distant trees to a model that uses a cheaper shader.<br />
<br />
<span id="SAS"></span><br />
<br />
== Shaders and Seams ==<br />
You need to use the right kind of shader to avoid seeing seams where UV breaks occur. It must be written to use the same [[#TangentBasis|tangent basis]] that was used during baking. If the shader doesn't, the lighting will either be inconsistent across UV borders or it will show smoothing errors from the low-poly vertex normals.<br />
<br />
Xnormal generates accurate normals when displayed in Xnormal, and the SDK includes a method to write your own custom tangent space generator for the tool. <br />
<br />
<span id="3MS"></span><br />
=== 3ds Max Shaders ===<br />
The "Render To Texture" tool in 3ds Max 2011 and older generates [[#TSNM|tangent-space]] normal maps that render correctly in the offline renderer (scanline) but do not render correctly in the realtime viewport with the 3ds Max shaders. Max is using a different [[#TangentBasis|tangent basis]] for each. This is readily apparent when creating non-organic hard surface normalmaps; smoothing errors appear in the viewport that do not appear when rendered. <br />
<br />
The errors can be fixed by using "Render To Texture" to bake a [[#TSNM|tangent-space]] or [[#OSNM|object-space]] map, and using the free [http://www.3pointstudios.com/3pointshader_about.shtml "3Point Shader"] by Christoph '[[CrazyButcher]]' Kubisch and Per 'perna' Abrahamsen. The shader uses the same tangent basis as the baking tool, so it produces nearly flawless results. It also works with old bakes.<br />
<br />
You can get OK results in the Max viewport using a tangent-space map baked in Maya, loading it in a Standard material, and enabling "Show Hardware Map in Viewport". Another method is to use Render To Texture to bake an [[#OSNM|object-space]] map then use [[#CBS|Nspace]] to convert it into a tangent-space map then load that in a DirectX material and use the RTTNormalMap.fx shader. <br />
<br />
Autodesk is aware of these issues, and plans to address them in an upcoming release. See these links for more information:<br />
* Christoph "[[CrazyButcher]]" Kubisch and Per "perna" Abrahamsen designed a shader/modifier combination approach that fixes the viewport problem, see the Polycount forum post [http://boards.polycount.net/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max].<br />
* Jean-Francois "jfyelle" Yelle, Autodesk Media & Entertainment Technical Product Manager, has [http://boards.polycount.net/showthread.php?p=1115812#post1115812 this post]. <br />
* Ben Cloward posted [http://boards.polycount.net/showthread.php?p=1100270#post1100270 workarounds and FX code].<br />
* Christopher "cdiggins" Diggins, SDK writer for 3ds Max, shares some of the SDK code in his blog posts "[http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping How the 3ds Max Scanline Renderer Computes Tangent and Binormal Vectors for Normal Mapping]" and "[http://area.autodesk.com/blogs/chris/3ds_max_normal_map_baking_and_face_angle_weighting_the_plot_thickens 3ds Max Normal Map Baking and Face Angle Weighting: The Plot Thickens]".<br />
<br />
[[image:nmtest_uv-splits_thumb.jpg|thumb|600px|none|Comparison of map baking methods in Maya and Max, and Ben Cloward's custom FX code.<br>Image by [http://www.bencloward.com/ Ben Cloward] and [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
[[image:normalmapfix_3pointstudios_thumb.jpg|frame|none|3 Point Studios' normal map display fix for 3ds Max.<br>image by [http://www.3pointstudios.com 3 Point Studios]]]<br />
<br />
{|class="wikitable"<br />
|[[image:max2010_normalmap_workarounds.png|thumb|400px|none|]]<br />
|[[image:max2010_normalmap_compare.png|thumb|400px|none|]]<br />
|-<br />
|Viewport methods in 3ds Max 2010.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick] <br />
|More baking methods in 3ds Max 2010.<br> Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
<span id="3MENT"></span><br />
<br />
=== 3ds Max Edit Normals Trick ===<br />
After baking, if you add an Edit Normals modifier to your low-poly normalmapped model, this seems to "relax" the vertex normals for more accurate viewport shading. The modifier can be collapsed if desired.<br />
<br />
<span id="MS"></span><br />
=== Maya Shaders ===<br />
Maya seems to correctly generate normals to view in realtime, with the correct [[#TangentBasis|tangent basis]], with much less smoothing errors than 3ds Max. <br />
* [http://www.mentalwarp.com/~brice/shader.php BRDF shader] by [http://www.mentalwarp.com/~brice/ Brice Vandemoortele] and [http://www.kjapi.com/ Cedric Caillaud] (more info in [http://boards.polycount.net/showthread.php?t=49920 this Polycount thread]) '''Update:''' [http://boards.polycount.net/showthread.php?p=821862#post821862 New version here] with many updates, including object-space normal maps, relief mapping, self-shadowing, etc. Make sure you enable cgFX shaders in the Maya plugin manager, then you can create them in the same way you create a Lambert, Phong etc. Switch OFF high quality rendering in the viewports to see them correctly too.<br />
* If you want to use the software renderer, use mental ray instead of Maya's software renderer because mental ray correctly interprets tangent space normals. The Maya renderer treats the normal map as a grayscale bump map, giving nasty results. Mental ray supports Maya's Phong shader just fine (amongst others), although it won't recognise a gloss map plugged into the "cosine power" slot. The slider still works though, if you don't mind having a uniform value for gloss. Spec maps work fine though. Just use the same set up as you would for viewport rendering. You'll need to have your textures saved as TGAs or similar for mental ray to work though. - from [http://boards.polycount.net/member.php?u=14235 CheeseOnToast]<br />
<br />
<br />
<span id="NMC"></span><br />
<br />
== Normal Map Compression ==<br />
see; [[Normal Map Compression]]<br />
<br />
== Links ==<br />
<br />
=== Related Pages ===<br />
* [[Curvature map]]<br />
* [[DuDv map]]<br />
* [[Flow map]]<br />
* [[Normal map]]<br />
* [[Radiosity normal map]]<br />
* [[Vector displacement map]]<br />
<br />
<span id="3DT"></span> <span id="Tools"></span> <span id="3DTools"></span><br />
=== 3D Tools ===<br />
See [[:Category:Tools#A3D_Normal_Map_Software|Category:Tools#3D_Normal_Map_Software]]<br />
<br />
<span id="2DT"></span><span id="2DTools"></span><br />
=== 2D Tools ===<br />
See [[:Category:Tools#A2D_Normal_Map_Software|Category:Tools#2D_Normal_Map_Software]]<br />
<br />
<span id="T"></span><span id="Tutorials"></span><br />
=== Tutorials ===<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh tutorial for Max and Xnormal] by [http://www.exisinteractive.com/ PeterK] to prevent heavy distortions when baking with a cage, without the need to add extra supporting vertices.<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games] by [http://www.polycount.com/forum/member.php?u=56680 'SuperFranky']<br />
* [http://area.autodesk.com/userdata/fckdata/239955/The%20Generation%20and%20Display%20of%20Normal%20Maps%20in%203ds%20Max.pdf The Generation and Display of Normal Maps in 3ds Max] (500kb PDF) <<BR>> Excellent whitepaper from Autodesk about normal mapping in 3ds Max and other apps.<br />
* [http://www.katsbits.com/htm/tutorials/blender-baking-normal-maps-from-models.htm Renderbump and baking normal maps from high poly models using Blender 3D] by ''[http://www.katsbits.com/htm/about.htm "katsbits"]''<<BR>>Baking normal maps in Blender.<br />
* [http://udn.epicgames.com/Three/CreatingNormalMaps.html Techniques for Creating Normal Maps] in the Unreal Developer Network's [http://udn.epicgames.com/Three/WebHome.html Unreal Engine 3 section] contains advice from [http://www.epicgames.com/ Epic Games] artists on creating normal maps for UE3. The [http://udn.epicgames.com/Three/DesignWorkflow.html#Creating%20normal%20maps%20from%20meshes Design Workflow page] has a summary.<br />
* [http://www.iddevnet.com/quake4/ArtReference_CreatingModels#head-3400c230e92ff7d57424b2a68f6e0ea75dee4afa Creating Models in Quake 4] by [http://www.ravensoft.com/ Raven Software] is a comprehensive guide to creating Quake 4 characters.<br />
* [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing and UVs can affect normal maps in Doom 3.<br />
* [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] is an overview of modeling for normal maps.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses how smoothing groups and bevels affect the topology of the low-poly model.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in-game, not the triangle or poly count.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm Normal map workflow] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] demonstrates his normal mapping workflow in 3ds Max and Photoshop.<br />
* [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa This video tutorial] by [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] shows in Maya how to subdivide the low-poly mesh so it more closely matches the high-poly mesh, to help solve wavy lines in the bake.<br />
* [http://www.bencloward.com/tutorials_normal_maps1.shtml Normal Mapping Tutorial] by [http://www.bencloward.com/ Ben Cloward] is a comprehensive tutorial about the entire normal map creation process.<br />
* [http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy] shows how to use a special lighting setup to render normal maps (instead of baking them).<br />
* [http://cgtextures.com/content.php?action=tutorial&name=normalmap Tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] shows how to create deep normal maps using multiple layers. Note: to use Overlay blend mode properly, make sure to change each layer's Levels ''Output Level'' to 128 instead of 255.<br />
* [http://www.poopinmymouth.com/process/tips/normalmap_deepening.jpg Normalmap Deepening] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to adjust normal maps, and how to layer together painted and baked normal maps.<br />
* [http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] helps to solve seams along horizontal or vertical UV edges, but not across angled UVs.<br />
* [http://planetpixelemporium.com/tutorialpages/normal.html Cinema 4D and Normal Maps For Games] by [http://planetpixelemporium.com/index.php James Hastings-Trew] describes normal maps in plain language, with tips on creating them in Cinema 4D.<br />
* [http://forums.cgsociety.org/showthread.php?f=39&t=359082 3ds Max normal mapping overview] by [http://www.alan-noon.com/ Alan Noon] is a great thread on CGTalk about the normal mapping process.<br />
* [http://forums.cgsociety.org/showthread.php?f=46&t=373024 Hard Surface Texture Painting] by [http://stefan-morrell.cgsociety.org/gallery/ Stefan Morrell] is a good introduction to painting textures for metal surfaces.<br />
<br />
<span id="D"></span><span id="Discussion"></span><br />
<br />
=== Discussion ===<br />
[http://boards.polycount.net/showthread.php?p=820218 Discuss this page on the Polycount forums]. Suggestions welcome.<br />
<br />
Even though only one person has been editing this page so far, the information here was gathered from many different sources. We wish to thank all the contributors for their hard-earned knowledge. It is much appreciated!<br />
<br />
----<br />
[[Category:TextureTypes]] [[Category:Bump map]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Normal_mapNormal map2015-04-22T14:53:10Z<p>Dustinbrown: /* Common Swizzle Coordinates */</p>
<hr />
<div>== Out of Date ==<br />
The information on this page is a bit old, it needs to be updated. See these links for more current information:<br />
<br />
* [http://farfarer.com/resources.htm RNM Normal Map Combiner], by [http://www.farfarer.com/ James "Farfarer" O'Hare]<br />
* [http://vincentcallebaut.com/CombineNormal.html Combine Normal], by [http://vincentcallebaut.comVincent "Vincentt" Callebaut], [http://www.polycount.com/forum/showthread.php?t=131819 Combine normal maps script for Photoshop] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showpost.php?p=2226864&postcount=51 Earthquake on separating smoothing groups in the UV]<br />
* [http://www.polycount.com/forum/showpost.php?p=2225535&postcount=40 JedTheKrampus on offsetting Mirrored UVs]<br />
* [http://www.polycount.com/forum/showthread.php?t=148303 Of Bit Depths, Banding and Normal Maps]<br />
* [http://www.polycount.com/forum/showthread.php?t=147227 Skew you buddy! Making sense of skewed normal map details.]<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games]<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh Tutorial]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?]<br />
* [http://www.laurenscorijn.com/future-xoliulshader-support.html Future Xoliulshader support] = why Xoliulshader doesn't work properly in 3ds Max 2013/2014.<br />
<br />
== Synched Workflow ==<br />
To eliminate seams and shading artifacts, the model renderer and the normal map baking tool should use the same tangent basis.<br />
<br />
FBX model format can store tangents, and some renderers use this data to synch the incoming normal maps.<br />
<br />
{| class="wikitable sortable" style="color:grey;"<br />
|- <br />
! Renderer !! Normal map baker<br />
|-<br />
| 3ds Max || 3ds Max, Handplane, ?<br />
|-<br />
| Blender || ?<br />
|-<br />
| Creation Engine || Handplane, ?<br />
|-<br />
| CryEngine || ?<br />
|-<br />
| Knald || ?<br />
|-<br />
| Marmoset Toolbag || 3ds Max, Maya, Xnormal, ?<br />
|-<br />
| Maya || Handplane, Maya, ?<br />
|-<br />
| Source || Handplane, Maya ([http://www.polycount.com/forum/showpost.php?p=2224653&postcount=28]), ?<br />
|-<br />
| Starcraft II || Handplane, ?<br />
|-<br />
| Substance Designer || ?<br />
|-<br />
| Unity([http://www.polycount.com/forum/showpost.php?p=2224781&postcount=29], [http://www.polycount.com/forum/showthread.php?p=2194353#post2194353]) || Handplane, Xnormal (via Asset Store), ?<br />
|-<br />
| Unreal Engine 4 || Handplane, Xnormal([http://www.polycount.com/forum/showpost.php?p=2224402&postcount=20]), ? <br />
|-<br />
| Xnormal || Xnormal, ?<br />
|}<br />
<br />
----<br />
<br />
== What is a Normal Map? ==<br />
A Normal Map is usually used to fake high-res geometry detail when it's mapped onto a low-res mesh. The pixels of the normal map each store a ''normal'', a vector that describes the surface slope of the original high-res mesh at that point. The red, green, and blue channels of the normal map are used to control the direction of each pixel's normal. <br />
<br />
When a normal map is applied to a low-poly mesh, the texture pixels control the direction each of the pixels on the low-poly mesh will be facing in 3D space, creating the illusion of more surface detail or better curvature. However, the silhouette of the model doesn't change. <br />
<br />
<gallery mode="packed"><br />
Whatif_normalmap_mapped2.jpg|A model with a normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_low.jpg|The model without its normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_high.jpg|The high-resolution model used to create the normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
</gallery><br />
<br />
==Tangent-Space vs. Object-Space==<br />
<br />
Normal maps can be made in either of two basic flavors: tangent-space or object-space. World-space is basically the same as object-space, except it requires the model to remain in its original orientation, neither rotating nor deforming, so it's almost never used.<br />
<br />
===Tangent-space normal map===<br />
[[image:normalmap_tangentspace.jpg|frame|none|A tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Predominantly-blue colors. Object can rotate and deform. Good for deforming meshes, like characters, animals, flags, etc.<br />
<br />
Pros:<br />
* Maps can be reused easily, like on differently-shaped meshes.<br />
* Maps can be tiled and mirrored easily, though some games might not support mirroring very well.<br />
* Easier to overlay painted details.<br />
* Easier to use image compression.<br />
<br />
Cons:<br />
* More difficult to avoid smoothing problems from the low-poly vertex normals (see Smoothing Groups and Hard Edges).<br />
* Slightly slower performance than an object-space map (but not by much).<br />
<br />
===Object-space normal map===<br />
[[image:normalmap_worldspace.jpg|frame|none|An object-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Rainbow colors. Objects can rotate, but usually shouldn't be deformed, unless the shader has been modified to support deformation. Object-space is also called local-space or model-space. <br />
<br />
Pros:<br />
* Easier to generate high-quality curvature because it completely ignores the crude smoothing of the low-poly vertex normals.<br />
* Slightly better performance than a tangent-space map (but not by much).<br />
<br />
Cons:<br />
* Can't easily reuse maps, different mesh shapes require unique maps.<br />
* Difficult to tile properly, and mirroring requires specific shader support.<br />
* Harder to overlay painted details because the base colors vary across the surface of the mesh. Painted details must be converted into Object Space to be combined properly with the OS map.<br />
* They don't compress very well, since the blue channel can't be recreated in the shader like with tangent-space maps. Also the three color channels contain very different data which doesn't compress well, creating many artifacts. Using a half-resolution object-space map is one option. <br />
<br />
<br clear="all"/><br />
<br />
=== Converting Between Spaces ===<br />
Normal maps can be converted between object space and tangent space, in order to use them with different blending tools and shaders, which require one type or the other. <br />
<br />
Object space maps can also be converted to maps with different tangent bases, to better match the normal maps with the renderer and thus avoid lighting errors.<br />
<br />
* [http://www.handplane3d.com Handplane] by [http://www.alecmoody.com/ Alec Moody] is a tool that converts object space maps into a variety of tangent spaces: 3ds Max, Creation Engine, Maya, Source, Unity, Unreal, etc. See the Polycount Forum thread [http://www.polycount.com/forum/showthread.php?t=116899 Official handplane support thread - Now freeware!!].<br />
<br />
[[File:handplane_illus_1.jpg|frame|none|Handplane interface. <br>Image by [http://www.alecmoody.com/ Alec Moody].]]<br />
<br />
<br />
* [http://boards.polycount.net/showthread.php?p=1072599#post1072599 NSpace] by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] is a tool that converts an object-space normal map into a tangent-space map, which then works seamlessly in the 3ds Max viewport. He converts the map by using the same tangent basis that 3ds Max uses for its hardware shader. To see the results, load the converted map via the ''Normal Bump'' map and enable "Show Hardware Map in Viewport". [http://gameartist.nl/ Osman "osman" Tsjardiwal] created a GUI for NSpace, you can [http://boards.polycount.net/showthread.php?p=1075143#post1075143 download it here], just put it in the same folder as the NSpace exe and run it. <br />
<br />
[[File:NSpace_Gui_osman.png|frame|none|NSpace interface. <br>Image by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] and [http://gameartist.nl Osman "osman" Tsjardiwal].]]<br />
<br />
[http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson] said: "[8Monkey Labs has] a tool that lets you load up your reference mesh and object space map. Then load up your tangent normals, and adjust some sliders for things like tile and amount. We need to load up a mesh to know how to correctly orient the tangent normals or else things will come out upside down or reverse etc. It mostly works, but it tends to "bend" the resulting normals, so you gotta split the mesh up into some smoothing groups before you run it, and then I usually will just composite this "combo" texture over my orig map in Photoshop."<br />
<br />
<span id="RGBC"></span><span id="RGBChannels"></span><br />
<br />
== RGB Channels ==<br />
Shaders can use different techniques to render tangent-space normal maps, but the normal map directions are usually consistent within a game. Usually the red channel of a tangent-space normal map stores the X axis (pointing the normals predominantly leftwards or rightwards), the green channel stores the Y axis (pointing the normals predominantly upwards or downwards), and the blue channel stores the Z axis (pointing the normals outwards away from the surface).<br />
<br />
[[image:tangentspace_rgb.jpg|frame|none|The red, green, and blue channels of a tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you see lighting coming from the wrong angle when you're looking at your normal-mapped model, and the model is using a tangent-space normal map, the normal map shader might be expecting the red or green channel (or both) to point in the opposite direction. To fix this either change the shader, or simply invert the appropriate color channels in an image editor, so that the black pixels become white and the white pixels become black.<br />
<br />
Some shaders expect the color channels to be swapped or re-arranged to work with a particular [[#NormalMapCompression|compression format]]. For example the DXT5_nm format usually expects the X axis to be in the alpha channel, the Y axis to be in the green channel, and the red and blue channels to be empty.<br />
<br />
== Tangent Basis ==<br />
[[#TangentSpaceVsObjectSpace|Tangent-space]] normal maps use a special kind of vertex data called the ''tangent basis''. This is similar to UV coordinates except it provides directionality across the surface, it forms a surface-relative coordinate system for the per-pixel normals stored in the normal map. This coordinate system is required to light a normal mapped surface.<br />
<br />
Each vertex in the tangent basis is a combination of three things: the mesh vertex's normal (influenced by smoothing), the vertex's tangent (usually derived from the V texture coordinate), and the vertex's bitangent (derived in code, also called the binormal). These three vectors create an axis for each vertex, giving it a specific orientation in the tangent space. These axes are used to properly transform the incoming lighting from world space into tangent space, so your normal-mapped model will be lit correctly.<br />
<br />
Light rays are in world space, but the normals stored in the normal map are in tangent space. When the model is being rendered, the light rays must be converted from world space into tangent space, using the tangent basis to get there. At that point the incoming light rays are compared against the directions of the normals in the normal map, and this determines how much each pixel is going to be lit. Alternatively, instead of converting the light rays some shaders will convert the normals in the normal map from tangent space into world space. Then those world-space normals are compared against the light rays, and the model is lit appropriately. The method depends on who wrote the shader, but the end result is the same. Both methods require a tangent basis to transform the lighting.<br />
<br />
When a triangle's vertex normals are pointing straight out, and a pixel in the normal map is neutral blue (128,128,255) this means the pixel's normal will be pointing straight out from the surface of the low-poly mesh. When that pixel normal is tilted towards the left or the right in the tangent coordinate space, it will get either more or less red color, depending on whether the normal map is set to store the X axis as either a positive or a negative value. Same goes for when the normal is tilted up or down in tangent space, it will either get more or less green color. If the vertex normals aren't exactly perpendicular to the triangle, the normal map pixels will be tinted away from neutral blue as well.<br />
<br />
Unfortunately for artists, there are many different ways to calculate the tangent basis: [http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping 3ds Max], [http://download.autodesk.com/us/maya/2011help/index.html?url=./files/Appendix_A_Tangent_and_binormal_vectors.htm,topicNumber=d0e227193 Maya], [http://www.codesampler.com/dx9src/dx9src_4.htm#dx9_dot3_bump_mapping DirectX 9], [http://developer.nvidia.com/object/NVMeshMender.html NVMeshMender], [http://www.terathon.com/code/tangent.html Eric Lengyel], a custom solution, etc. This means a normal map baked in one application probably won't shade correctly in another. Artists must do some testing with different [[#T|baking tools]] to find which works best with their output. When the renderer (or game engine) renders your game model, [[#ShadersAndSeams|the shader]] must use the same tangent basis as the normal map baker, otherwise you'll get incorrect lighting, especially across the seams between UV shells.<br />
<br />
The [http://www.xnormal.net/ xNormal] SDK supports custom tangent basis methods. When a programmer uses it to implement their renderer's own tangent basis, artists can then use Xnormal to bake normal maps that will match their renderer perfectly.<br />
<br />
[[image:tangentseams.jpg|frame|none|When shared edges are at different angles in UV space, different colors will show up<br />
along the seam. The tangent basis uses these colors to light the model properly. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
When you look at a tangent-space normal map for a character, you typically see different colors along the UV seams. This is because the UV shells are often oriented at different angles on the mesh, a necessary evil when translating the 3D mesh into 2D textures. The body might be mapped with a vertical shell, and the arm mapped with a horizontal one. This requires the normals in the normal map to be twisted for the different orientations of those UV shells. The UVs are twisted, so the normals must be twisted in order to compensate. The tangent basis helps reorient (twist) the lighting as it comes into the surface's local space, so the lighting will then look uniform across the normal mapped mesh.<br />
<br />
When an artist tiles a tangent-space normal map across an arbitrary mesh, like a landscape, this tends to shade correctly because the mesh has a uniform direction in tangent space. If the mesh has discontinuous UV coordinates (UV seams), or the normal map has large directional gradients across it, the tangent space won't be uniform anymore so the surface will probably have shading seams.<br />
<br />
== Common Swizzle Coordinates ==<br />
3D Software capable of displaying normal maps will have a native required direction, or "handedness" for the RGB channels in a normal map, sometimes referred to as "Swizzle Coordinates," though [[#SAS|shaders]] can often be written to override this native handedness. You may hear developers refer to "flipping the green channel" in order to get a normal map to display correctly, and this simply indicates that when the normal map was baked, it was authored with the incorrect handedness in the green channel.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
| '''Software''' <br />
| '''Red''' <br />
| '''Green''' <br />
| '''Blue''' <br />
|-<br />
|<#000000>| Maya<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| 3ds Max<br />
| X+<br />
| Y-<br />
| Z+ <br />
|-<br />
|<#000000>| Unreal Engine<br />
| X+ <br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Unity<br />
| X+<br />
| Y+<br />
| Z+<br />
|-<br />
|<#000000>| Toolbag<br />
| X+<br />
| Y+ <br />
| Z+<br />
|}<br />
<span id="MTLPM"></span><br />
<br />
== Modeling the Low-Poly Mesh ==<br />
The in-game mesh usually needs to be carefully optimized to create a good silhouette, define edge-loops for better deformation, and minimize extreme changes between the vertex normals for better shading (see [[#SmoothingGroupsAndHardEdges|Smoothing Groups & Hard Edges]]).<br />
<br />
In order to create an optimized in-game mesh including a good silhouette and loops for deforming in animation, you can start with the 2nd subdivision level of your [[DigitalSculpting|digital sculpt]], or in some cases with the base mesh itself. Then you can just collapse edge loops or cut in new edges to add/remove detail as necessary. Or you can [[DigitalSculpting#OART|re-toplogize]] from scratch if that works better for you.<br />
<br />
See [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts] on the Polycount forum.<br />
<br />
<span id="UVC"></span><span id="UVCoordinates"></span><br />
=== UV Coordinates ===<br />
Normal map baking tools only capture normals within the 0-1 UV square, any UV bits outside this area are ignored. <br />
<br />
Only one copy of the forward-facing UVs should remain in the 0-1 UV square at baking time. If the mesh uses overlapping UVs, this will likely cause artifacts to appear in the baked map, since the baker will try render each UV shell into the map. Before baking, it's best to move all the overlaps and mirrored bits outside the 0-1 square. <br />
<br />
[[image:Normalmap_uvcoord_offset.jpg|frame|none|The mirrored UVs (in red) are offset 1 unit before baking. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you move all the overlaps and mirrored bits exactly 1 UV unit (any whole number will do), then you can leave them there after the bake and they will still be mapped correctly. You can move them back if you want, it doesn't matter to most game engines. Be aware that ZBrush does use UV offsets to manage mesh visibility, however this usually doesn't matter because the ZBrush cage mesh is often a different mesh than the in-game mesh used for baking.<br />
<br />
You should avoid changing the UVs after baking the normal map, because rotating or mirroring UVs after baking will cause the normal map not to match the [[#TB|tangent basis]] anymore, which will likely cause lighting problems. <br />
<br />
In 3ds Max, W is a third texture coordinate. It's used for 3D procedural textures and for storing vertex color in UV channels (you need 3 axes for RGB, so UVW can store vertex color). Bake problems can be avoided by moving any overlapping UVs to -1 on the W axis, with the same results as moving them 1 unit on the U or V axes. The tool Render To Texture will always bake whatever UVs are the highest along the W axis. However using W can be messy... it's generally hidden unless you purposefully look for it (bad for team work), doesn't get preserved on export to other apps, and high W values can prevent selecting and/or welding UVs. <br />
<br />
<span id="M"></span><span id="Mirroring"></span><br />
<br />
=== Mirroring ===<br />
Normal maps can be mirrored across a model to create symmetrical details, and save UV space, which allows more detail in the normal map since the texture pixels are smaller on the model. <br />
<br />
With [[#OSNM|object-space]] maps, mirroring requires [http://boards.polycount.net/showthread.php?t=53986 specific shader support]. For [[#TSNM|tangent-space]] maps, mirroring typically creates a shading seam, but this can be reduced or hidden altogether, depending on the method used.<br />
<br />
<span id="TMW"></span><br />
==== Typical Mirroring Workflow ====<br />
# Delete the mesh half that will be mirrored. <br />
# Arrange the UVs for the remaining model, filling the UV square.<br />
# Mirror the model to create a "whole" mesh, welding the mesh vertices along the seam. <br />
# Move the mirrored UVs exactly 1 unit (or any whole number) out of the 0-1 UV square.<br />
# Bake the normal map.<br />
<br />
Sometimes an artist will decide to delete half of a symmetrical model before baking. <br />
<br />
This is a mistake however because often the vertex normals along the hole will bend towards the hole a bit; there are no faces on the other side to average the normals with. This will create a strong lighting seam in the normal map. <br />
<br />
It's typically best to use the complete mirrored model to bake the normal map, not just the unique half. <br />
<br />
To prevent the mirrored UVs from causing overlaps or baking errors, move the mirrored [[#UVC|UVs]] out of the 0-1 UV space, so only one copy of the non-mirrored UVs is left within the 0-1 square.<br />
<br />
To avoid texel "leaks" between the UV shells, make sure there's enough [[#Edge_padding|Edge Padding]] around each shell, including along the edges of the normal map. None of the UV shells should be touching the edge of the 0-1 UV square, unless they're meant to tile with the other side of the map.<br />
<br />
<span id="CM"></span><br />
<br />
==== Center Mirroring ====<br />
If the mirror seam runs along the surface of a continuous mesh, like down the center of a human face for example, then it will probably create a lighting seam. <br />
<br />
In Epic Games' [http://www.unrealtechnology.com/technology.php Unreal Engine 3] (UE3) their symmetrical models commonly use centered mirroring. Epic uses materials that mix a [[DetailMap]] with the normal maps; these seem to scatter the diffuse/specular lighting and help minimize the obviousness of the mirror seams. For their [[Light Map]]ped models they use [http://udn.epicgames.com/Three/LightMapUnwrapping.html a technique] that can almost completely hide the mirror seam.<br />
<br />
[[image:Epic_MirroringCicada.jpg|frame|none| In UE3 a center mirror seam is reduced by using a detail normal map. <br> Image by "[http://epicgames.com Epic Games]"]]<br />
<br />
'''''[http://www.zbrushcentral.com/showpost.php?p=573108&postcount=28 GOW2 normal map seams], [http://utforums.epicgames.com/showthread.php?p=27166791#post27166791 UDK normal map seams]'''''<br />
<br />
<span id="OM"></span><br />
<br />
==== Offset Mirroring ====<br />
Offset mirroring is a method where you move the mirror seam off to one side of the model, so the seam doesn't run exactly down the center. For example with a character's head, the UV seam can go down along the side of the head in front of the ear. The UV shell for the nearest ear can then be mirrored to use the area on the other side of the head. <br />
<br />
This avoids the "Rorschach" effect and allows non-symmetrical details, but it still saves texture space because the two sides of the head can be mirrored (they're never seen at the same time anyhow).<br />
<br />
Offset mirroring doesn't get rid of the seam, but it does move it off to a place where it can either be less obvious, or where it can be hidden in a natural seam on the model.<br />
<br />
<span id="FCM"></span><br />
==== Flat Color Mirroring ====<br />
[http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] solves seams by painting a flat set of normals along the seam, using neutral blue (128,128,255). However it only works along horizontal or vertical UV seams, not across any angled UVs. It also removes any details along the mirror seam, creating blank areas. <br />
<br />
<span id="EM"></span><br />
==== Element Mirroring ====<br />
The mirror seam can be avoided completely when it doesn't run directly through any mesh. For example if there's a detached mesh element that runs down the center of the model, this can be uniquely mapped, while the meshes on either side can be mirrors of each other. Whenever the mirrored parts don't share any vertex normals with the non-mirrored parts, there won't be any seams. <br />
<br />
[[image:normalmap_mirrored-binocs-racer445.jpg|frame|none|The middle part (highlighted in red) uses unique non-mirrored UVs, allowing the mesh on the right to be mirrored without any seams. <br>Image by [http://http://racer445.com/ "racer445"]]]<br />
<br />
<span id="SGAHE"></span><br />
<br />
=== Smoothing Groups & Hard Edges ===<br />
Each vertex in a mesh has at least one vertex normal. Vertex normals are used to control the direction a triangle will be lit from; if the normal is facing the light the triangle will be fully lit, if facing away from the light the triangle won't be lit. <br />
<br />
Each vertex however can have more than one vertex normal. When two triangles have different vertex normals along their shared edge, this creates a shading seam, called a ''hard edge'' in most modeling tools. 3ds Max uses ''Smoothing Groups'' to create hard/soft edges, Maya uses ''Harden Edge'' and ''Soften Edge''. These tools create hard and soft edges by splitting and combining the vertex normals.<br />
<br />
[[image:BenMathis_SmoothingGroups_Excerpt.gif|frame|none|Hard edges occur where the vertices have multiple normals. <br>Image by [http://poopinmymouth.com Ben 'poopinmymouth' Mathis] ([http://poopinmymouth.com/process/tips/smoothing_groups.jpg tutorial here])]]<br />
<br />
When a mesh uses all soft normals (a single smoothing group) the lighting has to be interpolated across the extreme differences between the vertex normals. If your renderer doesn't support the same [[#TangentBasis|tangent basis]] that the baker uses, this can produce extreme shading differences across the model, which creates shading artifacts. It is generally best to reduce these extremes when you can because a mismatched renderer can only do so much to counteract it.<br />
<br />
Hard edges are usually best where the model already has a natural seam. For example, you can add a hard edge along the rim of a car's wheel well, to prevent the inside of the wheel well from distorting the shading for the outside of the car body. Mechanical models usually need hard edges where ever the surface bends more than about 45 degrees. <br />
<br />
For most meshes, the best results usually come from adding hard edges where ever there are UV seams. There are no hard rules however, you must experiment with different approaches to find what works best in your game.<br />
<br />
When you use object-space normal maps the vertex normal problem goes away since you're no longer relying on the crude vertex normals of the mesh. An object-space normal map completely ignores vertex normals. Object-space mapping allows you to use all soft edges and no bevels on the low-res mesh, without showing lighting errors.<br />
<br />
<span id="HEDAT"></span><br />
==== Hard Edge Discussions & Tutorials ====<br />
* [http://www.polycount.com/forum/showthread.php?p=2090450#post2090450 Maya MEL Script help needed (UV border edges)]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=73593 Normal Maps: Can Somone Explain This "Black Edge" issue]<br />
* [http://www.polycount.com/forum/showthread.php?t=73566 Normal Maps: Can someone explain normals, tangents and split UVs?]<br />
* [http://www.polycount.com/forum/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max]<br />
* [http://boards.polycount.net/showthread.php?t=68173 Why you should NOT trust 3ds Max's viewport normal-map display!]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/10503-xsi-normal-mapped-cube-looks-bad.html XSI - normal mapped cube looks bad]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/11924-weird-maya-normal-map-seam-artifact-problem-am-i-making-simple-mistake.html Weird Maya normal map seam/artifact problem]<br />
* [http://boards.polycount.net/showthread.php?p=1080600 Seams in Normals when Creating Tiling Environment Trims and other Tiles]<br />
* The tutorial [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing can affect the normal map.<br />
* The tutorial: [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] shows how smoothing affects raycasting.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses the breaking of normals and smoothing groups in general terms.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in the game, not the triangle count.<br />
* The Crysis documentation [http://doc.crymod.com/AssetCreation/PolyBumpReference.html PolyBump Reference] has a section towards the bottom that shows how smoothing affects their baked normal maps.<br />
* The polycount thread [http://boards.polycount.net/showthread.php?t=60694 Toying around with normal map approaches] has a great discussion of how best to use smoothing groups and bevels for better shading.<br />
<br />
<span id="UB"></span><br />
==== Using Bevels ====<br />
Bevels/chamfers generally improve the silhouette of the model, and can also help reflect specular highlights better. <br />
<br />
However bevels tend to produce long thin triangles, which slow down the in-game rendering of your model. Real-time renderers have trouble rendering long thin triangles because they create a lot of sub-pixel areas to render. <br />
<br />
Bevels also balloon the vertex count, which can increase the transform cost and memory usage. Hard edges increase the vertex count too, but not when the edge also shares a seam in UV space. For a good explanation of the vertex count issue, see [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly].<br />
<br />
Using hard edges with matching UV shells tends to give better performance and better cosmetic results than using bevels. However there are differing opinions on this, see the Polycount thread "[http://boards.polycount.net/showthread.php?t=71760 Maya transfer maps help]".<br />
<br />
<span id="EVN"></span><br />
==== Edited Vertex Normals ====<br />
If you use bevels the shading will be improved by editing the vertex normals so the larger flat surfaces have perpendicular normals. The vertex normals are then forced to blend across the smaller bevel faces, instead of across the larger faces. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66139 Superspecular soft edges tutorial chapter 1].<br />
<br />
[[image:oliverio_bevel_normals.gif|frame|none|Bending normals on bevelled models. <br>From the tutorial [http://deadlineproof.com/model-shading-techniques-soft-edge-superspecular/ Shading techniques Superspecular soft edges]<br>Image by [http://deadlineproof.com/ Paolo Oliverio]]]<br />
<br />
== Level of Detail Models ==<br />
See [http://www.polycount.com/forum/showthread.php?p=1216945#post1216945 Problem if you're using 3point-style normals with an LOD].<br />
<br />
<span id="MTHPM"></span><br />
<br />
== Modeling The High-Poly Mesh ==<br />
[[Subdivision Surface Modeling]] and [[DigitalSculpting]] are the techniques most often used for modeling a normal map. <br />
<br />
Some artists prefer to model the in-game mesh first, other artists prefer to model the high-res mesh first, and others start somewhere in the middle. The modeling order is ultimately a personal choice though, all three methods can produce excellent results:<br />
* Build the in-game model, then up-res it and sculpt it.<br />
* Build and sculpt a high resolution model, then build a new in-game model around that.<br />
* Build a basemesh model, up-res and sculpt it, then step down a few levels of detail and use that as a base for building a better in-game mesh.<br />
If the in-game mesh is started from one of the subdivision levels of the basemesh sculpt, various edge loops can be collapsed or new edges can be cut to add/remove detail as necessary.<br />
<br />
<span id="SE"></span><br />
=== Sloped Extrusions ===<br />
[[image:normal_slopes_hatred.jpg|frame|none|Extrusions on the high-poly model should be sloped to make a better normal map. <br>Image by [http://www.hatred.gameartisans.org/ Krzysztof "Hatred" Dolas].]]<br />
<br />
=== Floating Geometry ===<br />
[[image:FloatingGeo.jpg|frame|none|Normal map stores the direction the surface is facing rather than real depth information, thus allowing to save time using floating geometry. <br>To correctly bake AO with floating geo make it a separate object and turn off it's shadow casting. <br>Image by [http://artisaverb.info/ Andrew "d1ver" Maximov].]]<br />
<br />
See also [[3DTutorials/Modeling High-Low Poly Models for Next Gen Games|Modeling High/Low Poly Models for Next Gen Games]] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa]<br />
<br />
<span id="ET"></span><br />
<br />
=== Edge Thickness ===<br />
[[image:normal_edge_thickness.jpg|frame|none|When creating edges of the Highpoly, sometimes you'll need to make them rounded than in real life to <br>work better at the size they will be seen.<br>Image by [http://racer445.com/Evan "racer445" Herbert]]]<br />
<br />
<span id="MRF"></span><span id="MRRCB"></span><br />
<br />
=== mental ray Round Corners Bump ===<br />
The mental ray renderer offers an automatic bevel rendering effect called Round Corners Bump that can be baked into a normal map. This is available in 3ds Max, Maya, and XSI. See [http://boards.polycount.net/showthread.php?t=71995 Zero Effort Beveling for normal maps] - by [http://boards.polycount.net/member.php?u=31662 Robert "r_fletch_r" Fletcher].<br />
<br />
[http://jeffpatton.net/ Jeff Patton] posted about [http://jeffpatton.cgsociety.org/blog/archive/2007/10/ how to expose Round Corners Bump] in 3ds Max so you can use it in other materials.<br />
<br />
[http://cryrid.com/art/ Michael "cryrid" Taylor] posted a tutorial about how to use [http://cryrid.com/images/temp/XSI/zeroeffort_bevels.jpg Round Corners in XSI].<br />
<br />
XSI is able to bake a good normal map with it, but 3ds Max seems to bake it incorrectly, and Maya isn't able to bake the effect at all. Maybe Max might be able to bake it correctly, if the .mi shader is edited to use the correct coordinate space?<br />
<br />
<span id="Baking"></span><span id="B"></span><br />
== Baking ==<br />
The process of transferring normals from the high-res model to the in-game model is often called baking. The baking tool usually starts projecting a certain numerical distance out from the low-poly mesh, and sends rays inwards towards the high-poly mesh. When a ray intersects the high-poly mesh, it records the mesh's surface normal and saves it in the normal map.<br />
<br />
To get an understanding of how all the options affect your normal map, do some test bakes on simple meshes like boxes. They generate quickly so you can experiment with [[#UVCoordinates|UV mirroring]], [[#SGAHE|smoothing groups]], etc. This helps you learn the settings that really matter.<br />
* The tutorial [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] has more examples of ray-casting, plus how to get better results from the bake.<br />
<br />
Baking sub-sections:<br />
# [[#Anti-Aliasing|Anti-Aliasing]]<br />
# [[#Baking_Transparency|Baking Transparency]]<br />
# [[#Edge_Padding|Edge Padding]]<br />
# [[#High_Poly_Materials|High Poly Materials]]<br />
# [[#Reset_Transforms|Reset Transforms]]<br />
# [[#Solving_Intersections|Solving Intersections]]<br />
# [[#Solving_Pixel_Artifacts|Solving Pixel Artifacts]]<br />
# [[#Solving_Wavy_Lines|Solving Wavy Lines]]<br />
# [[#Triangulating|Triangulating]]<br />
# [[#Working_with_Cages|Working with Cages]]<br />
<br />
<span id="AA"></span><br />
=== Anti-Aliasing ===<br />
Turning on super-sampling or anti-aliasing (or whatever multi-ray casting is called in your normal map baking tool) will help to fix any jagged edges where the high-res model overlaps itself within the UV borders of the low-poly mesh, or wherever the background shows through holes in the mesh. Unfortunately this tends to render much much slower, and takes more memory.<br />
<br />
[[image:normalmap_aliasing_knak47.jpg|frame|none|A bake without anti-aliasing shows artifacts where the high-poly mesh has overlaps. <br>Image by [http://www.polycount.com/forum/member.php?u=35938 'knak47']]]<br />
<br />
One trick to speed this up is to render 2x the intended image size then scale the normal map down 1/2 in a paint program like Photoshop. The reduction's pixel resampling will add anti-aliasing for you in a very quick process. After scaling, make sure to re-normalize the map if your game doesn't do that already, because the un-normalized pixels in your normalmap may cause pixelly artifacts in your specular highlights. Re-normalizing can be done with [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA's normal map filter] for Photoshop.<br />
<br />
3ds Max's supersampling doesn't work nicely with edge padding, it produces dark streaks in the padded pixels. If so then turn off padding and re-do the padding later, either by re-baking without supersampling or by using a Photoshop filter like the one that comes with [[#3DTools|Xnormal]].<br />
<br />
=== Baking Transparency ===<br />
Sometimes you need to bake a normal map from an object that uses opacity maps, like a branch with opacity-mapped leaves. Unfortunately baking apps often completely ignore any transparency mapping on your high-poly mesh.<br />
<br />
{|class="wikitable"<br />
|[[image:JoeWilson_ivynormals_error.jpg]] <br />
|[[image:JoeWilson_ivynormals_rendered.jpg]]<br />
|-<br />
|3ds Max's RTT baker causes transparency errors.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|The lighting method bakes perfect transparency.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|}<br />
<br />
To solve this, render a Top view of the mesh. This only works if you're using a planar UV projection for your low-poly mesh and you're baking a tangent-space normal map.<br />
<br />
* Make sure the Top view matches the dimensions of the planar UV projection used by the low-poly mesh. It helps to use an orthographic camera for precise placement.<br />
* On the high-poly mesh either use a specific lighting setup or a use special material shader:<br />
* 1) The lighting setup is described in these tutorials:<br />
* * [http://www.bencloward.com/tutorials_normal_maps11.shtml Creating A Normal Map Right In Your 3D App] by [http://www.bencloward.com/ Ben Cloward]<br />
* *[http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy], Graphics Techniques Consultant, Xbox Content and Design Team<br />
* 2) The material shader does the same thing, but doesn't require lights.<br />
* * [http://www.scriptspot.com/3ds-max/normaltexmap NormalTexMap] scripted map for 3ds Max by [http://www.scriptspot.com/users/dave-locke Dave Locke].<br />
* * [http://www.footools.com/3dsmax_plugins.html InfoTexture] map plugin for 3ds Max by [http://www.footools.com John Burnett]<br />
<br />
[[image:BenCloward_NormalMapLighting.gif|frame|none|The lighting setup for top-down rendering. <br>Image by [http://www.bencloward.com Ben Cloward]]]<br />
<br />
<span id="EP"></span><br />
<br />
=== Edge Padding ===<br />
If a normal map doesn't have enough [[Edge_padding |Edge Padding]], this will create shading seams on the UV borders.<br />
<br />
=== High Poly Materials ===<br />
3ds Max will not bake a normal map properly if the high-res model has a mental ray Arch & Design material applied. If your normal map comes out mostly blank, either use a Standard material or none at all. For an example see the Polycount thread [http://www.polycount.com/forum/showthread.php?t=74792 Render to Texture >:O].<br />
<br />
<span id="RT"></span><br />
=== Reset Transforms ===<br />
Before baking, make sure your low-poly model's transforms have been reset. '''''This is very important!''''' Often during the modeling process a model will be rotated and scaled, but these compounded transforms can create a messy local "space" for the model, which in turn often creates rendering errors for normal maps. <br />
<br />
In 3ds Max, use the Reset Xforms utility then Collapse the Modifier Stack. In Maya use Freeze Transformation. In XSI use the Freeze button.<br />
<br />
<span id="SI"></span><br />
<br />
=== Solving Intersections ===<br />
The projection process often causes problems like misses, or overlaps, or intersections. It can be difficult generating a clean normal map in areas where the high-poly mesh intersects or nearly intersects itself, like in between the fingers of a hand. Setting the ray distance too large will make the baker pick the other finger as the source normal, while setting the ray distance too small will lead to problems at other places on the mesh where the distances between in-game mesh and high-poly mesh are greater.<br />
<br />
Fortunately there are several methods for solving these problems.<br />
<br />
# Change the shape of the cage. Manually edit points on the projection cage to help solve tight bits like the gaps between fingers.<br />
# Limit the projection to matching materials, or matching UVs.<br />
# Explode the meshes. See the polycount thread [http://boards.polycount.net/showthread.php?t=62921 Explode script needed (for baking purposes)].<br />
# Bake two or more times using different cage sizes, and combine them in Photoshop.<br />
<br />
<span id="SPA"></span><br />
<br />
=== Solving Pixel Artifacts ===<br />
[[image:filterMaps_artifact.jpg|frame|none|Random pixel artifacts in the bake. <br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
If you are using 3ds Max's ''Render To Texture'' to bake from one UV layout to another, you may see stray pixels scattered across the bake. This only happens if you are using a copy of the original mesh in the Projection, and that mesh is using a different UV channel than the original mesh.<br />
<br />
There are two solutions for this:<br />
<br />
* Add a Push modifier to the copied mesh, and set it to a low value like 0.01.<br />
- or -<br />
<br />
* Turn off ''Filter Maps'' in the render settings (Rendering menu > Render Setup > Renderer tab > uncheck Filter Maps). To prevent aliasing you may want to enable the Global Supersampler in Render Setup.<br />
<br />
See also [[#Anti-Aliasing]].<br />
<br />
<span id="SWL"></span><br />
<br />
=== Solving Wavy Lines ===<br />
When capturing from a cylindrical shape, often the differences between the low-poly mesh and the high-poly mesh will create a wavy edge in the normal map. There are a couple ways to avoid this:<br />
<br />
# The best way... create your lowpoly model with better supporting edges. See the Polycount threads [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?], [http://boards.polycount.net/showthread.php?t=55754 approach to techy stuff], [http://www.polycount.com/forum/showthread.php?t=72713 Any tips for normal mapping curved surface?].<br />
# Adjust the shape of the cage to influence the directions the rays will be cast. Beware... this work will have to be re-done every time you edit the lowpoly mesh, as the cage will be invalidated. At the bottom of [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm this page of his normal map tutorial], [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to do this in 3ds Max. Same method can be seen in the image below.<br />
# Subdivide the low-res mesh so it more closely matches the high-res mesh. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] has a [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa video tutorial] that shows how to do this in Maya.<br />
# Paint out the wavy line. Beware... this work will have to be re-done every time you re-bake the normal map. The [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
# Use a separate planar-projected mesh for the details that wrap around the barrel area, so the ray-casting is more even. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. For example to add tread around a tire, the tread can be baked from a tread model that is laid out flat, then that bake can layered onto the bake from the cylindrical tire mesh in a paint program.<br />
<br />
[[image:timothy_evison_normalmap_projections.jpg|frame|none|Adjusting the shape of the cage to remove distortion. <br>Image by [http://users.cybercity.dk/~dsl11905/resume/resume.html Timothy "tpe" Evison]]]<br />
<br />
<span id="TRI"></span><br />
<br />
=== Triangulating ===<br />
Before baking, it is usually best to triangulate the low-poly model, converting it from polygons into pure triangles. This prevents the vertex normals from being changed later on, which can create specular artifacts.<br />
<br />
[[image:triangulation_modo_ohare.jpg|frame|none| When quads are triangulated in [http://www.luxology.com/modo/ Modo], the internal edges are sometimes flipped, which causes shading differences.<br>Image by [http://www.farfarer.com/|James "Talon" O'Hare]]]<br />
<br />
<br />
Sometimes a baking tool or a mesh exporter/importer will re-triangulate the polygons. A quad polygon is actually treated as two triangles, and the internal edge between them is often switched diagonally during modeling operations. When the vertices of the quad are moved around in certain shapes, the software's algorithm for polygon models tries to keep the quad surface in a "rational" non-overlapping shape. It does this by switching the internal edge between its triangles.<br />
<br />
<br />
[[image:triangulation_spec_tychovii.jpg|frame|none| The specular highlight is affected by triangulation. Flip edges to fix skewing. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66651 Skewed Specular Highlight?] for pictures and more info.<br> Image by [http://robertkreps.com Robert "TychoVII" Kreps]]]<br />
<br />
<br />
<span id="WWC"></span><br />
<br />
=== Working with Cages ===<br />
''Cage'' has two meanings in the normal-mapping process: a low-poly base for [[subdivision surface modeling]] (usually called the [[DigitalSculpting#BM|basemesh]]), or a ray-casting mesh used for normal map baking. This section covers the ray-casting cage.<br />
<br />
Most normal map baking tools allow you to use a distance-based raycast. A ray is sent outwards along each vertex normal, then at the distance you set a ray is cast back inwards. Where ever that ray intersects the high poly mesh, it will sample the normals from it. <br />
<br />
{|class="wikitable"<br />
|[[Image:Normalmap_raycasting_1.jpg]] <br />
|[[Image:Normalmap_raycasting_2.jpg]]<br />
|-<br />
|Hard edges and a distance-based raycast (gray areas) cause ray misses (yellow) and ray overlaps (cyan).<br> Image by [http://www.mankua.com/ Diego Castaño]<br />
|The gray area shows that using all soft edges (or hard edges and a cage-based raycast) will avoid ray-casting errors from split normals.<br> Image by [http://www.mankua.com/ Diego Castaño] <br />
|}<br />
<br />
Unfortunately with a distance-based raycast, [[#SGAHE|split vertex normals]] will cause the bake to miss parts of the high-res mesh, causing errors and seams. <br />
<br />
Some software allows you to use ''cage mesh'' option instead, which basically inflates a copy of the low-poly mesh, then raycasts inwards from each vertex. This ballooned-out mesh is the cage.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
|<tablebgcolor="#ffaaaa">| <br />
|}<br />
<br />
In 3ds Max the cage controls both the distance and the direction of the raycasting. <br />
<br />
In Maya the cage only controls the distance; the ray direction matches the vertex normals (inverted).<br />
<br />
<span style="text-decoration: line-through"> This may have been fixed in the latest release...<<BR>><br />
In Xnormal the cage is split everywhere the model has [[#SGAHE|hard edges]], causing ray misses in the bake. You can fix the hard edge split problem but it involves an overly complex workflow. You must also repeat the whole process any time you change your mesh:</span><br />
# <s> Load the 3d viewer.</s><br />
# <s> Turn on the cage editing tools.</s><br />
# <s> Select all of the vertices.</s><br />
# <s> Weld all vertices.</s><br />
# <s> Expand the cage as you normally would.</s><br />
# <s> Save out your mesh using the Xnormal format.</s><br />
# <s> Make sure Xnormal is loading the correct mesh.</s><br />
<br />
<span id="P"></span><span id="Painting"></span><br />
<br />
== Painting ==<br />
Don't be afraid to edit normal maps in Photoshop. After all it is just a texture, so you can clone, blur, copy, blend all you want... as long as it looks good of course. Some understanding of [[#RGBChannels|the way colors work]] in normal maps will go a long way in helping you paint effectively.<br />
<br />
A normal map sampled from a high-poly mesh will nearly always be better than one sampled from a texture, since you're actually grabbing "proper" normals from an accurate, highly detailed surface. That means your normal map's pixels will basically be recreating the surface angles of your high-poly mesh, resulting in a very believable look.<br />
<br />
If you only convert an image into a normal-map, it can look very flat, and in some cases it can be completely wrong unless you're very careful about your value ranges. Most image conversion tools assume the input is a heightmap, where black is low and white is high. If you try to convert a diffuse texture that you've painted, the results are often very poor. Often the best results are obtained by baking the large and mid-level details from a high-poly mesh, and then combined with photo-sourced "fine detail" normals for surface details such as fabric weave, scratches and grain.<br />
<br />
Sometimes creating a high poly surface takes more time than your budget allows. For character or significant environment assets then that is the best route, but for less significant environment surfaces working from a heightmap-based texture will provide a good enough result for a much less commitment in time.<br />
<br />
* [http://crazybump.com/ CrazyBump] is a commercial normal map converter.<br />
* [http://www.renderingsystems.com/support/showthread.php?tid=3 ShaderMap] is a commercial normal map converter.<br />
* [http://www.pixplant.com/ PixPlant] is a commercial normal map converter.<br />
* [http://boards.polycount.net/showthread.php?t=68860 NJob] is a free normal map converter.<br />
* [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA normalmap filter for Photoshop] is a free normal map converter.<br />
* [http://xnormal.net Xnormal height-to-normals filter for Photoshop] is a free normal map converter.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm Normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
<br />
=== Flat Color ===<br />
The color (128,128,255) creates normals that are completely perpendicular to the polygon, as long as the vertex normals are also perpendicular. Remember a normal map's per-pixel normals create ''offsets'' from the vertex normals. If you want an area in the normal map to be flat, so it creates no offsets from the vertex normals, then use the color (128,128,255). <br />
<br />
This becomes especially obvious when [[#Mirroring|mirroring a normal map]] and using a shader with a reflection ingredient. Reflection tends to accentuate the angles between the normals, so any errors become much more apparent.<br />
<br />
[[image:normalmap_127seam.jpg|thumb|600px|none| Mirrored normal maps show a seam when (127,127,255) is used for the flat color; 128 is better.<br>Image by [http://www.ericchadwick.com Eric Chadwick]]]<br />
<br />
In a purely logical way, 127 seems like it would be the halfway point between 0 and 255. However 128 is the color that actually works in practice. When a test is done comparing (127,127,255) versus (128,128,255) it becomes obvious that 127 creates a slightly bent normal, and 128 creates a flat one.<br />
<br />
This is because most game pipelines use ''unsigned'' normal maps. For details see the Polycount forum thread [http://www.polycount.com/forum/showpost.php?p=771360&postcount=22 tutorial: fixing mirrored normal map seams].<br />
<br />
<span id="BNMT"></span><br />
<br />
=== Blending Normal Maps Together ===<br />
Blending normal maps together is a quick way to add high-frequency detail like wrinkles, cracks, and the like. Fine details can be painted as a height map, then it can be converted into a normal map using one of the normal map tools. Then this "details" normal map can be blended with a geometry-derived normal map using one of the methods below. <br />
<br />
Here is a comparison of four of the blending methods. Note that in these examples the default values were used for CrazyBump (Intensity 50, Strength 33, Strength 33), but the tool allows each layer's strength to be adjusted individually for stronger or milder results. Each of the normal maps below were [[#Renormalizing|re-normalized]] after blending.<br />
<br />
{|class="wikitable"<br />
|[[image:nrmlmap_blending_methods_Maps.png]]<br />
|[[image:nrmlmap_blending_methods_RTTNormalMapFX.png]]<br />
|-<br />
|The blended normal maps.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|Screenshot of the 3dsmax viewport, using the RTTNormalMap.fx shader.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|}<br />
<br />
The four blending methods used above:<br />
# [http://www.crazybump.com CrazyBump] by Ryan Clark blends normal maps together using calculations in 3D space rather than just in 2D. This does probably the best job at preserving details, and each layer's strength settings can be tweaked individually. <br />
# [http://www.rodgreen.com/?p=4 Combining Normal Maps in Photoshop] by Rod Green blends normal maps together using Linear Dodge mode for the positive values and Difference mode for the negative values, along with a Photoshop Action to simplify the process. It's free, but the results may be less accurate than CrazyBump.<br />
# [http://www.paultosca.com/makingofvarga.html Making of Varga] by [http://www.paultosca.com/ Paul "paultosca" Tosca] blends normal maps together using Overlay mode for the red and green channels and Multiply mode for the blue channel. This gives a slightly stronger bump than the Overlay-only method. [http://www.leocov.com/ Leo "chronic" Covarrubias] has a step-by-step tutorial for this method in [http://www.cgbootcamp.com/tutorials/2009/12/9/photoshop-combine-normal-maps.html CG Bootcamp Combine Normal Maps].<br />
# [[3DTutorials/Normal Map Deepening|Normal Map Deepening]] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to blend normal maps together using Overlay mode. [http://cgtextures.com/content.php?action=tutorial&name=normalmap CGTextures tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] also shows how to create normalmaps using multiple layers (Note: to work with the Overlay blend mode each layer's Output Level should be 128 instead of 255, you can use the Levels tool for this).<br />
<br />
The [http://boards.polycount.net/showthread.php?t=69615 Getting good height from Nvidia-filter normalizing grayscale height] thread on the Polycount forum has a discussion of different painting/blending options. Also see the [[#2DT|2D Tools]] section for painting and conversion tools.<br />
<br />
<span id="PCT"></span><br />
<br />
=== Pre-Created Templates ===<br />
A library of shapes can be developed and stored for later use, to save creation time for future normal maps. Things like screws, ports, pipes, and other doo-dads. These shapes can be stored as bitmaps with transparency so they can be layered into baked normal maps.<br />
<br />
* [http://www.beautifulrobot.com/?p=69 Creating & Using NormalMap "Widgets"] - by ''[http://www.beautifulrobot.com Steev "kobra" Kelly]''<<BR>> How to set up and render template objects.<br />
* [http://www.akramparvez.com/portfolio/scripts/normalmap-widget-for-3ds-max/ NormalMap Widget for 3ds Max] - by ''[http://www.akramparvez.com Akram Parvez]''<<BR>>A script to automate the setup and rendering process.<br />
* See the section [[#BT|Baking Transparency]] for more template-rendering tools and tutorials.<br />
<br />
<span id="RN"></span><span id="Renormalizing"></span><br />
=== Re-normalizing ===<br />
Re-normalizing means resetting the length of each normal in the map to 1.<br />
<br />
A normal mapping shader takes the three color channels of a normal map and combines them to create the direction and length of each pixel's normal. These normals are then used to apply the scene lighting to the mesh. However if you edit normal maps by hand or if you blend multiple normal maps together this can cause those lengths to change. Most shaders expect the length of the normals to always be 1 (normalized), but some are written to re-normalize the normal map dynamically (for example, 3ds Max's Hardware Shaders do re-normalize).<br />
<br />
If the normals in your normal map are not normalized, and your shader doesn't re-normalize them either, then you may see artifacts on the shaded surface... the specular highlight may speckle like crazy, the surface may get patches of odd shadowing, etc. To help you avoid this NVIDIA's normal map filter for Photoshop provides an easy way to re-normalize a map after editing; just use the '''Normalize Only''' option. [http://xnormal.net Xnormal] also comes with a Normalize filter for Photoshop.<br />
<br />
[[image:normalize_only.jpg|frame|none|The re-normalize option in the NVIDIA filter.<br>Image by [http://hirezstudios.com/ Scott Warren]]]<br />
<br />
Some shaders use [[#NormalMapCompression|compressed normal maps]]. Usually this means the blue channel is thrown away completely, so it's recalculated on-the-fly in the shader. However the shader has to re-normalize in order to recreate that data, so any custom normal lengths that were edited into the map will be ignored completely. <br />
<br />
<span id="AOIANM"></span><span id="AmbientOcclusionIntoANormalMap"></span><br />
<br />
=== Ambient Occlusion into a Normal Map ===<br />
If the shader doesn't re-normalize the normal map, an [[Ambient Occlusion Map]] can actually be baked into the normal map. This will shorten the normals in the crevices of the surface, causing the surface to receive less light there. This works with both diffuse and specular, or any other pass that uses the normal map, like reflection.<br />
<br />
However it's usually best to keep the AO as a separate map (or in an alpha channel) and multiply it against the ambient lighting only. This is usually done with a custom [[:Category:Shaders|shader]]. If you multiply it against the diffuse map or normal map then it also occludes diffuse lighting which can make the model look dirty. Ambient occlusion is best when it occludes ambient lighting only, for example a [[DiffuselyConvolvedCubeMap|diffusely convolved cubemap]].<br />
<br />
[[image:nrmlmap_ao.jpg|frame|none| AO can be baked into a normal map, shortening the normals (lower left model).<br>Model by [http://www.3dartisan.net/~kuman/ James Ku]]]<br />
<br />
To bake the AO into a normal map, adjust the levels of the AO layer first so the darks only go as low as 128 gray, then set the AO layer to Darken mode. This will shorten the normals in the normalmap, causing the surface to receive less light in the darker areas. <br />
<br />
This trick doesn't work with any shaders that re-normalize, like 3ds Max's Hardware Shaders. The shader must be altered to actually use the lengths of your custom normals; most shaders just assume all normals are 1 in length because this makes the shader code simpler. Also this trick will not work with most of the common [[#NormalMapCompression|normal map compression formats]], which often discard the blue channel and recalculate it in the shader, which requires re-normalization.<br />
<br />
<span id="BLE"></span><br />
<br />
=== Back Lighting Example ===<br />
You can customize normal maps for some interesting effects. If you invert the blue channel of a tangent-space map, the normals will be pointing to the opposite side of the surface, which can simulate backlighting.<br />
<br />
{|class="wikitable"<br />
|[[image:tree_front.jpg]]||[[image:tree_back.jpg]]<br />
|-<br />
|Tree simulating subsurface scattering (front view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|Tree simulating subsurface scattering (back view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|-<br />
|colspan="2"|[[image:tree_maps.jpg]]<br />
|-<br />
|colspan="2"|The maps used for the leaves. The 2nd diffuse was simply color-inverted, hue-shifted 180°, and saturated.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
The tree leaves use a shader than adds together two diffuse maps, one using a regular tangent-space normal map, the other using the same normal map but with the blue channel inverted. This causes the diffuse map using the regular normal map to only get lit on the side facing the light (front view), while the diffuse map using the inverted normal map only gets lit on the opposite side of the leaves (back view). The leaf geometry is 2-sided but uses the same shader on both sides, so the effect works no matter the lighting angle. As an added bonus, because the tree is self-shadowing the leaves in shadow do not receive direct lighting, which means their backsides do not show the inverted normal map, so the fake subsurface scatter effect only appears where the light directly hits the leaves. This wouldn't work for a whole forest because of the computational cost of self-shadowing and double normal maps, but could be useful for a single "star" asset, or if LODs switched the distant trees to a model that uses a cheaper shader.<br />
<br />
<span id="SAS"></span><br />
<br />
== Shaders and Seams ==<br />
You need to use the right kind of shader to avoid seeing seams where UV breaks occur. It must be written to use the same [[#TangentBasis|tangent basis]] that was used during baking. If the shader doesn't, the lighting will either be inconsistent across UV borders or it will show smoothing errors from the low-poly vertex normals.<br />
<br />
Xnormal generates accurate normals when displayed in Xnormal, and the SDK includes a method to write your own custom tangent space generator for the tool. <br />
<br />
<span id="3MS"></span><br />
=== 3ds Max Shaders ===<br />
The "Render To Texture" tool in 3ds Max 2011 and older generates [[#TSNM|tangent-space]] normal maps that render correctly in the offline renderer (scanline) but do not render correctly in the realtime viewport with the 3ds Max shaders. Max is using a different [[#TangentBasis|tangent basis]] for each. This is readily apparent when creating non-organic hard surface normalmaps; smoothing errors appear in the viewport that do not appear when rendered. <br />
<br />
The errors can be fixed by using "Render To Texture" to bake a [[#TSNM|tangent-space]] or [[#OSNM|object-space]] map, and using the free [http://www.3pointstudios.com/3pointshader_about.shtml "3Point Shader"] by Christoph '[[CrazyButcher]]' Kubisch and Per 'perna' Abrahamsen. The shader uses the same tangent basis as the baking tool, so it produces nearly flawless results. It also works with old bakes.<br />
<br />
You can get OK results in the Max viewport using a tangent-space map baked in Maya, loading it in a Standard material, and enabling "Show Hardware Map in Viewport". Another method is to use Render To Texture to bake an [[#OSNM|object-space]] map then use [[#CBS|Nspace]] to convert it into a tangent-space map then load that in a DirectX material and use the RTTNormalMap.fx shader. <br />
<br />
Autodesk is aware of these issues, and plans to address them in an upcoming release. See these links for more information:<br />
* Christoph "[[CrazyButcher]]" Kubisch and Per "perna" Abrahamsen designed a shader/modifier combination approach that fixes the viewport problem, see the Polycount forum post [http://boards.polycount.net/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max].<br />
* Jean-Francois "jfyelle" Yelle, Autodesk Media & Entertainment Technical Product Manager, has [http://boards.polycount.net/showthread.php?p=1115812#post1115812 this post]. <br />
* Ben Cloward posted [http://boards.polycount.net/showthread.php?p=1100270#post1100270 workarounds and FX code].<br />
* Christopher "cdiggins" Diggins, SDK writer for 3ds Max, shares some of the SDK code in his blog posts "[http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping How the 3ds Max Scanline Renderer Computes Tangent and Binormal Vectors for Normal Mapping]" and "[http://area.autodesk.com/blogs/chris/3ds_max_normal_map_baking_and_face_angle_weighting_the_plot_thickens 3ds Max Normal Map Baking and Face Angle Weighting: The Plot Thickens]".<br />
<br />
[[image:nmtest_uv-splits_thumb.jpg|thumb|600px|none|Comparison of map baking methods in Maya and Max, and Ben Cloward's custom FX code.<br>Image by [http://www.bencloward.com/ Ben Cloward] and [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
[[image:normalmapfix_3pointstudios_thumb.jpg|frame|none|3 Point Studios' normal map display fix for 3ds Max.<br>image by [http://www.3pointstudios.com 3 Point Studios]]]<br />
<br />
{|class="wikitable"<br />
|[[image:max2010_normalmap_workarounds.png|thumb|400px|none|]]<br />
|[[image:max2010_normalmap_compare.png|thumb|400px|none|]]<br />
|-<br />
|Viewport methods in 3ds Max 2010.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick] <br />
|More baking methods in 3ds Max 2010.<br> Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
<span id="3MENT"></span><br />
<br />
=== 3ds Max Edit Normals Trick ===<br />
After baking, if you add an Edit Normals modifier to your low-poly normalmapped model, this seems to "relax" the vertex normals for more accurate viewport shading. The modifier can be collapsed if desired.<br />
<br />
<span id="MS"></span><br />
=== Maya Shaders ===<br />
Maya seems to correctly generate normals to view in realtime, with the correct [[#TangentBasis|tangent basis]], with much less smoothing errors than 3ds Max. <br />
* [http://www.mentalwarp.com/~brice/shader.php BRDF shader] by [http://www.mentalwarp.com/~brice/ Brice Vandemoortele] and [http://www.kjapi.com/ Cedric Caillaud] (more info in [http://boards.polycount.net/showthread.php?t=49920 this Polycount thread]) '''Update:''' [http://boards.polycount.net/showthread.php?p=821862#post821862 New version here] with many updates, including object-space normal maps, relief mapping, self-shadowing, etc. Make sure you enable cgFX shaders in the Maya plugin manager, then you can create them in the same way you create a Lambert, Phong etc. Switch OFF high quality rendering in the viewports to see them correctly too.<br />
* If you want to use the software renderer, use mental ray instead of Maya's software renderer because mental ray correctly interprets tangent space normals. The Maya renderer treats the normal map as a grayscale bump map, giving nasty results. Mental ray supports Maya's Phong shader just fine (amongst others), although it won't recognise a gloss map plugged into the "cosine power" slot. The slider still works though, if you don't mind having a uniform value for gloss. Spec maps work fine though. Just use the same set up as you would for viewport rendering. You'll need to have your textures saved as TGAs or similar for mental ray to work though. - from [http://boards.polycount.net/member.php?u=14235 CheeseOnToast]<br />
<br />
<br />
<span id="NMC"></span><br />
<br />
== Normal Map Compression ==<br />
see; [[Normal Map Compression]]<br />
<br />
== Links ==<br />
<br />
=== Related Pages ===<br />
* [[Curvature map]]<br />
* [[DuDv map]]<br />
* [[Flow map]]<br />
* [[Normal map]]<br />
* [[Radiosity normal map]]<br />
* [[Vector displacement map]]<br />
<br />
<span id="3DT"></span> <span id="Tools"></span> <span id="3DTools"></span><br />
=== 3D Tools ===<br />
See [[:Category:Tools#A3D_Normal_Map_Software|Category:Tools#3D_Normal_Map_Software]]<br />
<br />
<span id="2DT"></span><span id="2DTools"></span><br />
=== 2D Tools ===<br />
See [[:Category:Tools#A2D_Normal_Map_Software|Category:Tools#2D_Normal_Map_Software]]<br />
<br />
<span id="T"></span><span id="Tutorials"></span><br />
=== Tutorials ===<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh tutorial for Max and Xnormal] by [http://www.exisinteractive.com/ PeterK] to prevent heavy distortions when baking with a cage, without the need to add extra supporting vertices.<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games] by [http://www.polycount.com/forum/member.php?u=56680 'SuperFranky']<br />
* [http://area.autodesk.com/userdata/fckdata/239955/The%20Generation%20and%20Display%20of%20Normal%20Maps%20in%203ds%20Max.pdf The Generation and Display of Normal Maps in 3ds Max] (500kb PDF) <<BR>> Excellent whitepaper from Autodesk about normal mapping in 3ds Max and other apps.<br />
* [http://www.katsbits.com/htm/tutorials/blender-baking-normal-maps-from-models.htm Renderbump and baking normal maps from high poly models using Blender 3D] by ''[http://www.katsbits.com/htm/about.htm "katsbits"]''<<BR>>Baking normal maps in Blender.<br />
* [http://udn.epicgames.com/Three/CreatingNormalMaps.html Techniques for Creating Normal Maps] in the Unreal Developer Network's [http://udn.epicgames.com/Three/WebHome.html Unreal Engine 3 section] contains advice from [http://www.epicgames.com/ Epic Games] artists on creating normal maps for UE3. The [http://udn.epicgames.com/Three/DesignWorkflow.html#Creating%20normal%20maps%20from%20meshes Design Workflow page] has a summary.<br />
* [http://www.iddevnet.com/quake4/ArtReference_CreatingModels#head-3400c230e92ff7d57424b2a68f6e0ea75dee4afa Creating Models in Quake 4] by [http://www.ravensoft.com/ Raven Software] is a comprehensive guide to creating Quake 4 characters.<br />
* [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing and UVs can affect normal maps in Doom 3.<br />
* [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] is an overview of modeling for normal maps.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses how smoothing groups and bevels affect the topology of the low-poly model.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in-game, not the triangle or poly count.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm Normal map workflow] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] demonstrates his normal mapping workflow in 3ds Max and Photoshop.<br />
* [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa This video tutorial] by [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] shows in Maya how to subdivide the low-poly mesh so it more closely matches the high-poly mesh, to help solve wavy lines in the bake.<br />
* [http://www.bencloward.com/tutorials_normal_maps1.shtml Normal Mapping Tutorial] by [http://www.bencloward.com/ Ben Cloward] is a comprehensive tutorial about the entire normal map creation process.<br />
* [http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy] shows how to use a special lighting setup to render normal maps (instead of baking them).<br />
* [http://cgtextures.com/content.php?action=tutorial&name=normalmap Tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] shows how to create deep normal maps using multiple layers. Note: to use Overlay blend mode properly, make sure to change each layer's Levels ''Output Level'' to 128 instead of 255.<br />
* [http://www.poopinmymouth.com/process/tips/normalmap_deepening.jpg Normalmap Deepening] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to adjust normal maps, and how to layer together painted and baked normal maps.<br />
* [http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] helps to solve seams along horizontal or vertical UV edges, but not across angled UVs.<br />
* [http://planetpixelemporium.com/tutorialpages/normal.html Cinema 4D and Normal Maps For Games] by [http://planetpixelemporium.com/index.php James Hastings-Trew] describes normal maps in plain language, with tips on creating them in Cinema 4D.<br />
* [http://forums.cgsociety.org/showthread.php?f=39&t=359082 3ds Max normal mapping overview] by [http://www.alan-noon.com/ Alan Noon] is a great thread on CGTalk about the normal mapping process.<br />
* [http://forums.cgsociety.org/showthread.php?f=46&t=373024 Hard Surface Texture Painting] by [http://stefan-morrell.cgsociety.org/gallery/ Stefan Morrell] is a good introduction to painting textures for metal surfaces.<br />
<br />
<span id="D"></span><span id="Discussion"></span><br />
<br />
=== Discussion ===<br />
[http://boards.polycount.net/showthread.php?p=820218 Discuss this page on the Polycount forums]. Suggestions welcome.<br />
<br />
Even though only one person has been editing this page so far, the information here was gathered from many different sources. We wish to thank all the contributors for their hard-earned knowledge. It is much appreciated!<br />
<br />
----<br />
[[Category:TextureTypes]] [[Category:Bump map]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Normal_mapNormal map2015-04-22T14:51:56Z<p>Dustinbrown: /* Common Swizzle Coordinates */</p>
<hr />
<div>== Out of Date ==<br />
The information on this page is a bit old, it needs to be updated. See these links for more current information:<br />
<br />
* [http://farfarer.com/resources.htm RNM Normal Map Combiner], by [http://www.farfarer.com/ James "Farfarer" O'Hare]<br />
* [http://vincentcallebaut.com/CombineNormal.html Combine Normal], by [http://vincentcallebaut.comVincent "Vincentt" Callebaut], [http://www.polycount.com/forum/showthread.php?t=131819 Combine normal maps script for Photoshop] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showpost.php?p=2226864&postcount=51 Earthquake on separating smoothing groups in the UV]<br />
* [http://www.polycount.com/forum/showpost.php?p=2225535&postcount=40 JedTheKrampus on offsetting Mirrored UVs]<br />
* [http://www.polycount.com/forum/showthread.php?t=148303 Of Bit Depths, Banding and Normal Maps]<br />
* [http://www.polycount.com/forum/showthread.php?t=147227 Skew you buddy! Making sense of skewed normal map details.]<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games]<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh Tutorial]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?]<br />
* [http://www.laurenscorijn.com/future-xoliulshader-support.html Future Xoliulshader support] = why Xoliulshader doesn't work properly in 3ds Max 2013/2014.<br />
<br />
== Synched Workflow ==<br />
To eliminate seams and shading artifacts, the model renderer and the normal map baking tool should use the same tangent basis.<br />
<br />
FBX model format can store tangents, and some renderers use this data to synch the incoming normal maps.<br />
<br />
{| class="wikitable sortable" style="color:grey;"<br />
|- <br />
! Renderer !! Normal map baker<br />
|-<br />
| 3ds Max || 3ds Max, Handplane, ?<br />
|-<br />
| Blender || ?<br />
|-<br />
| Creation Engine || Handplane, ?<br />
|-<br />
| CryEngine || ?<br />
|-<br />
| Knald || ?<br />
|-<br />
| Marmoset Toolbag || 3ds Max, Maya, Xnormal, ?<br />
|-<br />
| Maya || Handplane, Maya, ?<br />
|-<br />
| Source || Handplane, Maya ([http://www.polycount.com/forum/showpost.php?p=2224653&postcount=28]), ?<br />
|-<br />
| Starcraft II || Handplane, ?<br />
|-<br />
| Substance Designer || ?<br />
|-<br />
| Unity([http://www.polycount.com/forum/showpost.php?p=2224781&postcount=29], [http://www.polycount.com/forum/showthread.php?p=2194353#post2194353]) || Handplane, Xnormal (via Asset Store), ?<br />
|-<br />
| Unreal Engine 4 || Handplane, Xnormal([http://www.polycount.com/forum/showpost.php?p=2224402&postcount=20]), ? <br />
|-<br />
| Xnormal || Xnormal, ?<br />
|}<br />
<br />
----<br />
<br />
== What is a Normal Map? ==<br />
A Normal Map is usually used to fake high-res geometry detail when it's mapped onto a low-res mesh. The pixels of the normal map each store a ''normal'', a vector that describes the surface slope of the original high-res mesh at that point. The red, green, and blue channels of the normal map are used to control the direction of each pixel's normal. <br />
<br />
When a normal map is applied to a low-poly mesh, the texture pixels control the direction each of the pixels on the low-poly mesh will be facing in 3D space, creating the illusion of more surface detail or better curvature. However, the silhouette of the model doesn't change. <br />
<br />
<gallery mode="packed"><br />
Whatif_normalmap_mapped2.jpg|A model with a normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_low.jpg|The model without its normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_high.jpg|The high-resolution model used to create the normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
</gallery><br />
<br />
==Tangent-Space vs. Object-Space==<br />
<br />
Normal maps can be made in either of two basic flavors: tangent-space or object-space. World-space is basically the same as object-space, except it requires the model to remain in its original orientation, neither rotating nor deforming, so it's almost never used.<br />
<br />
===Tangent-space normal map===<br />
[[image:normalmap_tangentspace.jpg|frame|none|A tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Predominantly-blue colors. Object can rotate and deform. Good for deforming meshes, like characters, animals, flags, etc.<br />
<br />
Pros:<br />
* Maps can be reused easily, like on differently-shaped meshes.<br />
* Maps can be tiled and mirrored easily, though some games might not support mirroring very well.<br />
* Easier to overlay painted details.<br />
* Easier to use image compression.<br />
<br />
Cons:<br />
* More difficult to avoid smoothing problems from the low-poly vertex normals (see Smoothing Groups and Hard Edges).<br />
* Slightly slower performance than an object-space map (but not by much).<br />
<br />
===Object-space normal map===<br />
[[image:normalmap_worldspace.jpg|frame|none|An object-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Rainbow colors. Objects can rotate, but usually shouldn't be deformed, unless the shader has been modified to support deformation. Object-space is also called local-space or model-space. <br />
<br />
Pros:<br />
* Easier to generate high-quality curvature because it completely ignores the crude smoothing of the low-poly vertex normals.<br />
* Slightly better performance than a tangent-space map (but not by much).<br />
<br />
Cons:<br />
* Can't easily reuse maps, different mesh shapes require unique maps.<br />
* Difficult to tile properly, and mirroring requires specific shader support.<br />
* Harder to overlay painted details because the base colors vary across the surface of the mesh. Painted details must be converted into Object Space to be combined properly with the OS map.<br />
* They don't compress very well, since the blue channel can't be recreated in the shader like with tangent-space maps. Also the three color channels contain very different data which doesn't compress well, creating many artifacts. Using a half-resolution object-space map is one option. <br />
<br />
<br clear="all"/><br />
<br />
=== Converting Between Spaces ===<br />
Normal maps can be converted between object space and tangent space, in order to use them with different blending tools and shaders, which require one type or the other. <br />
<br />
Object space maps can also be converted to maps with different tangent bases, to better match the normal maps with the renderer and thus avoid lighting errors.<br />
<br />
* [http://www.handplane3d.com Handplane] by [http://www.alecmoody.com/ Alec Moody] is a tool that converts object space maps into a variety of tangent spaces: 3ds Max, Creation Engine, Maya, Source, Unity, Unreal, etc. See the Polycount Forum thread [http://www.polycount.com/forum/showthread.php?t=116899 Official handplane support thread - Now freeware!!].<br />
<br />
[[File:handplane_illus_1.jpg|frame|none|Handplane interface. <br>Image by [http://www.alecmoody.com/ Alec Moody].]]<br />
<br />
<br />
* [http://boards.polycount.net/showthread.php?p=1072599#post1072599 NSpace] by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] is a tool that converts an object-space normal map into a tangent-space map, which then works seamlessly in the 3ds Max viewport. He converts the map by using the same tangent basis that 3ds Max uses for its hardware shader. To see the results, load the converted map via the ''Normal Bump'' map and enable "Show Hardware Map in Viewport". [http://gameartist.nl/ Osman "osman" Tsjardiwal] created a GUI for NSpace, you can [http://boards.polycount.net/showthread.php?p=1075143#post1075143 download it here], just put it in the same folder as the NSpace exe and run it. <br />
<br />
[[File:NSpace_Gui_osman.png|frame|none|NSpace interface. <br>Image by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] and [http://gameartist.nl Osman "osman" Tsjardiwal].]]<br />
<br />
[http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson] said: "[8Monkey Labs has] a tool that lets you load up your reference mesh and object space map. Then load up your tangent normals, and adjust some sliders for things like tile and amount. We need to load up a mesh to know how to correctly orient the tangent normals or else things will come out upside down or reverse etc. It mostly works, but it tends to "bend" the resulting normals, so you gotta split the mesh up into some smoothing groups before you run it, and then I usually will just composite this "combo" texture over my orig map in Photoshop."<br />
<br />
<span id="RGBC"></span><span id="RGBChannels"></span><br />
<br />
== RGB Channels ==<br />
Shaders can use different techniques to render tangent-space normal maps, but the normal map directions are usually consistent within a game. Usually the red channel of a tangent-space normal map stores the X axis (pointing the normals predominantly leftwards or rightwards), the green channel stores the Y axis (pointing the normals predominantly upwards or downwards), and the blue channel stores the Z axis (pointing the normals outwards away from the surface).<br />
<br />
[[image:tangentspace_rgb.jpg|frame|none|The red, green, and blue channels of a tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you see lighting coming from the wrong angle when you're looking at your normal-mapped model, and the model is using a tangent-space normal map, the normal map shader might be expecting the red or green channel (or both) to point in the opposite direction. To fix this either change the shader, or simply invert the appropriate color channels in an image editor, so that the black pixels become white and the white pixels become black.<br />
<br />
Some shaders expect the color channels to be swapped or re-arranged to work with a particular [[#NormalMapCompression|compression format]]. For example the DXT5_nm format usually expects the X axis to be in the alpha channel, the Y axis to be in the green channel, and the red and blue channels to be empty.<br />
<br />
== Tangent Basis ==<br />
[[#TangentSpaceVsObjectSpace|Tangent-space]] normal maps use a special kind of vertex data called the ''tangent basis''. This is similar to UV coordinates except it provides directionality across the surface, it forms a surface-relative coordinate system for the per-pixel normals stored in the normal map. This coordinate system is required to light a normal mapped surface.<br />
<br />
Each vertex in the tangent basis is a combination of three things: the mesh vertex's normal (influenced by smoothing), the vertex's tangent (usually derived from the V texture coordinate), and the vertex's bitangent (derived in code, also called the binormal). These three vectors create an axis for each vertex, giving it a specific orientation in the tangent space. These axes are used to properly transform the incoming lighting from world space into tangent space, so your normal-mapped model will be lit correctly.<br />
<br />
Light rays are in world space, but the normals stored in the normal map are in tangent space. When the model is being rendered, the light rays must be converted from world space into tangent space, using the tangent basis to get there. At that point the incoming light rays are compared against the directions of the normals in the normal map, and this determines how much each pixel is going to be lit. Alternatively, instead of converting the light rays some shaders will convert the normals in the normal map from tangent space into world space. Then those world-space normals are compared against the light rays, and the model is lit appropriately. The method depends on who wrote the shader, but the end result is the same. Both methods require a tangent basis to transform the lighting.<br />
<br />
When a triangle's vertex normals are pointing straight out, and a pixel in the normal map is neutral blue (128,128,255) this means the pixel's normal will be pointing straight out from the surface of the low-poly mesh. When that pixel normal is tilted towards the left or the right in the tangent coordinate space, it will get either more or less red color, depending on whether the normal map is set to store the X axis as either a positive or a negative value. Same goes for when the normal is tilted up or down in tangent space, it will either get more or less green color. If the vertex normals aren't exactly perpendicular to the triangle, the normal map pixels will be tinted away from neutral blue as well.<br />
<br />
Unfortunately for artists, there are many different ways to calculate the tangent basis: [http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping 3ds Max], [http://download.autodesk.com/us/maya/2011help/index.html?url=./files/Appendix_A_Tangent_and_binormal_vectors.htm,topicNumber=d0e227193 Maya], [http://www.codesampler.com/dx9src/dx9src_4.htm#dx9_dot3_bump_mapping DirectX 9], [http://developer.nvidia.com/object/NVMeshMender.html NVMeshMender], [http://www.terathon.com/code/tangent.html Eric Lengyel], a custom solution, etc. This means a normal map baked in one application probably won't shade correctly in another. Artists must do some testing with different [[#T|baking tools]] to find which works best with their output. When the renderer (or game engine) renders your game model, [[#ShadersAndSeams|the shader]] must use the same tangent basis as the normal map baker, otherwise you'll get incorrect lighting, especially across the seams between UV shells.<br />
<br />
The [http://www.xnormal.net/ xNormal] SDK supports custom tangent basis methods. When a programmer uses it to implement their renderer's own tangent basis, artists can then use Xnormal to bake normal maps that will match their renderer perfectly.<br />
<br />
[[image:tangentseams.jpg|frame|none|When shared edges are at different angles in UV space, different colors will show up<br />
along the seam. The tangent basis uses these colors to light the model properly. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
When you look at a tangent-space normal map for a character, you typically see different colors along the UV seams. This is because the UV shells are often oriented at different angles on the mesh, a necessary evil when translating the 3D mesh into 2D textures. The body might be mapped with a vertical shell, and the arm mapped with a horizontal one. This requires the normals in the normal map to be twisted for the different orientations of those UV shells. The UVs are twisted, so the normals must be twisted in order to compensate. The tangent basis helps reorient (twist) the lighting as it comes into the surface's local space, so the lighting will then look uniform across the normal mapped mesh.<br />
<br />
When an artist tiles a tangent-space normal map across an arbitrary mesh, like a landscape, this tends to shade correctly because the mesh has a uniform direction in tangent space. If the mesh has discontinuous UV coordinates (UV seams), or the normal map has large directional gradients across it, the tangent space won't be uniform anymore so the surface will probably have shading seams.<br />
<br />
== Common Swizzle Coordinates ==<br />
3D Software capable of displaying normal maps will have a native required direction, or "handedness" for the RGB channels in a normal map, sometimes referred to as "Swizzle Coordinates," though [[#SAS|shaders]] can often be written to override this native handedness. You may hear developers refer to "flipping the green channel," and this simply indicates that when the normal map was baked, it was authored with the incorrect handedness in the green channel.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
| '''Software''' <br />
| '''Red''' <br />
| '''Green''' <br />
| '''Blue''' <br />
|-<br />
|<#000000>| Maya<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| 3ds Max<br />
| X+<br />
| Y-<br />
| Z+ <br />
|-<br />
|<#000000>| Unreal Engine<br />
| X+ <br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Unity<br />
| X+<br />
| Y+<br />
| Z+<br />
|-<br />
|<#000000>| Toolbag<br />
| X+<br />
| Y+ <br />
| Z+<br />
|}<br />
<span id="MTLPM"></span><br />
<br />
== Modeling the Low-Poly Mesh ==<br />
The in-game mesh usually needs to be carefully optimized to create a good silhouette, define edge-loops for better deformation, and minimize extreme changes between the vertex normals for better shading (see [[#SmoothingGroupsAndHardEdges|Smoothing Groups & Hard Edges]]).<br />
<br />
In order to create an optimized in-game mesh including a good silhouette and loops for deforming in animation, you can start with the 2nd subdivision level of your [[DigitalSculpting|digital sculpt]], or in some cases with the base mesh itself. Then you can just collapse edge loops or cut in new edges to add/remove detail as necessary. Or you can [[DigitalSculpting#OART|re-toplogize]] from scratch if that works better for you.<br />
<br />
See [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts] on the Polycount forum.<br />
<br />
<span id="UVC"></span><span id="UVCoordinates"></span><br />
=== UV Coordinates ===<br />
Normal map baking tools only capture normals within the 0-1 UV square, any UV bits outside this area are ignored. <br />
<br />
Only one copy of the forward-facing UVs should remain in the 0-1 UV square at baking time. If the mesh uses overlapping UVs, this will likely cause artifacts to appear in the baked map, since the baker will try render each UV shell into the map. Before baking, it's best to move all the overlaps and mirrored bits outside the 0-1 square. <br />
<br />
[[image:Normalmap_uvcoord_offset.jpg|frame|none|The mirrored UVs (in red) are offset 1 unit before baking. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you move all the overlaps and mirrored bits exactly 1 UV unit (any whole number will do), then you can leave them there after the bake and they will still be mapped correctly. You can move them back if you want, it doesn't matter to most game engines. Be aware that ZBrush does use UV offsets to manage mesh visibility, however this usually doesn't matter because the ZBrush cage mesh is often a different mesh than the in-game mesh used for baking.<br />
<br />
You should avoid changing the UVs after baking the normal map, because rotating or mirroring UVs after baking will cause the normal map not to match the [[#TB|tangent basis]] anymore, which will likely cause lighting problems. <br />
<br />
In 3ds Max, W is a third texture coordinate. It's used for 3D procedural textures and for storing vertex color in UV channels (you need 3 axes for RGB, so UVW can store vertex color). Bake problems can be avoided by moving any overlapping UVs to -1 on the W axis, with the same results as moving them 1 unit on the U or V axes. The tool Render To Texture will always bake whatever UVs are the highest along the W axis. However using W can be messy... it's generally hidden unless you purposefully look for it (bad for team work), doesn't get preserved on export to other apps, and high W values can prevent selecting and/or welding UVs. <br />
<br />
<span id="M"></span><span id="Mirroring"></span><br />
<br />
=== Mirroring ===<br />
Normal maps can be mirrored across a model to create symmetrical details, and save UV space, which allows more detail in the normal map since the texture pixels are smaller on the model. <br />
<br />
With [[#OSNM|object-space]] maps, mirroring requires [http://boards.polycount.net/showthread.php?t=53986 specific shader support]. For [[#TSNM|tangent-space]] maps, mirroring typically creates a shading seam, but this can be reduced or hidden altogether, depending on the method used.<br />
<br />
<span id="TMW"></span><br />
==== Typical Mirroring Workflow ====<br />
# Delete the mesh half that will be mirrored. <br />
# Arrange the UVs for the remaining model, filling the UV square.<br />
# Mirror the model to create a "whole" mesh, welding the mesh vertices along the seam. <br />
# Move the mirrored UVs exactly 1 unit (or any whole number) out of the 0-1 UV square.<br />
# Bake the normal map.<br />
<br />
Sometimes an artist will decide to delete half of a symmetrical model before baking. <br />
<br />
This is a mistake however because often the vertex normals along the hole will bend towards the hole a bit; there are no faces on the other side to average the normals with. This will create a strong lighting seam in the normal map. <br />
<br />
It's typically best to use the complete mirrored model to bake the normal map, not just the unique half. <br />
<br />
To prevent the mirrored UVs from causing overlaps or baking errors, move the mirrored [[#UVC|UVs]] out of the 0-1 UV space, so only one copy of the non-mirrored UVs is left within the 0-1 square.<br />
<br />
To avoid texel "leaks" between the UV shells, make sure there's enough [[#Edge_padding|Edge Padding]] around each shell, including along the edges of the normal map. None of the UV shells should be touching the edge of the 0-1 UV square, unless they're meant to tile with the other side of the map.<br />
<br />
<span id="CM"></span><br />
<br />
==== Center Mirroring ====<br />
If the mirror seam runs along the surface of a continuous mesh, like down the center of a human face for example, then it will probably create a lighting seam. <br />
<br />
In Epic Games' [http://www.unrealtechnology.com/technology.php Unreal Engine 3] (UE3) their symmetrical models commonly use centered mirroring. Epic uses materials that mix a [[DetailMap]] with the normal maps; these seem to scatter the diffuse/specular lighting and help minimize the obviousness of the mirror seams. For their [[Light Map]]ped models they use [http://udn.epicgames.com/Three/LightMapUnwrapping.html a technique] that can almost completely hide the mirror seam.<br />
<br />
[[image:Epic_MirroringCicada.jpg|frame|none| In UE3 a center mirror seam is reduced by using a detail normal map. <br> Image by "[http://epicgames.com Epic Games]"]]<br />
<br />
'''''[http://www.zbrushcentral.com/showpost.php?p=573108&postcount=28 GOW2 normal map seams], [http://utforums.epicgames.com/showthread.php?p=27166791#post27166791 UDK normal map seams]'''''<br />
<br />
<span id="OM"></span><br />
<br />
==== Offset Mirroring ====<br />
Offset mirroring is a method where you move the mirror seam off to one side of the model, so the seam doesn't run exactly down the center. For example with a character's head, the UV seam can go down along the side of the head in front of the ear. The UV shell for the nearest ear can then be mirrored to use the area on the other side of the head. <br />
<br />
This avoids the "Rorschach" effect and allows non-symmetrical details, but it still saves texture space because the two sides of the head can be mirrored (they're never seen at the same time anyhow).<br />
<br />
Offset mirroring doesn't get rid of the seam, but it does move it off to a place where it can either be less obvious, or where it can be hidden in a natural seam on the model.<br />
<br />
<span id="FCM"></span><br />
==== Flat Color Mirroring ====<br />
[http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] solves seams by painting a flat set of normals along the seam, using neutral blue (128,128,255). However it only works along horizontal or vertical UV seams, not across any angled UVs. It also removes any details along the mirror seam, creating blank areas. <br />
<br />
<span id="EM"></span><br />
==== Element Mirroring ====<br />
The mirror seam can be avoided completely when it doesn't run directly through any mesh. For example if there's a detached mesh element that runs down the center of the model, this can be uniquely mapped, while the meshes on either side can be mirrors of each other. Whenever the mirrored parts don't share any vertex normals with the non-mirrored parts, there won't be any seams. <br />
<br />
[[image:normalmap_mirrored-binocs-racer445.jpg|frame|none|The middle part (highlighted in red) uses unique non-mirrored UVs, allowing the mesh on the right to be mirrored without any seams. <br>Image by [http://http://racer445.com/ "racer445"]]]<br />
<br />
<span id="SGAHE"></span><br />
<br />
=== Smoothing Groups & Hard Edges ===<br />
Each vertex in a mesh has at least one vertex normal. Vertex normals are used to control the direction a triangle will be lit from; if the normal is facing the light the triangle will be fully lit, if facing away from the light the triangle won't be lit. <br />
<br />
Each vertex however can have more than one vertex normal. When two triangles have different vertex normals along their shared edge, this creates a shading seam, called a ''hard edge'' in most modeling tools. 3ds Max uses ''Smoothing Groups'' to create hard/soft edges, Maya uses ''Harden Edge'' and ''Soften Edge''. These tools create hard and soft edges by splitting and combining the vertex normals.<br />
<br />
[[image:BenMathis_SmoothingGroups_Excerpt.gif|frame|none|Hard edges occur where the vertices have multiple normals. <br>Image by [http://poopinmymouth.com Ben 'poopinmymouth' Mathis] ([http://poopinmymouth.com/process/tips/smoothing_groups.jpg tutorial here])]]<br />
<br />
When a mesh uses all soft normals (a single smoothing group) the lighting has to be interpolated across the extreme differences between the vertex normals. If your renderer doesn't support the same [[#TangentBasis|tangent basis]] that the baker uses, this can produce extreme shading differences across the model, which creates shading artifacts. It is generally best to reduce these extremes when you can because a mismatched renderer can only do so much to counteract it.<br />
<br />
Hard edges are usually best where the model already has a natural seam. For example, you can add a hard edge along the rim of a car's wheel well, to prevent the inside of the wheel well from distorting the shading for the outside of the car body. Mechanical models usually need hard edges where ever the surface bends more than about 45 degrees. <br />
<br />
For most meshes, the best results usually come from adding hard edges where ever there are UV seams. There are no hard rules however, you must experiment with different approaches to find what works best in your game.<br />
<br />
When you use object-space normal maps the vertex normal problem goes away since you're no longer relying on the crude vertex normals of the mesh. An object-space normal map completely ignores vertex normals. Object-space mapping allows you to use all soft edges and no bevels on the low-res mesh, without showing lighting errors.<br />
<br />
<span id="HEDAT"></span><br />
==== Hard Edge Discussions & Tutorials ====<br />
* [http://www.polycount.com/forum/showthread.php?p=2090450#post2090450 Maya MEL Script help needed (UV border edges)]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=73593 Normal Maps: Can Somone Explain This "Black Edge" issue]<br />
* [http://www.polycount.com/forum/showthread.php?t=73566 Normal Maps: Can someone explain normals, tangents and split UVs?]<br />
* [http://www.polycount.com/forum/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max]<br />
* [http://boards.polycount.net/showthread.php?t=68173 Why you should NOT trust 3ds Max's viewport normal-map display!]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/10503-xsi-normal-mapped-cube-looks-bad.html XSI - normal mapped cube looks bad]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/11924-weird-maya-normal-map-seam-artifact-problem-am-i-making-simple-mistake.html Weird Maya normal map seam/artifact problem]<br />
* [http://boards.polycount.net/showthread.php?p=1080600 Seams in Normals when Creating Tiling Environment Trims and other Tiles]<br />
* The tutorial [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing can affect the normal map.<br />
* The tutorial: [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] shows how smoothing affects raycasting.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses the breaking of normals and smoothing groups in general terms.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in the game, not the triangle count.<br />
* The Crysis documentation [http://doc.crymod.com/AssetCreation/PolyBumpReference.html PolyBump Reference] has a section towards the bottom that shows how smoothing affects their baked normal maps.<br />
* The polycount thread [http://boards.polycount.net/showthread.php?t=60694 Toying around with normal map approaches] has a great discussion of how best to use smoothing groups and bevels for better shading.<br />
<br />
<span id="UB"></span><br />
==== Using Bevels ====<br />
Bevels/chamfers generally improve the silhouette of the model, and can also help reflect specular highlights better. <br />
<br />
However bevels tend to produce long thin triangles, which slow down the in-game rendering of your model. Real-time renderers have trouble rendering long thin triangles because they create a lot of sub-pixel areas to render. <br />
<br />
Bevels also balloon the vertex count, which can increase the transform cost and memory usage. Hard edges increase the vertex count too, but not when the edge also shares a seam in UV space. For a good explanation of the vertex count issue, see [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly].<br />
<br />
Using hard edges with matching UV shells tends to give better performance and better cosmetic results than using bevels. However there are differing opinions on this, see the Polycount thread "[http://boards.polycount.net/showthread.php?t=71760 Maya transfer maps help]".<br />
<br />
<span id="EVN"></span><br />
==== Edited Vertex Normals ====<br />
If you use bevels the shading will be improved by editing the vertex normals so the larger flat surfaces have perpendicular normals. The vertex normals are then forced to blend across the smaller bevel faces, instead of across the larger faces. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66139 Superspecular soft edges tutorial chapter 1].<br />
<br />
[[image:oliverio_bevel_normals.gif|frame|none|Bending normals on bevelled models. <br>From the tutorial [http://deadlineproof.com/model-shading-techniques-soft-edge-superspecular/ Shading techniques Superspecular soft edges]<br>Image by [http://deadlineproof.com/ Paolo Oliverio]]]<br />
<br />
== Level of Detail Models ==<br />
See [http://www.polycount.com/forum/showthread.php?p=1216945#post1216945 Problem if you're using 3point-style normals with an LOD].<br />
<br />
<span id="MTHPM"></span><br />
<br />
== Modeling The High-Poly Mesh ==<br />
[[Subdivision Surface Modeling]] and [[DigitalSculpting]] are the techniques most often used for modeling a normal map. <br />
<br />
Some artists prefer to model the in-game mesh first, other artists prefer to model the high-res mesh first, and others start somewhere in the middle. The modeling order is ultimately a personal choice though, all three methods can produce excellent results:<br />
* Build the in-game model, then up-res it and sculpt it.<br />
* Build and sculpt a high resolution model, then build a new in-game model around that.<br />
* Build a basemesh model, up-res and sculpt it, then step down a few levels of detail and use that as a base for building a better in-game mesh.<br />
If the in-game mesh is started from one of the subdivision levels of the basemesh sculpt, various edge loops can be collapsed or new edges can be cut to add/remove detail as necessary.<br />
<br />
<span id="SE"></span><br />
=== Sloped Extrusions ===<br />
[[image:normal_slopes_hatred.jpg|frame|none|Extrusions on the high-poly model should be sloped to make a better normal map. <br>Image by [http://www.hatred.gameartisans.org/ Krzysztof "Hatred" Dolas].]]<br />
<br />
=== Floating Geometry ===<br />
[[image:FloatingGeo.jpg|frame|none|Normal map stores the direction the surface is facing rather than real depth information, thus allowing to save time using floating geometry. <br>To correctly bake AO with floating geo make it a separate object and turn off it's shadow casting. <br>Image by [http://artisaverb.info/ Andrew "d1ver" Maximov].]]<br />
<br />
See also [[3DTutorials/Modeling High-Low Poly Models for Next Gen Games|Modeling High/Low Poly Models for Next Gen Games]] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa]<br />
<br />
<span id="ET"></span><br />
<br />
=== Edge Thickness ===<br />
[[image:normal_edge_thickness.jpg|frame|none|When creating edges of the Highpoly, sometimes you'll need to make them rounded than in real life to <br>work better at the size they will be seen.<br>Image by [http://racer445.com/Evan "racer445" Herbert]]]<br />
<br />
<span id="MRF"></span><span id="MRRCB"></span><br />
<br />
=== mental ray Round Corners Bump ===<br />
The mental ray renderer offers an automatic bevel rendering effect called Round Corners Bump that can be baked into a normal map. This is available in 3ds Max, Maya, and XSI. See [http://boards.polycount.net/showthread.php?t=71995 Zero Effort Beveling for normal maps] - by [http://boards.polycount.net/member.php?u=31662 Robert "r_fletch_r" Fletcher].<br />
<br />
[http://jeffpatton.net/ Jeff Patton] posted about [http://jeffpatton.cgsociety.org/blog/archive/2007/10/ how to expose Round Corners Bump] in 3ds Max so you can use it in other materials.<br />
<br />
[http://cryrid.com/art/ Michael "cryrid" Taylor] posted a tutorial about how to use [http://cryrid.com/images/temp/XSI/zeroeffort_bevels.jpg Round Corners in XSI].<br />
<br />
XSI is able to bake a good normal map with it, but 3ds Max seems to bake it incorrectly, and Maya isn't able to bake the effect at all. Maybe Max might be able to bake it correctly, if the .mi shader is edited to use the correct coordinate space?<br />
<br />
<span id="Baking"></span><span id="B"></span><br />
== Baking ==<br />
The process of transferring normals from the high-res model to the in-game model is often called baking. The baking tool usually starts projecting a certain numerical distance out from the low-poly mesh, and sends rays inwards towards the high-poly mesh. When a ray intersects the high-poly mesh, it records the mesh's surface normal and saves it in the normal map.<br />
<br />
To get an understanding of how all the options affect your normal map, do some test bakes on simple meshes like boxes. They generate quickly so you can experiment with [[#UVCoordinates|UV mirroring]], [[#SGAHE|smoothing groups]], etc. This helps you learn the settings that really matter.<br />
* The tutorial [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] has more examples of ray-casting, plus how to get better results from the bake.<br />
<br />
Baking sub-sections:<br />
# [[#Anti-Aliasing|Anti-Aliasing]]<br />
# [[#Baking_Transparency|Baking Transparency]]<br />
# [[#Edge_Padding|Edge Padding]]<br />
# [[#High_Poly_Materials|High Poly Materials]]<br />
# [[#Reset_Transforms|Reset Transforms]]<br />
# [[#Solving_Intersections|Solving Intersections]]<br />
# [[#Solving_Pixel_Artifacts|Solving Pixel Artifacts]]<br />
# [[#Solving_Wavy_Lines|Solving Wavy Lines]]<br />
# [[#Triangulating|Triangulating]]<br />
# [[#Working_with_Cages|Working with Cages]]<br />
<br />
<span id="AA"></span><br />
=== Anti-Aliasing ===<br />
Turning on super-sampling or anti-aliasing (or whatever multi-ray casting is called in your normal map baking tool) will help to fix any jagged edges where the high-res model overlaps itself within the UV borders of the low-poly mesh, or wherever the background shows through holes in the mesh. Unfortunately this tends to render much much slower, and takes more memory.<br />
<br />
[[image:normalmap_aliasing_knak47.jpg|frame|none|A bake without anti-aliasing shows artifacts where the high-poly mesh has overlaps. <br>Image by [http://www.polycount.com/forum/member.php?u=35938 'knak47']]]<br />
<br />
One trick to speed this up is to render 2x the intended image size then scale the normal map down 1/2 in a paint program like Photoshop. The reduction's pixel resampling will add anti-aliasing for you in a very quick process. After scaling, make sure to re-normalize the map if your game doesn't do that already, because the un-normalized pixels in your normalmap may cause pixelly artifacts in your specular highlights. Re-normalizing can be done with [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA's normal map filter] for Photoshop.<br />
<br />
3ds Max's supersampling doesn't work nicely with edge padding, it produces dark streaks in the padded pixels. If so then turn off padding and re-do the padding later, either by re-baking without supersampling or by using a Photoshop filter like the one that comes with [[#3DTools|Xnormal]].<br />
<br />
=== Baking Transparency ===<br />
Sometimes you need to bake a normal map from an object that uses opacity maps, like a branch with opacity-mapped leaves. Unfortunately baking apps often completely ignore any transparency mapping on your high-poly mesh.<br />
<br />
{|class="wikitable"<br />
|[[image:JoeWilson_ivynormals_error.jpg]] <br />
|[[image:JoeWilson_ivynormals_rendered.jpg]]<br />
|-<br />
|3ds Max's RTT baker causes transparency errors.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|The lighting method bakes perfect transparency.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|}<br />
<br />
To solve this, render a Top view of the mesh. This only works if you're using a planar UV projection for your low-poly mesh and you're baking a tangent-space normal map.<br />
<br />
* Make sure the Top view matches the dimensions of the planar UV projection used by the low-poly mesh. It helps to use an orthographic camera for precise placement.<br />
* On the high-poly mesh either use a specific lighting setup or a use special material shader:<br />
* 1) The lighting setup is described in these tutorials:<br />
* * [http://www.bencloward.com/tutorials_normal_maps11.shtml Creating A Normal Map Right In Your 3D App] by [http://www.bencloward.com/ Ben Cloward]<br />
* *[http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy], Graphics Techniques Consultant, Xbox Content and Design Team<br />
* 2) The material shader does the same thing, but doesn't require lights.<br />
* * [http://www.scriptspot.com/3ds-max/normaltexmap NormalTexMap] scripted map for 3ds Max by [http://www.scriptspot.com/users/dave-locke Dave Locke].<br />
* * [http://www.footools.com/3dsmax_plugins.html InfoTexture] map plugin for 3ds Max by [http://www.footools.com John Burnett]<br />
<br />
[[image:BenCloward_NormalMapLighting.gif|frame|none|The lighting setup for top-down rendering. <br>Image by [http://www.bencloward.com Ben Cloward]]]<br />
<br />
<span id="EP"></span><br />
<br />
=== Edge Padding ===<br />
If a normal map doesn't have enough [[Edge_padding |Edge Padding]], this will create shading seams on the UV borders.<br />
<br />
=== High Poly Materials ===<br />
3ds Max will not bake a normal map properly if the high-res model has a mental ray Arch & Design material applied. If your normal map comes out mostly blank, either use a Standard material or none at all. For an example see the Polycount thread [http://www.polycount.com/forum/showthread.php?t=74792 Render to Texture >:O].<br />
<br />
<span id="RT"></span><br />
=== Reset Transforms ===<br />
Before baking, make sure your low-poly model's transforms have been reset. '''''This is very important!''''' Often during the modeling process a model will be rotated and scaled, but these compounded transforms can create a messy local "space" for the model, which in turn often creates rendering errors for normal maps. <br />
<br />
In 3ds Max, use the Reset Xforms utility then Collapse the Modifier Stack. In Maya use Freeze Transformation. In XSI use the Freeze button.<br />
<br />
<span id="SI"></span><br />
<br />
=== Solving Intersections ===<br />
The projection process often causes problems like misses, or overlaps, or intersections. It can be difficult generating a clean normal map in areas where the high-poly mesh intersects or nearly intersects itself, like in between the fingers of a hand. Setting the ray distance too large will make the baker pick the other finger as the source normal, while setting the ray distance too small will lead to problems at other places on the mesh where the distances between in-game mesh and high-poly mesh are greater.<br />
<br />
Fortunately there are several methods for solving these problems.<br />
<br />
# Change the shape of the cage. Manually edit points on the projection cage to help solve tight bits like the gaps between fingers.<br />
# Limit the projection to matching materials, or matching UVs.<br />
# Explode the meshes. See the polycount thread [http://boards.polycount.net/showthread.php?t=62921 Explode script needed (for baking purposes)].<br />
# Bake two or more times using different cage sizes, and combine them in Photoshop.<br />
<br />
<span id="SPA"></span><br />
<br />
=== Solving Pixel Artifacts ===<br />
[[image:filterMaps_artifact.jpg|frame|none|Random pixel artifacts in the bake. <br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
If you are using 3ds Max's ''Render To Texture'' to bake from one UV layout to another, you may see stray pixels scattered across the bake. This only happens if you are using a copy of the original mesh in the Projection, and that mesh is using a different UV channel than the original mesh.<br />
<br />
There are two solutions for this:<br />
<br />
* Add a Push modifier to the copied mesh, and set it to a low value like 0.01.<br />
- or -<br />
<br />
* Turn off ''Filter Maps'' in the render settings (Rendering menu > Render Setup > Renderer tab > uncheck Filter Maps). To prevent aliasing you may want to enable the Global Supersampler in Render Setup.<br />
<br />
See also [[#Anti-Aliasing]].<br />
<br />
<span id="SWL"></span><br />
<br />
=== Solving Wavy Lines ===<br />
When capturing from a cylindrical shape, often the differences between the low-poly mesh and the high-poly mesh will create a wavy edge in the normal map. There are a couple ways to avoid this:<br />
<br />
# The best way... create your lowpoly model with better supporting edges. See the Polycount threads [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?], [http://boards.polycount.net/showthread.php?t=55754 approach to techy stuff], [http://www.polycount.com/forum/showthread.php?t=72713 Any tips for normal mapping curved surface?].<br />
# Adjust the shape of the cage to influence the directions the rays will be cast. Beware... this work will have to be re-done every time you edit the lowpoly mesh, as the cage will be invalidated. At the bottom of [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm this page of his normal map tutorial], [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to do this in 3ds Max. Same method can be seen in the image below.<br />
# Subdivide the low-res mesh so it more closely matches the high-res mesh. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] has a [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa video tutorial] that shows how to do this in Maya.<br />
# Paint out the wavy line. Beware... this work will have to be re-done every time you re-bake the normal map. The [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
# Use a separate planar-projected mesh for the details that wrap around the barrel area, so the ray-casting is more even. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. For example to add tread around a tire, the tread can be baked from a tread model that is laid out flat, then that bake can layered onto the bake from the cylindrical tire mesh in a paint program.<br />
<br />
[[image:timothy_evison_normalmap_projections.jpg|frame|none|Adjusting the shape of the cage to remove distortion. <br>Image by [http://users.cybercity.dk/~dsl11905/resume/resume.html Timothy "tpe" Evison]]]<br />
<br />
<span id="TRI"></span><br />
<br />
=== Triangulating ===<br />
Before baking, it is usually best to triangulate the low-poly model, converting it from polygons into pure triangles. This prevents the vertex normals from being changed later on, which can create specular artifacts.<br />
<br />
[[image:triangulation_modo_ohare.jpg|frame|none| When quads are triangulated in [http://www.luxology.com/modo/ Modo], the internal edges are sometimes flipped, which causes shading differences.<br>Image by [http://www.farfarer.com/|James "Talon" O'Hare]]]<br />
<br />
<br />
Sometimes a baking tool or a mesh exporter/importer will re-triangulate the polygons. A quad polygon is actually treated as two triangles, and the internal edge between them is often switched diagonally during modeling operations. When the vertices of the quad are moved around in certain shapes, the software's algorithm for polygon models tries to keep the quad surface in a "rational" non-overlapping shape. It does this by switching the internal edge between its triangles.<br />
<br />
<br />
[[image:triangulation_spec_tychovii.jpg|frame|none| The specular highlight is affected by triangulation. Flip edges to fix skewing. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66651 Skewed Specular Highlight?] for pictures and more info.<br> Image by [http://robertkreps.com Robert "TychoVII" Kreps]]]<br />
<br />
<br />
<span id="WWC"></span><br />
<br />
=== Working with Cages ===<br />
''Cage'' has two meanings in the normal-mapping process: a low-poly base for [[subdivision surface modeling]] (usually called the [[DigitalSculpting#BM|basemesh]]), or a ray-casting mesh used for normal map baking. This section covers the ray-casting cage.<br />
<br />
Most normal map baking tools allow you to use a distance-based raycast. A ray is sent outwards along each vertex normal, then at the distance you set a ray is cast back inwards. Where ever that ray intersects the high poly mesh, it will sample the normals from it. <br />
<br />
{|class="wikitable"<br />
|[[Image:Normalmap_raycasting_1.jpg]] <br />
|[[Image:Normalmap_raycasting_2.jpg]]<br />
|-<br />
|Hard edges and a distance-based raycast (gray areas) cause ray misses (yellow) and ray overlaps (cyan).<br> Image by [http://www.mankua.com/ Diego Castaño]<br />
|The gray area shows that using all soft edges (or hard edges and a cage-based raycast) will avoid ray-casting errors from split normals.<br> Image by [http://www.mankua.com/ Diego Castaño] <br />
|}<br />
<br />
Unfortunately with a distance-based raycast, [[#SGAHE|split vertex normals]] will cause the bake to miss parts of the high-res mesh, causing errors and seams. <br />
<br />
Some software allows you to use ''cage mesh'' option instead, which basically inflates a copy of the low-poly mesh, then raycasts inwards from each vertex. This ballooned-out mesh is the cage.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
|<tablebgcolor="#ffaaaa">| <br />
|}<br />
<br />
In 3ds Max the cage controls both the distance and the direction of the raycasting. <br />
<br />
In Maya the cage only controls the distance; the ray direction matches the vertex normals (inverted).<br />
<br />
<span style="text-decoration: line-through"> This may have been fixed in the latest release...<<BR>><br />
In Xnormal the cage is split everywhere the model has [[#SGAHE|hard edges]], causing ray misses in the bake. You can fix the hard edge split problem but it involves an overly complex workflow. You must also repeat the whole process any time you change your mesh:</span><br />
# <s> Load the 3d viewer.</s><br />
# <s> Turn on the cage editing tools.</s><br />
# <s> Select all of the vertices.</s><br />
# <s> Weld all vertices.</s><br />
# <s> Expand the cage as you normally would.</s><br />
# <s> Save out your mesh using the Xnormal format.</s><br />
# <s> Make sure Xnormal is loading the correct mesh.</s><br />
<br />
<span id="P"></span><span id="Painting"></span><br />
<br />
== Painting ==<br />
Don't be afraid to edit normal maps in Photoshop. After all it is just a texture, so you can clone, blur, copy, blend all you want... as long as it looks good of course. Some understanding of [[#RGBChannels|the way colors work]] in normal maps will go a long way in helping you paint effectively.<br />
<br />
A normal map sampled from a high-poly mesh will nearly always be better than one sampled from a texture, since you're actually grabbing "proper" normals from an accurate, highly detailed surface. That means your normal map's pixels will basically be recreating the surface angles of your high-poly mesh, resulting in a very believable look.<br />
<br />
If you only convert an image into a normal-map, it can look very flat, and in some cases it can be completely wrong unless you're very careful about your value ranges. Most image conversion tools assume the input is a heightmap, where black is low and white is high. If you try to convert a diffuse texture that you've painted, the results are often very poor. Often the best results are obtained by baking the large and mid-level details from a high-poly mesh, and then combined with photo-sourced "fine detail" normals for surface details such as fabric weave, scratches and grain.<br />
<br />
Sometimes creating a high poly surface takes more time than your budget allows. For character or significant environment assets then that is the best route, but for less significant environment surfaces working from a heightmap-based texture will provide a good enough result for a much less commitment in time.<br />
<br />
* [http://crazybump.com/ CrazyBump] is a commercial normal map converter.<br />
* [http://www.renderingsystems.com/support/showthread.php?tid=3 ShaderMap] is a commercial normal map converter.<br />
* [http://www.pixplant.com/ PixPlant] is a commercial normal map converter.<br />
* [http://boards.polycount.net/showthread.php?t=68860 NJob] is a free normal map converter.<br />
* [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA normalmap filter for Photoshop] is a free normal map converter.<br />
* [http://xnormal.net Xnormal height-to-normals filter for Photoshop] is a free normal map converter.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm Normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
<br />
=== Flat Color ===<br />
The color (128,128,255) creates normals that are completely perpendicular to the polygon, as long as the vertex normals are also perpendicular. Remember a normal map's per-pixel normals create ''offsets'' from the vertex normals. If you want an area in the normal map to be flat, so it creates no offsets from the vertex normals, then use the color (128,128,255). <br />
<br />
This becomes especially obvious when [[#Mirroring|mirroring a normal map]] and using a shader with a reflection ingredient. Reflection tends to accentuate the angles between the normals, so any errors become much more apparent.<br />
<br />
[[image:normalmap_127seam.jpg|thumb|600px|none| Mirrored normal maps show a seam when (127,127,255) is used for the flat color; 128 is better.<br>Image by [http://www.ericchadwick.com Eric Chadwick]]]<br />
<br />
In a purely logical way, 127 seems like it would be the halfway point between 0 and 255. However 128 is the color that actually works in practice. When a test is done comparing (127,127,255) versus (128,128,255) it becomes obvious that 127 creates a slightly bent normal, and 128 creates a flat one.<br />
<br />
This is because most game pipelines use ''unsigned'' normal maps. For details see the Polycount forum thread [http://www.polycount.com/forum/showpost.php?p=771360&postcount=22 tutorial: fixing mirrored normal map seams].<br />
<br />
<span id="BNMT"></span><br />
<br />
=== Blending Normal Maps Together ===<br />
Blending normal maps together is a quick way to add high-frequency detail like wrinkles, cracks, and the like. Fine details can be painted as a height map, then it can be converted into a normal map using one of the normal map tools. Then this "details" normal map can be blended with a geometry-derived normal map using one of the methods below. <br />
<br />
Here is a comparison of four of the blending methods. Note that in these examples the default values were used for CrazyBump (Intensity 50, Strength 33, Strength 33), but the tool allows each layer's strength to be adjusted individually for stronger or milder results. Each of the normal maps below were [[#Renormalizing|re-normalized]] after blending.<br />
<br />
{|class="wikitable"<br />
|[[image:nrmlmap_blending_methods_Maps.png]]<br />
|[[image:nrmlmap_blending_methods_RTTNormalMapFX.png]]<br />
|-<br />
|The blended normal maps.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|Screenshot of the 3dsmax viewport, using the RTTNormalMap.fx shader.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|}<br />
<br />
The four blending methods used above:<br />
# [http://www.crazybump.com CrazyBump] by Ryan Clark blends normal maps together using calculations in 3D space rather than just in 2D. This does probably the best job at preserving details, and each layer's strength settings can be tweaked individually. <br />
# [http://www.rodgreen.com/?p=4 Combining Normal Maps in Photoshop] by Rod Green blends normal maps together using Linear Dodge mode for the positive values and Difference mode for the negative values, along with a Photoshop Action to simplify the process. It's free, but the results may be less accurate than CrazyBump.<br />
# [http://www.paultosca.com/makingofvarga.html Making of Varga] by [http://www.paultosca.com/ Paul "paultosca" Tosca] blends normal maps together using Overlay mode for the red and green channels and Multiply mode for the blue channel. This gives a slightly stronger bump than the Overlay-only method. [http://www.leocov.com/ Leo "chronic" Covarrubias] has a step-by-step tutorial for this method in [http://www.cgbootcamp.com/tutorials/2009/12/9/photoshop-combine-normal-maps.html CG Bootcamp Combine Normal Maps].<br />
# [[3DTutorials/Normal Map Deepening|Normal Map Deepening]] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to blend normal maps together using Overlay mode. [http://cgtextures.com/content.php?action=tutorial&name=normalmap CGTextures tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] also shows how to create normalmaps using multiple layers (Note: to work with the Overlay blend mode each layer's Output Level should be 128 instead of 255, you can use the Levels tool for this).<br />
<br />
The [http://boards.polycount.net/showthread.php?t=69615 Getting good height from Nvidia-filter normalizing grayscale height] thread on the Polycount forum has a discussion of different painting/blending options. Also see the [[#2DT|2D Tools]] section for painting and conversion tools.<br />
<br />
<span id="PCT"></span><br />
<br />
=== Pre-Created Templates ===<br />
A library of shapes can be developed and stored for later use, to save creation time for future normal maps. Things like screws, ports, pipes, and other doo-dads. These shapes can be stored as bitmaps with transparency so they can be layered into baked normal maps.<br />
<br />
* [http://www.beautifulrobot.com/?p=69 Creating & Using NormalMap "Widgets"] - by ''[http://www.beautifulrobot.com Steev "kobra" Kelly]''<<BR>> How to set up and render template objects.<br />
* [http://www.akramparvez.com/portfolio/scripts/normalmap-widget-for-3ds-max/ NormalMap Widget for 3ds Max] - by ''[http://www.akramparvez.com Akram Parvez]''<<BR>>A script to automate the setup and rendering process.<br />
* See the section [[#BT|Baking Transparency]] for more template-rendering tools and tutorials.<br />
<br />
<span id="RN"></span><span id="Renormalizing"></span><br />
=== Re-normalizing ===<br />
Re-normalizing means resetting the length of each normal in the map to 1.<br />
<br />
A normal mapping shader takes the three color channels of a normal map and combines them to create the direction and length of each pixel's normal. These normals are then used to apply the scene lighting to the mesh. However if you edit normal maps by hand or if you blend multiple normal maps together this can cause those lengths to change. Most shaders expect the length of the normals to always be 1 (normalized), but some are written to re-normalize the normal map dynamically (for example, 3ds Max's Hardware Shaders do re-normalize).<br />
<br />
If the normals in your normal map are not normalized, and your shader doesn't re-normalize them either, then you may see artifacts on the shaded surface... the specular highlight may speckle like crazy, the surface may get patches of odd shadowing, etc. To help you avoid this NVIDIA's normal map filter for Photoshop provides an easy way to re-normalize a map after editing; just use the '''Normalize Only''' option. [http://xnormal.net Xnormal] also comes with a Normalize filter for Photoshop.<br />
<br />
[[image:normalize_only.jpg|frame|none|The re-normalize option in the NVIDIA filter.<br>Image by [http://hirezstudios.com/ Scott Warren]]]<br />
<br />
Some shaders use [[#NormalMapCompression|compressed normal maps]]. Usually this means the blue channel is thrown away completely, so it's recalculated on-the-fly in the shader. However the shader has to re-normalize in order to recreate that data, so any custom normal lengths that were edited into the map will be ignored completely. <br />
<br />
<span id="AOIANM"></span><span id="AmbientOcclusionIntoANormalMap"></span><br />
<br />
=== Ambient Occlusion into a Normal Map ===<br />
If the shader doesn't re-normalize the normal map, an [[Ambient Occlusion Map]] can actually be baked into the normal map. This will shorten the normals in the crevices of the surface, causing the surface to receive less light there. This works with both diffuse and specular, or any other pass that uses the normal map, like reflection.<br />
<br />
However it's usually best to keep the AO as a separate map (or in an alpha channel) and multiply it against the ambient lighting only. This is usually done with a custom [[:Category:Shaders|shader]]. If you multiply it against the diffuse map or normal map then it also occludes diffuse lighting which can make the model look dirty. Ambient occlusion is best when it occludes ambient lighting only, for example a [[DiffuselyConvolvedCubeMap|diffusely convolved cubemap]].<br />
<br />
[[image:nrmlmap_ao.jpg|frame|none| AO can be baked into a normal map, shortening the normals (lower left model).<br>Model by [http://www.3dartisan.net/~kuman/ James Ku]]]<br />
<br />
To bake the AO into a normal map, adjust the levels of the AO layer first so the darks only go as low as 128 gray, then set the AO layer to Darken mode. This will shorten the normals in the normalmap, causing the surface to receive less light in the darker areas. <br />
<br />
This trick doesn't work with any shaders that re-normalize, like 3ds Max's Hardware Shaders. The shader must be altered to actually use the lengths of your custom normals; most shaders just assume all normals are 1 in length because this makes the shader code simpler. Also this trick will not work with most of the common [[#NormalMapCompression|normal map compression formats]], which often discard the blue channel and recalculate it in the shader, which requires re-normalization.<br />
<br />
<span id="BLE"></span><br />
<br />
=== Back Lighting Example ===<br />
You can customize normal maps for some interesting effects. If you invert the blue channel of a tangent-space map, the normals will be pointing to the opposite side of the surface, which can simulate backlighting.<br />
<br />
{|class="wikitable"<br />
|[[image:tree_front.jpg]]||[[image:tree_back.jpg]]<br />
|-<br />
|Tree simulating subsurface scattering (front view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|Tree simulating subsurface scattering (back view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|-<br />
|colspan="2"|[[image:tree_maps.jpg]]<br />
|-<br />
|colspan="2"|The maps used for the leaves. The 2nd diffuse was simply color-inverted, hue-shifted 180°, and saturated.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
The tree leaves use a shader than adds together two diffuse maps, one using a regular tangent-space normal map, the other using the same normal map but with the blue channel inverted. This causes the diffuse map using the regular normal map to only get lit on the side facing the light (front view), while the diffuse map using the inverted normal map only gets lit on the opposite side of the leaves (back view). The leaf geometry is 2-sided but uses the same shader on both sides, so the effect works no matter the lighting angle. As an added bonus, because the tree is self-shadowing the leaves in shadow do not receive direct lighting, which means their backsides do not show the inverted normal map, so the fake subsurface scatter effect only appears where the light directly hits the leaves. This wouldn't work for a whole forest because of the computational cost of self-shadowing and double normal maps, but could be useful for a single "star" asset, or if LODs switched the distant trees to a model that uses a cheaper shader.<br />
<br />
<span id="SAS"></span><br />
<br />
== Shaders and Seams ==<br />
You need to use the right kind of shader to avoid seeing seams where UV breaks occur. It must be written to use the same [[#TangentBasis|tangent basis]] that was used during baking. If the shader doesn't, the lighting will either be inconsistent across UV borders or it will show smoothing errors from the low-poly vertex normals.<br />
<br />
Xnormal generates accurate normals when displayed in Xnormal, and the SDK includes a method to write your own custom tangent space generator for the tool. <br />
<br />
<span id="3MS"></span><br />
=== 3ds Max Shaders ===<br />
The "Render To Texture" tool in 3ds Max 2011 and older generates [[#TSNM|tangent-space]] normal maps that render correctly in the offline renderer (scanline) but do not render correctly in the realtime viewport with the 3ds Max shaders. Max is using a different [[#TangentBasis|tangent basis]] for each. This is readily apparent when creating non-organic hard surface normalmaps; smoothing errors appear in the viewport that do not appear when rendered. <br />
<br />
The errors can be fixed by using "Render To Texture" to bake a [[#TSNM|tangent-space]] or [[#OSNM|object-space]] map, and using the free [http://www.3pointstudios.com/3pointshader_about.shtml "3Point Shader"] by Christoph '[[CrazyButcher]]' Kubisch and Per 'perna' Abrahamsen. The shader uses the same tangent basis as the baking tool, so it produces nearly flawless results. It also works with old bakes.<br />
<br />
You can get OK results in the Max viewport using a tangent-space map baked in Maya, loading it in a Standard material, and enabling "Show Hardware Map in Viewport". Another method is to use Render To Texture to bake an [[#OSNM|object-space]] map then use [[#CBS|Nspace]] to convert it into a tangent-space map then load that in a DirectX material and use the RTTNormalMap.fx shader. <br />
<br />
Autodesk is aware of these issues, and plans to address them in an upcoming release. See these links for more information:<br />
* Christoph "[[CrazyButcher]]" Kubisch and Per "perna" Abrahamsen designed a shader/modifier combination approach that fixes the viewport problem, see the Polycount forum post [http://boards.polycount.net/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max].<br />
* Jean-Francois "jfyelle" Yelle, Autodesk Media & Entertainment Technical Product Manager, has [http://boards.polycount.net/showthread.php?p=1115812#post1115812 this post]. <br />
* Ben Cloward posted [http://boards.polycount.net/showthread.php?p=1100270#post1100270 workarounds and FX code].<br />
* Christopher "cdiggins" Diggins, SDK writer for 3ds Max, shares some of the SDK code in his blog posts "[http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping How the 3ds Max Scanline Renderer Computes Tangent and Binormal Vectors for Normal Mapping]" and "[http://area.autodesk.com/blogs/chris/3ds_max_normal_map_baking_and_face_angle_weighting_the_plot_thickens 3ds Max Normal Map Baking and Face Angle Weighting: The Plot Thickens]".<br />
<br />
[[image:nmtest_uv-splits_thumb.jpg|thumb|600px|none|Comparison of map baking methods in Maya and Max, and Ben Cloward's custom FX code.<br>Image by [http://www.bencloward.com/ Ben Cloward] and [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
[[image:normalmapfix_3pointstudios_thumb.jpg|frame|none|3 Point Studios' normal map display fix for 3ds Max.<br>image by [http://www.3pointstudios.com 3 Point Studios]]]<br />
<br />
{|class="wikitable"<br />
|[[image:max2010_normalmap_workarounds.png|thumb|400px|none|]]<br />
|[[image:max2010_normalmap_compare.png|thumb|400px|none|]]<br />
|-<br />
|Viewport methods in 3ds Max 2010.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick] <br />
|More baking methods in 3ds Max 2010.<br> Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
<span id="3MENT"></span><br />
<br />
=== 3ds Max Edit Normals Trick ===<br />
After baking, if you add an Edit Normals modifier to your low-poly normalmapped model, this seems to "relax" the vertex normals for more accurate viewport shading. The modifier can be collapsed if desired.<br />
<br />
<span id="MS"></span><br />
=== Maya Shaders ===<br />
Maya seems to correctly generate normals to view in realtime, with the correct [[#TangentBasis|tangent basis]], with much less smoothing errors than 3ds Max. <br />
* [http://www.mentalwarp.com/~brice/shader.php BRDF shader] by [http://www.mentalwarp.com/~brice/ Brice Vandemoortele] and [http://www.kjapi.com/ Cedric Caillaud] (more info in [http://boards.polycount.net/showthread.php?t=49920 this Polycount thread]) '''Update:''' [http://boards.polycount.net/showthread.php?p=821862#post821862 New version here] with many updates, including object-space normal maps, relief mapping, self-shadowing, etc. Make sure you enable cgFX shaders in the Maya plugin manager, then you can create them in the same way you create a Lambert, Phong etc. Switch OFF high quality rendering in the viewports to see them correctly too.<br />
* If you want to use the software renderer, use mental ray instead of Maya's software renderer because mental ray correctly interprets tangent space normals. The Maya renderer treats the normal map as a grayscale bump map, giving nasty results. Mental ray supports Maya's Phong shader just fine (amongst others), although it won't recognise a gloss map plugged into the "cosine power" slot. The slider still works though, if you don't mind having a uniform value for gloss. Spec maps work fine though. Just use the same set up as you would for viewport rendering. You'll need to have your textures saved as TGAs or similar for mental ray to work though. - from [http://boards.polycount.net/member.php?u=14235 CheeseOnToast]<br />
<br />
<br />
<span id="NMC"></span><br />
<br />
== Normal Map Compression ==<br />
see; [[Normal Map Compression]]<br />
<br />
== Links ==<br />
<br />
=== Related Pages ===<br />
* [[Curvature map]]<br />
* [[DuDv map]]<br />
* [[Flow map]]<br />
* [[Normal map]]<br />
* [[Radiosity normal map]]<br />
* [[Vector displacement map]]<br />
<br />
<span id="3DT"></span> <span id="Tools"></span> <span id="3DTools"></span><br />
=== 3D Tools ===<br />
See [[:Category:Tools#A3D_Normal_Map_Software|Category:Tools#3D_Normal_Map_Software]]<br />
<br />
<span id="2DT"></span><span id="2DTools"></span><br />
=== 2D Tools ===<br />
See [[:Category:Tools#A2D_Normal_Map_Software|Category:Tools#2D_Normal_Map_Software]]<br />
<br />
<span id="T"></span><span id="Tutorials"></span><br />
=== Tutorials ===<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh tutorial for Max and Xnormal] by [http://www.exisinteractive.com/ PeterK] to prevent heavy distortions when baking with a cage, without the need to add extra supporting vertices.<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games] by [http://www.polycount.com/forum/member.php?u=56680 'SuperFranky']<br />
* [http://area.autodesk.com/userdata/fckdata/239955/The%20Generation%20and%20Display%20of%20Normal%20Maps%20in%203ds%20Max.pdf The Generation and Display of Normal Maps in 3ds Max] (500kb PDF) <<BR>> Excellent whitepaper from Autodesk about normal mapping in 3ds Max and other apps.<br />
* [http://www.katsbits.com/htm/tutorials/blender-baking-normal-maps-from-models.htm Renderbump and baking normal maps from high poly models using Blender 3D] by ''[http://www.katsbits.com/htm/about.htm "katsbits"]''<<BR>>Baking normal maps in Blender.<br />
* [http://udn.epicgames.com/Three/CreatingNormalMaps.html Techniques for Creating Normal Maps] in the Unreal Developer Network's [http://udn.epicgames.com/Three/WebHome.html Unreal Engine 3 section] contains advice from [http://www.epicgames.com/ Epic Games] artists on creating normal maps for UE3. The [http://udn.epicgames.com/Three/DesignWorkflow.html#Creating%20normal%20maps%20from%20meshes Design Workflow page] has a summary.<br />
* [http://www.iddevnet.com/quake4/ArtReference_CreatingModels#head-3400c230e92ff7d57424b2a68f6e0ea75dee4afa Creating Models in Quake 4] by [http://www.ravensoft.com/ Raven Software] is a comprehensive guide to creating Quake 4 characters.<br />
* [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing and UVs can affect normal maps in Doom 3.<br />
* [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] is an overview of modeling for normal maps.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses how smoothing groups and bevels affect the topology of the low-poly model.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in-game, not the triangle or poly count.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm Normal map workflow] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] demonstrates his normal mapping workflow in 3ds Max and Photoshop.<br />
* [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa This video tutorial] by [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] shows in Maya how to subdivide the low-poly mesh so it more closely matches the high-poly mesh, to help solve wavy lines in the bake.<br />
* [http://www.bencloward.com/tutorials_normal_maps1.shtml Normal Mapping Tutorial] by [http://www.bencloward.com/ Ben Cloward] is a comprehensive tutorial about the entire normal map creation process.<br />
* [http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy] shows how to use a special lighting setup to render normal maps (instead of baking them).<br />
* [http://cgtextures.com/content.php?action=tutorial&name=normalmap Tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] shows how to create deep normal maps using multiple layers. Note: to use Overlay blend mode properly, make sure to change each layer's Levels ''Output Level'' to 128 instead of 255.<br />
* [http://www.poopinmymouth.com/process/tips/normalmap_deepening.jpg Normalmap Deepening] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to adjust normal maps, and how to layer together painted and baked normal maps.<br />
* [http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] helps to solve seams along horizontal or vertical UV edges, but not across angled UVs.<br />
* [http://planetpixelemporium.com/tutorialpages/normal.html Cinema 4D and Normal Maps For Games] by [http://planetpixelemporium.com/index.php James Hastings-Trew] describes normal maps in plain language, with tips on creating them in Cinema 4D.<br />
* [http://forums.cgsociety.org/showthread.php?f=39&t=359082 3ds Max normal mapping overview] by [http://www.alan-noon.com/ Alan Noon] is a great thread on CGTalk about the normal mapping process.<br />
* [http://forums.cgsociety.org/showthread.php?f=46&t=373024 Hard Surface Texture Painting] by [http://stefan-morrell.cgsociety.org/gallery/ Stefan Morrell] is a good introduction to painting textures for metal surfaces.<br />
<br />
<span id="D"></span><span id="Discussion"></span><br />
<br />
=== Discussion ===<br />
[http://boards.polycount.net/showthread.php?p=820218 Discuss this page on the Polycount forums]. Suggestions welcome.<br />
<br />
Even though only one person has been editing this page so far, the information here was gathered from many different sources. We wish to thank all the contributors for their hard-earned knowledge. It is much appreciated!<br />
<br />
----<br />
[[Category:TextureTypes]] [[Category:Bump map]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Normal_mapNormal map2015-04-22T14:51:41Z<p>Dustinbrown: /* Tangent Basis */</p>
<hr />
<div>== Out of Date ==<br />
The information on this page is a bit old, it needs to be updated. See these links for more current information:<br />
<br />
* [http://farfarer.com/resources.htm RNM Normal Map Combiner], by [http://www.farfarer.com/ James "Farfarer" O'Hare]<br />
* [http://vincentcallebaut.com/CombineNormal.html Combine Normal], by [http://vincentcallebaut.comVincent "Vincentt" Callebaut], [http://www.polycount.com/forum/showthread.php?t=131819 Combine normal maps script for Photoshop] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showpost.php?p=2226864&postcount=51 Earthquake on separating smoothing groups in the UV]<br />
* [http://www.polycount.com/forum/showpost.php?p=2225535&postcount=40 JedTheKrampus on offsetting Mirrored UVs]<br />
* [http://www.polycount.com/forum/showthread.php?t=148303 Of Bit Depths, Banding and Normal Maps]<br />
* [http://www.polycount.com/forum/showthread.php?t=147227 Skew you buddy! Making sense of skewed normal map details.]<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games]<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh Tutorial]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?]<br />
* [http://www.laurenscorijn.com/future-xoliulshader-support.html Future Xoliulshader support] = why Xoliulshader doesn't work properly in 3ds Max 2013/2014.<br />
<br />
== Synched Workflow ==<br />
To eliminate seams and shading artifacts, the model renderer and the normal map baking tool should use the same tangent basis.<br />
<br />
FBX model format can store tangents, and some renderers use this data to synch the incoming normal maps.<br />
<br />
{| class="wikitable sortable" style="color:grey;"<br />
|- <br />
! Renderer !! Normal map baker<br />
|-<br />
| 3ds Max || 3ds Max, Handplane, ?<br />
|-<br />
| Blender || ?<br />
|-<br />
| Creation Engine || Handplane, ?<br />
|-<br />
| CryEngine || ?<br />
|-<br />
| Knald || ?<br />
|-<br />
| Marmoset Toolbag || 3ds Max, Maya, Xnormal, ?<br />
|-<br />
| Maya || Handplane, Maya, ?<br />
|-<br />
| Source || Handplane, Maya ([http://www.polycount.com/forum/showpost.php?p=2224653&postcount=28]), ?<br />
|-<br />
| Starcraft II || Handplane, ?<br />
|-<br />
| Substance Designer || ?<br />
|-<br />
| Unity([http://www.polycount.com/forum/showpost.php?p=2224781&postcount=29], [http://www.polycount.com/forum/showthread.php?p=2194353#post2194353]) || Handplane, Xnormal (via Asset Store), ?<br />
|-<br />
| Unreal Engine 4 || Handplane, Xnormal([http://www.polycount.com/forum/showpost.php?p=2224402&postcount=20]), ? <br />
|-<br />
| Xnormal || Xnormal, ?<br />
|}<br />
<br />
----<br />
<br />
== What is a Normal Map? ==<br />
A Normal Map is usually used to fake high-res geometry detail when it's mapped onto a low-res mesh. The pixels of the normal map each store a ''normal'', a vector that describes the surface slope of the original high-res mesh at that point. The red, green, and blue channels of the normal map are used to control the direction of each pixel's normal. <br />
<br />
When a normal map is applied to a low-poly mesh, the texture pixels control the direction each of the pixels on the low-poly mesh will be facing in 3D space, creating the illusion of more surface detail or better curvature. However, the silhouette of the model doesn't change. <br />
<br />
<gallery mode="packed"><br />
Whatif_normalmap_mapped2.jpg|A model with a normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_low.jpg|The model without its normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_high.jpg|The high-resolution model used to create the normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
</gallery><br />
<br />
==Tangent-Space vs. Object-Space==<br />
<br />
Normal maps can be made in either of two basic flavors: tangent-space or object-space. World-space is basically the same as object-space, except it requires the model to remain in its original orientation, neither rotating nor deforming, so it's almost never used.<br />
<br />
===Tangent-space normal map===<br />
[[image:normalmap_tangentspace.jpg|frame|none|A tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Predominantly-blue colors. Object can rotate and deform. Good for deforming meshes, like characters, animals, flags, etc.<br />
<br />
Pros:<br />
* Maps can be reused easily, like on differently-shaped meshes.<br />
* Maps can be tiled and mirrored easily, though some games might not support mirroring very well.<br />
* Easier to overlay painted details.<br />
* Easier to use image compression.<br />
<br />
Cons:<br />
* More difficult to avoid smoothing problems from the low-poly vertex normals (see Smoothing Groups and Hard Edges).<br />
* Slightly slower performance than an object-space map (but not by much).<br />
<br />
===Object-space normal map===<br />
[[image:normalmap_worldspace.jpg|frame|none|An object-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Rainbow colors. Objects can rotate, but usually shouldn't be deformed, unless the shader has been modified to support deformation. Object-space is also called local-space or model-space. <br />
<br />
Pros:<br />
* Easier to generate high-quality curvature because it completely ignores the crude smoothing of the low-poly vertex normals.<br />
* Slightly better performance than a tangent-space map (but not by much).<br />
<br />
Cons:<br />
* Can't easily reuse maps, different mesh shapes require unique maps.<br />
* Difficult to tile properly, and mirroring requires specific shader support.<br />
* Harder to overlay painted details because the base colors vary across the surface of the mesh. Painted details must be converted into Object Space to be combined properly with the OS map.<br />
* They don't compress very well, since the blue channel can't be recreated in the shader like with tangent-space maps. Also the three color channels contain very different data which doesn't compress well, creating many artifacts. Using a half-resolution object-space map is one option. <br />
<br />
<br clear="all"/><br />
<br />
=== Converting Between Spaces ===<br />
Normal maps can be converted between object space and tangent space, in order to use them with different blending tools and shaders, which require one type or the other. <br />
<br />
Object space maps can also be converted to maps with different tangent bases, to better match the normal maps with the renderer and thus avoid lighting errors.<br />
<br />
* [http://www.handplane3d.com Handplane] by [http://www.alecmoody.com/ Alec Moody] is a tool that converts object space maps into a variety of tangent spaces: 3ds Max, Creation Engine, Maya, Source, Unity, Unreal, etc. See the Polycount Forum thread [http://www.polycount.com/forum/showthread.php?t=116899 Official handplane support thread - Now freeware!!].<br />
<br />
[[File:handplane_illus_1.jpg|frame|none|Handplane interface. <br>Image by [http://www.alecmoody.com/ Alec Moody].]]<br />
<br />
<br />
* [http://boards.polycount.net/showthread.php?p=1072599#post1072599 NSpace] by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] is a tool that converts an object-space normal map into a tangent-space map, which then works seamlessly in the 3ds Max viewport. He converts the map by using the same tangent basis that 3ds Max uses for its hardware shader. To see the results, load the converted map via the ''Normal Bump'' map and enable "Show Hardware Map in Viewport". [http://gameartist.nl/ Osman "osman" Tsjardiwal] created a GUI for NSpace, you can [http://boards.polycount.net/showthread.php?p=1075143#post1075143 download it here], just put it in the same folder as the NSpace exe and run it. <br />
<br />
[[File:NSpace_Gui_osman.png|frame|none|NSpace interface. <br>Image by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] and [http://gameartist.nl Osman "osman" Tsjardiwal].]]<br />
<br />
[http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson] said: "[8Monkey Labs has] a tool that lets you load up your reference mesh and object space map. Then load up your tangent normals, and adjust some sliders for things like tile and amount. We need to load up a mesh to know how to correctly orient the tangent normals or else things will come out upside down or reverse etc. It mostly works, but it tends to "bend" the resulting normals, so you gotta split the mesh up into some smoothing groups before you run it, and then I usually will just composite this "combo" texture over my orig map in Photoshop."<br />
<br />
<span id="RGBC"></span><span id="RGBChannels"></span><br />
<br />
== RGB Channels ==<br />
Shaders can use different techniques to render tangent-space normal maps, but the normal map directions are usually consistent within a game. Usually the red channel of a tangent-space normal map stores the X axis (pointing the normals predominantly leftwards or rightwards), the green channel stores the Y axis (pointing the normals predominantly upwards or downwards), and the blue channel stores the Z axis (pointing the normals outwards away from the surface).<br />
<br />
[[image:tangentspace_rgb.jpg|frame|none|The red, green, and blue channels of a tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you see lighting coming from the wrong angle when you're looking at your normal-mapped model, and the model is using a tangent-space normal map, the normal map shader might be expecting the red or green channel (or both) to point in the opposite direction. To fix this either change the shader, or simply invert the appropriate color channels in an image editor, so that the black pixels become white and the white pixels become black.<br />
<br />
Some shaders expect the color channels to be swapped or re-arranged to work with a particular [[#NormalMapCompression|compression format]]. For example the DXT5_nm format usually expects the X axis to be in the alpha channel, the Y axis to be in the green channel, and the red and blue channels to be empty.<br />
<br />
== Tangent Basis ==<br />
[[#TangentSpaceVsObjectSpace|Tangent-space]] normal maps use a special kind of vertex data called the ''tangent basis''. This is similar to UV coordinates except it provides directionality across the surface, it forms a surface-relative coordinate system for the per-pixel normals stored in the normal map. This coordinate system is required to light a normal mapped surface.<br />
<br />
Each vertex in the tangent basis is a combination of three things: the mesh vertex's normal (influenced by smoothing), the vertex's tangent (usually derived from the V texture coordinate), and the vertex's bitangent (derived in code, also called the binormal). These three vectors create an axis for each vertex, giving it a specific orientation in the tangent space. These axes are used to properly transform the incoming lighting from world space into tangent space, so your normal-mapped model will be lit correctly.<br />
<br />
Light rays are in world space, but the normals stored in the normal map are in tangent space. When the model is being rendered, the light rays must be converted from world space into tangent space, using the tangent basis to get there. At that point the incoming light rays are compared against the directions of the normals in the normal map, and this determines how much each pixel is going to be lit. Alternatively, instead of converting the light rays some shaders will convert the normals in the normal map from tangent space into world space. Then those world-space normals are compared against the light rays, and the model is lit appropriately. The method depends on who wrote the shader, but the end result is the same. Both methods require a tangent basis to transform the lighting.<br />
<br />
When a triangle's vertex normals are pointing straight out, and a pixel in the normal map is neutral blue (128,128,255) this means the pixel's normal will be pointing straight out from the surface of the low-poly mesh. When that pixel normal is tilted towards the left or the right in the tangent coordinate space, it will get either more or less red color, depending on whether the normal map is set to store the X axis as either a positive or a negative value. Same goes for when the normal is tilted up or down in tangent space, it will either get more or less green color. If the vertex normals aren't exactly perpendicular to the triangle, the normal map pixels will be tinted away from neutral blue as well.<br />
<br />
Unfortunately for artists, there are many different ways to calculate the tangent basis: [http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping 3ds Max], [http://download.autodesk.com/us/maya/2011help/index.html?url=./files/Appendix_A_Tangent_and_binormal_vectors.htm,topicNumber=d0e227193 Maya], [http://www.codesampler.com/dx9src/dx9src_4.htm#dx9_dot3_bump_mapping DirectX 9], [http://developer.nvidia.com/object/NVMeshMender.html NVMeshMender], [http://www.terathon.com/code/tangent.html Eric Lengyel], a custom solution, etc. This means a normal map baked in one application probably won't shade correctly in another. Artists must do some testing with different [[#T|baking tools]] to find which works best with their output. When the renderer (or game engine) renders your game model, [[#ShadersAndSeams|the shader]] must use the same tangent basis as the normal map baker, otherwise you'll get incorrect lighting, especially across the seams between UV shells.<br />
<br />
The [http://www.xnormal.net/ xNormal] SDK supports custom tangent basis methods. When a programmer uses it to implement their renderer's own tangent basis, artists can then use Xnormal to bake normal maps that will match their renderer perfectly.<br />
<br />
[[image:tangentseams.jpg|frame|none|When shared edges are at different angles in UV space, different colors will show up<br />
along the seam. The tangent basis uses these colors to light the model properly. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
When you look at a tangent-space normal map for a character, you typically see different colors along the UV seams. This is because the UV shells are often oriented at different angles on the mesh, a necessary evil when translating the 3D mesh into 2D textures. The body might be mapped with a vertical shell, and the arm mapped with a horizontal one. This requires the normals in the normal map to be twisted for the different orientations of those UV shells. The UVs are twisted, so the normals must be twisted in order to compensate. The tangent basis helps reorient (twist) the lighting as it comes into the surface's local space, so the lighting will then look uniform across the normal mapped mesh.<br />
<br />
When an artist tiles a tangent-space normal map across an arbitrary mesh, like a landscape, this tends to shade correctly because the mesh has a uniform direction in tangent space. If the mesh has discontinuous UV coordinates (UV seams), or the normal map has large directional gradients across it, the tangent space won't be uniform anymore so the surface will probably have shading seams.<br />
<br />
== Common Swizzle Coordinates ==<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
| '''Software''' <br />
| '''Red''' <br />
| '''Green''' <br />
| '''Blue''' <br />
|-<br />
|<#000000>| Maya<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| 3ds Max<br />
| X+<br />
| Y-<br />
| Z+ <br />
|-<br />
|<#000000>| Unreal Engine<br />
| X+ <br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Unity<br />
| X+<br />
| Y+<br />
| Z+<br />
|-<br />
|<#000000>| Toolbag<br />
| X+<br />
| Y+ <br />
| Z+<br />
|}<br />
<span id="MTLPM"></span><br />
<br />
== Modeling the Low-Poly Mesh ==<br />
The in-game mesh usually needs to be carefully optimized to create a good silhouette, define edge-loops for better deformation, and minimize extreme changes between the vertex normals for better shading (see [[#SmoothingGroupsAndHardEdges|Smoothing Groups & Hard Edges]]).<br />
<br />
In order to create an optimized in-game mesh including a good silhouette and loops for deforming in animation, you can start with the 2nd subdivision level of your [[DigitalSculpting|digital sculpt]], or in some cases with the base mesh itself. Then you can just collapse edge loops or cut in new edges to add/remove detail as necessary. Or you can [[DigitalSculpting#OART|re-toplogize]] from scratch if that works better for you.<br />
<br />
See [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts] on the Polycount forum.<br />
<br />
<span id="UVC"></span><span id="UVCoordinates"></span><br />
=== UV Coordinates ===<br />
Normal map baking tools only capture normals within the 0-1 UV square, any UV bits outside this area are ignored. <br />
<br />
Only one copy of the forward-facing UVs should remain in the 0-1 UV square at baking time. If the mesh uses overlapping UVs, this will likely cause artifacts to appear in the baked map, since the baker will try render each UV shell into the map. Before baking, it's best to move all the overlaps and mirrored bits outside the 0-1 square. <br />
<br />
[[image:Normalmap_uvcoord_offset.jpg|frame|none|The mirrored UVs (in red) are offset 1 unit before baking. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you move all the overlaps and mirrored bits exactly 1 UV unit (any whole number will do), then you can leave them there after the bake and they will still be mapped correctly. You can move them back if you want, it doesn't matter to most game engines. Be aware that ZBrush does use UV offsets to manage mesh visibility, however this usually doesn't matter because the ZBrush cage mesh is often a different mesh than the in-game mesh used for baking.<br />
<br />
You should avoid changing the UVs after baking the normal map, because rotating or mirroring UVs after baking will cause the normal map not to match the [[#TB|tangent basis]] anymore, which will likely cause lighting problems. <br />
<br />
In 3ds Max, W is a third texture coordinate. It's used for 3D procedural textures and for storing vertex color in UV channels (you need 3 axes for RGB, so UVW can store vertex color). Bake problems can be avoided by moving any overlapping UVs to -1 on the W axis, with the same results as moving them 1 unit on the U or V axes. The tool Render To Texture will always bake whatever UVs are the highest along the W axis. However using W can be messy... it's generally hidden unless you purposefully look for it (bad for team work), doesn't get preserved on export to other apps, and high W values can prevent selecting and/or welding UVs. <br />
<br />
<span id="M"></span><span id="Mirroring"></span><br />
<br />
=== Mirroring ===<br />
Normal maps can be mirrored across a model to create symmetrical details, and save UV space, which allows more detail in the normal map since the texture pixels are smaller on the model. <br />
<br />
With [[#OSNM|object-space]] maps, mirroring requires [http://boards.polycount.net/showthread.php?t=53986 specific shader support]. For [[#TSNM|tangent-space]] maps, mirroring typically creates a shading seam, but this can be reduced or hidden altogether, depending on the method used.<br />
<br />
<span id="TMW"></span><br />
==== Typical Mirroring Workflow ====<br />
# Delete the mesh half that will be mirrored. <br />
# Arrange the UVs for the remaining model, filling the UV square.<br />
# Mirror the model to create a "whole" mesh, welding the mesh vertices along the seam. <br />
# Move the mirrored UVs exactly 1 unit (or any whole number) out of the 0-1 UV square.<br />
# Bake the normal map.<br />
<br />
Sometimes an artist will decide to delete half of a symmetrical model before baking. <br />
<br />
This is a mistake however because often the vertex normals along the hole will bend towards the hole a bit; there are no faces on the other side to average the normals with. This will create a strong lighting seam in the normal map. <br />
<br />
It's typically best to use the complete mirrored model to bake the normal map, not just the unique half. <br />
<br />
To prevent the mirrored UVs from causing overlaps or baking errors, move the mirrored [[#UVC|UVs]] out of the 0-1 UV space, so only one copy of the non-mirrored UVs is left within the 0-1 square.<br />
<br />
To avoid texel "leaks" between the UV shells, make sure there's enough [[#Edge_padding|Edge Padding]] around each shell, including along the edges of the normal map. None of the UV shells should be touching the edge of the 0-1 UV square, unless they're meant to tile with the other side of the map.<br />
<br />
<span id="CM"></span><br />
<br />
==== Center Mirroring ====<br />
If the mirror seam runs along the surface of a continuous mesh, like down the center of a human face for example, then it will probably create a lighting seam. <br />
<br />
In Epic Games' [http://www.unrealtechnology.com/technology.php Unreal Engine 3] (UE3) their symmetrical models commonly use centered mirroring. Epic uses materials that mix a [[DetailMap]] with the normal maps; these seem to scatter the diffuse/specular lighting and help minimize the obviousness of the mirror seams. For their [[Light Map]]ped models they use [http://udn.epicgames.com/Three/LightMapUnwrapping.html a technique] that can almost completely hide the mirror seam.<br />
<br />
[[image:Epic_MirroringCicada.jpg|frame|none| In UE3 a center mirror seam is reduced by using a detail normal map. <br> Image by "[http://epicgames.com Epic Games]"]]<br />
<br />
'''''[http://www.zbrushcentral.com/showpost.php?p=573108&postcount=28 GOW2 normal map seams], [http://utforums.epicgames.com/showthread.php?p=27166791#post27166791 UDK normal map seams]'''''<br />
<br />
<span id="OM"></span><br />
<br />
==== Offset Mirroring ====<br />
Offset mirroring is a method where you move the mirror seam off to one side of the model, so the seam doesn't run exactly down the center. For example with a character's head, the UV seam can go down along the side of the head in front of the ear. The UV shell for the nearest ear can then be mirrored to use the area on the other side of the head. <br />
<br />
This avoids the "Rorschach" effect and allows non-symmetrical details, but it still saves texture space because the two sides of the head can be mirrored (they're never seen at the same time anyhow).<br />
<br />
Offset mirroring doesn't get rid of the seam, but it does move it off to a place where it can either be less obvious, or where it can be hidden in a natural seam on the model.<br />
<br />
<span id="FCM"></span><br />
==== Flat Color Mirroring ====<br />
[http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] solves seams by painting a flat set of normals along the seam, using neutral blue (128,128,255). However it only works along horizontal or vertical UV seams, not across any angled UVs. It also removes any details along the mirror seam, creating blank areas. <br />
<br />
<span id="EM"></span><br />
==== Element Mirroring ====<br />
The mirror seam can be avoided completely when it doesn't run directly through any mesh. For example if there's a detached mesh element that runs down the center of the model, this can be uniquely mapped, while the meshes on either side can be mirrors of each other. Whenever the mirrored parts don't share any vertex normals with the non-mirrored parts, there won't be any seams. <br />
<br />
[[image:normalmap_mirrored-binocs-racer445.jpg|frame|none|The middle part (highlighted in red) uses unique non-mirrored UVs, allowing the mesh on the right to be mirrored without any seams. <br>Image by [http://http://racer445.com/ "racer445"]]]<br />
<br />
<span id="SGAHE"></span><br />
<br />
=== Smoothing Groups & Hard Edges ===<br />
Each vertex in a mesh has at least one vertex normal. Vertex normals are used to control the direction a triangle will be lit from; if the normal is facing the light the triangle will be fully lit, if facing away from the light the triangle won't be lit. <br />
<br />
Each vertex however can have more than one vertex normal. When two triangles have different vertex normals along their shared edge, this creates a shading seam, called a ''hard edge'' in most modeling tools. 3ds Max uses ''Smoothing Groups'' to create hard/soft edges, Maya uses ''Harden Edge'' and ''Soften Edge''. These tools create hard and soft edges by splitting and combining the vertex normals.<br />
<br />
[[image:BenMathis_SmoothingGroups_Excerpt.gif|frame|none|Hard edges occur where the vertices have multiple normals. <br>Image by [http://poopinmymouth.com Ben 'poopinmymouth' Mathis] ([http://poopinmymouth.com/process/tips/smoothing_groups.jpg tutorial here])]]<br />
<br />
When a mesh uses all soft normals (a single smoothing group) the lighting has to be interpolated across the extreme differences between the vertex normals. If your renderer doesn't support the same [[#TangentBasis|tangent basis]] that the baker uses, this can produce extreme shading differences across the model, which creates shading artifacts. It is generally best to reduce these extremes when you can because a mismatched renderer can only do so much to counteract it.<br />
<br />
Hard edges are usually best where the model already has a natural seam. For example, you can add a hard edge along the rim of a car's wheel well, to prevent the inside of the wheel well from distorting the shading for the outside of the car body. Mechanical models usually need hard edges where ever the surface bends more than about 45 degrees. <br />
<br />
For most meshes, the best results usually come from adding hard edges where ever there are UV seams. There are no hard rules however, you must experiment with different approaches to find what works best in your game.<br />
<br />
When you use object-space normal maps the vertex normal problem goes away since you're no longer relying on the crude vertex normals of the mesh. An object-space normal map completely ignores vertex normals. Object-space mapping allows you to use all soft edges and no bevels on the low-res mesh, without showing lighting errors.<br />
<br />
<span id="HEDAT"></span><br />
==== Hard Edge Discussions & Tutorials ====<br />
* [http://www.polycount.com/forum/showthread.php?p=2090450#post2090450 Maya MEL Script help needed (UV border edges)]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=73593 Normal Maps: Can Somone Explain This "Black Edge" issue]<br />
* [http://www.polycount.com/forum/showthread.php?t=73566 Normal Maps: Can someone explain normals, tangents and split UVs?]<br />
* [http://www.polycount.com/forum/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max]<br />
* [http://boards.polycount.net/showthread.php?t=68173 Why you should NOT trust 3ds Max's viewport normal-map display!]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/10503-xsi-normal-mapped-cube-looks-bad.html XSI - normal mapped cube looks bad]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/11924-weird-maya-normal-map-seam-artifact-problem-am-i-making-simple-mistake.html Weird Maya normal map seam/artifact problem]<br />
* [http://boards.polycount.net/showthread.php?p=1080600 Seams in Normals when Creating Tiling Environment Trims and other Tiles]<br />
* The tutorial [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing can affect the normal map.<br />
* The tutorial: [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] shows how smoothing affects raycasting.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses the breaking of normals and smoothing groups in general terms.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in the game, not the triangle count.<br />
* The Crysis documentation [http://doc.crymod.com/AssetCreation/PolyBumpReference.html PolyBump Reference] has a section towards the bottom that shows how smoothing affects their baked normal maps.<br />
* The polycount thread [http://boards.polycount.net/showthread.php?t=60694 Toying around with normal map approaches] has a great discussion of how best to use smoothing groups and bevels for better shading.<br />
<br />
<span id="UB"></span><br />
==== Using Bevels ====<br />
Bevels/chamfers generally improve the silhouette of the model, and can also help reflect specular highlights better. <br />
<br />
However bevels tend to produce long thin triangles, which slow down the in-game rendering of your model. Real-time renderers have trouble rendering long thin triangles because they create a lot of sub-pixel areas to render. <br />
<br />
Bevels also balloon the vertex count, which can increase the transform cost and memory usage. Hard edges increase the vertex count too, but not when the edge also shares a seam in UV space. For a good explanation of the vertex count issue, see [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly].<br />
<br />
Using hard edges with matching UV shells tends to give better performance and better cosmetic results than using bevels. However there are differing opinions on this, see the Polycount thread "[http://boards.polycount.net/showthread.php?t=71760 Maya transfer maps help]".<br />
<br />
<span id="EVN"></span><br />
==== Edited Vertex Normals ====<br />
If you use bevels the shading will be improved by editing the vertex normals so the larger flat surfaces have perpendicular normals. The vertex normals are then forced to blend across the smaller bevel faces, instead of across the larger faces. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66139 Superspecular soft edges tutorial chapter 1].<br />
<br />
[[image:oliverio_bevel_normals.gif|frame|none|Bending normals on bevelled models. <br>From the tutorial [http://deadlineproof.com/model-shading-techniques-soft-edge-superspecular/ Shading techniques Superspecular soft edges]<br>Image by [http://deadlineproof.com/ Paolo Oliverio]]]<br />
<br />
== Level of Detail Models ==<br />
See [http://www.polycount.com/forum/showthread.php?p=1216945#post1216945 Problem if you're using 3point-style normals with an LOD].<br />
<br />
<span id="MTHPM"></span><br />
<br />
== Modeling The High-Poly Mesh ==<br />
[[Subdivision Surface Modeling]] and [[DigitalSculpting]] are the techniques most often used for modeling a normal map. <br />
<br />
Some artists prefer to model the in-game mesh first, other artists prefer to model the high-res mesh first, and others start somewhere in the middle. The modeling order is ultimately a personal choice though, all three methods can produce excellent results:<br />
* Build the in-game model, then up-res it and sculpt it.<br />
* Build and sculpt a high resolution model, then build a new in-game model around that.<br />
* Build a basemesh model, up-res and sculpt it, then step down a few levels of detail and use that as a base for building a better in-game mesh.<br />
If the in-game mesh is started from one of the subdivision levels of the basemesh sculpt, various edge loops can be collapsed or new edges can be cut to add/remove detail as necessary.<br />
<br />
<span id="SE"></span><br />
=== Sloped Extrusions ===<br />
[[image:normal_slopes_hatred.jpg|frame|none|Extrusions on the high-poly model should be sloped to make a better normal map. <br>Image by [http://www.hatred.gameartisans.org/ Krzysztof "Hatred" Dolas].]]<br />
<br />
=== Floating Geometry ===<br />
[[image:FloatingGeo.jpg|frame|none|Normal map stores the direction the surface is facing rather than real depth information, thus allowing to save time using floating geometry. <br>To correctly bake AO with floating geo make it a separate object and turn off it's shadow casting. <br>Image by [http://artisaverb.info/ Andrew "d1ver" Maximov].]]<br />
<br />
See also [[3DTutorials/Modeling High-Low Poly Models for Next Gen Games|Modeling High/Low Poly Models for Next Gen Games]] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa]<br />
<br />
<span id="ET"></span><br />
<br />
=== Edge Thickness ===<br />
[[image:normal_edge_thickness.jpg|frame|none|When creating edges of the Highpoly, sometimes you'll need to make them rounded than in real life to <br>work better at the size they will be seen.<br>Image by [http://racer445.com/Evan "racer445" Herbert]]]<br />
<br />
<span id="MRF"></span><span id="MRRCB"></span><br />
<br />
=== mental ray Round Corners Bump ===<br />
The mental ray renderer offers an automatic bevel rendering effect called Round Corners Bump that can be baked into a normal map. This is available in 3ds Max, Maya, and XSI. See [http://boards.polycount.net/showthread.php?t=71995 Zero Effort Beveling for normal maps] - by [http://boards.polycount.net/member.php?u=31662 Robert "r_fletch_r" Fletcher].<br />
<br />
[http://jeffpatton.net/ Jeff Patton] posted about [http://jeffpatton.cgsociety.org/blog/archive/2007/10/ how to expose Round Corners Bump] in 3ds Max so you can use it in other materials.<br />
<br />
[http://cryrid.com/art/ Michael "cryrid" Taylor] posted a tutorial about how to use [http://cryrid.com/images/temp/XSI/zeroeffort_bevels.jpg Round Corners in XSI].<br />
<br />
XSI is able to bake a good normal map with it, but 3ds Max seems to bake it incorrectly, and Maya isn't able to bake the effect at all. Maybe Max might be able to bake it correctly, if the .mi shader is edited to use the correct coordinate space?<br />
<br />
<span id="Baking"></span><span id="B"></span><br />
== Baking ==<br />
The process of transferring normals from the high-res model to the in-game model is often called baking. The baking tool usually starts projecting a certain numerical distance out from the low-poly mesh, and sends rays inwards towards the high-poly mesh. When a ray intersects the high-poly mesh, it records the mesh's surface normal and saves it in the normal map.<br />
<br />
To get an understanding of how all the options affect your normal map, do some test bakes on simple meshes like boxes. They generate quickly so you can experiment with [[#UVCoordinates|UV mirroring]], [[#SGAHE|smoothing groups]], etc. This helps you learn the settings that really matter.<br />
* The tutorial [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] has more examples of ray-casting, plus how to get better results from the bake.<br />
<br />
Baking sub-sections:<br />
# [[#Anti-Aliasing|Anti-Aliasing]]<br />
# [[#Baking_Transparency|Baking Transparency]]<br />
# [[#Edge_Padding|Edge Padding]]<br />
# [[#High_Poly_Materials|High Poly Materials]]<br />
# [[#Reset_Transforms|Reset Transforms]]<br />
# [[#Solving_Intersections|Solving Intersections]]<br />
# [[#Solving_Pixel_Artifacts|Solving Pixel Artifacts]]<br />
# [[#Solving_Wavy_Lines|Solving Wavy Lines]]<br />
# [[#Triangulating|Triangulating]]<br />
# [[#Working_with_Cages|Working with Cages]]<br />
<br />
<span id="AA"></span><br />
=== Anti-Aliasing ===<br />
Turning on super-sampling or anti-aliasing (or whatever multi-ray casting is called in your normal map baking tool) will help to fix any jagged edges where the high-res model overlaps itself within the UV borders of the low-poly mesh, or wherever the background shows through holes in the mesh. Unfortunately this tends to render much much slower, and takes more memory.<br />
<br />
[[image:normalmap_aliasing_knak47.jpg|frame|none|A bake without anti-aliasing shows artifacts where the high-poly mesh has overlaps. <br>Image by [http://www.polycount.com/forum/member.php?u=35938 'knak47']]]<br />
<br />
One trick to speed this up is to render 2x the intended image size then scale the normal map down 1/2 in a paint program like Photoshop. The reduction's pixel resampling will add anti-aliasing for you in a very quick process. After scaling, make sure to re-normalize the map if your game doesn't do that already, because the un-normalized pixels in your normalmap may cause pixelly artifacts in your specular highlights. Re-normalizing can be done with [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA's normal map filter] for Photoshop.<br />
<br />
3ds Max's supersampling doesn't work nicely with edge padding, it produces dark streaks in the padded pixels. If so then turn off padding and re-do the padding later, either by re-baking without supersampling or by using a Photoshop filter like the one that comes with [[#3DTools|Xnormal]].<br />
<br />
=== Baking Transparency ===<br />
Sometimes you need to bake a normal map from an object that uses opacity maps, like a branch with opacity-mapped leaves. Unfortunately baking apps often completely ignore any transparency mapping on your high-poly mesh.<br />
<br />
{|class="wikitable"<br />
|[[image:JoeWilson_ivynormals_error.jpg]] <br />
|[[image:JoeWilson_ivynormals_rendered.jpg]]<br />
|-<br />
|3ds Max's RTT baker causes transparency errors.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|The lighting method bakes perfect transparency.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|}<br />
<br />
To solve this, render a Top view of the mesh. This only works if you're using a planar UV projection for your low-poly mesh and you're baking a tangent-space normal map.<br />
<br />
* Make sure the Top view matches the dimensions of the planar UV projection used by the low-poly mesh. It helps to use an orthographic camera for precise placement.<br />
* On the high-poly mesh either use a specific lighting setup or a use special material shader:<br />
* 1) The lighting setup is described in these tutorials:<br />
* * [http://www.bencloward.com/tutorials_normal_maps11.shtml Creating A Normal Map Right In Your 3D App] by [http://www.bencloward.com/ Ben Cloward]<br />
* *[http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy], Graphics Techniques Consultant, Xbox Content and Design Team<br />
* 2) The material shader does the same thing, but doesn't require lights.<br />
* * [http://www.scriptspot.com/3ds-max/normaltexmap NormalTexMap] scripted map for 3ds Max by [http://www.scriptspot.com/users/dave-locke Dave Locke].<br />
* * [http://www.footools.com/3dsmax_plugins.html InfoTexture] map plugin for 3ds Max by [http://www.footools.com John Burnett]<br />
<br />
[[image:BenCloward_NormalMapLighting.gif|frame|none|The lighting setup for top-down rendering. <br>Image by [http://www.bencloward.com Ben Cloward]]]<br />
<br />
<span id="EP"></span><br />
<br />
=== Edge Padding ===<br />
If a normal map doesn't have enough [[Edge_padding |Edge Padding]], this will create shading seams on the UV borders.<br />
<br />
=== High Poly Materials ===<br />
3ds Max will not bake a normal map properly if the high-res model has a mental ray Arch & Design material applied. If your normal map comes out mostly blank, either use a Standard material or none at all. For an example see the Polycount thread [http://www.polycount.com/forum/showthread.php?t=74792 Render to Texture >:O].<br />
<br />
<span id="RT"></span><br />
=== Reset Transforms ===<br />
Before baking, make sure your low-poly model's transforms have been reset. '''''This is very important!''''' Often during the modeling process a model will be rotated and scaled, but these compounded transforms can create a messy local "space" for the model, which in turn often creates rendering errors for normal maps. <br />
<br />
In 3ds Max, use the Reset Xforms utility then Collapse the Modifier Stack. In Maya use Freeze Transformation. In XSI use the Freeze button.<br />
<br />
<span id="SI"></span><br />
<br />
=== Solving Intersections ===<br />
The projection process often causes problems like misses, or overlaps, or intersections. It can be difficult generating a clean normal map in areas where the high-poly mesh intersects or nearly intersects itself, like in between the fingers of a hand. Setting the ray distance too large will make the baker pick the other finger as the source normal, while setting the ray distance too small will lead to problems at other places on the mesh where the distances between in-game mesh and high-poly mesh are greater.<br />
<br />
Fortunately there are several methods for solving these problems.<br />
<br />
# Change the shape of the cage. Manually edit points on the projection cage to help solve tight bits like the gaps between fingers.<br />
# Limit the projection to matching materials, or matching UVs.<br />
# Explode the meshes. See the polycount thread [http://boards.polycount.net/showthread.php?t=62921 Explode script needed (for baking purposes)].<br />
# Bake two or more times using different cage sizes, and combine them in Photoshop.<br />
<br />
<span id="SPA"></span><br />
<br />
=== Solving Pixel Artifacts ===<br />
[[image:filterMaps_artifact.jpg|frame|none|Random pixel artifacts in the bake. <br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
If you are using 3ds Max's ''Render To Texture'' to bake from one UV layout to another, you may see stray pixels scattered across the bake. This only happens if you are using a copy of the original mesh in the Projection, and that mesh is using a different UV channel than the original mesh.<br />
<br />
There are two solutions for this:<br />
<br />
* Add a Push modifier to the copied mesh, and set it to a low value like 0.01.<br />
- or -<br />
<br />
* Turn off ''Filter Maps'' in the render settings (Rendering menu > Render Setup > Renderer tab > uncheck Filter Maps). To prevent aliasing you may want to enable the Global Supersampler in Render Setup.<br />
<br />
See also [[#Anti-Aliasing]].<br />
<br />
<span id="SWL"></span><br />
<br />
=== Solving Wavy Lines ===<br />
When capturing from a cylindrical shape, often the differences between the low-poly mesh and the high-poly mesh will create a wavy edge in the normal map. There are a couple ways to avoid this:<br />
<br />
# The best way... create your lowpoly model with better supporting edges. See the Polycount threads [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?], [http://boards.polycount.net/showthread.php?t=55754 approach to techy stuff], [http://www.polycount.com/forum/showthread.php?t=72713 Any tips for normal mapping curved surface?].<br />
# Adjust the shape of the cage to influence the directions the rays will be cast. Beware... this work will have to be re-done every time you edit the lowpoly mesh, as the cage will be invalidated. At the bottom of [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm this page of his normal map tutorial], [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to do this in 3ds Max. Same method can be seen in the image below.<br />
# Subdivide the low-res mesh so it more closely matches the high-res mesh. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] has a [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa video tutorial] that shows how to do this in Maya.<br />
# Paint out the wavy line. Beware... this work will have to be re-done every time you re-bake the normal map. The [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
# Use a separate planar-projected mesh for the details that wrap around the barrel area, so the ray-casting is more even. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. For example to add tread around a tire, the tread can be baked from a tread model that is laid out flat, then that bake can layered onto the bake from the cylindrical tire mesh in a paint program.<br />
<br />
[[image:timothy_evison_normalmap_projections.jpg|frame|none|Adjusting the shape of the cage to remove distortion. <br>Image by [http://users.cybercity.dk/~dsl11905/resume/resume.html Timothy "tpe" Evison]]]<br />
<br />
<span id="TRI"></span><br />
<br />
=== Triangulating ===<br />
Before baking, it is usually best to triangulate the low-poly model, converting it from polygons into pure triangles. This prevents the vertex normals from being changed later on, which can create specular artifacts.<br />
<br />
[[image:triangulation_modo_ohare.jpg|frame|none| When quads are triangulated in [http://www.luxology.com/modo/ Modo], the internal edges are sometimes flipped, which causes shading differences.<br>Image by [http://www.farfarer.com/|James "Talon" O'Hare]]]<br />
<br />
<br />
Sometimes a baking tool or a mesh exporter/importer will re-triangulate the polygons. A quad polygon is actually treated as two triangles, and the internal edge between them is often switched diagonally during modeling operations. When the vertices of the quad are moved around in certain shapes, the software's algorithm for polygon models tries to keep the quad surface in a "rational" non-overlapping shape. It does this by switching the internal edge between its triangles.<br />
<br />
<br />
[[image:triangulation_spec_tychovii.jpg|frame|none| The specular highlight is affected by triangulation. Flip edges to fix skewing. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66651 Skewed Specular Highlight?] for pictures and more info.<br> Image by [http://robertkreps.com Robert "TychoVII" Kreps]]]<br />
<br />
<br />
<span id="WWC"></span><br />
<br />
=== Working with Cages ===<br />
''Cage'' has two meanings in the normal-mapping process: a low-poly base for [[subdivision surface modeling]] (usually called the [[DigitalSculpting#BM|basemesh]]), or a ray-casting mesh used for normal map baking. This section covers the ray-casting cage.<br />
<br />
Most normal map baking tools allow you to use a distance-based raycast. A ray is sent outwards along each vertex normal, then at the distance you set a ray is cast back inwards. Where ever that ray intersects the high poly mesh, it will sample the normals from it. <br />
<br />
{|class="wikitable"<br />
|[[Image:Normalmap_raycasting_1.jpg]] <br />
|[[Image:Normalmap_raycasting_2.jpg]]<br />
|-<br />
|Hard edges and a distance-based raycast (gray areas) cause ray misses (yellow) and ray overlaps (cyan).<br> Image by [http://www.mankua.com/ Diego Castaño]<br />
|The gray area shows that using all soft edges (or hard edges and a cage-based raycast) will avoid ray-casting errors from split normals.<br> Image by [http://www.mankua.com/ Diego Castaño] <br />
|}<br />
<br />
Unfortunately with a distance-based raycast, [[#SGAHE|split vertex normals]] will cause the bake to miss parts of the high-res mesh, causing errors and seams. <br />
<br />
Some software allows you to use ''cage mesh'' option instead, which basically inflates a copy of the low-poly mesh, then raycasts inwards from each vertex. This ballooned-out mesh is the cage.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
|<tablebgcolor="#ffaaaa">| <br />
|}<br />
<br />
In 3ds Max the cage controls both the distance and the direction of the raycasting. <br />
<br />
In Maya the cage only controls the distance; the ray direction matches the vertex normals (inverted).<br />
<br />
<span style="text-decoration: line-through"> This may have been fixed in the latest release...<<BR>><br />
In Xnormal the cage is split everywhere the model has [[#SGAHE|hard edges]], causing ray misses in the bake. You can fix the hard edge split problem but it involves an overly complex workflow. You must also repeat the whole process any time you change your mesh:</span><br />
# <s> Load the 3d viewer.</s><br />
# <s> Turn on the cage editing tools.</s><br />
# <s> Select all of the vertices.</s><br />
# <s> Weld all vertices.</s><br />
# <s> Expand the cage as you normally would.</s><br />
# <s> Save out your mesh using the Xnormal format.</s><br />
# <s> Make sure Xnormal is loading the correct mesh.</s><br />
<br />
<span id="P"></span><span id="Painting"></span><br />
<br />
== Painting ==<br />
Don't be afraid to edit normal maps in Photoshop. After all it is just a texture, so you can clone, blur, copy, blend all you want... as long as it looks good of course. Some understanding of [[#RGBChannels|the way colors work]] in normal maps will go a long way in helping you paint effectively.<br />
<br />
A normal map sampled from a high-poly mesh will nearly always be better than one sampled from a texture, since you're actually grabbing "proper" normals from an accurate, highly detailed surface. That means your normal map's pixels will basically be recreating the surface angles of your high-poly mesh, resulting in a very believable look.<br />
<br />
If you only convert an image into a normal-map, it can look very flat, and in some cases it can be completely wrong unless you're very careful about your value ranges. Most image conversion tools assume the input is a heightmap, where black is low and white is high. If you try to convert a diffuse texture that you've painted, the results are often very poor. Often the best results are obtained by baking the large and mid-level details from a high-poly mesh, and then combined with photo-sourced "fine detail" normals for surface details such as fabric weave, scratches and grain.<br />
<br />
Sometimes creating a high poly surface takes more time than your budget allows. For character or significant environment assets then that is the best route, but for less significant environment surfaces working from a heightmap-based texture will provide a good enough result for a much less commitment in time.<br />
<br />
* [http://crazybump.com/ CrazyBump] is a commercial normal map converter.<br />
* [http://www.renderingsystems.com/support/showthread.php?tid=3 ShaderMap] is a commercial normal map converter.<br />
* [http://www.pixplant.com/ PixPlant] is a commercial normal map converter.<br />
* [http://boards.polycount.net/showthread.php?t=68860 NJob] is a free normal map converter.<br />
* [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA normalmap filter for Photoshop] is a free normal map converter.<br />
* [http://xnormal.net Xnormal height-to-normals filter for Photoshop] is a free normal map converter.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm Normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
<br />
=== Flat Color ===<br />
The color (128,128,255) creates normals that are completely perpendicular to the polygon, as long as the vertex normals are also perpendicular. Remember a normal map's per-pixel normals create ''offsets'' from the vertex normals. If you want an area in the normal map to be flat, so it creates no offsets from the vertex normals, then use the color (128,128,255). <br />
<br />
This becomes especially obvious when [[#Mirroring|mirroring a normal map]] and using a shader with a reflection ingredient. Reflection tends to accentuate the angles between the normals, so any errors become much more apparent.<br />
<br />
[[image:normalmap_127seam.jpg|thumb|600px|none| Mirrored normal maps show a seam when (127,127,255) is used for the flat color; 128 is better.<br>Image by [http://www.ericchadwick.com Eric Chadwick]]]<br />
<br />
In a purely logical way, 127 seems like it would be the halfway point between 0 and 255. However 128 is the color that actually works in practice. When a test is done comparing (127,127,255) versus (128,128,255) it becomes obvious that 127 creates a slightly bent normal, and 128 creates a flat one.<br />
<br />
This is because most game pipelines use ''unsigned'' normal maps. For details see the Polycount forum thread [http://www.polycount.com/forum/showpost.php?p=771360&postcount=22 tutorial: fixing mirrored normal map seams].<br />
<br />
<span id="BNMT"></span><br />
<br />
=== Blending Normal Maps Together ===<br />
Blending normal maps together is a quick way to add high-frequency detail like wrinkles, cracks, and the like. Fine details can be painted as a height map, then it can be converted into a normal map using one of the normal map tools. Then this "details" normal map can be blended with a geometry-derived normal map using one of the methods below. <br />
<br />
Here is a comparison of four of the blending methods. Note that in these examples the default values were used for CrazyBump (Intensity 50, Strength 33, Strength 33), but the tool allows each layer's strength to be adjusted individually for stronger or milder results. Each of the normal maps below were [[#Renormalizing|re-normalized]] after blending.<br />
<br />
{|class="wikitable"<br />
|[[image:nrmlmap_blending_methods_Maps.png]]<br />
|[[image:nrmlmap_blending_methods_RTTNormalMapFX.png]]<br />
|-<br />
|The blended normal maps.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|Screenshot of the 3dsmax viewport, using the RTTNormalMap.fx shader.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|}<br />
<br />
The four blending methods used above:<br />
# [http://www.crazybump.com CrazyBump] by Ryan Clark blends normal maps together using calculations in 3D space rather than just in 2D. This does probably the best job at preserving details, and each layer's strength settings can be tweaked individually. <br />
# [http://www.rodgreen.com/?p=4 Combining Normal Maps in Photoshop] by Rod Green blends normal maps together using Linear Dodge mode for the positive values and Difference mode for the negative values, along with a Photoshop Action to simplify the process. It's free, but the results may be less accurate than CrazyBump.<br />
# [http://www.paultosca.com/makingofvarga.html Making of Varga] by [http://www.paultosca.com/ Paul "paultosca" Tosca] blends normal maps together using Overlay mode for the red and green channels and Multiply mode for the blue channel. This gives a slightly stronger bump than the Overlay-only method. [http://www.leocov.com/ Leo "chronic" Covarrubias] has a step-by-step tutorial for this method in [http://www.cgbootcamp.com/tutorials/2009/12/9/photoshop-combine-normal-maps.html CG Bootcamp Combine Normal Maps].<br />
# [[3DTutorials/Normal Map Deepening|Normal Map Deepening]] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to blend normal maps together using Overlay mode. [http://cgtextures.com/content.php?action=tutorial&name=normalmap CGTextures tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] also shows how to create normalmaps using multiple layers (Note: to work with the Overlay blend mode each layer's Output Level should be 128 instead of 255, you can use the Levels tool for this).<br />
<br />
The [http://boards.polycount.net/showthread.php?t=69615 Getting good height from Nvidia-filter normalizing grayscale height] thread on the Polycount forum has a discussion of different painting/blending options. Also see the [[#2DT|2D Tools]] section for painting and conversion tools.<br />
<br />
<span id="PCT"></span><br />
<br />
=== Pre-Created Templates ===<br />
A library of shapes can be developed and stored for later use, to save creation time for future normal maps. Things like screws, ports, pipes, and other doo-dads. These shapes can be stored as bitmaps with transparency so they can be layered into baked normal maps.<br />
<br />
* [http://www.beautifulrobot.com/?p=69 Creating & Using NormalMap "Widgets"] - by ''[http://www.beautifulrobot.com Steev "kobra" Kelly]''<<BR>> How to set up and render template objects.<br />
* [http://www.akramparvez.com/portfolio/scripts/normalmap-widget-for-3ds-max/ NormalMap Widget for 3ds Max] - by ''[http://www.akramparvez.com Akram Parvez]''<<BR>>A script to automate the setup and rendering process.<br />
* See the section [[#BT|Baking Transparency]] for more template-rendering tools and tutorials.<br />
<br />
<span id="RN"></span><span id="Renormalizing"></span><br />
=== Re-normalizing ===<br />
Re-normalizing means resetting the length of each normal in the map to 1.<br />
<br />
A normal mapping shader takes the three color channels of a normal map and combines them to create the direction and length of each pixel's normal. These normals are then used to apply the scene lighting to the mesh. However if you edit normal maps by hand or if you blend multiple normal maps together this can cause those lengths to change. Most shaders expect the length of the normals to always be 1 (normalized), but some are written to re-normalize the normal map dynamically (for example, 3ds Max's Hardware Shaders do re-normalize).<br />
<br />
If the normals in your normal map are not normalized, and your shader doesn't re-normalize them either, then you may see artifacts on the shaded surface... the specular highlight may speckle like crazy, the surface may get patches of odd shadowing, etc. To help you avoid this NVIDIA's normal map filter for Photoshop provides an easy way to re-normalize a map after editing; just use the '''Normalize Only''' option. [http://xnormal.net Xnormal] also comes with a Normalize filter for Photoshop.<br />
<br />
[[image:normalize_only.jpg|frame|none|The re-normalize option in the NVIDIA filter.<br>Image by [http://hirezstudios.com/ Scott Warren]]]<br />
<br />
Some shaders use [[#NormalMapCompression|compressed normal maps]]. Usually this means the blue channel is thrown away completely, so it's recalculated on-the-fly in the shader. However the shader has to re-normalize in order to recreate that data, so any custom normal lengths that were edited into the map will be ignored completely. <br />
<br />
<span id="AOIANM"></span><span id="AmbientOcclusionIntoANormalMap"></span><br />
<br />
=== Ambient Occlusion into a Normal Map ===<br />
If the shader doesn't re-normalize the normal map, an [[Ambient Occlusion Map]] can actually be baked into the normal map. This will shorten the normals in the crevices of the surface, causing the surface to receive less light there. This works with both diffuse and specular, or any other pass that uses the normal map, like reflection.<br />
<br />
However it's usually best to keep the AO as a separate map (or in an alpha channel) and multiply it against the ambient lighting only. This is usually done with a custom [[:Category:Shaders|shader]]. If you multiply it against the diffuse map or normal map then it also occludes diffuse lighting which can make the model look dirty. Ambient occlusion is best when it occludes ambient lighting only, for example a [[DiffuselyConvolvedCubeMap|diffusely convolved cubemap]].<br />
<br />
[[image:nrmlmap_ao.jpg|frame|none| AO can be baked into a normal map, shortening the normals (lower left model).<br>Model by [http://www.3dartisan.net/~kuman/ James Ku]]]<br />
<br />
To bake the AO into a normal map, adjust the levels of the AO layer first so the darks only go as low as 128 gray, then set the AO layer to Darken mode. This will shorten the normals in the normalmap, causing the surface to receive less light in the darker areas. <br />
<br />
This trick doesn't work with any shaders that re-normalize, like 3ds Max's Hardware Shaders. The shader must be altered to actually use the lengths of your custom normals; most shaders just assume all normals are 1 in length because this makes the shader code simpler. Also this trick will not work with most of the common [[#NormalMapCompression|normal map compression formats]], which often discard the blue channel and recalculate it in the shader, which requires re-normalization.<br />
<br />
<span id="BLE"></span><br />
<br />
=== Back Lighting Example ===<br />
You can customize normal maps for some interesting effects. If you invert the blue channel of a tangent-space map, the normals will be pointing to the opposite side of the surface, which can simulate backlighting.<br />
<br />
{|class="wikitable"<br />
|[[image:tree_front.jpg]]||[[image:tree_back.jpg]]<br />
|-<br />
|Tree simulating subsurface scattering (front view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|Tree simulating subsurface scattering (back view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|-<br />
|colspan="2"|[[image:tree_maps.jpg]]<br />
|-<br />
|colspan="2"|The maps used for the leaves. The 2nd diffuse was simply color-inverted, hue-shifted 180°, and saturated.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
The tree leaves use a shader than adds together two diffuse maps, one using a regular tangent-space normal map, the other using the same normal map but with the blue channel inverted. This causes the diffuse map using the regular normal map to only get lit on the side facing the light (front view), while the diffuse map using the inverted normal map only gets lit on the opposite side of the leaves (back view). The leaf geometry is 2-sided but uses the same shader on both sides, so the effect works no matter the lighting angle. As an added bonus, because the tree is self-shadowing the leaves in shadow do not receive direct lighting, which means their backsides do not show the inverted normal map, so the fake subsurface scatter effect only appears where the light directly hits the leaves. This wouldn't work for a whole forest because of the computational cost of self-shadowing and double normal maps, but could be useful for a single "star" asset, or if LODs switched the distant trees to a model that uses a cheaper shader.<br />
<br />
<span id="SAS"></span><br />
<br />
== Shaders and Seams ==<br />
You need to use the right kind of shader to avoid seeing seams where UV breaks occur. It must be written to use the same [[#TangentBasis|tangent basis]] that was used during baking. If the shader doesn't, the lighting will either be inconsistent across UV borders or it will show smoothing errors from the low-poly vertex normals.<br />
<br />
Xnormal generates accurate normals when displayed in Xnormal, and the SDK includes a method to write your own custom tangent space generator for the tool. <br />
<br />
<span id="3MS"></span><br />
=== 3ds Max Shaders ===<br />
The "Render To Texture" tool in 3ds Max 2011 and older generates [[#TSNM|tangent-space]] normal maps that render correctly in the offline renderer (scanline) but do not render correctly in the realtime viewport with the 3ds Max shaders. Max is using a different [[#TangentBasis|tangent basis]] for each. This is readily apparent when creating non-organic hard surface normalmaps; smoothing errors appear in the viewport that do not appear when rendered. <br />
<br />
The errors can be fixed by using "Render To Texture" to bake a [[#TSNM|tangent-space]] or [[#OSNM|object-space]] map, and using the free [http://www.3pointstudios.com/3pointshader_about.shtml "3Point Shader"] by Christoph '[[CrazyButcher]]' Kubisch and Per 'perna' Abrahamsen. The shader uses the same tangent basis as the baking tool, so it produces nearly flawless results. It also works with old bakes.<br />
<br />
You can get OK results in the Max viewport using a tangent-space map baked in Maya, loading it in a Standard material, and enabling "Show Hardware Map in Viewport". Another method is to use Render To Texture to bake an [[#OSNM|object-space]] map then use [[#CBS|Nspace]] to convert it into a tangent-space map then load that in a DirectX material and use the RTTNormalMap.fx shader. <br />
<br />
Autodesk is aware of these issues, and plans to address them in an upcoming release. See these links for more information:<br />
* Christoph "[[CrazyButcher]]" Kubisch and Per "perna" Abrahamsen designed a shader/modifier combination approach that fixes the viewport problem, see the Polycount forum post [http://boards.polycount.net/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max].<br />
* Jean-Francois "jfyelle" Yelle, Autodesk Media & Entertainment Technical Product Manager, has [http://boards.polycount.net/showthread.php?p=1115812#post1115812 this post]. <br />
* Ben Cloward posted [http://boards.polycount.net/showthread.php?p=1100270#post1100270 workarounds and FX code].<br />
* Christopher "cdiggins" Diggins, SDK writer for 3ds Max, shares some of the SDK code in his blog posts "[http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping How the 3ds Max Scanline Renderer Computes Tangent and Binormal Vectors for Normal Mapping]" and "[http://area.autodesk.com/blogs/chris/3ds_max_normal_map_baking_and_face_angle_weighting_the_plot_thickens 3ds Max Normal Map Baking and Face Angle Weighting: The Plot Thickens]".<br />
<br />
[[image:nmtest_uv-splits_thumb.jpg|thumb|600px|none|Comparison of map baking methods in Maya and Max, and Ben Cloward's custom FX code.<br>Image by [http://www.bencloward.com/ Ben Cloward] and [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
[[image:normalmapfix_3pointstudios_thumb.jpg|frame|none|3 Point Studios' normal map display fix for 3ds Max.<br>image by [http://www.3pointstudios.com 3 Point Studios]]]<br />
<br />
{|class="wikitable"<br />
|[[image:max2010_normalmap_workarounds.png|thumb|400px|none|]]<br />
|[[image:max2010_normalmap_compare.png|thumb|400px|none|]]<br />
|-<br />
|Viewport methods in 3ds Max 2010.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick] <br />
|More baking methods in 3ds Max 2010.<br> Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
<span id="3MENT"></span><br />
<br />
=== 3ds Max Edit Normals Trick ===<br />
After baking, if you add an Edit Normals modifier to your low-poly normalmapped model, this seems to "relax" the vertex normals for more accurate viewport shading. The modifier can be collapsed if desired.<br />
<br />
<span id="MS"></span><br />
=== Maya Shaders ===<br />
Maya seems to correctly generate normals to view in realtime, with the correct [[#TangentBasis|tangent basis]], with much less smoothing errors than 3ds Max. <br />
* [http://www.mentalwarp.com/~brice/shader.php BRDF shader] by [http://www.mentalwarp.com/~brice/ Brice Vandemoortele] and [http://www.kjapi.com/ Cedric Caillaud] (more info in [http://boards.polycount.net/showthread.php?t=49920 this Polycount thread]) '''Update:''' [http://boards.polycount.net/showthread.php?p=821862#post821862 New version here] with many updates, including object-space normal maps, relief mapping, self-shadowing, etc. Make sure you enable cgFX shaders in the Maya plugin manager, then you can create them in the same way you create a Lambert, Phong etc. Switch OFF high quality rendering in the viewports to see them correctly too.<br />
* If you want to use the software renderer, use mental ray instead of Maya's software renderer because mental ray correctly interprets tangent space normals. The Maya renderer treats the normal map as a grayscale bump map, giving nasty results. Mental ray supports Maya's Phong shader just fine (amongst others), although it won't recognise a gloss map plugged into the "cosine power" slot. The slider still works though, if you don't mind having a uniform value for gloss. Spec maps work fine though. Just use the same set up as you would for viewport rendering. You'll need to have your textures saved as TGAs or similar for mental ray to work though. - from [http://boards.polycount.net/member.php?u=14235 CheeseOnToast]<br />
<br />
<br />
<span id="NMC"></span><br />
<br />
== Normal Map Compression ==<br />
see; [[Normal Map Compression]]<br />
<br />
== Links ==<br />
<br />
=== Related Pages ===<br />
* [[Curvature map]]<br />
* [[DuDv map]]<br />
* [[Flow map]]<br />
* [[Normal map]]<br />
* [[Radiosity normal map]]<br />
* [[Vector displacement map]]<br />
<br />
<span id="3DT"></span> <span id="Tools"></span> <span id="3DTools"></span><br />
=== 3D Tools ===<br />
See [[:Category:Tools#A3D_Normal_Map_Software|Category:Tools#3D_Normal_Map_Software]]<br />
<br />
<span id="2DT"></span><span id="2DTools"></span><br />
=== 2D Tools ===<br />
See [[:Category:Tools#A2D_Normal_Map_Software|Category:Tools#2D_Normal_Map_Software]]<br />
<br />
<span id="T"></span><span id="Tutorials"></span><br />
=== Tutorials ===<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh tutorial for Max and Xnormal] by [http://www.exisinteractive.com/ PeterK] to prevent heavy distortions when baking with a cage, without the need to add extra supporting vertices.<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games] by [http://www.polycount.com/forum/member.php?u=56680 'SuperFranky']<br />
* [http://area.autodesk.com/userdata/fckdata/239955/The%20Generation%20and%20Display%20of%20Normal%20Maps%20in%203ds%20Max.pdf The Generation and Display of Normal Maps in 3ds Max] (500kb PDF) <<BR>> Excellent whitepaper from Autodesk about normal mapping in 3ds Max and other apps.<br />
* [http://www.katsbits.com/htm/tutorials/blender-baking-normal-maps-from-models.htm Renderbump and baking normal maps from high poly models using Blender 3D] by ''[http://www.katsbits.com/htm/about.htm "katsbits"]''<<BR>>Baking normal maps in Blender.<br />
* [http://udn.epicgames.com/Three/CreatingNormalMaps.html Techniques for Creating Normal Maps] in the Unreal Developer Network's [http://udn.epicgames.com/Three/WebHome.html Unreal Engine 3 section] contains advice from [http://www.epicgames.com/ Epic Games] artists on creating normal maps for UE3. The [http://udn.epicgames.com/Three/DesignWorkflow.html#Creating%20normal%20maps%20from%20meshes Design Workflow page] has a summary.<br />
* [http://www.iddevnet.com/quake4/ArtReference_CreatingModels#head-3400c230e92ff7d57424b2a68f6e0ea75dee4afa Creating Models in Quake 4] by [http://www.ravensoft.com/ Raven Software] is a comprehensive guide to creating Quake 4 characters.<br />
* [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing and UVs can affect normal maps in Doom 3.<br />
* [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] is an overview of modeling for normal maps.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses how smoothing groups and bevels affect the topology of the low-poly model.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in-game, not the triangle or poly count.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm Normal map workflow] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] demonstrates his normal mapping workflow in 3ds Max and Photoshop.<br />
* [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa This video tutorial] by [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] shows in Maya how to subdivide the low-poly mesh so it more closely matches the high-poly mesh, to help solve wavy lines in the bake.<br />
* [http://www.bencloward.com/tutorials_normal_maps1.shtml Normal Mapping Tutorial] by [http://www.bencloward.com/ Ben Cloward] is a comprehensive tutorial about the entire normal map creation process.<br />
* [http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy] shows how to use a special lighting setup to render normal maps (instead of baking them).<br />
* [http://cgtextures.com/content.php?action=tutorial&name=normalmap Tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] shows how to create deep normal maps using multiple layers. Note: to use Overlay blend mode properly, make sure to change each layer's Levels ''Output Level'' to 128 instead of 255.<br />
* [http://www.poopinmymouth.com/process/tips/normalmap_deepening.jpg Normalmap Deepening] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to adjust normal maps, and how to layer together painted and baked normal maps.<br />
* [http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] helps to solve seams along horizontal or vertical UV edges, but not across angled UVs.<br />
* [http://planetpixelemporium.com/tutorialpages/normal.html Cinema 4D and Normal Maps For Games] by [http://planetpixelemporium.com/index.php James Hastings-Trew] describes normal maps in plain language, with tips on creating them in Cinema 4D.<br />
* [http://forums.cgsociety.org/showthread.php?f=39&t=359082 3ds Max normal mapping overview] by [http://www.alan-noon.com/ Alan Noon] is a great thread on CGTalk about the normal mapping process.<br />
* [http://forums.cgsociety.org/showthread.php?f=46&t=373024 Hard Surface Texture Painting] by [http://stefan-morrell.cgsociety.org/gallery/ Stefan Morrell] is a good introduction to painting textures for metal surfaces.<br />
<br />
<span id="D"></span><span id="Discussion"></span><br />
<br />
=== Discussion ===<br />
[http://boards.polycount.net/showthread.php?p=820218 Discuss this page on the Polycount forums]. Suggestions welcome.<br />
<br />
Even though only one person has been editing this page so far, the information here was gathered from many different sources. We wish to thank all the contributors for their hard-earned knowledge. It is much appreciated!<br />
<br />
----<br />
[[Category:TextureTypes]] [[Category:Bump map]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Normal_mapNormal map2015-04-21T20:58:49Z<p>Dustinbrown: /* Tangent Basis */</p>
<hr />
<div>== Out of Date ==<br />
The information on this page is a bit old, it needs to be updated. See these links for more current information:<br />
<br />
* [http://farfarer.com/resources.htm RNM Normal Map Combiner], by [http://www.farfarer.com/ James "Farfarer" O'Hare]<br />
* [http://vincentcallebaut.com/CombineNormal.html Combine Normal], by [http://vincentcallebaut.comVincent "Vincentt" Callebaut], [http://www.polycount.com/forum/showthread.php?t=131819 Combine normal maps script for Photoshop] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showpost.php?p=2226864&postcount=51 Earthquake on separating smoothing groups in the UV]<br />
* [http://www.polycount.com/forum/showpost.php?p=2225535&postcount=40 JedTheKrampus on offsetting Mirrored UVs]<br />
* [http://www.polycount.com/forum/showthread.php?t=148303 Of Bit Depths, Banding and Normal Maps]<br />
* [http://www.polycount.com/forum/showthread.php?t=147227 Skew you buddy! Making sense of skewed normal map details.]<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games]<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh Tutorial]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?]<br />
* [http://www.laurenscorijn.com/future-xoliulshader-support.html Future Xoliulshader support] = why Xoliulshader doesn't work properly in 3ds Max 2013/2014.<br />
<br />
== Synched Workflow ==<br />
To eliminate seams and shading artifacts, the model renderer and the normal map baking tool should use the same tangent basis.<br />
<br />
FBX model format can store tangents, and some renderers use this data to synch the incoming normal maps.<br />
<br />
{| class="wikitable sortable" style="color:grey;"<br />
|- <br />
! Renderer !! Normal map baker<br />
|-<br />
| 3ds Max || 3ds Max, Handplane, ?<br />
|-<br />
| Blender || ?<br />
|-<br />
| Creation Engine || Handplane, ?<br />
|-<br />
| CryEngine || ?<br />
|-<br />
| Knald || ?<br />
|-<br />
| Marmoset Toolbag || 3ds Max, Maya, Xnormal, ?<br />
|-<br />
| Maya || Handplane, Maya, ?<br />
|-<br />
| Source || Handplane, Maya ([http://www.polycount.com/forum/showpost.php?p=2224653&postcount=28]), ?<br />
|-<br />
| Starcraft II || Handplane, ?<br />
|-<br />
| Substance Designer || ?<br />
|-<br />
| Unity([http://www.polycount.com/forum/showpost.php?p=2224781&postcount=29], [http://www.polycount.com/forum/showthread.php?p=2194353#post2194353]) || Handplane, Xnormal (via Asset Store), ?<br />
|-<br />
| Unreal Engine 4 || Handplane, Xnormal([http://www.polycount.com/forum/showpost.php?p=2224402&postcount=20]), ? <br />
|-<br />
| Xnormal || Xnormal, ?<br />
|}<br />
<br />
----<br />
<br />
== What is a Normal Map? ==<br />
A Normal Map is usually used to fake high-res geometry detail when it's mapped onto a low-res mesh. The pixels of the normal map each store a ''normal'', a vector that describes the surface slope of the original high-res mesh at that point. The red, green, and blue channels of the normal map are used to control the direction of each pixel's normal. <br />
<br />
When a normal map is applied to a low-poly mesh, the texture pixels control the direction each of the pixels on the low-poly mesh will be facing in 3D space, creating the illusion of more surface detail or better curvature. However, the silhouette of the model doesn't change. <br />
<br />
<gallery mode="packed"><br />
Whatif_normalmap_mapped2.jpg|A model with a normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_low.jpg|The model without its normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_high.jpg|The high-resolution model used to create the normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
</gallery><br />
<br />
==Tangent-Space vs. Object-Space==<br />
<br />
Normal maps can be made in either of two basic flavors: tangent-space or object-space. World-space is basically the same as object-space, except it requires the model to remain in its original orientation, neither rotating nor deforming, so it's almost never used.<br />
<br />
===Tangent-space normal map===<br />
[[image:normalmap_tangentspace.jpg|frame|none|A tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Predominantly-blue colors. Object can rotate and deform. Good for deforming meshes, like characters, animals, flags, etc.<br />
<br />
Pros:<br />
* Maps can be reused easily, like on differently-shaped meshes.<br />
* Maps can be tiled and mirrored easily, though some games might not support mirroring very well.<br />
* Easier to overlay painted details.<br />
* Easier to use image compression.<br />
<br />
Cons:<br />
* More difficult to avoid smoothing problems from the low-poly vertex normals (see Smoothing Groups and Hard Edges).<br />
* Slightly slower performance than an object-space map (but not by much).<br />
<br />
===Object-space normal map===<br />
[[image:normalmap_worldspace.jpg|frame|none|An object-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Rainbow colors. Objects can rotate, but usually shouldn't be deformed, unless the shader has been modified to support deformation. Object-space is also called local-space or model-space. <br />
<br />
Pros:<br />
* Easier to generate high-quality curvature because it completely ignores the crude smoothing of the low-poly vertex normals.<br />
* Slightly better performance than a tangent-space map (but not by much).<br />
<br />
Cons:<br />
* Can't easily reuse maps, different mesh shapes require unique maps.<br />
* Difficult to tile properly, and mirroring requires specific shader support.<br />
* Harder to overlay painted details because the base colors vary across the surface of the mesh. Painted details must be converted into Object Space to be combined properly with the OS map.<br />
* They don't compress very well, since the blue channel can't be recreated in the shader like with tangent-space maps. Also the three color channels contain very different data which doesn't compress well, creating many artifacts. Using a half-resolution object-space map is one option. <br />
<br />
<br clear="all"/><br />
<br />
=== Converting Between Spaces ===<br />
Normal maps can be converted between object space and tangent space, in order to use them with different blending tools and shaders, which require one type or the other. <br />
<br />
Object space maps can also be converted to maps with different tangent bases, to better match the normal maps with the renderer and thus avoid lighting errors.<br />
<br />
* [http://www.handplane3d.com Handplane] by [http://www.alecmoody.com/ Alec Moody] is a tool that converts object space maps into a variety of tangent spaces: 3ds Max, Creation Engine, Maya, Source, Unity, Unreal, etc. See the Polycount Forum thread [http://www.polycount.com/forum/showthread.php?t=116899 Official handplane support thread - Now freeware!!].<br />
<br />
[[File:handplane_illus_1.jpg|frame|none|Handplane interface. <br>Image by [http://www.alecmoody.com/ Alec Moody].]]<br />
<br />
<br />
* [http://boards.polycount.net/showthread.php?p=1072599#post1072599 NSpace] by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] is a tool that converts an object-space normal map into a tangent-space map, which then works seamlessly in the 3ds Max viewport. He converts the map by using the same tangent basis that 3ds Max uses for its hardware shader. To see the results, load the converted map via the ''Normal Bump'' map and enable "Show Hardware Map in Viewport". [http://gameartist.nl/ Osman "osman" Tsjardiwal] created a GUI for NSpace, you can [http://boards.polycount.net/showthread.php?p=1075143#post1075143 download it here], just put it in the same folder as the NSpace exe and run it. <br />
<br />
[[File:NSpace_Gui_osman.png|frame|none|NSpace interface. <br>Image by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] and [http://gameartist.nl Osman "osman" Tsjardiwal].]]<br />
<br />
[http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson] said: "[8Monkey Labs has] a tool that lets you load up your reference mesh and object space map. Then load up your tangent normals, and adjust some sliders for things like tile and amount. We need to load up a mesh to know how to correctly orient the tangent normals or else things will come out upside down or reverse etc. It mostly works, but it tends to "bend" the resulting normals, so you gotta split the mesh up into some smoothing groups before you run it, and then I usually will just composite this "combo" texture over my orig map in Photoshop."<br />
<br />
<span id="RGBC"></span><span id="RGBChannels"></span><br />
<br />
== RGB Channels ==<br />
Shaders can use different techniques to render tangent-space normal maps, but the normal map directions are usually consistent within a game. Usually the red channel of a tangent-space normal map stores the X axis (pointing the normals predominantly leftwards or rightwards), the green channel stores the Y axis (pointing the normals predominantly upwards or downwards), and the blue channel stores the Z axis (pointing the normals outwards away from the surface).<br />
<br />
[[image:tangentspace_rgb.jpg|frame|none|The red, green, and blue channels of a tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you see lighting coming from the wrong angle when you're looking at your normal-mapped model, and the model is using a tangent-space normal map, the normal map shader might be expecting the red or green channel (or both) to point in the opposite direction. To fix this either change the shader, or simply invert the appropriate color channels in an image editor, so that the black pixels become white and the white pixels become black.<br />
<br />
Some shaders expect the color channels to be swapped or re-arranged to work with a particular [[#NormalMapCompression|compression format]]. For example the DXT5_nm format usually expects the X axis to be in the alpha channel, the Y axis to be in the green channel, and the red and blue channels to be empty.<br />
<br />
== Tangent Basis ==<br />
[[#TangentSpaceVsObjectSpace|Tangent-space]] normal maps use a special kind of vertex data called the ''tangent basis''. This is similar to UV coordinates except it provides directionality across the surface, it forms a surface-relative coordinate system for the per-pixel normals stored in the normal map. This coordinate system is required to light a normal mapped surface.<br />
<br />
Each vertex in the tangent basis is a combination of three things: the mesh vertex's normal (influenced by smoothing), the vertex's tangent (usually derived from the V texture coordinate), and the vertex's bitangent (derived in code, also called the binormal). These three vectors create an axis for each vertex, giving it a specific orientation in the tangent space. These axes are used to properly transform the incoming lighting from world space into tangent space, so your normal-mapped model will be lit correctly.<br />
<br />
Light rays are in world space, but the normals stored in the normal map are in tangent space. When the model is being rendered, the light rays must be converted from world space into tangent space, using the tangent basis to get there. At that point the incoming light rays are compared against the directions of the normals in the normal map, and this determines how much each pixel is going to be lit. Alternatively, instead of converting the light rays some shaders will convert the normals in the normal map from tangent space into world space. Then those world-space normals are compared against the light rays, and the model is lit appropriately. The method depends on who wrote the shader, but the end result is the same. Both methods require a tangent basis to transform the lighting.<br />
<br />
When a triangle's vertex normals are pointing straight out, and a pixel in the normal map is neutral blue (128,128,255) this means the pixel's normal will be pointing straight out from the surface of the low-poly mesh. When that pixel normal is tilted towards the left or the right in the tangent coordinate space, it will get either more or less red color, depending on whether the normal map is set to store the X axis as either a positive or a negative value. Same goes for when the normal is tilted up or down in tangent space, it will either get more or less green color. If the vertex normals aren't exactly perpendicular to the triangle, the normal map pixels will be tinted away from neutral blue as well.<br />
<br />
Unfortunately for artists, there are many different ways to calculate the tangent basis: [http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping 3ds Max], [http://download.autodesk.com/us/maya/2011help/index.html?url=./files/Appendix_A_Tangent_and_binormal_vectors.htm,topicNumber=d0e227193 Maya], [http://www.codesampler.com/dx9src/dx9src_4.htm#dx9_dot3_bump_mapping DirectX 9], [http://developer.nvidia.com/object/NVMeshMender.html NVMeshMender], [http://www.terathon.com/code/tangent.html Eric Lengyel], a custom solution, etc. This means a normal map baked in one application probably won't shade correctly in another. Artists must do some testing with different [[#T|baking tools]] to find which works best with their output. When the renderer (or game engine) renders your game model, [[#ShadersAndSeams|the shader]] must use the same tangent basis as the normal map baker, otherwise you'll get incorrect lighting, especially across the seams between UV shells.<br />
<br />
The [http://www.xnormal.net/ xNormal] SDK supports custom tangent basis methods. When a programmer uses it to implement their renderer's own tangent basis, artists can then use Xnormal to bake normal maps that will match their renderer perfectly.<br />
<br />
[[image:tangentseams.jpg|frame|none|When shared edges are at different angles in UV space, different colors will show up<br />
along the seam. The tangent basis uses these colors to light the model properly. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
When you look at a tangent-space normal map for a character, you typically see different colors along the UV seams. This is because the UV shells are often oriented at different angles on the mesh, a necessary evil when translating the 3D mesh into 2D textures. The body might be mapped with a vertical shell, and the arm mapped with a horizontal one. This requires the normals in the normal map to be twisted for the different orientations of those UV shells. The UVs are twisted, so the normals must be twisted in order to compensate. The tangent basis helps reorient (twist) the lighting as it comes into the surface's local space, so the lighting will then look uniform across the normal mapped mesh.<br />
<br />
When an artist tiles a tangent-space normal map across an arbitrary mesh, like a landscape, this tends to shade correctly because the mesh has a uniform direction in tangent space. If the mesh has discontinuous UV coordinates (UV seams), or the normal map has large directional gradients across it, the tangent space won't be uniform anymore so the surface will probably have shading seams.<br />
<br />
3D Software capable of displaying normal maps will have a native required direction, or "handedness" for the RGB channels in a normal map, sometimes referred to as "Swizzle Coordinates," though [[#SAS|shaders]] can often be written to override this native handedness. You may hear developers refer to "flipping the green channel," and this simply indicates that when the normal map was baked, it was authored with the incorrect handedness in the green channel.<br />
<br />
== Common Swizzle Coordinates ==<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
| '''Software''' <br />
| '''Red''' <br />
| '''Green''' <br />
| '''Blue''' <br />
|-<br />
|<#000000>| Maya<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| 3ds Max<br />
| X+<br />
| Y-<br />
| Z+ <br />
|-<br />
|<#000000>| Unreal Engine<br />
| X+ <br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Unity<br />
| X+<br />
| Y+<br />
| Z+<br />
|-<br />
|<#000000>| Toolbag<br />
| X+<br />
| Y+ <br />
| Z+<br />
|}<br />
<span id="MTLPM"></span><br />
<br />
== Modeling the Low-Poly Mesh ==<br />
The in-game mesh usually needs to be carefully optimized to create a good silhouette, define edge-loops for better deformation, and minimize extreme changes between the vertex normals for better shading (see [[#SmoothingGroupsAndHardEdges|Smoothing Groups & Hard Edges]]).<br />
<br />
In order to create an optimized in-game mesh including a good silhouette and loops for deforming in animation, you can start with the 2nd subdivision level of your [[DigitalSculpting|digital sculpt]], or in some cases with the base mesh itself. Then you can just collapse edge loops or cut in new edges to add/remove detail as necessary. Or you can [[DigitalSculpting#OART|re-toplogize]] from scratch if that works better for you.<br />
<br />
See [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts] on the Polycount forum.<br />
<br />
<span id="UVC"></span><span id="UVCoordinates"></span><br />
=== UV Coordinates ===<br />
Normal map baking tools only capture normals within the 0-1 UV square, any UV bits outside this area are ignored. <br />
<br />
Only one copy of the forward-facing UVs should remain in the 0-1 UV square at baking time. If the mesh uses overlapping UVs, this will likely cause artifacts to appear in the baked map, since the baker will try render each UV shell into the map. Before baking, it's best to move all the overlaps and mirrored bits outside the 0-1 square. <br />
<br />
[[image:Normalmap_uvcoord_offset.jpg|frame|none|The mirrored UVs (in red) are offset 1 unit before baking. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you move all the overlaps and mirrored bits exactly 1 UV unit (any whole number will do), then you can leave them there after the bake and they will still be mapped correctly. You can move them back if you want, it doesn't matter to most game engines. Be aware that ZBrush does use UV offsets to manage mesh visibility, however this usually doesn't matter because the ZBrush cage mesh is often a different mesh than the in-game mesh used for baking.<br />
<br />
You should avoid changing the UVs after baking the normal map, because rotating or mirroring UVs after baking will cause the normal map not to match the [[#TB|tangent basis]] anymore, which will likely cause lighting problems. <br />
<br />
In 3ds Max, W is a third texture coordinate. It's used for 3D procedural textures and for storing vertex color in UV channels (you need 3 axes for RGB, so UVW can store vertex color). Bake problems can be avoided by moving any overlapping UVs to -1 on the W axis, with the same results as moving them 1 unit on the U or V axes. The tool Render To Texture will always bake whatever UVs are the highest along the W axis. However using W can be messy... it's generally hidden unless you purposefully look for it (bad for team work), doesn't get preserved on export to other apps, and high W values can prevent selecting and/or welding UVs. <br />
<br />
<span id="M"></span><span id="Mirroring"></span><br />
<br />
=== Mirroring ===<br />
Normal maps can be mirrored across a model to create symmetrical details, and save UV space, which allows more detail in the normal map since the texture pixels are smaller on the model. <br />
<br />
With [[#OSNM|object-space]] maps, mirroring requires [http://boards.polycount.net/showthread.php?t=53986 specific shader support]. For [[#TSNM|tangent-space]] maps, mirroring typically creates a shading seam, but this can be reduced or hidden altogether, depending on the method used.<br />
<br />
<span id="TMW"></span><br />
==== Typical Mirroring Workflow ====<br />
# Delete the mesh half that will be mirrored. <br />
# Arrange the UVs for the remaining model, filling the UV square.<br />
# Mirror the model to create a "whole" mesh, welding the mesh vertices along the seam. <br />
# Move the mirrored UVs exactly 1 unit (or any whole number) out of the 0-1 UV square.<br />
# Bake the normal map.<br />
<br />
Sometimes an artist will decide to delete half of a symmetrical model before baking. <br />
<br />
This is a mistake however because often the vertex normals along the hole will bend towards the hole a bit; there are no faces on the other side to average the normals with. This will create a strong lighting seam in the normal map. <br />
<br />
It's typically best to use the complete mirrored model to bake the normal map, not just the unique half. <br />
<br />
To prevent the mirrored UVs from causing overlaps or baking errors, move the mirrored [[#UVC|UVs]] out of the 0-1 UV space, so only one copy of the non-mirrored UVs is left within the 0-1 square.<br />
<br />
To avoid texel "leaks" between the UV shells, make sure there's enough [[#Edge_padding|Edge Padding]] around each shell, including along the edges of the normal map. None of the UV shells should be touching the edge of the 0-1 UV square, unless they're meant to tile with the other side of the map.<br />
<br />
<span id="CM"></span><br />
<br />
==== Center Mirroring ====<br />
If the mirror seam runs along the surface of a continuous mesh, like down the center of a human face for example, then it will probably create a lighting seam. <br />
<br />
In Epic Games' [http://www.unrealtechnology.com/technology.php Unreal Engine 3] (UE3) their symmetrical models commonly use centered mirroring. Epic uses materials that mix a [[DetailMap]] with the normal maps; these seem to scatter the diffuse/specular lighting and help minimize the obviousness of the mirror seams. For their [[Light Map]]ped models they use [http://udn.epicgames.com/Three/LightMapUnwrapping.html a technique] that can almost completely hide the mirror seam.<br />
<br />
[[image:Epic_MirroringCicada.jpg|frame|none| In UE3 a center mirror seam is reduced by using a detail normal map. <br> Image by "[http://epicgames.com Epic Games]"]]<br />
<br />
'''''[http://www.zbrushcentral.com/showpost.php?p=573108&postcount=28 GOW2 normal map seams], [http://utforums.epicgames.com/showthread.php?p=27166791#post27166791 UDK normal map seams]'''''<br />
<br />
<span id="OM"></span><br />
<br />
==== Offset Mirroring ====<br />
Offset mirroring is a method where you move the mirror seam off to one side of the model, so the seam doesn't run exactly down the center. For example with a character's head, the UV seam can go down along the side of the head in front of the ear. The UV shell for the nearest ear can then be mirrored to use the area on the other side of the head. <br />
<br />
This avoids the "Rorschach" effect and allows non-symmetrical details, but it still saves texture space because the two sides of the head can be mirrored (they're never seen at the same time anyhow).<br />
<br />
Offset mirroring doesn't get rid of the seam, but it does move it off to a place where it can either be less obvious, or where it can be hidden in a natural seam on the model.<br />
<br />
<span id="FCM"></span><br />
==== Flat Color Mirroring ====<br />
[http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] solves seams by painting a flat set of normals along the seam, using neutral blue (128,128,255). However it only works along horizontal or vertical UV seams, not across any angled UVs. It also removes any details along the mirror seam, creating blank areas. <br />
<br />
<span id="EM"></span><br />
==== Element Mirroring ====<br />
The mirror seam can be avoided completely when it doesn't run directly through any mesh. For example if there's a detached mesh element that runs down the center of the model, this can be uniquely mapped, while the meshes on either side can be mirrors of each other. Whenever the mirrored parts don't share any vertex normals with the non-mirrored parts, there won't be any seams. <br />
<br />
[[image:normalmap_mirrored-binocs-racer445.jpg|frame|none|The middle part (highlighted in red) uses unique non-mirrored UVs, allowing the mesh on the right to be mirrored without any seams. <br>Image by [http://http://racer445.com/ "racer445"]]]<br />
<br />
<span id="SGAHE"></span><br />
<br />
=== Smoothing Groups & Hard Edges ===<br />
Each vertex in a mesh has at least one vertex normal. Vertex normals are used to control the direction a triangle will be lit from; if the normal is facing the light the triangle will be fully lit, if facing away from the light the triangle won't be lit. <br />
<br />
Each vertex however can have more than one vertex normal. When two triangles have different vertex normals along their shared edge, this creates a shading seam, called a ''hard edge'' in most modeling tools. 3ds Max uses ''Smoothing Groups'' to create hard/soft edges, Maya uses ''Harden Edge'' and ''Soften Edge''. These tools create hard and soft edges by splitting and combining the vertex normals.<br />
<br />
[[image:BenMathis_SmoothingGroups_Excerpt.gif|frame|none|Hard edges occur where the vertices have multiple normals. <br>Image by [http://poopinmymouth.com Ben 'poopinmymouth' Mathis] ([http://poopinmymouth.com/process/tips/smoothing_groups.jpg tutorial here])]]<br />
<br />
When a mesh uses all soft normals (a single smoothing group) the lighting has to be interpolated across the extreme differences between the vertex normals. If your renderer doesn't support the same [[#TangentBasis|tangent basis]] that the baker uses, this can produce extreme shading differences across the model, which creates shading artifacts. It is generally best to reduce these extremes when you can because a mismatched renderer can only do so much to counteract it.<br />
<br />
Hard edges are usually best where the model already has a natural seam. For example, you can add a hard edge along the rim of a car's wheel well, to prevent the inside of the wheel well from distorting the shading for the outside of the car body. Mechanical models usually need hard edges where ever the surface bends more than about 45 degrees. <br />
<br />
For most meshes, the best results usually come from adding hard edges where ever there are UV seams. There are no hard rules however, you must experiment with different approaches to find what works best in your game.<br />
<br />
When you use object-space normal maps the vertex normal problem goes away since you're no longer relying on the crude vertex normals of the mesh. An object-space normal map completely ignores vertex normals. Object-space mapping allows you to use all soft edges and no bevels on the low-res mesh, without showing lighting errors.<br />
<br />
<span id="HEDAT"></span><br />
==== Hard Edge Discussions & Tutorials ====<br />
* [http://www.polycount.com/forum/showthread.php?p=2090450#post2090450 Maya MEL Script help needed (UV border edges)]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=73593 Normal Maps: Can Somone Explain This "Black Edge" issue]<br />
* [http://www.polycount.com/forum/showthread.php?t=73566 Normal Maps: Can someone explain normals, tangents and split UVs?]<br />
* [http://www.polycount.com/forum/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max]<br />
* [http://boards.polycount.net/showthread.php?t=68173 Why you should NOT trust 3ds Max's viewport normal-map display!]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/10503-xsi-normal-mapped-cube-looks-bad.html XSI - normal mapped cube looks bad]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/11924-weird-maya-normal-map-seam-artifact-problem-am-i-making-simple-mistake.html Weird Maya normal map seam/artifact problem]<br />
* [http://boards.polycount.net/showthread.php?p=1080600 Seams in Normals when Creating Tiling Environment Trims and other Tiles]<br />
* The tutorial [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing can affect the normal map.<br />
* The tutorial: [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] shows how smoothing affects raycasting.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses the breaking of normals and smoothing groups in general terms.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in the game, not the triangle count.<br />
* The Crysis documentation [http://doc.crymod.com/AssetCreation/PolyBumpReference.html PolyBump Reference] has a section towards the bottom that shows how smoothing affects their baked normal maps.<br />
* The polycount thread [http://boards.polycount.net/showthread.php?t=60694 Toying around with normal map approaches] has a great discussion of how best to use smoothing groups and bevels for better shading.<br />
<br />
<span id="UB"></span><br />
==== Using Bevels ====<br />
Bevels/chamfers generally improve the silhouette of the model, and can also help reflect specular highlights better. <br />
<br />
However bevels tend to produce long thin triangles, which slow down the in-game rendering of your model. Real-time renderers have trouble rendering long thin triangles because they create a lot of sub-pixel areas to render. <br />
<br />
Bevels also balloon the vertex count, which can increase the transform cost and memory usage. Hard edges increase the vertex count too, but not when the edge also shares a seam in UV space. For a good explanation of the vertex count issue, see [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly].<br />
<br />
Using hard edges with matching UV shells tends to give better performance and better cosmetic results than using bevels. However there are differing opinions on this, see the Polycount thread "[http://boards.polycount.net/showthread.php?t=71760 Maya transfer maps help]".<br />
<br />
<span id="EVN"></span><br />
==== Edited Vertex Normals ====<br />
If you use bevels the shading will be improved by editing the vertex normals so the larger flat surfaces have perpendicular normals. The vertex normals are then forced to blend across the smaller bevel faces, instead of across the larger faces. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66139 Superspecular soft edges tutorial chapter 1].<br />
<br />
[[image:oliverio_bevel_normals.gif|frame|none|Bending normals on bevelled models. <br>From the tutorial [http://deadlineproof.com/model-shading-techniques-soft-edge-superspecular/ Shading techniques Superspecular soft edges]<br>Image by [http://deadlineproof.com/ Paolo Oliverio]]]<br />
<br />
== Level of Detail Models ==<br />
See [http://www.polycount.com/forum/showthread.php?p=1216945#post1216945 Problem if you're using 3point-style normals with an LOD].<br />
<br />
<span id="MTHPM"></span><br />
<br />
== Modeling The High-Poly Mesh ==<br />
[[Subdivision Surface Modeling]] and [[DigitalSculpting]] are the techniques most often used for modeling a normal map. <br />
<br />
Some artists prefer to model the in-game mesh first, other artists prefer to model the high-res mesh first, and others start somewhere in the middle. The modeling order is ultimately a personal choice though, all three methods can produce excellent results:<br />
* Build the in-game model, then up-res it and sculpt it.<br />
* Build and sculpt a high resolution model, then build a new in-game model around that.<br />
* Build a basemesh model, up-res and sculpt it, then step down a few levels of detail and use that as a base for building a better in-game mesh.<br />
If the in-game mesh is started from one of the subdivision levels of the basemesh sculpt, various edge loops can be collapsed or new edges can be cut to add/remove detail as necessary.<br />
<br />
<span id="SE"></span><br />
=== Sloped Extrusions ===<br />
[[image:normal_slopes_hatred.jpg|frame|none|Extrusions on the high-poly model should be sloped to make a better normal map. <br>Image by [http://www.hatred.gameartisans.org/ Krzysztof "Hatred" Dolas].]]<br />
<br />
=== Floating Geometry ===<br />
[[image:FloatingGeo.jpg|frame|none|Normal map stores the direction the surface is facing rather than real depth information, thus allowing to save time using floating geometry. <br>To correctly bake AO with floating geo make it a separate object and turn off it's shadow casting. <br>Image by [http://artisaverb.info/ Andrew "d1ver" Maximov].]]<br />
<br />
See also [[3DTutorials/Modeling High-Low Poly Models for Next Gen Games|Modeling High/Low Poly Models for Next Gen Games]] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa]<br />
<br />
<span id="ET"></span><br />
<br />
=== Edge Thickness ===<br />
[[image:normal_edge_thickness.jpg|frame|none|When creating edges of the Highpoly, sometimes you'll need to make them rounded than in real life to <br>work better at the size they will be seen.<br>Image by [http://racer445.com/Evan "racer445" Herbert]]]<br />
<br />
<span id="MRF"></span><span id="MRRCB"></span><br />
<br />
=== mental ray Round Corners Bump ===<br />
The mental ray renderer offers an automatic bevel rendering effect called Round Corners Bump that can be baked into a normal map. This is available in 3ds Max, Maya, and XSI. See [http://boards.polycount.net/showthread.php?t=71995 Zero Effort Beveling for normal maps] - by [http://boards.polycount.net/member.php?u=31662 Robert "r_fletch_r" Fletcher].<br />
<br />
[http://jeffpatton.net/ Jeff Patton] posted about [http://jeffpatton.cgsociety.org/blog/archive/2007/10/ how to expose Round Corners Bump] in 3ds Max so you can use it in other materials.<br />
<br />
[http://cryrid.com/art/ Michael "cryrid" Taylor] posted a tutorial about how to use [http://cryrid.com/images/temp/XSI/zeroeffort_bevels.jpg Round Corners in XSI].<br />
<br />
XSI is able to bake a good normal map with it, but 3ds Max seems to bake it incorrectly, and Maya isn't able to bake the effect at all. Maybe Max might be able to bake it correctly, if the .mi shader is edited to use the correct coordinate space?<br />
<br />
<span id="Baking"></span><span id="B"></span><br />
== Baking ==<br />
The process of transferring normals from the high-res model to the in-game model is often called baking. The baking tool usually starts projecting a certain numerical distance out from the low-poly mesh, and sends rays inwards towards the high-poly mesh. When a ray intersects the high-poly mesh, it records the mesh's surface normal and saves it in the normal map.<br />
<br />
To get an understanding of how all the options affect your normal map, do some test bakes on simple meshes like boxes. They generate quickly so you can experiment with [[#UVCoordinates|UV mirroring]], [[#SGAHE|smoothing groups]], etc. This helps you learn the settings that really matter.<br />
* The tutorial [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] has more examples of ray-casting, plus how to get better results from the bake.<br />
<br />
Baking sub-sections:<br />
# [[#Anti-Aliasing|Anti-Aliasing]]<br />
# [[#Baking_Transparency|Baking Transparency]]<br />
# [[#Edge_Padding|Edge Padding]]<br />
# [[#High_Poly_Materials|High Poly Materials]]<br />
# [[#Reset_Transforms|Reset Transforms]]<br />
# [[#Solving_Intersections|Solving Intersections]]<br />
# [[#Solving_Pixel_Artifacts|Solving Pixel Artifacts]]<br />
# [[#Solving_Wavy_Lines|Solving Wavy Lines]]<br />
# [[#Triangulating|Triangulating]]<br />
# [[#Working_with_Cages|Working with Cages]]<br />
<br />
<span id="AA"></span><br />
=== Anti-Aliasing ===<br />
Turning on super-sampling or anti-aliasing (or whatever multi-ray casting is called in your normal map baking tool) will help to fix any jagged edges where the high-res model overlaps itself within the UV borders of the low-poly mesh, or wherever the background shows through holes in the mesh. Unfortunately this tends to render much much slower, and takes more memory.<br />
<br />
[[image:normalmap_aliasing_knak47.jpg|frame|none|A bake without anti-aliasing shows artifacts where the high-poly mesh has overlaps. <br>Image by [http://www.polycount.com/forum/member.php?u=35938 'knak47']]]<br />
<br />
One trick to speed this up is to render 2x the intended image size then scale the normal map down 1/2 in a paint program like Photoshop. The reduction's pixel resampling will add anti-aliasing for you in a very quick process. After scaling, make sure to re-normalize the map if your game doesn't do that already, because the un-normalized pixels in your normalmap may cause pixelly artifacts in your specular highlights. Re-normalizing can be done with [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA's normal map filter] for Photoshop.<br />
<br />
3ds Max's supersampling doesn't work nicely with edge padding, it produces dark streaks in the padded pixels. If so then turn off padding and re-do the padding later, either by re-baking without supersampling or by using a Photoshop filter like the one that comes with [[#3DTools|Xnormal]].<br />
<br />
=== Baking Transparency ===<br />
Sometimes you need to bake a normal map from an object that uses opacity maps, like a branch with opacity-mapped leaves. Unfortunately baking apps often completely ignore any transparency mapping on your high-poly mesh.<br />
<br />
{|class="wikitable"<br />
|[[image:JoeWilson_ivynormals_error.jpg]] <br />
|[[image:JoeWilson_ivynormals_rendered.jpg]]<br />
|-<br />
|3ds Max's RTT baker causes transparency errors.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|The lighting method bakes perfect transparency.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|}<br />
<br />
To solve this, render a Top view of the mesh. This only works if you're using a planar UV projection for your low-poly mesh and you're baking a tangent-space normal map.<br />
<br />
* Make sure the Top view matches the dimensions of the planar UV projection used by the low-poly mesh. It helps to use an orthographic camera for precise placement.<br />
* On the high-poly mesh either use a specific lighting setup or a use special material shader:<br />
* 1) The lighting setup is described in these tutorials:<br />
* * [http://www.bencloward.com/tutorials_normal_maps11.shtml Creating A Normal Map Right In Your 3D App] by [http://www.bencloward.com/ Ben Cloward]<br />
* *[http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy], Graphics Techniques Consultant, Xbox Content and Design Team<br />
* 2) The material shader does the same thing, but doesn't require lights.<br />
* * [http://www.scriptspot.com/3ds-max/normaltexmap NormalTexMap] scripted map for 3ds Max by [http://www.scriptspot.com/users/dave-locke Dave Locke].<br />
* * [http://www.footools.com/3dsmax_plugins.html InfoTexture] map plugin for 3ds Max by [http://www.footools.com John Burnett]<br />
<br />
[[image:BenCloward_NormalMapLighting.gif|frame|none|The lighting setup for top-down rendering. <br>Image by [http://www.bencloward.com Ben Cloward]]]<br />
<br />
<span id="EP"></span><br />
<br />
=== Edge Padding ===<br />
If a normal map doesn't have enough [[Edge_padding |Edge Padding]], this will create shading seams on the UV borders.<br />
<br />
=== High Poly Materials ===<br />
3ds Max will not bake a normal map properly if the high-res model has a mental ray Arch & Design material applied. If your normal map comes out mostly blank, either use a Standard material or none at all. For an example see the Polycount thread [http://www.polycount.com/forum/showthread.php?t=74792 Render to Texture >:O].<br />
<br />
<span id="RT"></span><br />
=== Reset Transforms ===<br />
Before baking, make sure your low-poly model's transforms have been reset. '''''This is very important!''''' Often during the modeling process a model will be rotated and scaled, but these compounded transforms can create a messy local "space" for the model, which in turn often creates rendering errors for normal maps. <br />
<br />
In 3ds Max, use the Reset Xforms utility then Collapse the Modifier Stack. In Maya use Freeze Transformation. In XSI use the Freeze button.<br />
<br />
<span id="SI"></span><br />
<br />
=== Solving Intersections ===<br />
The projection process often causes problems like misses, or overlaps, or intersections. It can be difficult generating a clean normal map in areas where the high-poly mesh intersects or nearly intersects itself, like in between the fingers of a hand. Setting the ray distance too large will make the baker pick the other finger as the source normal, while setting the ray distance too small will lead to problems at other places on the mesh where the distances between in-game mesh and high-poly mesh are greater.<br />
<br />
Fortunately there are several methods for solving these problems.<br />
<br />
# Change the shape of the cage. Manually edit points on the projection cage to help solve tight bits like the gaps between fingers.<br />
# Limit the projection to matching materials, or matching UVs.<br />
# Explode the meshes. See the polycount thread [http://boards.polycount.net/showthread.php?t=62921 Explode script needed (for baking purposes)].<br />
# Bake two or more times using different cage sizes, and combine them in Photoshop.<br />
<br />
<span id="SPA"></span><br />
<br />
=== Solving Pixel Artifacts ===<br />
[[image:filterMaps_artifact.jpg|frame|none|Random pixel artifacts in the bake. <br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
If you are using 3ds Max's ''Render To Texture'' to bake from one UV layout to another, you may see stray pixels scattered across the bake. This only happens if you are using a copy of the original mesh in the Projection, and that mesh is using a different UV channel than the original mesh.<br />
<br />
There are two solutions for this:<br />
<br />
* Add a Push modifier to the copied mesh, and set it to a low value like 0.01.<br />
- or -<br />
<br />
* Turn off ''Filter Maps'' in the render settings (Rendering menu > Render Setup > Renderer tab > uncheck Filter Maps). To prevent aliasing you may want to enable the Global Supersampler in Render Setup.<br />
<br />
See also [[#Anti-Aliasing]].<br />
<br />
<span id="SWL"></span><br />
<br />
=== Solving Wavy Lines ===<br />
When capturing from a cylindrical shape, often the differences between the low-poly mesh and the high-poly mesh will create a wavy edge in the normal map. There are a couple ways to avoid this:<br />
<br />
# The best way... create your lowpoly model with better supporting edges. See the Polycount threads [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?], [http://boards.polycount.net/showthread.php?t=55754 approach to techy stuff], [http://www.polycount.com/forum/showthread.php?t=72713 Any tips for normal mapping curved surface?].<br />
# Adjust the shape of the cage to influence the directions the rays will be cast. Beware... this work will have to be re-done every time you edit the lowpoly mesh, as the cage will be invalidated. At the bottom of [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm this page of his normal map tutorial], [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to do this in 3ds Max. Same method can be seen in the image below.<br />
# Subdivide the low-res mesh so it more closely matches the high-res mesh. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] has a [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa video tutorial] that shows how to do this in Maya.<br />
# Paint out the wavy line. Beware... this work will have to be re-done every time you re-bake the normal map. The [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
# Use a separate planar-projected mesh for the details that wrap around the barrel area, so the ray-casting is more even. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. For example to add tread around a tire, the tread can be baked from a tread model that is laid out flat, then that bake can layered onto the bake from the cylindrical tire mesh in a paint program.<br />
<br />
[[image:timothy_evison_normalmap_projections.jpg|frame|none|Adjusting the shape of the cage to remove distortion. <br>Image by [http://users.cybercity.dk/~dsl11905/resume/resume.html Timothy "tpe" Evison]]]<br />
<br />
<span id="TRI"></span><br />
<br />
=== Triangulating ===<br />
Before baking, it is usually best to triangulate the low-poly model, converting it from polygons into pure triangles. This prevents the vertex normals from being changed later on, which can create specular artifacts.<br />
<br />
[[image:triangulation_modo_ohare.jpg|frame|none| When quads are triangulated in [http://www.luxology.com/modo/ Modo], the internal edges are sometimes flipped, which causes shading differences.<br>Image by [http://www.farfarer.com/|James "Talon" O'Hare]]]<br />
<br />
<br />
Sometimes a baking tool or a mesh exporter/importer will re-triangulate the polygons. A quad polygon is actually treated as two triangles, and the internal edge between them is often switched diagonally during modeling operations. When the vertices of the quad are moved around in certain shapes, the software's algorithm for polygon models tries to keep the quad surface in a "rational" non-overlapping shape. It does this by switching the internal edge between its triangles.<br />
<br />
<br />
[[image:triangulation_spec_tychovii.jpg|frame|none| The specular highlight is affected by triangulation. Flip edges to fix skewing. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66651 Skewed Specular Highlight?] for pictures and more info.<br> Image by [http://robertkreps.com Robert "TychoVII" Kreps]]]<br />
<br />
<br />
<span id="WWC"></span><br />
<br />
=== Working with Cages ===<br />
''Cage'' has two meanings in the normal-mapping process: a low-poly base for [[subdivision surface modeling]] (usually called the [[DigitalSculpting#BM|basemesh]]), or a ray-casting mesh used for normal map baking. This section covers the ray-casting cage.<br />
<br />
Most normal map baking tools allow you to use a distance-based raycast. A ray is sent outwards along each vertex normal, then at the distance you set a ray is cast back inwards. Where ever that ray intersects the high poly mesh, it will sample the normals from it. <br />
<br />
{|class="wikitable"<br />
|[[Image:Normalmap_raycasting_1.jpg]] <br />
|[[Image:Normalmap_raycasting_2.jpg]]<br />
|-<br />
|Hard edges and a distance-based raycast (gray areas) cause ray misses (yellow) and ray overlaps (cyan).<br> Image by [http://www.mankua.com/ Diego Castaño]<br />
|The gray area shows that using all soft edges (or hard edges and a cage-based raycast) will avoid ray-casting errors from split normals.<br> Image by [http://www.mankua.com/ Diego Castaño] <br />
|}<br />
<br />
Unfortunately with a distance-based raycast, [[#SGAHE|split vertex normals]] will cause the bake to miss parts of the high-res mesh, causing errors and seams. <br />
<br />
Some software allows you to use ''cage mesh'' option instead, which basically inflates a copy of the low-poly mesh, then raycasts inwards from each vertex. This ballooned-out mesh is the cage.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
|<tablebgcolor="#ffaaaa">| <br />
|}<br />
<br />
In 3ds Max the cage controls both the distance and the direction of the raycasting. <br />
<br />
In Maya the cage only controls the distance; the ray direction matches the vertex normals (inverted).<br />
<br />
<span style="text-decoration: line-through"> This may have been fixed in the latest release...<<BR>><br />
In Xnormal the cage is split everywhere the model has [[#SGAHE|hard edges]], causing ray misses in the bake. You can fix the hard edge split problem but it involves an overly complex workflow. You must also repeat the whole process any time you change your mesh:</span><br />
# <s> Load the 3d viewer.</s><br />
# <s> Turn on the cage editing tools.</s><br />
# <s> Select all of the vertices.</s><br />
# <s> Weld all vertices.</s><br />
# <s> Expand the cage as you normally would.</s><br />
# <s> Save out your mesh using the Xnormal format.</s><br />
# <s> Make sure Xnormal is loading the correct mesh.</s><br />
<br />
<span id="P"></span><span id="Painting"></span><br />
<br />
== Painting ==<br />
Don't be afraid to edit normal maps in Photoshop. After all it is just a texture, so you can clone, blur, copy, blend all you want... as long as it looks good of course. Some understanding of [[#RGBChannels|the way colors work]] in normal maps will go a long way in helping you paint effectively.<br />
<br />
A normal map sampled from a high-poly mesh will nearly always be better than one sampled from a texture, since you're actually grabbing "proper" normals from an accurate, highly detailed surface. That means your normal map's pixels will basically be recreating the surface angles of your high-poly mesh, resulting in a very believable look.<br />
<br />
If you only convert an image into a normal-map, it can look very flat, and in some cases it can be completely wrong unless you're very careful about your value ranges. Most image conversion tools assume the input is a heightmap, where black is low and white is high. If you try to convert a diffuse texture that you've painted, the results are often very poor. Often the best results are obtained by baking the large and mid-level details from a high-poly mesh, and then combined with photo-sourced "fine detail" normals for surface details such as fabric weave, scratches and grain.<br />
<br />
Sometimes creating a high poly surface takes more time than your budget allows. For character or significant environment assets then that is the best route, but for less significant environment surfaces working from a heightmap-based texture will provide a good enough result for a much less commitment in time.<br />
<br />
* [http://crazybump.com/ CrazyBump] is a commercial normal map converter.<br />
* [http://www.renderingsystems.com/support/showthread.php?tid=3 ShaderMap] is a commercial normal map converter.<br />
* [http://www.pixplant.com/ PixPlant] is a commercial normal map converter.<br />
* [http://boards.polycount.net/showthread.php?t=68860 NJob] is a free normal map converter.<br />
* [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA normalmap filter for Photoshop] is a free normal map converter.<br />
* [http://xnormal.net Xnormal height-to-normals filter for Photoshop] is a free normal map converter.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm Normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
<br />
=== Flat Color ===<br />
The color (128,128,255) creates normals that are completely perpendicular to the polygon, as long as the vertex normals are also perpendicular. Remember a normal map's per-pixel normals create ''offsets'' from the vertex normals. If you want an area in the normal map to be flat, so it creates no offsets from the vertex normals, then use the color (128,128,255). <br />
<br />
This becomes especially obvious when [[#Mirroring|mirroring a normal map]] and using a shader with a reflection ingredient. Reflection tends to accentuate the angles between the normals, so any errors become much more apparent.<br />
<br />
[[image:normalmap_127seam.jpg|thumb|600px|none| Mirrored normal maps show a seam when (127,127,255) is used for the flat color; 128 is better.<br>Image by [http://www.ericchadwick.com Eric Chadwick]]]<br />
<br />
In a purely logical way, 127 seems like it would be the halfway point between 0 and 255. However 128 is the color that actually works in practice. When a test is done comparing (127,127,255) versus (128,128,255) it becomes obvious that 127 creates a slightly bent normal, and 128 creates a flat one.<br />
<br />
This is because most game pipelines use ''unsigned'' normal maps. For details see the Polycount forum thread [http://www.polycount.com/forum/showpost.php?p=771360&postcount=22 tutorial: fixing mirrored normal map seams].<br />
<br />
<span id="BNMT"></span><br />
<br />
=== Blending Normal Maps Together ===<br />
Blending normal maps together is a quick way to add high-frequency detail like wrinkles, cracks, and the like. Fine details can be painted as a height map, then it can be converted into a normal map using one of the normal map tools. Then this "details" normal map can be blended with a geometry-derived normal map using one of the methods below. <br />
<br />
Here is a comparison of four of the blending methods. Note that in these examples the default values were used for CrazyBump (Intensity 50, Strength 33, Strength 33), but the tool allows each layer's strength to be adjusted individually for stronger or milder results. Each of the normal maps below were [[#Renormalizing|re-normalized]] after blending.<br />
<br />
{|class="wikitable"<br />
|[[image:nrmlmap_blending_methods_Maps.png]]<br />
|[[image:nrmlmap_blending_methods_RTTNormalMapFX.png]]<br />
|-<br />
|The blended normal maps.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|Screenshot of the 3dsmax viewport, using the RTTNormalMap.fx shader.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|}<br />
<br />
The four blending methods used above:<br />
# [http://www.crazybump.com CrazyBump] by Ryan Clark blends normal maps together using calculations in 3D space rather than just in 2D. This does probably the best job at preserving details, and each layer's strength settings can be tweaked individually. <br />
# [http://www.rodgreen.com/?p=4 Combining Normal Maps in Photoshop] by Rod Green blends normal maps together using Linear Dodge mode for the positive values and Difference mode for the negative values, along with a Photoshop Action to simplify the process. It's free, but the results may be less accurate than CrazyBump.<br />
# [http://www.paultosca.com/makingofvarga.html Making of Varga] by [http://www.paultosca.com/ Paul "paultosca" Tosca] blends normal maps together using Overlay mode for the red and green channels and Multiply mode for the blue channel. This gives a slightly stronger bump than the Overlay-only method. [http://www.leocov.com/ Leo "chronic" Covarrubias] has a step-by-step tutorial for this method in [http://www.cgbootcamp.com/tutorials/2009/12/9/photoshop-combine-normal-maps.html CG Bootcamp Combine Normal Maps].<br />
# [[3DTutorials/Normal Map Deepening|Normal Map Deepening]] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to blend normal maps together using Overlay mode. [http://cgtextures.com/content.php?action=tutorial&name=normalmap CGTextures tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] also shows how to create normalmaps using multiple layers (Note: to work with the Overlay blend mode each layer's Output Level should be 128 instead of 255, you can use the Levels tool for this).<br />
<br />
The [http://boards.polycount.net/showthread.php?t=69615 Getting good height from Nvidia-filter normalizing grayscale height] thread on the Polycount forum has a discussion of different painting/blending options. Also see the [[#2DT|2D Tools]] section for painting and conversion tools.<br />
<br />
<span id="PCT"></span><br />
<br />
=== Pre-Created Templates ===<br />
A library of shapes can be developed and stored for later use, to save creation time for future normal maps. Things like screws, ports, pipes, and other doo-dads. These shapes can be stored as bitmaps with transparency so they can be layered into baked normal maps.<br />
<br />
* [http://www.beautifulrobot.com/?p=69 Creating & Using NormalMap "Widgets"] - by ''[http://www.beautifulrobot.com Steev "kobra" Kelly]''<<BR>> How to set up and render template objects.<br />
* [http://www.akramparvez.com/portfolio/scripts/normalmap-widget-for-3ds-max/ NormalMap Widget for 3ds Max] - by ''[http://www.akramparvez.com Akram Parvez]''<<BR>>A script to automate the setup and rendering process.<br />
* See the section [[#BT|Baking Transparency]] for more template-rendering tools and tutorials.<br />
<br />
<span id="RN"></span><span id="Renormalizing"></span><br />
=== Re-normalizing ===<br />
Re-normalizing means resetting the length of each normal in the map to 1.<br />
<br />
A normal mapping shader takes the three color channels of a normal map and combines them to create the direction and length of each pixel's normal. These normals are then used to apply the scene lighting to the mesh. However if you edit normal maps by hand or if you blend multiple normal maps together this can cause those lengths to change. Most shaders expect the length of the normals to always be 1 (normalized), but some are written to re-normalize the normal map dynamically (for example, 3ds Max's Hardware Shaders do re-normalize).<br />
<br />
If the normals in your normal map are not normalized, and your shader doesn't re-normalize them either, then you may see artifacts on the shaded surface... the specular highlight may speckle like crazy, the surface may get patches of odd shadowing, etc. To help you avoid this NVIDIA's normal map filter for Photoshop provides an easy way to re-normalize a map after editing; just use the '''Normalize Only''' option. [http://xnormal.net Xnormal] also comes with a Normalize filter for Photoshop.<br />
<br />
[[image:normalize_only.jpg|frame|none|The re-normalize option in the NVIDIA filter.<br>Image by [http://hirezstudios.com/ Scott Warren]]]<br />
<br />
Some shaders use [[#NormalMapCompression|compressed normal maps]]. Usually this means the blue channel is thrown away completely, so it's recalculated on-the-fly in the shader. However the shader has to re-normalize in order to recreate that data, so any custom normal lengths that were edited into the map will be ignored completely. <br />
<br />
<span id="AOIANM"></span><span id="AmbientOcclusionIntoANormalMap"></span><br />
<br />
=== Ambient Occlusion into a Normal Map ===<br />
If the shader doesn't re-normalize the normal map, an [[Ambient Occlusion Map]] can actually be baked into the normal map. This will shorten the normals in the crevices of the surface, causing the surface to receive less light there. This works with both diffuse and specular, or any other pass that uses the normal map, like reflection.<br />
<br />
However it's usually best to keep the AO as a separate map (or in an alpha channel) and multiply it against the ambient lighting only. This is usually done with a custom [[:Category:Shaders|shader]]. If you multiply it against the diffuse map or normal map then it also occludes diffuse lighting which can make the model look dirty. Ambient occlusion is best when it occludes ambient lighting only, for example a [[DiffuselyConvolvedCubeMap|diffusely convolved cubemap]].<br />
<br />
[[image:nrmlmap_ao.jpg|frame|none| AO can be baked into a normal map, shortening the normals (lower left model).<br>Model by [http://www.3dartisan.net/~kuman/ James Ku]]]<br />
<br />
To bake the AO into a normal map, adjust the levels of the AO layer first so the darks only go as low as 128 gray, then set the AO layer to Darken mode. This will shorten the normals in the normalmap, causing the surface to receive less light in the darker areas. <br />
<br />
This trick doesn't work with any shaders that re-normalize, like 3ds Max's Hardware Shaders. The shader must be altered to actually use the lengths of your custom normals; most shaders just assume all normals are 1 in length because this makes the shader code simpler. Also this trick will not work with most of the common [[#NormalMapCompression|normal map compression formats]], which often discard the blue channel and recalculate it in the shader, which requires re-normalization.<br />
<br />
<span id="BLE"></span><br />
<br />
=== Back Lighting Example ===<br />
You can customize normal maps for some interesting effects. If you invert the blue channel of a tangent-space map, the normals will be pointing to the opposite side of the surface, which can simulate backlighting.<br />
<br />
{|class="wikitable"<br />
|[[image:tree_front.jpg]]||[[image:tree_back.jpg]]<br />
|-<br />
|Tree simulating subsurface scattering (front view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|Tree simulating subsurface scattering (back view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|-<br />
|colspan="2"|[[image:tree_maps.jpg]]<br />
|-<br />
|colspan="2"|The maps used for the leaves. The 2nd diffuse was simply color-inverted, hue-shifted 180°, and saturated.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
The tree leaves use a shader than adds together two diffuse maps, one using a regular tangent-space normal map, the other using the same normal map but with the blue channel inverted. This causes the diffuse map using the regular normal map to only get lit on the side facing the light (front view), while the diffuse map using the inverted normal map only gets lit on the opposite side of the leaves (back view). The leaf geometry is 2-sided but uses the same shader on both sides, so the effect works no matter the lighting angle. As an added bonus, because the tree is self-shadowing the leaves in shadow do not receive direct lighting, which means their backsides do not show the inverted normal map, so the fake subsurface scatter effect only appears where the light directly hits the leaves. This wouldn't work for a whole forest because of the computational cost of self-shadowing and double normal maps, but could be useful for a single "star" asset, or if LODs switched the distant trees to a model that uses a cheaper shader.<br />
<br />
<span id="SAS"></span><br />
<br />
== Shaders and Seams ==<br />
You need to use the right kind of shader to avoid seeing seams where UV breaks occur. It must be written to use the same [[#TangentBasis|tangent basis]] that was used during baking. If the shader doesn't, the lighting will either be inconsistent across UV borders or it will show smoothing errors from the low-poly vertex normals.<br />
<br />
Xnormal generates accurate normals when displayed in Xnormal, and the SDK includes a method to write your own custom tangent space generator for the tool. <br />
<br />
<span id="3MS"></span><br />
=== 3ds Max Shaders ===<br />
The "Render To Texture" tool in 3ds Max 2011 and older generates [[#TSNM|tangent-space]] normal maps that render correctly in the offline renderer (scanline) but do not render correctly in the realtime viewport with the 3ds Max shaders. Max is using a different [[#TangentBasis|tangent basis]] for each. This is readily apparent when creating non-organic hard surface normalmaps; smoothing errors appear in the viewport that do not appear when rendered. <br />
<br />
The errors can be fixed by using "Render To Texture" to bake a [[#TSNM|tangent-space]] or [[#OSNM|object-space]] map, and using the free [http://www.3pointstudios.com/3pointshader_about.shtml "3Point Shader"] by Christoph '[[CrazyButcher]]' Kubisch and Per 'perna' Abrahamsen. The shader uses the same tangent basis as the baking tool, so it produces nearly flawless results. It also works with old bakes.<br />
<br />
You can get OK results in the Max viewport using a tangent-space map baked in Maya, loading it in a Standard material, and enabling "Show Hardware Map in Viewport". Another method is to use Render To Texture to bake an [[#OSNM|object-space]] map then use [[#CBS|Nspace]] to convert it into a tangent-space map then load that in a DirectX material and use the RTTNormalMap.fx shader. <br />
<br />
Autodesk is aware of these issues, and plans to address them in an upcoming release. See these links for more information:<br />
* Christoph "[[CrazyButcher]]" Kubisch and Per "perna" Abrahamsen designed a shader/modifier combination approach that fixes the viewport problem, see the Polycount forum post [http://boards.polycount.net/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max].<br />
* Jean-Francois "jfyelle" Yelle, Autodesk Media & Entertainment Technical Product Manager, has [http://boards.polycount.net/showthread.php?p=1115812#post1115812 this post]. <br />
* Ben Cloward posted [http://boards.polycount.net/showthread.php?p=1100270#post1100270 workarounds and FX code].<br />
* Christopher "cdiggins" Diggins, SDK writer for 3ds Max, shares some of the SDK code in his blog posts "[http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping How the 3ds Max Scanline Renderer Computes Tangent and Binormal Vectors for Normal Mapping]" and "[http://area.autodesk.com/blogs/chris/3ds_max_normal_map_baking_and_face_angle_weighting_the_plot_thickens 3ds Max Normal Map Baking and Face Angle Weighting: The Plot Thickens]".<br />
<br />
[[image:nmtest_uv-splits_thumb.jpg|thumb|600px|none|Comparison of map baking methods in Maya and Max, and Ben Cloward's custom FX code.<br>Image by [http://www.bencloward.com/ Ben Cloward] and [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
[[image:normalmapfix_3pointstudios_thumb.jpg|frame|none|3 Point Studios' normal map display fix for 3ds Max.<br>image by [http://www.3pointstudios.com 3 Point Studios]]]<br />
<br />
{|class="wikitable"<br />
|[[image:max2010_normalmap_workarounds.png|thumb|400px|none|]]<br />
|[[image:max2010_normalmap_compare.png|thumb|400px|none|]]<br />
|-<br />
|Viewport methods in 3ds Max 2010.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick] <br />
|More baking methods in 3ds Max 2010.<br> Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
<span id="3MENT"></span><br />
<br />
=== 3ds Max Edit Normals Trick ===<br />
After baking, if you add an Edit Normals modifier to your low-poly normalmapped model, this seems to "relax" the vertex normals for more accurate viewport shading. The modifier can be collapsed if desired.<br />
<br />
<span id="MS"></span><br />
=== Maya Shaders ===<br />
Maya seems to correctly generate normals to view in realtime, with the correct [[#TangentBasis|tangent basis]], with much less smoothing errors than 3ds Max. <br />
* [http://www.mentalwarp.com/~brice/shader.php BRDF shader] by [http://www.mentalwarp.com/~brice/ Brice Vandemoortele] and [http://www.kjapi.com/ Cedric Caillaud] (more info in [http://boards.polycount.net/showthread.php?t=49920 this Polycount thread]) '''Update:''' [http://boards.polycount.net/showthread.php?p=821862#post821862 New version here] with many updates, including object-space normal maps, relief mapping, self-shadowing, etc. Make sure you enable cgFX shaders in the Maya plugin manager, then you can create them in the same way you create a Lambert, Phong etc. Switch OFF high quality rendering in the viewports to see them correctly too.<br />
* If you want to use the software renderer, use mental ray instead of Maya's software renderer because mental ray correctly interprets tangent space normals. The Maya renderer treats the normal map as a grayscale bump map, giving nasty results. Mental ray supports Maya's Phong shader just fine (amongst others), although it won't recognise a gloss map plugged into the "cosine power" slot. The slider still works though, if you don't mind having a uniform value for gloss. Spec maps work fine though. Just use the same set up as you would for viewport rendering. You'll need to have your textures saved as TGAs or similar for mental ray to work though. - from [http://boards.polycount.net/member.php?u=14235 CheeseOnToast]<br />
<br />
<br />
<span id="NMC"></span><br />
<br />
== Normal Map Compression ==<br />
see; [[Normal Map Compression]]<br />
<br />
== Links ==<br />
<br />
=== Related Pages ===<br />
* [[Curvature map]]<br />
* [[DuDv map]]<br />
* [[Flow map]]<br />
* [[Normal map]]<br />
* [[Radiosity normal map]]<br />
* [[Vector displacement map]]<br />
<br />
<span id="3DT"></span> <span id="Tools"></span> <span id="3DTools"></span><br />
=== 3D Tools ===<br />
See [[:Category:Tools#A3D_Normal_Map_Software|Category:Tools#3D_Normal_Map_Software]]<br />
<br />
<span id="2DT"></span><span id="2DTools"></span><br />
=== 2D Tools ===<br />
See [[:Category:Tools#A2D_Normal_Map_Software|Category:Tools#2D_Normal_Map_Software]]<br />
<br />
<span id="T"></span><span id="Tutorials"></span><br />
=== Tutorials ===<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh tutorial for Max and Xnormal] by [http://www.exisinteractive.com/ PeterK] to prevent heavy distortions when baking with a cage, without the need to add extra supporting vertices.<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games] by [http://www.polycount.com/forum/member.php?u=56680 'SuperFranky']<br />
* [http://area.autodesk.com/userdata/fckdata/239955/The%20Generation%20and%20Display%20of%20Normal%20Maps%20in%203ds%20Max.pdf The Generation and Display of Normal Maps in 3ds Max] (500kb PDF) <<BR>> Excellent whitepaper from Autodesk about normal mapping in 3ds Max and other apps.<br />
* [http://www.katsbits.com/htm/tutorials/blender-baking-normal-maps-from-models.htm Renderbump and baking normal maps from high poly models using Blender 3D] by ''[http://www.katsbits.com/htm/about.htm "katsbits"]''<<BR>>Baking normal maps in Blender.<br />
* [http://udn.epicgames.com/Three/CreatingNormalMaps.html Techniques for Creating Normal Maps] in the Unreal Developer Network's [http://udn.epicgames.com/Three/WebHome.html Unreal Engine 3 section] contains advice from [http://www.epicgames.com/ Epic Games] artists on creating normal maps for UE3. The [http://udn.epicgames.com/Three/DesignWorkflow.html#Creating%20normal%20maps%20from%20meshes Design Workflow page] has a summary.<br />
* [http://www.iddevnet.com/quake4/ArtReference_CreatingModels#head-3400c230e92ff7d57424b2a68f6e0ea75dee4afa Creating Models in Quake 4] by [http://www.ravensoft.com/ Raven Software] is a comprehensive guide to creating Quake 4 characters.<br />
* [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing and UVs can affect normal maps in Doom 3.<br />
* [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] is an overview of modeling for normal maps.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses how smoothing groups and bevels affect the topology of the low-poly model.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in-game, not the triangle or poly count.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm Normal map workflow] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] demonstrates his normal mapping workflow in 3ds Max and Photoshop.<br />
* [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa This video tutorial] by [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] shows in Maya how to subdivide the low-poly mesh so it more closely matches the high-poly mesh, to help solve wavy lines in the bake.<br />
* [http://www.bencloward.com/tutorials_normal_maps1.shtml Normal Mapping Tutorial] by [http://www.bencloward.com/ Ben Cloward] is a comprehensive tutorial about the entire normal map creation process.<br />
* [http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy] shows how to use a special lighting setup to render normal maps (instead of baking them).<br />
* [http://cgtextures.com/content.php?action=tutorial&name=normalmap Tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] shows how to create deep normal maps using multiple layers. Note: to use Overlay blend mode properly, make sure to change each layer's Levels ''Output Level'' to 128 instead of 255.<br />
* [http://www.poopinmymouth.com/process/tips/normalmap_deepening.jpg Normalmap Deepening] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to adjust normal maps, and how to layer together painted and baked normal maps.<br />
* [http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] helps to solve seams along horizontal or vertical UV edges, but not across angled UVs.<br />
* [http://planetpixelemporium.com/tutorialpages/normal.html Cinema 4D and Normal Maps For Games] by [http://planetpixelemporium.com/index.php James Hastings-Trew] describes normal maps in plain language, with tips on creating them in Cinema 4D.<br />
* [http://forums.cgsociety.org/showthread.php?f=39&t=359082 3ds Max normal mapping overview] by [http://www.alan-noon.com/ Alan Noon] is a great thread on CGTalk about the normal mapping process.<br />
* [http://forums.cgsociety.org/showthread.php?f=46&t=373024 Hard Surface Texture Painting] by [http://stefan-morrell.cgsociety.org/gallery/ Stefan Morrell] is a good introduction to painting textures for metal surfaces.<br />
<br />
<span id="D"></span><span id="Discussion"></span><br />
<br />
=== Discussion ===<br />
[http://boards.polycount.net/showthread.php?p=820218 Discuss this page on the Polycount forums]. Suggestions welcome.<br />
<br />
Even though only one person has been editing this page so far, the information here was gathered from many different sources. We wish to thank all the contributors for their hard-earned knowledge. It is much appreciated!<br />
<br />
----<br />
[[Category:TextureTypes]] [[Category:Bump map]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Normal_mapNormal map2015-04-21T20:50:10Z<p>Dustinbrown: /* Tangent Basis */</p>
<hr />
<div>== Out of Date ==<br />
The information on this page is a bit old, it needs to be updated. See these links for more current information:<br />
<br />
* [http://farfarer.com/resources.htm RNM Normal Map Combiner], by [http://www.farfarer.com/ James "Farfarer" O'Hare]<br />
* [http://vincentcallebaut.com/CombineNormal.html Combine Normal], by [http://vincentcallebaut.comVincent "Vincentt" Callebaut], [http://www.polycount.com/forum/showthread.php?t=131819 Combine normal maps script for Photoshop] Polycount Forum thread.<br />
* [http://www.polycount.com/forum/showpost.php?p=2226864&postcount=51 Earthquake on separating smoothing groups in the UV]<br />
* [http://www.polycount.com/forum/showpost.php?p=2225535&postcount=40 JedTheKrampus on offsetting Mirrored UVs]<br />
* [http://www.polycount.com/forum/showthread.php?t=148303 Of Bit Depths, Banding and Normal Maps]<br />
* [http://www.polycount.com/forum/showthread.php?t=147227 Skew you buddy! Making sense of skewed normal map details.]<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games]<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh Tutorial]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?]<br />
* [http://www.laurenscorijn.com/future-xoliulshader-support.html Future Xoliulshader support] = why Xoliulshader doesn't work properly in 3ds Max 2013/2014.<br />
<br />
== Synched Workflow ==<br />
To eliminate seams and shading artifacts, the model renderer and the normal map baking tool should use the same tangent basis.<br />
<br />
FBX model format can store tangents, and some renderers use this data to synch the incoming normal maps.<br />
<br />
{| class="wikitable sortable" style="color:grey;"<br />
|- <br />
! Renderer !! Normal map baker<br />
|-<br />
| 3ds Max || 3ds Max, Handplane, ?<br />
|-<br />
| Blender || ?<br />
|-<br />
| Creation Engine || Handplane, ?<br />
|-<br />
| CryEngine || ?<br />
|-<br />
| Knald || ?<br />
|-<br />
| Marmoset Toolbag || 3ds Max, Maya, Xnormal, ?<br />
|-<br />
| Maya || Handplane, Maya, ?<br />
|-<br />
| Source || Handplane, Maya ([http://www.polycount.com/forum/showpost.php?p=2224653&postcount=28]), ?<br />
|-<br />
| Starcraft II || Handplane, ?<br />
|-<br />
| Substance Designer || ?<br />
|-<br />
| Unity([http://www.polycount.com/forum/showpost.php?p=2224781&postcount=29], [http://www.polycount.com/forum/showthread.php?p=2194353#post2194353]) || Handplane, Xnormal (via Asset Store), ?<br />
|-<br />
| Unreal Engine 4 || Handplane, Xnormal([http://www.polycount.com/forum/showpost.php?p=2224402&postcount=20]), ? <br />
|-<br />
| Xnormal || Xnormal, ?<br />
|}<br />
<br />
----<br />
<br />
== What is a Normal Map? ==<br />
A Normal Map is usually used to fake high-res geometry detail when it's mapped onto a low-res mesh. The pixels of the normal map each store a ''normal'', a vector that describes the surface slope of the original high-res mesh at that point. The red, green, and blue channels of the normal map are used to control the direction of each pixel's normal. <br />
<br />
When a normal map is applied to a low-poly mesh, the texture pixels control the direction each of the pixels on the low-poly mesh will be facing in 3D space, creating the illusion of more surface detail or better curvature. However, the silhouette of the model doesn't change. <br />
<br />
<gallery mode="packed"><br />
Whatif_normalmap_mapped2.jpg|A model with a normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_low.jpg|The model without its normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
Whatif_normalmap_high.jpg|The high-resolution model used to create the normal map.<br>Image by [http://www.jameskuart.com/ James Ku].<br />
</gallery><br />
<br />
==Tangent-Space vs. Object-Space==<br />
<br />
Normal maps can be made in either of two basic flavors: tangent-space or object-space. World-space is basically the same as object-space, except it requires the model to remain in its original orientation, neither rotating nor deforming, so it's almost never used.<br />
<br />
===Tangent-space normal map===<br />
[[image:normalmap_tangentspace.jpg|frame|none|A tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Predominantly-blue colors. Object can rotate and deform. Good for deforming meshes, like characters, animals, flags, etc.<br />
<br />
Pros:<br />
* Maps can be reused easily, like on differently-shaped meshes.<br />
* Maps can be tiled and mirrored easily, though some games might not support mirroring very well.<br />
* Easier to overlay painted details.<br />
* Easier to use image compression.<br />
<br />
Cons:<br />
* More difficult to avoid smoothing problems from the low-poly vertex normals (see Smoothing Groups and Hard Edges).<br />
* Slightly slower performance than an object-space map (but not by much).<br />
<br />
===Object-space normal map===<br />
[[image:normalmap_worldspace.jpg|frame|none|An object-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
Rainbow colors. Objects can rotate, but usually shouldn't be deformed, unless the shader has been modified to support deformation. Object-space is also called local-space or model-space. <br />
<br />
Pros:<br />
* Easier to generate high-quality curvature because it completely ignores the crude smoothing of the low-poly vertex normals.<br />
* Slightly better performance than a tangent-space map (but not by much).<br />
<br />
Cons:<br />
* Can't easily reuse maps, different mesh shapes require unique maps.<br />
* Difficult to tile properly, and mirroring requires specific shader support.<br />
* Harder to overlay painted details because the base colors vary across the surface of the mesh. Painted details must be converted into Object Space to be combined properly with the OS map.<br />
* They don't compress very well, since the blue channel can't be recreated in the shader like with tangent-space maps. Also the three color channels contain very different data which doesn't compress well, creating many artifacts. Using a half-resolution object-space map is one option. <br />
<br />
<br clear="all"/><br />
<br />
=== Converting Between Spaces ===<br />
Normal maps can be converted between object space and tangent space, in order to use them with different blending tools and shaders, which require one type or the other. <br />
<br />
Object space maps can also be converted to maps with different tangent bases, to better match the normal maps with the renderer and thus avoid lighting errors.<br />
<br />
* [http://www.handplane3d.com Handplane] by [http://www.alecmoody.com/ Alec Moody] is a tool that converts object space maps into a variety of tangent spaces: 3ds Max, Creation Engine, Maya, Source, Unity, Unreal, etc. See the Polycount Forum thread [http://www.polycount.com/forum/showthread.php?t=116899 Official handplane support thread - Now freeware!!].<br />
<br />
[[File:handplane_illus_1.jpg|frame|none|Handplane interface. <br>Image by [http://www.alecmoody.com/ Alec Moody].]]<br />
<br />
<br />
* [http://boards.polycount.net/showthread.php?p=1072599#post1072599 NSpace] by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] is a tool that converts an object-space normal map into a tangent-space map, which then works seamlessly in the 3ds Max viewport. He converts the map by using the same tangent basis that 3ds Max uses for its hardware shader. To see the results, load the converted map via the ''Normal Bump'' map and enable "Show Hardware Map in Viewport". [http://gameartist.nl/ Osman "osman" Tsjardiwal] created a GUI for NSpace, you can [http://boards.polycount.net/showthread.php?p=1075143#post1075143 download it here], just put it in the same folder as the NSpace exe and run it. <br />
<br />
[[File:NSpace_Gui_osman.png|frame|none|NSpace interface. <br>Image by [http://diogo.codingcorner.net Diogo "fozi" Teixeira] and [http://gameartist.nl Osman "osman" Tsjardiwal].]]<br />
<br />
[http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson] said: "[8Monkey Labs has] a tool that lets you load up your reference mesh and object space map. Then load up your tangent normals, and adjust some sliders for things like tile and amount. We need to load up a mesh to know how to correctly orient the tangent normals or else things will come out upside down or reverse etc. It mostly works, but it tends to "bend" the resulting normals, so you gotta split the mesh up into some smoothing groups before you run it, and then I usually will just composite this "combo" texture over my orig map in Photoshop."<br />
<br />
<span id="RGBC"></span><span id="RGBChannels"></span><br />
<br />
== RGB Channels ==<br />
Shaders can use different techniques to render tangent-space normal maps, but the normal map directions are usually consistent within a game. Usually the red channel of a tangent-space normal map stores the X axis (pointing the normals predominantly leftwards or rightwards), the green channel stores the Y axis (pointing the normals predominantly upwards or downwards), and the blue channel stores the Z axis (pointing the normals outwards away from the surface).<br />
<br />
[[image:tangentspace_rgb.jpg|frame|none|The red, green, and blue channels of a tangent-space normal map. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you see lighting coming from the wrong angle when you're looking at your normal-mapped model, and the model is using a tangent-space normal map, the normal map shader might be expecting the red or green channel (or both) to point in the opposite direction. To fix this either change the shader, or simply invert the appropriate color channels in an image editor, so that the black pixels become white and the white pixels become black.<br />
<br />
Some shaders expect the color channels to be swapped or re-arranged to work with a particular [[#NormalMapCompression|compression format]]. For example the DXT5_nm format usually expects the X axis to be in the alpha channel, the Y axis to be in the green channel, and the red and blue channels to be empty.<br />
<br />
== Tangent Basis ==<br />
[[#TangentSpaceVsObjectSpace|Tangent-space]] normal maps use a special kind of vertex data called the ''tangent basis''. This is similar to UV coordinates except it provides directionality across the surface, it forms a surface-relative coordinate system for the per-pixel normals stored in the normal map. This coordinate system is required to light a normal mapped surface.<br />
<br />
Each vertex in the tangent basis is a combination of three things: the mesh vertex's normal (influenced by smoothing), the vertex's tangent (usually derived from the V texture coordinate), and the vertex's bitangent (derived in code, also called the binormal). These three vectors create an axis for each vertex, giving it a specific orientation in the tangent space. These axes are used to properly transform the incoming lighting from world space into tangent space, so your normal-mapped model will be lit correctly.<br />
<br />
Light rays are in world space, but the normals stored in the normal map are in tangent space. When the model is being rendered, the light rays must be converted from world space into tangent space, using the tangent basis to get there. At that point the incoming light rays are compared against the directions of the normals in the normal map, and this determines how much each pixel is going to be lit. Alternatively, instead of converting the light rays some shaders will convert the normals in the normal map from tangent space into world space. Then those world-space normals are compared against the light rays, and the model is lit appropriately. The method depends on who wrote the shader, but the end result is the same. Both methods require a tangent basis to transform the lighting.<br />
<br />
When a triangle's vertex normals are pointing straight out, and a pixel in the normal map is neutral blue (128,128,255) this means the pixel's normal will be pointing straight out from the surface of the low-poly mesh. When that pixel normal is tilted towards the left or the right in the tangent coordinate space, it will get either more or less red color, depending on whether the normal map is set to store the X axis as either a positive or a negative value. Same goes for when the normal is tilted up or down in tangent space, it will either get more or less green color. If the vertex normals aren't exactly perpendicular to the triangle, the normal map pixels will be tinted away from neutral blue as well.<br />
<br />
Unfortunately for artists, there are many different ways to calculate the tangent basis: [http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping 3ds Max], [http://download.autodesk.com/us/maya/2011help/index.html?url=./files/Appendix_A_Tangent_and_binormal_vectors.htm,topicNumber=d0e227193 Maya], [http://www.codesampler.com/dx9src/dx9src_4.htm#dx9_dot3_bump_mapping DirectX 9], [http://developer.nvidia.com/object/NVMeshMender.html NVMeshMender], [http://www.terathon.com/code/tangent.html Eric Lengyel], a custom solution, etc. This means a normal map baked in one application probably won't shade correctly in another. Artists must do some testing with different [[#T|baking tools]] to find which works best with their output. When the renderer (or game engine) renders your game model, [[#ShadersAndSeams|the shader]] must use the same tangent basis as the normal map baker, otherwise you'll get incorrect lighting, especially across the seams between UV shells.<br />
<br />
The [http://www.xnormal.net/ xNormal] SDK supports custom tangent basis methods. When a programmer uses it to implement their renderer's own tangent basis, artists can then use Xnormal to bake normal maps that will match their renderer perfectly.<br />
<br />
[[image:tangentseams.jpg|frame|none|When shared edges are at different angles in UV space, different colors will show up<br />
along the seam. The tangent basis uses these colors to light the model properly. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
When you look at a tangent-space normal map for a character, you typically see different colors along the UV seams. This is because the UV shells are often oriented at different angles on the mesh, a necessary evil when translating the 3D mesh into 2D textures. The body might be mapped with a vertical shell, and the arm mapped with a horizontal one. This requires the normals in the normal map to be twisted for the different orientations of those UV shells. The UVs are twisted, so the normals must be twisted in order to compensate. The tangent basis helps reorient (twist) the lighting as it comes into the surface's local space, so the lighting will then look uniform across the normal mapped mesh.<br />
<br />
When an artist tiles a tangent-space normal map across an arbitrary mesh, like a landscape, this tends to shade correctly because the mesh has a uniform direction in tangent space. If the mesh has discontinuous UV coordinates (UV seams), or the normal map has large directional gradients across it, the tangent space won't be uniform anymore so the surface will probably have shading seams.<br />
<br />
[[#SAS|Shaders]] are written to use a particular direction or "handedness" for the RGB channels in a normal map, sometimes referred to as "Swizzle Coordinates."<br />
<br />
== Common Swizzle Coordinates ==<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
| '''Software''' <br />
| '''Red''' <br />
| '''Green''' <br />
| '''Blue''' <br />
|-<br />
|<#000000>| Maya<br />
| X+<br />
| Y+<br />
| Z+ <br />
|-<br />
|<#000000>| 3ds Max<br />
| X+<br />
| Y-<br />
| Z+ <br />
|-<br />
|<#000000>| Unreal Engine<br />
| X+ <br />
| Y-<br />
| Z+<br />
|-<br />
|<#000000>| Unity<br />
| X+<br />
| Y+<br />
| Z+<br />
|-<br />
|<#000000>| Toolbag<br />
| X+<br />
| Y+ <br />
| Z+<br />
|}<br />
<span id="MTLPM"></span><br />
<br />
== Modeling the Low-Poly Mesh ==<br />
The in-game mesh usually needs to be carefully optimized to create a good silhouette, define edge-loops for better deformation, and minimize extreme changes between the vertex normals for better shading (see [[#SmoothingGroupsAndHardEdges|Smoothing Groups & Hard Edges]]).<br />
<br />
In order to create an optimized in-game mesh including a good silhouette and loops for deforming in animation, you can start with the 2nd subdivision level of your [[DigitalSculpting|digital sculpt]], or in some cases with the base mesh itself. Then you can just collapse edge loops or cut in new edges to add/remove detail as necessary. Or you can [[DigitalSculpting#OART|re-toplogize]] from scratch if that works better for you.<br />
<br />
See [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts] on the Polycount forum.<br />
<br />
<span id="UVC"></span><span id="UVCoordinates"></span><br />
=== UV Coordinates ===<br />
Normal map baking tools only capture normals within the 0-1 UV square, any UV bits outside this area are ignored. <br />
<br />
Only one copy of the forward-facing UVs should remain in the 0-1 UV square at baking time. If the mesh uses overlapping UVs, this will likely cause artifacts to appear in the baked map, since the baker will try render each UV shell into the map. Before baking, it's best to move all the overlaps and mirrored bits outside the 0-1 square. <br />
<br />
[[image:Normalmap_uvcoord_offset.jpg|frame|none|The mirrored UVs (in red) are offset 1 unit before baking. <br>Image by [http://ericchadwick.com Eric Chadwick].]]<br />
<br />
If you move all the overlaps and mirrored bits exactly 1 UV unit (any whole number will do), then you can leave them there after the bake and they will still be mapped correctly. You can move them back if you want, it doesn't matter to most game engines. Be aware that ZBrush does use UV offsets to manage mesh visibility, however this usually doesn't matter because the ZBrush cage mesh is often a different mesh than the in-game mesh used for baking.<br />
<br />
You should avoid changing the UVs after baking the normal map, because rotating or mirroring UVs after baking will cause the normal map not to match the [[#TB|tangent basis]] anymore, which will likely cause lighting problems. <br />
<br />
In 3ds Max, W is a third texture coordinate. It's used for 3D procedural textures and for storing vertex color in UV channels (you need 3 axes for RGB, so UVW can store vertex color). Bake problems can be avoided by moving any overlapping UVs to -1 on the W axis, with the same results as moving them 1 unit on the U or V axes. The tool Render To Texture will always bake whatever UVs are the highest along the W axis. However using W can be messy... it's generally hidden unless you purposefully look for it (bad for team work), doesn't get preserved on export to other apps, and high W values can prevent selecting and/or welding UVs. <br />
<br />
<span id="M"></span><span id="Mirroring"></span><br />
<br />
=== Mirroring ===<br />
Normal maps can be mirrored across a model to create symmetrical details, and save UV space, which allows more detail in the normal map since the texture pixels are smaller on the model. <br />
<br />
With [[#OSNM|object-space]] maps, mirroring requires [http://boards.polycount.net/showthread.php?t=53986 specific shader support]. For [[#TSNM|tangent-space]] maps, mirroring typically creates a shading seam, but this can be reduced or hidden altogether, depending on the method used.<br />
<br />
<span id="TMW"></span><br />
==== Typical Mirroring Workflow ====<br />
# Delete the mesh half that will be mirrored. <br />
# Arrange the UVs for the remaining model, filling the UV square.<br />
# Mirror the model to create a "whole" mesh, welding the mesh vertices along the seam. <br />
# Move the mirrored UVs exactly 1 unit (or any whole number) out of the 0-1 UV square.<br />
# Bake the normal map.<br />
<br />
Sometimes an artist will decide to delete half of a symmetrical model before baking. <br />
<br />
This is a mistake however because often the vertex normals along the hole will bend towards the hole a bit; there are no faces on the other side to average the normals with. This will create a strong lighting seam in the normal map. <br />
<br />
It's typically best to use the complete mirrored model to bake the normal map, not just the unique half. <br />
<br />
To prevent the mirrored UVs from causing overlaps or baking errors, move the mirrored [[#UVC|UVs]] out of the 0-1 UV space, so only one copy of the non-mirrored UVs is left within the 0-1 square.<br />
<br />
To avoid texel "leaks" between the UV shells, make sure there's enough [[#Edge_padding|Edge Padding]] around each shell, including along the edges of the normal map. None of the UV shells should be touching the edge of the 0-1 UV square, unless they're meant to tile with the other side of the map.<br />
<br />
<span id="CM"></span><br />
<br />
==== Center Mirroring ====<br />
If the mirror seam runs along the surface of a continuous mesh, like down the center of a human face for example, then it will probably create a lighting seam. <br />
<br />
In Epic Games' [http://www.unrealtechnology.com/technology.php Unreal Engine 3] (UE3) their symmetrical models commonly use centered mirroring. Epic uses materials that mix a [[DetailMap]] with the normal maps; these seem to scatter the diffuse/specular lighting and help minimize the obviousness of the mirror seams. For their [[Light Map]]ped models they use [http://udn.epicgames.com/Three/LightMapUnwrapping.html a technique] that can almost completely hide the mirror seam.<br />
<br />
[[image:Epic_MirroringCicada.jpg|frame|none| In UE3 a center mirror seam is reduced by using a detail normal map. <br> Image by "[http://epicgames.com Epic Games]"]]<br />
<br />
'''''[http://www.zbrushcentral.com/showpost.php?p=573108&postcount=28 GOW2 normal map seams], [http://utforums.epicgames.com/showthread.php?p=27166791#post27166791 UDK normal map seams]'''''<br />
<br />
<span id="OM"></span><br />
<br />
==== Offset Mirroring ====<br />
Offset mirroring is a method where you move the mirror seam off to one side of the model, so the seam doesn't run exactly down the center. For example with a character's head, the UV seam can go down along the side of the head in front of the ear. The UV shell for the nearest ear can then be mirrored to use the area on the other side of the head. <br />
<br />
This avoids the "Rorschach" effect and allows non-symmetrical details, but it still saves texture space because the two sides of the head can be mirrored (they're never seen at the same time anyhow).<br />
<br />
Offset mirroring doesn't get rid of the seam, but it does move it off to a place where it can either be less obvious, or where it can be hidden in a natural seam on the model.<br />
<br />
<span id="FCM"></span><br />
==== Flat Color Mirroring ====<br />
[http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] solves seams by painting a flat set of normals along the seam, using neutral blue (128,128,255). However it only works along horizontal or vertical UV seams, not across any angled UVs. It also removes any details along the mirror seam, creating blank areas. <br />
<br />
<span id="EM"></span><br />
==== Element Mirroring ====<br />
The mirror seam can be avoided completely when it doesn't run directly through any mesh. For example if there's a detached mesh element that runs down the center of the model, this can be uniquely mapped, while the meshes on either side can be mirrors of each other. Whenever the mirrored parts don't share any vertex normals with the non-mirrored parts, there won't be any seams. <br />
<br />
[[image:normalmap_mirrored-binocs-racer445.jpg|frame|none|The middle part (highlighted in red) uses unique non-mirrored UVs, allowing the mesh on the right to be mirrored without any seams. <br>Image by [http://http://racer445.com/ "racer445"]]]<br />
<br />
<span id="SGAHE"></span><br />
<br />
=== Smoothing Groups & Hard Edges ===<br />
Each vertex in a mesh has at least one vertex normal. Vertex normals are used to control the direction a triangle will be lit from; if the normal is facing the light the triangle will be fully lit, if facing away from the light the triangle won't be lit. <br />
<br />
Each vertex however can have more than one vertex normal. When two triangles have different vertex normals along their shared edge, this creates a shading seam, called a ''hard edge'' in most modeling tools. 3ds Max uses ''Smoothing Groups'' to create hard/soft edges, Maya uses ''Harden Edge'' and ''Soften Edge''. These tools create hard and soft edges by splitting and combining the vertex normals.<br />
<br />
[[image:BenMathis_SmoothingGroups_Excerpt.gif|frame|none|Hard edges occur where the vertices have multiple normals. <br>Image by [http://poopinmymouth.com Ben 'poopinmymouth' Mathis] ([http://poopinmymouth.com/process/tips/smoothing_groups.jpg tutorial here])]]<br />
<br />
When a mesh uses all soft normals (a single smoothing group) the lighting has to be interpolated across the extreme differences between the vertex normals. If your renderer doesn't support the same [[#TangentBasis|tangent basis]] that the baker uses, this can produce extreme shading differences across the model, which creates shading artifacts. It is generally best to reduce these extremes when you can because a mismatched renderer can only do so much to counteract it.<br />
<br />
Hard edges are usually best where the model already has a natural seam. For example, you can add a hard edge along the rim of a car's wheel well, to prevent the inside of the wheel well from distorting the shading for the outside of the car body. Mechanical models usually need hard edges where ever the surface bends more than about 45 degrees. <br />
<br />
For most meshes, the best results usually come from adding hard edges where ever there are UV seams. There are no hard rules however, you must experiment with different approaches to find what works best in your game.<br />
<br />
When you use object-space normal maps the vertex normal problem goes away since you're no longer relying on the crude vertex normals of the mesh. An object-space normal map completely ignores vertex normals. Object-space mapping allows you to use all soft edges and no bevels on the low-res mesh, without showing lighting errors.<br />
<br />
<span id="HEDAT"></span><br />
==== Hard Edge Discussions & Tutorials ====<br />
* [http://www.polycount.com/forum/showthread.php?p=2090450#post2090450 Maya MEL Script help needed (UV border edges)]<br />
* [http://www.polycount.com/forum/showthread.php?t=107196 You're making me hard. Making sense of hard edges, uvs, normal maps and vertex counts]<br />
* [http://www.polycount.com/forum/showthread.php?t=73593 Normal Maps: Can Somone Explain This "Black Edge" issue]<br />
* [http://www.polycount.com/forum/showthread.php?t=73566 Normal Maps: Can someone explain normals, tangents and split UVs?]<br />
* [http://www.polycount.com/forum/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max]<br />
* [http://boards.polycount.net/showthread.php?t=68173 Why you should NOT trust 3ds Max's viewport normal-map display!]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/10503-xsi-normal-mapped-cube-looks-bad.html XSI - normal mapped cube looks bad]<br />
* [http://www.game-artist.net/forums/support-tech-discussion/11924-weird-maya-normal-map-seam-artifact-problem-am-i-making-simple-mistake.html Weird Maya normal map seam/artifact problem]<br />
* [http://boards.polycount.net/showthread.php?p=1080600 Seams in Normals when Creating Tiling Environment Trims and other Tiles]<br />
* The tutorial [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing can affect the normal map.<br />
* The tutorial: [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] shows how smoothing affects raycasting.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses the breaking of normals and smoothing groups in general terms.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in the game, not the triangle count.<br />
* The Crysis documentation [http://doc.crymod.com/AssetCreation/PolyBumpReference.html PolyBump Reference] has a section towards the bottom that shows how smoothing affects their baked normal maps.<br />
* The polycount thread [http://boards.polycount.net/showthread.php?t=60694 Toying around with normal map approaches] has a great discussion of how best to use smoothing groups and bevels for better shading.<br />
<br />
<span id="UB"></span><br />
==== Using Bevels ====<br />
Bevels/chamfers generally improve the silhouette of the model, and can also help reflect specular highlights better. <br />
<br />
However bevels tend to produce long thin triangles, which slow down the in-game rendering of your model. Real-time renderers have trouble rendering long thin triangles because they create a lot of sub-pixel areas to render. <br />
<br />
Bevels also balloon the vertex count, which can increase the transform cost and memory usage. Hard edges increase the vertex count too, but not when the edge also shares a seam in UV space. For a good explanation of the vertex count issue, see [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly].<br />
<br />
Using hard edges with matching UV shells tends to give better performance and better cosmetic results than using bevels. However there are differing opinions on this, see the Polycount thread "[http://boards.polycount.net/showthread.php?t=71760 Maya transfer maps help]".<br />
<br />
<span id="EVN"></span><br />
==== Edited Vertex Normals ====<br />
If you use bevels the shading will be improved by editing the vertex normals so the larger flat surfaces have perpendicular normals. The vertex normals are then forced to blend across the smaller bevel faces, instead of across the larger faces. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66139 Superspecular soft edges tutorial chapter 1].<br />
<br />
[[image:oliverio_bevel_normals.gif|frame|none|Bending normals on bevelled models. <br>From the tutorial [http://deadlineproof.com/model-shading-techniques-soft-edge-superspecular/ Shading techniques Superspecular soft edges]<br>Image by [http://deadlineproof.com/ Paolo Oliverio]]]<br />
<br />
== Level of Detail Models ==<br />
See [http://www.polycount.com/forum/showthread.php?p=1216945#post1216945 Problem if you're using 3point-style normals with an LOD].<br />
<br />
<span id="MTHPM"></span><br />
<br />
== Modeling The High-Poly Mesh ==<br />
[[Subdivision Surface Modeling]] and [[DigitalSculpting]] are the techniques most often used for modeling a normal map. <br />
<br />
Some artists prefer to model the in-game mesh first, other artists prefer to model the high-res mesh first, and others start somewhere in the middle. The modeling order is ultimately a personal choice though, all three methods can produce excellent results:<br />
* Build the in-game model, then up-res it and sculpt it.<br />
* Build and sculpt a high resolution model, then build a new in-game model around that.<br />
* Build a basemesh model, up-res and sculpt it, then step down a few levels of detail and use that as a base for building a better in-game mesh.<br />
If the in-game mesh is started from one of the subdivision levels of the basemesh sculpt, various edge loops can be collapsed or new edges can be cut to add/remove detail as necessary.<br />
<br />
<span id="SE"></span><br />
=== Sloped Extrusions ===<br />
[[image:normal_slopes_hatred.jpg|frame|none|Extrusions on the high-poly model should be sloped to make a better normal map. <br>Image by [http://www.hatred.gameartisans.org/ Krzysztof "Hatred" Dolas].]]<br />
<br />
=== Floating Geometry ===<br />
[[image:FloatingGeo.jpg|frame|none|Normal map stores the direction the surface is facing rather than real depth information, thus allowing to save time using floating geometry. <br>To correctly bake AO with floating geo make it a separate object and turn off it's shadow casting. <br>Image by [http://artisaverb.info/ Andrew "d1ver" Maximov].]]<br />
<br />
See also [[3DTutorials/Modeling High-Low Poly Models for Next Gen Games|Modeling High/Low Poly Models for Next Gen Games]] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa]<br />
<br />
<span id="ET"></span><br />
<br />
=== Edge Thickness ===<br />
[[image:normal_edge_thickness.jpg|frame|none|When creating edges of the Highpoly, sometimes you'll need to make them rounded than in real life to <br>work better at the size they will be seen.<br>Image by [http://racer445.com/Evan "racer445" Herbert]]]<br />
<br />
<span id="MRF"></span><span id="MRRCB"></span><br />
<br />
=== mental ray Round Corners Bump ===<br />
The mental ray renderer offers an automatic bevel rendering effect called Round Corners Bump that can be baked into a normal map. This is available in 3ds Max, Maya, and XSI. See [http://boards.polycount.net/showthread.php?t=71995 Zero Effort Beveling for normal maps] - by [http://boards.polycount.net/member.php?u=31662 Robert "r_fletch_r" Fletcher].<br />
<br />
[http://jeffpatton.net/ Jeff Patton] posted about [http://jeffpatton.cgsociety.org/blog/archive/2007/10/ how to expose Round Corners Bump] in 3ds Max so you can use it in other materials.<br />
<br />
[http://cryrid.com/art/ Michael "cryrid" Taylor] posted a tutorial about how to use [http://cryrid.com/images/temp/XSI/zeroeffort_bevels.jpg Round Corners in XSI].<br />
<br />
XSI is able to bake a good normal map with it, but 3ds Max seems to bake it incorrectly, and Maya isn't able to bake the effect at all. Maybe Max might be able to bake it correctly, if the .mi shader is edited to use the correct coordinate space?<br />
<br />
<span id="Baking"></span><span id="B"></span><br />
== Baking ==<br />
The process of transferring normals from the high-res model to the in-game model is often called baking. The baking tool usually starts projecting a certain numerical distance out from the low-poly mesh, and sends rays inwards towards the high-poly mesh. When a ray intersects the high-poly mesh, it records the mesh's surface normal and saves it in the normal map.<br />
<br />
To get an understanding of how all the options affect your normal map, do some test bakes on simple meshes like boxes. They generate quickly so you can experiment with [[#UVCoordinates|UV mirroring]], [[#SGAHE|smoothing groups]], etc. This helps you learn the settings that really matter.<br />
* The tutorial [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] has more examples of ray-casting, plus how to get better results from the bake.<br />
<br />
Baking sub-sections:<br />
# [[#Anti-Aliasing|Anti-Aliasing]]<br />
# [[#Baking_Transparency|Baking Transparency]]<br />
# [[#Edge_Padding|Edge Padding]]<br />
# [[#High_Poly_Materials|High Poly Materials]]<br />
# [[#Reset_Transforms|Reset Transforms]]<br />
# [[#Solving_Intersections|Solving Intersections]]<br />
# [[#Solving_Pixel_Artifacts|Solving Pixel Artifacts]]<br />
# [[#Solving_Wavy_Lines|Solving Wavy Lines]]<br />
# [[#Triangulating|Triangulating]]<br />
# [[#Working_with_Cages|Working with Cages]]<br />
<br />
<span id="AA"></span><br />
=== Anti-Aliasing ===<br />
Turning on super-sampling or anti-aliasing (or whatever multi-ray casting is called in your normal map baking tool) will help to fix any jagged edges where the high-res model overlaps itself within the UV borders of the low-poly mesh, or wherever the background shows through holes in the mesh. Unfortunately this tends to render much much slower, and takes more memory.<br />
<br />
[[image:normalmap_aliasing_knak47.jpg|frame|none|A bake without anti-aliasing shows artifacts where the high-poly mesh has overlaps. <br>Image by [http://www.polycount.com/forum/member.php?u=35938 'knak47']]]<br />
<br />
One trick to speed this up is to render 2x the intended image size then scale the normal map down 1/2 in a paint program like Photoshop. The reduction's pixel resampling will add anti-aliasing for you in a very quick process. After scaling, make sure to re-normalize the map if your game doesn't do that already, because the un-normalized pixels in your normalmap may cause pixelly artifacts in your specular highlights. Re-normalizing can be done with [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA's normal map filter] for Photoshop.<br />
<br />
3ds Max's supersampling doesn't work nicely with edge padding, it produces dark streaks in the padded pixels. If so then turn off padding and re-do the padding later, either by re-baking without supersampling or by using a Photoshop filter like the one that comes with [[#3DTools|Xnormal]].<br />
<br />
=== Baking Transparency ===<br />
Sometimes you need to bake a normal map from an object that uses opacity maps, like a branch with opacity-mapped leaves. Unfortunately baking apps often completely ignore any transparency mapping on your high-poly mesh.<br />
<br />
{|class="wikitable"<br />
|[[image:JoeWilson_ivynormals_error.jpg]] <br />
|[[image:JoeWilson_ivynormals_rendered.jpg]]<br />
|-<br />
|3ds Max's RTT baker causes transparency errors.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|The lighting method bakes perfect transparency.<br>image by [http://www.linkedin.com/in/earthquake Joe "EarthQuake" Wilson]<br />
|}<br />
<br />
To solve this, render a Top view of the mesh. This only works if you're using a planar UV projection for your low-poly mesh and you're baking a tangent-space normal map.<br />
<br />
* Make sure the Top view matches the dimensions of the planar UV projection used by the low-poly mesh. It helps to use an orthographic camera for precise placement.<br />
* On the high-poly mesh either use a specific lighting setup or a use special material shader:<br />
* 1) The lighting setup is described in these tutorials:<br />
* * [http://www.bencloward.com/tutorials_normal_maps11.shtml Creating A Normal Map Right In Your 3D App] by [http://www.bencloward.com/ Ben Cloward]<br />
* *[http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy], Graphics Techniques Consultant, Xbox Content and Design Team<br />
* 2) The material shader does the same thing, but doesn't require lights.<br />
* * [http://www.scriptspot.com/3ds-max/normaltexmap NormalTexMap] scripted map for 3ds Max by [http://www.scriptspot.com/users/dave-locke Dave Locke].<br />
* * [http://www.footools.com/3dsmax_plugins.html InfoTexture] map plugin for 3ds Max by [http://www.footools.com John Burnett]<br />
<br />
[[image:BenCloward_NormalMapLighting.gif|frame|none|The lighting setup for top-down rendering. <br>Image by [http://www.bencloward.com Ben Cloward]]]<br />
<br />
<span id="EP"></span><br />
<br />
=== Edge Padding ===<br />
If a normal map doesn't have enough [[Edge_padding |Edge Padding]], this will create shading seams on the UV borders.<br />
<br />
=== High Poly Materials ===<br />
3ds Max will not bake a normal map properly if the high-res model has a mental ray Arch & Design material applied. If your normal map comes out mostly blank, either use a Standard material or none at all. For an example see the Polycount thread [http://www.polycount.com/forum/showthread.php?t=74792 Render to Texture >:O].<br />
<br />
<span id="RT"></span><br />
=== Reset Transforms ===<br />
Before baking, make sure your low-poly model's transforms have been reset. '''''This is very important!''''' Often during the modeling process a model will be rotated and scaled, but these compounded transforms can create a messy local "space" for the model, which in turn often creates rendering errors for normal maps. <br />
<br />
In 3ds Max, use the Reset Xforms utility then Collapse the Modifier Stack. In Maya use Freeze Transformation. In XSI use the Freeze button.<br />
<br />
<span id="SI"></span><br />
<br />
=== Solving Intersections ===<br />
The projection process often causes problems like misses, or overlaps, or intersections. It can be difficult generating a clean normal map in areas where the high-poly mesh intersects or nearly intersects itself, like in between the fingers of a hand. Setting the ray distance too large will make the baker pick the other finger as the source normal, while setting the ray distance too small will lead to problems at other places on the mesh where the distances between in-game mesh and high-poly mesh are greater.<br />
<br />
Fortunately there are several methods for solving these problems.<br />
<br />
# Change the shape of the cage. Manually edit points on the projection cage to help solve tight bits like the gaps between fingers.<br />
# Limit the projection to matching materials, or matching UVs.<br />
# Explode the meshes. See the polycount thread [http://boards.polycount.net/showthread.php?t=62921 Explode script needed (for baking purposes)].<br />
# Bake two or more times using different cage sizes, and combine them in Photoshop.<br />
<br />
<span id="SPA"></span><br />
<br />
=== Solving Pixel Artifacts ===<br />
[[image:filterMaps_artifact.jpg|frame|none|Random pixel artifacts in the bake. <br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
If you are using 3ds Max's ''Render To Texture'' to bake from one UV layout to another, you may see stray pixels scattered across the bake. This only happens if you are using a copy of the original mesh in the Projection, and that mesh is using a different UV channel than the original mesh.<br />
<br />
There are two solutions for this:<br />
<br />
* Add a Push modifier to the copied mesh, and set it to a low value like 0.01.<br />
- or -<br />
<br />
* Turn off ''Filter Maps'' in the render settings (Rendering menu > Render Setup > Renderer tab > uncheck Filter Maps). To prevent aliasing you may want to enable the Global Supersampler in Render Setup.<br />
<br />
See also [[#Anti-Aliasing]].<br />
<br />
<span id="SWL"></span><br />
<br />
=== Solving Wavy Lines ===<br />
When capturing from a cylindrical shape, often the differences between the low-poly mesh and the high-poly mesh will create a wavy edge in the normal map. There are a couple ways to avoid this:<br />
<br />
# The best way... create your lowpoly model with better supporting edges. See the Polycount threads [http://www.polycount.com/forum/showthread.php?t=81154 Understanding averaged normals and ray projection/Who put waviness in my normal map?], [http://boards.polycount.net/showthread.php?t=55754 approach to techy stuff], [http://www.polycount.com/forum/showthread.php?t=72713 Any tips for normal mapping curved surface?].<br />
# Adjust the shape of the cage to influence the directions the rays will be cast. Beware... this work will have to be re-done every time you edit the lowpoly mesh, as the cage will be invalidated. At the bottom of [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm this page of his normal map tutorial], [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to do this in 3ds Max. Same method can be seen in the image below.<br />
# Subdivide the low-res mesh so it more closely matches the high-res mesh. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] has a [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa video tutorial] that shows how to do this in Maya.<br />
# Paint out the wavy line. Beware... this work will have to be re-done every time you re-bake the normal map. The [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
# Use a separate planar-projected mesh for the details that wrap around the barrel area, so the ray-casting is more even. Beware... this will cause the normal map not to match your lowpoly vertex normals, probably causing shading errors. For example to add tread around a tire, the tread can be baked from a tread model that is laid out flat, then that bake can layered onto the bake from the cylindrical tire mesh in a paint program.<br />
<br />
[[image:timothy_evison_normalmap_projections.jpg|frame|none|Adjusting the shape of the cage to remove distortion. <br>Image by [http://users.cybercity.dk/~dsl11905/resume/resume.html Timothy "tpe" Evison]]]<br />
<br />
<span id="TRI"></span><br />
<br />
=== Triangulating ===<br />
Before baking, it is usually best to triangulate the low-poly model, converting it from polygons into pure triangles. This prevents the vertex normals from being changed later on, which can create specular artifacts.<br />
<br />
[[image:triangulation_modo_ohare.jpg|frame|none| When quads are triangulated in [http://www.luxology.com/modo/ Modo], the internal edges are sometimes flipped, which causes shading differences.<br>Image by [http://www.farfarer.com/|James "Talon" O'Hare]]]<br />
<br />
<br />
Sometimes a baking tool or a mesh exporter/importer will re-triangulate the polygons. A quad polygon is actually treated as two triangles, and the internal edge between them is often switched diagonally during modeling operations. When the vertices of the quad are moved around in certain shapes, the software's algorithm for polygon models tries to keep the quad surface in a "rational" non-overlapping shape. It does this by switching the internal edge between its triangles.<br />
<br />
<br />
[[image:triangulation_spec_tychovii.jpg|frame|none| The specular highlight is affected by triangulation. Flip edges to fix skewing. See the Polycount thread [http://boards.polycount.net/showthread.php?t=66651 Skewed Specular Highlight?] for pictures and more info.<br> Image by [http://robertkreps.com Robert "TychoVII" Kreps]]]<br />
<br />
<br />
<span id="WWC"></span><br />
<br />
=== Working with Cages ===<br />
''Cage'' has two meanings in the normal-mapping process: a low-poly base for [[subdivision surface modeling]] (usually called the [[DigitalSculpting#BM|basemesh]]), or a ray-casting mesh used for normal map baking. This section covers the ray-casting cage.<br />
<br />
Most normal map baking tools allow you to use a distance-based raycast. A ray is sent outwards along each vertex normal, then at the distance you set a ray is cast back inwards. Where ever that ray intersects the high poly mesh, it will sample the normals from it. <br />
<br />
{|class="wikitable"<br />
|[[Image:Normalmap_raycasting_1.jpg]] <br />
|[[Image:Normalmap_raycasting_2.jpg]]<br />
|-<br />
|Hard edges and a distance-based raycast (gray areas) cause ray misses (yellow) and ray overlaps (cyan).<br> Image by [http://www.mankua.com/ Diego Castaño]<br />
|The gray area shows that using all soft edges (or hard edges and a cage-based raycast) will avoid ray-casting errors from split normals.<br> Image by [http://www.mankua.com/ Diego Castaño] <br />
|}<br />
<br />
Unfortunately with a distance-based raycast, [[#SGAHE|split vertex normals]] will cause the bake to miss parts of the high-res mesh, causing errors and seams. <br />
<br />
Some software allows you to use ''cage mesh'' option instead, which basically inflates a copy of the low-poly mesh, then raycasts inwards from each vertex. This ballooned-out mesh is the cage.<br />
<br />
{| border="1" cellpadding="2" cellspacing="0"<br />
|<tablebgcolor="#ffaaaa">| <br />
|}<br />
<br />
In 3ds Max the cage controls both the distance and the direction of the raycasting. <br />
<br />
In Maya the cage only controls the distance; the ray direction matches the vertex normals (inverted).<br />
<br />
<span style="text-decoration: line-through"> This may have been fixed in the latest release...<<BR>><br />
In Xnormal the cage is split everywhere the model has [[#SGAHE|hard edges]], causing ray misses in the bake. You can fix the hard edge split problem but it involves an overly complex workflow. You must also repeat the whole process any time you change your mesh:</span><br />
# <s> Load the 3d viewer.</s><br />
# <s> Turn on the cage editing tools.</s><br />
# <s> Select all of the vertices.</s><br />
# <s> Weld all vertices.</s><br />
# <s> Expand the cage as you normally would.</s><br />
# <s> Save out your mesh using the Xnormal format.</s><br />
# <s> Make sure Xnormal is loading the correct mesh.</s><br />
<br />
<span id="P"></span><span id="Painting"></span><br />
<br />
== Painting ==<br />
Don't be afraid to edit normal maps in Photoshop. After all it is just a texture, so you can clone, blur, copy, blend all you want... as long as it looks good of course. Some understanding of [[#RGBChannels|the way colors work]] in normal maps will go a long way in helping you paint effectively.<br />
<br />
A normal map sampled from a high-poly mesh will nearly always be better than one sampled from a texture, since you're actually grabbing "proper" normals from an accurate, highly detailed surface. That means your normal map's pixels will basically be recreating the surface angles of your high-poly mesh, resulting in a very believable look.<br />
<br />
If you only convert an image into a normal-map, it can look very flat, and in some cases it can be completely wrong unless you're very careful about your value ranges. Most image conversion tools assume the input is a heightmap, where black is low and white is high. If you try to convert a diffuse texture that you've painted, the results are often very poor. Often the best results are obtained by baking the large and mid-level details from a high-poly mesh, and then combined with photo-sourced "fine detail" normals for surface details such as fabric weave, scratches and grain.<br />
<br />
Sometimes creating a high poly surface takes more time than your budget allows. For character or significant environment assets then that is the best route, but for less significant environment surfaces working from a heightmap-based texture will provide a good enough result for a much less commitment in time.<br />
<br />
* [http://crazybump.com/ CrazyBump] is a commercial normal map converter.<br />
* [http://www.renderingsystems.com/support/showthread.php?tid=3 ShaderMap] is a commercial normal map converter.<br />
* [http://www.pixplant.com/ PixPlant] is a commercial normal map converter.<br />
* [http://boards.polycount.net/showthread.php?t=68860 NJob] is a free normal map converter.<br />
* [http://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop NVIDIA normalmap filter for Photoshop] is a free normal map converter.<br />
* [http://xnormal.net Xnormal height-to-normals filter for Photoshop] is a free normal map converter.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_3.htm Normal map process tutorial] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] includes an example of painting out wavy lines in a baked normal map.<br />
<br />
=== Flat Color ===<br />
The color (128,128,255) creates normals that are completely perpendicular to the polygon, as long as the vertex normals are also perpendicular. Remember a normal map's per-pixel normals create ''offsets'' from the vertex normals. If you want an area in the normal map to be flat, so it creates no offsets from the vertex normals, then use the color (128,128,255). <br />
<br />
This becomes especially obvious when [[#Mirroring|mirroring a normal map]] and using a shader with a reflection ingredient. Reflection tends to accentuate the angles between the normals, so any errors become much more apparent.<br />
<br />
[[image:normalmap_127seam.jpg|thumb|600px|none| Mirrored normal maps show a seam when (127,127,255) is used for the flat color; 128 is better.<br>Image by [http://www.ericchadwick.com Eric Chadwick]]]<br />
<br />
In a purely logical way, 127 seems like it would be the halfway point between 0 and 255. However 128 is the color that actually works in practice. When a test is done comparing (127,127,255) versus (128,128,255) it becomes obvious that 127 creates a slightly bent normal, and 128 creates a flat one.<br />
<br />
This is because most game pipelines use ''unsigned'' normal maps. For details see the Polycount forum thread [http://www.polycount.com/forum/showpost.php?p=771360&postcount=22 tutorial: fixing mirrored normal map seams].<br />
<br />
<span id="BNMT"></span><br />
<br />
=== Blending Normal Maps Together ===<br />
Blending normal maps together is a quick way to add high-frequency detail like wrinkles, cracks, and the like. Fine details can be painted as a height map, then it can be converted into a normal map using one of the normal map tools. Then this "details" normal map can be blended with a geometry-derived normal map using one of the methods below. <br />
<br />
Here is a comparison of four of the blending methods. Note that in these examples the default values were used for CrazyBump (Intensity 50, Strength 33, Strength 33), but the tool allows each layer's strength to be adjusted individually for stronger or milder results. Each of the normal maps below were [[#Renormalizing|re-normalized]] after blending.<br />
<br />
{|class="wikitable"<br />
|[[image:nrmlmap_blending_methods_Maps.png]]<br />
|[[image:nrmlmap_blending_methods_RTTNormalMapFX.png]]<br />
|-<br />
|The blended normal maps.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|Screenshot of the 3dsmax viewport, using the RTTNormalMap.fx shader.<br>Image by [http://www.ericchadwick.com Eric Chadwick]<br />
|}<br />
<br />
The four blending methods used above:<br />
# [http://www.crazybump.com CrazyBump] by Ryan Clark blends normal maps together using calculations in 3D space rather than just in 2D. This does probably the best job at preserving details, and each layer's strength settings can be tweaked individually. <br />
# [http://www.rodgreen.com/?p=4 Combining Normal Maps in Photoshop] by Rod Green blends normal maps together using Linear Dodge mode for the positive values and Difference mode for the negative values, along with a Photoshop Action to simplify the process. It's free, but the results may be less accurate than CrazyBump.<br />
# [http://www.paultosca.com/makingofvarga.html Making of Varga] by [http://www.paultosca.com/ Paul "paultosca" Tosca] blends normal maps together using Overlay mode for the red and green channels and Multiply mode for the blue channel. This gives a slightly stronger bump than the Overlay-only method. [http://www.leocov.com/ Leo "chronic" Covarrubias] has a step-by-step tutorial for this method in [http://www.cgbootcamp.com/tutorials/2009/12/9/photoshop-combine-normal-maps.html CG Bootcamp Combine Normal Maps].<br />
# [[3DTutorials/Normal Map Deepening|Normal Map Deepening]] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to blend normal maps together using Overlay mode. [http://cgtextures.com/content.php?action=tutorial&name=normalmap CGTextures tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] also shows how to create normalmaps using multiple layers (Note: to work with the Overlay blend mode each layer's Output Level should be 128 instead of 255, you can use the Levels tool for this).<br />
<br />
The [http://boards.polycount.net/showthread.php?t=69615 Getting good height from Nvidia-filter normalizing grayscale height] thread on the Polycount forum has a discussion of different painting/blending options. Also see the [[#2DT|2D Tools]] section for painting and conversion tools.<br />
<br />
<span id="PCT"></span><br />
<br />
=== Pre-Created Templates ===<br />
A library of shapes can be developed and stored for later use, to save creation time for future normal maps. Things like screws, ports, pipes, and other doo-dads. These shapes can be stored as bitmaps with transparency so they can be layered into baked normal maps.<br />
<br />
* [http://www.beautifulrobot.com/?p=69 Creating & Using NormalMap "Widgets"] - by ''[http://www.beautifulrobot.com Steev "kobra" Kelly]''<<BR>> How to set up and render template objects.<br />
* [http://www.akramparvez.com/portfolio/scripts/normalmap-widget-for-3ds-max/ NormalMap Widget for 3ds Max] - by ''[http://www.akramparvez.com Akram Parvez]''<<BR>>A script to automate the setup and rendering process.<br />
* See the section [[#BT|Baking Transparency]] for more template-rendering tools and tutorials.<br />
<br />
<span id="RN"></span><span id="Renormalizing"></span><br />
=== Re-normalizing ===<br />
Re-normalizing means resetting the length of each normal in the map to 1.<br />
<br />
A normal mapping shader takes the three color channels of a normal map and combines them to create the direction and length of each pixel's normal. These normals are then used to apply the scene lighting to the mesh. However if you edit normal maps by hand or if you blend multiple normal maps together this can cause those lengths to change. Most shaders expect the length of the normals to always be 1 (normalized), but some are written to re-normalize the normal map dynamically (for example, 3ds Max's Hardware Shaders do re-normalize).<br />
<br />
If the normals in your normal map are not normalized, and your shader doesn't re-normalize them either, then you may see artifacts on the shaded surface... the specular highlight may speckle like crazy, the surface may get patches of odd shadowing, etc. To help you avoid this NVIDIA's normal map filter for Photoshop provides an easy way to re-normalize a map after editing; just use the '''Normalize Only''' option. [http://xnormal.net Xnormal] also comes with a Normalize filter for Photoshop.<br />
<br />
[[image:normalize_only.jpg|frame|none|The re-normalize option in the NVIDIA filter.<br>Image by [http://hirezstudios.com/ Scott Warren]]]<br />
<br />
Some shaders use [[#NormalMapCompression|compressed normal maps]]. Usually this means the blue channel is thrown away completely, so it's recalculated on-the-fly in the shader. However the shader has to re-normalize in order to recreate that data, so any custom normal lengths that were edited into the map will be ignored completely. <br />
<br />
<span id="AOIANM"></span><span id="AmbientOcclusionIntoANormalMap"></span><br />
<br />
=== Ambient Occlusion into a Normal Map ===<br />
If the shader doesn't re-normalize the normal map, an [[Ambient Occlusion Map]] can actually be baked into the normal map. This will shorten the normals in the crevices of the surface, causing the surface to receive less light there. This works with both diffuse and specular, or any other pass that uses the normal map, like reflection.<br />
<br />
However it's usually best to keep the AO as a separate map (or in an alpha channel) and multiply it against the ambient lighting only. This is usually done with a custom [[:Category:Shaders|shader]]. If you multiply it against the diffuse map or normal map then it also occludes diffuse lighting which can make the model look dirty. Ambient occlusion is best when it occludes ambient lighting only, for example a [[DiffuselyConvolvedCubeMap|diffusely convolved cubemap]].<br />
<br />
[[image:nrmlmap_ao.jpg|frame|none| AO can be baked into a normal map, shortening the normals (lower left model).<br>Model by [http://www.3dartisan.net/~kuman/ James Ku]]]<br />
<br />
To bake the AO into a normal map, adjust the levels of the AO layer first so the darks only go as low as 128 gray, then set the AO layer to Darken mode. This will shorten the normals in the normalmap, causing the surface to receive less light in the darker areas. <br />
<br />
This trick doesn't work with any shaders that re-normalize, like 3ds Max's Hardware Shaders. The shader must be altered to actually use the lengths of your custom normals; most shaders just assume all normals are 1 in length because this makes the shader code simpler. Also this trick will not work with most of the common [[#NormalMapCompression|normal map compression formats]], which often discard the blue channel and recalculate it in the shader, which requires re-normalization.<br />
<br />
<span id="BLE"></span><br />
<br />
=== Back Lighting Example ===<br />
You can customize normal maps for some interesting effects. If you invert the blue channel of a tangent-space map, the normals will be pointing to the opposite side of the surface, which can simulate backlighting.<br />
<br />
{|class="wikitable"<br />
|[[image:tree_front.jpg]]||[[image:tree_back.jpg]]<br />
|-<br />
|Tree simulating subsurface scattering (front view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|Tree simulating subsurface scattering (back view).<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|-<br />
|colspan="2"|[[image:tree_maps.jpg]]<br />
|-<br />
|colspan="2"|The maps used for the leaves. The 2nd diffuse was simply color-inverted, hue-shifted 180°, and saturated.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
The tree leaves use a shader than adds together two diffuse maps, one using a regular tangent-space normal map, the other using the same normal map but with the blue channel inverted. This causes the diffuse map using the regular normal map to only get lit on the side facing the light (front view), while the diffuse map using the inverted normal map only gets lit on the opposite side of the leaves (back view). The leaf geometry is 2-sided but uses the same shader on both sides, so the effect works no matter the lighting angle. As an added bonus, because the tree is self-shadowing the leaves in shadow do not receive direct lighting, which means their backsides do not show the inverted normal map, so the fake subsurface scatter effect only appears where the light directly hits the leaves. This wouldn't work for a whole forest because of the computational cost of self-shadowing and double normal maps, but could be useful for a single "star" asset, or if LODs switched the distant trees to a model that uses a cheaper shader.<br />
<br />
<span id="SAS"></span><br />
<br />
== Shaders and Seams ==<br />
You need to use the right kind of shader to avoid seeing seams where UV breaks occur. It must be written to use the same [[#TangentBasis|tangent basis]] that was used during baking. If the shader doesn't, the lighting will either be inconsistent across UV borders or it will show smoothing errors from the low-poly vertex normals.<br />
<br />
Xnormal generates accurate normals when displayed in Xnormal, and the SDK includes a method to write your own custom tangent space generator for the tool. <br />
<br />
<span id="3MS"></span><br />
=== 3ds Max Shaders ===<br />
The "Render To Texture" tool in 3ds Max 2011 and older generates [[#TSNM|tangent-space]] normal maps that render correctly in the offline renderer (scanline) but do not render correctly in the realtime viewport with the 3ds Max shaders. Max is using a different [[#TangentBasis|tangent basis]] for each. This is readily apparent when creating non-organic hard surface normalmaps; smoothing errors appear in the viewport that do not appear when rendered. <br />
<br />
The errors can be fixed by using "Render To Texture" to bake a [[#TSNM|tangent-space]] or [[#OSNM|object-space]] map, and using the free [http://www.3pointstudios.com/3pointshader_about.shtml "3Point Shader"] by Christoph '[[CrazyButcher]]' Kubisch and Per 'perna' Abrahamsen. The shader uses the same tangent basis as the baking tool, so it produces nearly flawless results. It also works with old bakes.<br />
<br />
You can get OK results in the Max viewport using a tangent-space map baked in Maya, loading it in a Standard material, and enabling "Show Hardware Map in Viewport". Another method is to use Render To Texture to bake an [[#OSNM|object-space]] map then use [[#CBS|Nspace]] to convert it into a tangent-space map then load that in a DirectX material and use the RTTNormalMap.fx shader. <br />
<br />
Autodesk is aware of these issues, and plans to address them in an upcoming release. See these links for more information:<br />
* Christoph "[[CrazyButcher]]" Kubisch and Per "perna" Abrahamsen designed a shader/modifier combination approach that fixes the viewport problem, see the Polycount forum post [http://boards.polycount.net/showthread.php?t=72861 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max].<br />
* Jean-Francois "jfyelle" Yelle, Autodesk Media & Entertainment Technical Product Manager, has [http://boards.polycount.net/showthread.php?p=1115812#post1115812 this post]. <br />
* Ben Cloward posted [http://boards.polycount.net/showthread.php?p=1100270#post1100270 workarounds and FX code].<br />
* Christopher "cdiggins" Diggins, SDK writer for 3ds Max, shares some of the SDK code in his blog posts "[http://area.autodesk.com/blogs/chris/how_the_3ds_max_scanline_renderer_computes_tangent_and_binormal_vectors_for_normal_mapping How the 3ds Max Scanline Renderer Computes Tangent and Binormal Vectors for Normal Mapping]" and "[http://area.autodesk.com/blogs/chris/3ds_max_normal_map_baking_and_face_angle_weighting_the_plot_thickens 3ds Max Normal Map Baking and Face Angle Weighting: The Plot Thickens]".<br />
<br />
[[image:nmtest_uv-splits_thumb.jpg|thumb|600px|none|Comparison of map baking methods in Maya and Max, and Ben Cloward's custom FX code.<br>Image by [http://www.bencloward.com/ Ben Cloward] and [http://www.linkedin.com/in/ericchadwick Eric Chadwick]]]<br />
<br />
[[image:normalmapfix_3pointstudios_thumb.jpg|frame|none|3 Point Studios' normal map display fix for 3ds Max.<br>image by [http://www.3pointstudios.com 3 Point Studios]]]<br />
<br />
{|class="wikitable"<br />
|[[image:max2010_normalmap_workarounds.png|thumb|400px|none|]]<br />
|[[image:max2010_normalmap_compare.png|thumb|400px|none|]]<br />
|-<br />
|Viewport methods in 3ds Max 2010.<br>Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick] <br />
|More baking methods in 3ds Max 2010.<br> Image by [http://www.linkedin.com/in/ericchadwick Eric Chadwick]<br />
|}<br />
<br />
<span id="3MENT"></span><br />
<br />
=== 3ds Max Edit Normals Trick ===<br />
After baking, if you add an Edit Normals modifier to your low-poly normalmapped model, this seems to "relax" the vertex normals for more accurate viewport shading. The modifier can be collapsed if desired.<br />
<br />
<span id="MS"></span><br />
=== Maya Shaders ===<br />
Maya seems to correctly generate normals to view in realtime, with the correct [[#TangentBasis|tangent basis]], with much less smoothing errors than 3ds Max. <br />
* [http://www.mentalwarp.com/~brice/shader.php BRDF shader] by [http://www.mentalwarp.com/~brice/ Brice Vandemoortele] and [http://www.kjapi.com/ Cedric Caillaud] (more info in [http://boards.polycount.net/showthread.php?t=49920 this Polycount thread]) '''Update:''' [http://boards.polycount.net/showthread.php?p=821862#post821862 New version here] with many updates, including object-space normal maps, relief mapping, self-shadowing, etc. Make sure you enable cgFX shaders in the Maya plugin manager, then you can create them in the same way you create a Lambert, Phong etc. Switch OFF high quality rendering in the viewports to see them correctly too.<br />
* If you want to use the software renderer, use mental ray instead of Maya's software renderer because mental ray correctly interprets tangent space normals. The Maya renderer treats the normal map as a grayscale bump map, giving nasty results. Mental ray supports Maya's Phong shader just fine (amongst others), although it won't recognise a gloss map plugged into the "cosine power" slot. The slider still works though, if you don't mind having a uniform value for gloss. Spec maps work fine though. Just use the same set up as you would for viewport rendering. You'll need to have your textures saved as TGAs or similar for mental ray to work though. - from [http://boards.polycount.net/member.php?u=14235 CheeseOnToast]<br />
<br />
<br />
<span id="NMC"></span><br />
<br />
== Normal Map Compression ==<br />
see; [[Normal Map Compression]]<br />
<br />
== Links ==<br />
<br />
=== Related Pages ===<br />
* [[Curvature map]]<br />
* [[DuDv map]]<br />
* [[Flow map]]<br />
* [[Normal map]]<br />
* [[Radiosity normal map]]<br />
* [[Vector displacement map]]<br />
<br />
<span id="3DT"></span> <span id="Tools"></span> <span id="3DTools"></span><br />
=== 3D Tools ===<br />
See [[:Category:Tools#A3D_Normal_Map_Software|Category:Tools#3D_Normal_Map_Software]]<br />
<br />
<span id="2DT"></span><span id="2DTools"></span><br />
=== 2D Tools ===<br />
See [[:Category:Tools#A2D_Normal_Map_Software|Category:Tools#2D_Normal_Map_Software]]<br />
<br />
<span id="T"></span><span id="Tutorials"></span><br />
=== Tutorials ===<br />
* [http://www.polycount.com/forum/showthread.php?t=144715 Skewmesh tutorial for Max and Xnormal] by [http://www.exisinteractive.com/ PeterK] to prevent heavy distortions when baking with a cage, without the need to add extra supporting vertices.<br />
* [http://www.polycount.com/forum/showthread.php?t=146667 A Practical Guide On Normal Mapping For Games] by [http://www.polycount.com/forum/member.php?u=56680 'SuperFranky']<br />
* [http://area.autodesk.com/userdata/fckdata/239955/The%20Generation%20and%20Display%20of%20Normal%20Maps%20in%203ds%20Max.pdf The Generation and Display of Normal Maps in 3ds Max] (500kb PDF) <<BR>> Excellent whitepaper from Autodesk about normal mapping in 3ds Max and other apps.<br />
* [http://www.katsbits.com/htm/tutorials/blender-baking-normal-maps-from-models.htm Renderbump and baking normal maps from high poly models using Blender 3D] by ''[http://www.katsbits.com/htm/about.htm "katsbits"]''<<BR>>Baking normal maps in Blender.<br />
* [http://udn.epicgames.com/Three/CreatingNormalMaps.html Techniques for Creating Normal Maps] in the Unreal Developer Network's [http://udn.epicgames.com/Three/WebHome.html Unreal Engine 3 section] contains advice from [http://www.epicgames.com/ Epic Games] artists on creating normal maps for UE3. The [http://udn.epicgames.com/Three/DesignWorkflow.html#Creating%20normal%20maps%20from%20meshes Design Workflow page] has a summary.<br />
* [http://www.iddevnet.com/quake4/ArtReference_CreatingModels#head-3400c230e92ff7d57424b2a68f6e0ea75dee4afa Creating Models in Quake 4] by [http://www.ravensoft.com/ Raven Software] is a comprehensive guide to creating Quake 4 characters.<br />
* [http://www.svartberg.com/tutorials/article_normalmaps/normalmaps.html Normalmaps for the Technical Game Modeler] by [http://www.svartberg.com Ariel Chai] shows how low-poly smoothing and UVs can affect normal maps in Doom 3.<br />
* [http://wiki.polycount.net/3D_Tutorials/Modeling_High-Low_Poly_Models_for_Next_Gen_Games Modeling High/Low Poly Models for Next Gen Games] by [http://www.acetylenegames.com/artbymasa/ João "Masakari" Costa] is an overview of modeling for normal maps.<br />
* The [http://tech-artists.org/wiki/Beveling Beveling section on the Tech-Artists.Org Wiki] discusses how smoothing groups and bevels affect the topology of the low-poly model.<br />
* The two-part article [http://www.ericchadwick.com/examples/provost/byf2.html#wts Beautiful, Yet Friendly] by [http://www.linkedin.com/in/gprovost Guillaume Provost] explains how smoothing groups and other mesh attributes cause vertices to be duplicated in the game. The vertex count is actually what matters in-game, not the triangle or poly count.<br />
* [http://www.poopinmymouth.com/tutorial/normal_workflow_2.htm Normal map workflow] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] demonstrates his normal mapping workflow in 3ds Max and Photoshop.<br />
* [http://dodownload.filefront.com/9086954//72f71c0147df53765045a22253c18361a29a6d532425842007ead644d39cbb85d0794ab560365cfa This video tutorial] by [http://www.custom-airbrush.com/ Jeff "airbrush" Ross] shows in Maya how to subdivide the low-poly mesh so it more closely matches the high-poly mesh, to help solve wavy lines in the bake.<br />
* [http://www.bencloward.com/tutorials_normal_maps1.shtml Normal Mapping Tutorial] by [http://www.bencloward.com/ Ben Cloward] is a comprehensive tutorial about the entire normal map creation process.<br />
* [http://www.pinwire.com/articles/26/1/Generating-High-Fidelity-Normal-Maps-with-3-D-Software.html Generating High Fidelity Normal Maps with 3-D Software] by [http://www.linkedin.com/pub/0/277/4AB Dave McCoy] shows how to use a special lighting setup to render normal maps (instead of baking them).<br />
* [http://cgtextures.com/content.php?action=tutorial&name=normalmap Tutorial for the NVIDIA Photoshop filter] by [http://hirezstudios.com/ Scott Warren] shows how to create deep normal maps using multiple layers. Note: to use Overlay blend mode properly, make sure to change each layer's Levels ''Output Level'' to 128 instead of 255.<br />
* [http://www.poopinmymouth.com/process/tips/normalmap_deepening.jpg Normalmap Deepening] by [http://www.poopinmymouth.com/ Ben "poopinmymouth" Mathis] shows how to adjust normal maps, and how to layer together painted and baked normal maps.<br />
* [http://boards.polycount.net/showthread.php?t=51088 Tutorial for painting out seams on mirrored tangent-space normal maps] by [http://www.warbeast.de/ warby] helps to solve seams along horizontal or vertical UV edges, but not across angled UVs.<br />
* [http://planetpixelemporium.com/tutorialpages/normal.html Cinema 4D and Normal Maps For Games] by [http://planetpixelemporium.com/index.php James Hastings-Trew] describes normal maps in plain language, with tips on creating them in Cinema 4D.<br />
* [http://forums.cgsociety.org/showthread.php?f=39&t=359082 3ds Max normal mapping overview] by [http://www.alan-noon.com/ Alan Noon] is a great thread on CGTalk about the normal mapping process.<br />
* [http://forums.cgsociety.org/showthread.php?f=46&t=373024 Hard Surface Texture Painting] by [http://stefan-morrell.cgsociety.org/gallery/ Stefan Morrell] is a good introduction to painting textures for metal surfaces.<br />
<br />
<span id="D"></span><span id="Discussion"></span><br />
<br />
=== Discussion ===<br />
[http://boards.polycount.net/showthread.php?p=820218 Discuss this page on the Polycount forums]. Suggestions welcome.<br />
<br />
Even though only one person has been editing this page so far, the information here was gathered from many different sources. We wish to thank all the contributors for their hard-earned knowledge. It is much appreciated!<br />
<br />
----<br />
[[Category:TextureTypes]] [[Category:Bump map]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Game_IndustryGame Industry2014-12-17T20:06:51Z<p>Dustinbrown: /* Negotiation */</p>
<hr />
<div><br />
Links and articles about the game industry: how to get game jobs, how to manage your role, etc.<br />
<br />
__TOC__<br />
<br />
== How to Get In ==<br />
* [http://www.polycount.com/forum/showthread.php?t=134547 Getting that first job] Polycount Forum thread Good advice for an artist trying to enter a game studio.<br />
* [http://www.polycount.com/forum/showthread.php?t=89972 Getting into the Game Industry (Inspiration of a different kind)] - Polycount Forum thread. Amazing thread full of information from working game artists about how they got into the industry.<br />
* [http://www.ineedtomakegames.com How to Break Into the Industry] - by [http://www.linkedin.com/pub/destin-bales/1/2aa/95b Destin Bales] A treasure trove of great advice by a veteran game developer. Multiple topics covered: understanding the industry, education, resumes and portfolios, finding jobs, interview prep, career development, etc. <br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16967104&gid=59205 Why is it hard to find a job in game industry?] Discussion on LinkedIn about what it takes to get that first game industry job.<br />
* [http://athey.deviantart.com/art/Game-Industry-Advice-to-studen-145619882 Game Industry Advice to students] - by [http://athey.deviantart.com/ Athey Moravetz] A great article by a 5-year veteran game artist about what it takes to get into a game artist job. Very straightforward and accurate.<br />
<br />
== Being a Developer ==<br />
* [http://www.polycount.com/forum/showthread.php?t=137206 What has the games industry been like for you?] Polycount Forum thread Game art veterans share what it's really like to be working in game development.<br />
* [http://www.penny-arcade.com/report/article/na Is the games industry really dying?] by Dan Teasdale Analysis of game industry layoff data.<br />
* [http://www.valvetime.net/threads/valve-employee-hand-book-released.189828/ Valve Employee Hand Book] Greg Coomer says "We wrote this book to make it as easy as we could for new people to join the company. It was fun to capture these thoughts and put them all in one place. Let us know what you think." Cached: [[attachment:Valve_Employee_Handbook.pdf]]<br />
* [http://www.gdcvault.com/play/1012343/The-Belly-of-the-Whale The Belly of the Whale: Living a Creative Life in the Game Industry] - by [http://www.bobbates.com/ Bob Bates] GDC 2010 lecture about how creative types can survive and thrive in the game industry. Highly recommended [http://www.polycount.com/forum/showthread.php?t=74876 by many Polycounters].<br />
* [http://www.thejonjones.com/2010/08/09/how-not-to-hire-an-artist/ How NOT to hire an artist] - by [http://www.thejonjones.com Jon Jones] Response to the inflammatory article [http://kaitol.com/how-to-hire-an-artist/ How to hire an artist] by [http://kaitol.com/about/ Christopher 'xdragonx10' Gregorio].<br />
* [http://www.polycount.com/2010/08/11/the-co-worker/ The Co-worker] - by [http://www.adambromell.com/ Adam Bromell] Polycount News article about what makes a good team co-worker.<br />
<br />
== Art Disciplines ==<br />
* [[:Category:Discipline]] lists the various artist roles in game development:<br />
<br />
* [http://www.polycount.com/forum/showthread.php?t=134325 Leadership in the Games Industry] Polycount forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=81832 What Game artist career is more difficult?] Polycount forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=45470 Lack of Environment Artists] Polycount forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=82424 Difference between Environment and Prop Artists?] Polycount forum thread<br />
* [http://boards.polycount.net/showthread.php?t=52862 Percentage of environment artists .vs. character artists at most studios] Polycount forum thread<br />
* [http://boards.polycount.net/showthread.php?t=52412 What's the difference between a level designer and environment artist?] Polycount forum thread<br />
* [[NateWhitePortfolioAdvice]] has succinct summaries for what the various game disciplines should show in their portfolios, also all-around good advice for entry-level people.<br />
<br />
== Education ==<br />
The basic argument in the Polycount community is between going the self-taught route or going the formal education route. The best path seems to depend on what kind of person you are: self-motivated or team-motivated.<br />
<br />
Artists on Polycount generally agree it is rare to find schools that teach current high-quality game art techniques. The web and forums are often the best places to learn these, maybe even [[:Category:Tutorials|our wiki]] |-) . We see it time and again... the students who succeed at entering the work force after graduation are almost exclusively those that work on their own side projects, beyond the course material. Would they have been better served without using a school? <br />
<br />
Beware of education scams and debt! Schools can cost a lot of money and some promise easy employment afterwards, but unfortunately the reality is not so forgiving. Student loan debt can also be a crushing burden for many years, especially with the relatively low wages most game artists make. See the blog post [https://medium.com/i-m-h-o/138c5efd45e9 Don’t go to art school], the Polycount forum thread [http://www.polycount.com/forum/showthread.php?t=75796 Profit Schools - Can we condemn them publicly?], and the Penny Arcade episode [http://penny-arcade.com/patv/episode/on-game-schools "On Game Schools"].<br />
<br />
There are many Polycount forum threads about game art education, for a great list see [http://www.polycount.com/forum/showthread.php?t=108342 Education In The Games Industry: Yes or No?], or you can do a [http://www.polycount.com/forum/search.php forum search] for ''education''.<br />
<br />
* [http://k0k0k0.wordpress.com/51-things-every-game-student-should-know/ 100 Things Every Game Student Should Know] - by [http://k0k0k0.wordpress.com/ Kaye Elling] 100 fugly slides of things that every budding game developer (who is studying at university) should know. Read it! <br />
<br />
== Portfolios ==<br />
* [[:Category:Portfolio]] has links to tutorials and advice about creating an artist portfolio for a career in game development. <br />
<br />
== Resumes ==<br />
* [http://windmillnetworking.com/2009/08/11/linkedin-profile-tips-the-10-mistakes-you-want-to-avoid-and-why/ LinkedIn Profile Tips: The 10 Mistakes You Want to Avoid and Why] - by ''[http://windmillnetworking.com/about/ Neal Schaffer]''<br />
* [http://www.joelonsoftware.com/articles/ResumeRead.html Getting Your Résumé Read] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
* [http://www.joelonsoftware.com/articles/SortingResumes.html Sorting Resumes] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]''<br />
<br />
== Cover Letters ==<br />
* [http://www.polycount.com/forum/showthread.php?t=41014 Writing that all important cover letter?] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=85192 Cover Letter] Polycount Forum thread<br />
* [http://www.polycount.com/forum/showthread.php?t=118092 Resume / Cover Letter Critique request - Riot Games]] Polycount Forum thread<br />
<br />
== Job Searching ==<br />
Most game developers get their jobs by word of mouth, this industry puts personal contacts first and foremost. Networking is key; keep in contact with your friends and former co-workers.<br />
* [http://www.polycount.com/forum/forumdisplay.php?f=39 Work Opportunities] Polycount Forum section has job postings. <br />
* [http://www.polycount.com/forum/showthread.php?t=134982 Another website to find a video game industry job] Polycount Forum thread has several links.<br />
* [http://boards.polycount.net/showthread.php?t=38472 Game and Mod Development Article] and [http://boards.polycount.net/showthread.php?t=42157 Some mod guidelines] Polycount Forum threads have advice about joining a mod team.<br />
* [http://www.facebook.com/note.php?note_id=195778565716 Industry tips: How to find a job in the game industry] - by ''[http://www.boomzap.com/ Christopher Natsuume]'' has some frank advice about job searching.<br />
* [http://www.joelonsoftware.com/articles/ThePhoneScreen.html The Phone Screen] - by ''[http://www.joelonsoftware.com/ Joel 'joelonsoftware' Spolsky]'' has info about how companies weed out applicants.<br />
* [http://www.polycount.com/forum/showthread.php?t=99400 It seems to be impossible to find a job as a Modeler in this industry] - this Polycount forum thread has good advice about how to actually get hired as an artist in game development. <br />
* [http://www.cgstepinside.com/cg-studio/ cgStepInside Studio Map] - map of animation and game development companies.<br />
* [http://gamedevmap.com gamedevmap] - map of game development companies. <br />
<br />
== Going Indie ==<br />
Indie means developing, marketing, and publishing a game independently.<br />
* [http://forums.tigsource.com/index.php?topic=18.msg147#msg147 How to Start an Indie Game Business (WIP)] TIGSource Forum thread with links to resources <br />
<br />
== Freelancing ==<br />
Freelancing means creating assets for pay, working alone as an individual. See [[Freelance]].<br />
<br />
== Interviews ==<br />
* [http://www.polycount.com/forum/showthread.php?t=106081 Job Interview in a hour or so, what questions should I expect?] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=105266 When eyeballing a studio...] thread on the Polycount forum (what questions should you ask during your interview).<br />
* [http://www.polycount.com/forum/showthread.php?t=69142 Interview Advice] thread on the Polycount forum.<br />
* [http://www.polycount.com/forum/showthread.php?t=80507 In need of interview advice] thread on the Polycount forum.<br />
* [http://www.boston.com/bostonworks/galleries/job_interview_tips?pg=2 10 Tips for Your First Interview] - by ''Dave Sanford'' Time-tested interview strategies:<br />
*# Research<br />
*# Practice<br />
*# Clothing<br />
*# Get there early<br />
*# Observe<br />
*# Know thyself<br />
*# Handshake<br />
*# Listen<br />
*# Finishing<br />
*# Follow up<br />
* [http://hotjobs.yahoo.com/career-experts-four_steps_to_a_better_job_interview-51 Four Steps to a Better Job Interview] - by ''Brad Karsh'' Four simple things to improve your interviews.<br />
*# Relax, not a battle of wits.<br />
*# Job description = questions that you'll be asked.<br />
*# Have answers about why you did certain things.<br />
*# Have questions about them.<br />
* [http://www.jobbankusa.com/interviews/articles_tips/10_follow_up_rules.html Ten Tips for the Interview Follow Up] - by ''Carole Martin'' How to avoid a non-response after your interview.<br />
* [http://boards.polycount.net/showthread.php?t=57317 job interview, 2-3 hours, why so long?] Polycount forum thread Game developers talking about the interview process they do, or have been through.<br />
<br />
== Art Tests ==<br />
Game companies often ask their art applicants to complete an art test, to gauge their talent relative to that company's particular needs, and to make sure you can actually do the work (portfolios can be faked or stolen).<br />
* [http://forum.gameartisans.org/forums/showthread.php?t=5970 Art Test Master List] GameArtisans forum thread has some example art tests.<br />
* [http://www.linkedin.com/groupAnswers?viewQuestionAndAnswers=&discussionID=16136725&gid=1842071 "Large art tests as the first stage of candidate selection. Acceptable?"] LinkedIn discussion (registration required) with seasoned artists weighing in on their art test experiences: unpaid vs. paid tests, how long is too long for a company to ask you to spend on it, plagiarism horror stories, non-response after submission, etc.<br />
<br />
Art test threads and links:<br />
* [http://www.polycount.com/forum/showthread.php?t=87657 Jagex Art Test]<br />
* [http://jcricreate.tumblr.com/post/5461504341/the-art-test Naughty Dog texture artist test]<br />
* [http://www.polycount.com/forum/showthread.php?t=84418 Environment Art Test advice?]<br />
* [http://www.polycount.com/forum/showthread.php?t=81681 Art test and no response, normal?]<br />
* [http://www.polycount.com/forum/showthread.php?t=81015 Is it bad to ask for tips on an art test? There isn't an NDA]<br />
* [http://www.polycount.com/forum/showthread.php?t=80861 Art tests]<br />
* [http://www.polycount.com/forum/showthread.php?t=77279 Art Tests : How much time to spend?]<br />
* [http://www.polycount.com/forum/showthread.php?t=76208 Art Test Help/Suggestions]<br />
<br />
== Salary Research ==<br />
Do the research to figure out what a fair offer is for your skill level and geographic area.<br />
* [http://www.gamecareerguide.com/features/1108/game_developer_salary_survey_2012.php 2012 Game Industry Salary Survey] - from ''[http://www.gdmag.com/ Game Developer magazine]'' (mostly USA). See also [http://gamedeveloper.texterity.com/gamedeveloper/201104#pg9 2010], [http://gamedeveloper.texterity.com/gamedeveloper/2009fall/#pg33 2009], [http://gamedeveloper.texterity.com/gamedeveloper/2008careerguide/#pg13 2008], [http://www.gamecareerguide.com/features/416/the_game_industry_salary_survey_.php?page=1 2007], [http://www.gamecareerguide.com/features/266/are_you_in_demand_2006_game_.php?page=1 2006].<br />
* [http://www.glassdoor.com/Salaries/us-computer-software-senior-artist-salary-SRCH_IL.0,2_IN1_II1121.3,20_KO21,34_SDAS.htm# Senior Artist Salaries at Computer Software companies in United States] - from ''[http://www.glassdoor.com Glassdoor.com]'' (USA) Customize your search, and enter your salary data for full access.<br />
* [http://www.payscale.com/research/US/Job=3d_Artist/Salary 3D Artist Salaries in the United States] - from ''[http://www.payscale.com Payscale.com]'' (other countries available)<br />
* [http://www.flcdatacenter.com/CaseH1B.aspx The Foreign Labor Certification Data Center - Online Wage Library] (H1B Visa Applications) - from the ''[http://www.doleta.gov/ US Department of Labor]'' (USA)<br />
* [http://vfxsoldier.wordpress.com/2010/08/16/wages-in-the-vfx-animation-and-games-industry/ Wages In The VFX, Animation, And Games Industry] - by [http://vfxsoldier.wordpress.com 'VFX Soldier'] features a spreadsheet of wage data mined from the H1B Visa database.<br />
* [http://www.mcvuk.com/news/read/uk-games-industry-salary-survey-what-are-you-worth/0110018 2012 UK Games Industry Salary Survey]. See also [http://www.develop-online.net/features/429/The-2009-UK-Games-Development-Salary-Survey 2009] (UK)<br />
* [http://www.vfxwages.com/ VFXWages] - a global database of hourly monetary rates of people in the film and television visual effects, animation, motion graphics, and gaming industry. <br />
* [[Freelance#Freelance_Rates]]<br />
<br />
== Negotiation ==<br />
Salary negotiation is an essential skill that will be put to the test after a successful interview. <br />
* [http://realtimecollisiondetection.net/blog/?p=70 Salary of a game programmer (artist, designer, or producer)] - by ''[http://realtimecollisiondetection.net Christer Ericcson]'', Sony Computer Entertainment<br />
* [https://www.facebook.com/note.php?note_id=191791235716 Industry tips: How to not ask for money] - by ''[http://www.boomzap.com/ Christopher Natsuume]''<br />
* [http://www.kclabor.org/kyrmpp.htm Know Your Rights - The Myth of Pay Privacy] - by ''[http://www.kclabor.org KC Labor]'' (USA)<br />
* [http://www.amazon.com/Bargaining-Advantage-Negotiation-Strategies-Reasonable/dp/0143036971 Bargaining for Advantage: Negotiation Strategies for Reasonable People] ($) - by ''[http://www.amazon.com/G.-Richard-Shell/e/B001H6KG6E G. Richard Shell]''<br />
* [http://www.polycount.com/forum/showthread.php?p=2067860 New Job Negotiations]<br />
<br />
== Relocation ==<br />
* [http://www.polycount.com/forum/showthread.php?t=99113 The game industry and relocation, how bad is it?] - Polycount Forum thread. Insight into the relocation process.<br />
<br />
== Employee Rights ==<br />
* [http://www.graphicartistsguild.org/handbook/ Graphic Artists Guild Handbook: Pricing & Ethical Guidelines] is an excellent resource on a great range of employment issues. Pricing guidelines, legal info, copyright law, sample contracts, how to negotiate, and more. Highly recommended!<br />
* [http://www.nlrb.gov/about_us/overview/national_labor_relations_act.aspx National Labor Relations Board] (USA)<br />
* [http://www.acas.org.uk/index.aspx?articleid=1390 ACAS: Advisory, Conciliation and Arbitration Service] (UK)<br />
* [http://www.direct.gov.uk/en/Employment/Employees/index.htm Directgov Employment Terms and Conditions] (UK)<br />
* [http://www.kclabor.org/know_your_rights1.htm Know Your Rights] - by [http://www.kclabor.org KC Labor] (USA)<br />
* [http://boards.polycount.net/showthread.php?t=71929 Discussing issues at work, grounds for firing?] Polycount forum thread has information about workers discussing their compensation with one another.<br />
* [http://www.polycount.com/forum/showthread.php?t=97910 EA rumored to layoff 500+] Polycount forum thread with cautionary tales about what happens when people get laid off or fired, or when companies close. Back up your work regularly, for portfolio use!<br />
<br />
<br />
----<br />
[[Category:Information]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Category:CharacterCategory:Character2014-08-04T17:55:56Z<p>Dustinbrown: /* Category Character */</p>
<hr />
<div>__NOTOC__<br />
= Category Character =<br />
There are playable and non-playable characters (NPCs). Hero characters, which are typically provided extra visual fidelity, and characters which are deemed less important. There are animals, invented creatures, monsters, minibosses, and final bosses. Basically, if it moves and it isn't a vehicle, weapon, part of the environment or the user interface, it's probably a character.<br />
<br />
== Pages in This Category ==<br />
<br />
<br />
== Character Process ==<br />
<br />
Characters for games are usually created as a group effort, involving an Art Director, Concept Artist, and at least one Character Artist. Concept art is almost always used as the starting point because it's a more loose, fast, and efficient way to iterate and find the best character design than 3D.<br />
<br />
For most modern game characters, a high poly model is first created using a combination of modeling and digital sculpting software. These high resolution models are later modeled over, or retopologized, into the game resolution, or low poly model.<br />
<br />
The surface details from the high poly model are transferred to the in-game model using [http://wiki.polycount.com/wiki/Category:Texturing textures] and [http://wiki.polycount.com/wiki/Shaders shaders] though a process called baking. This baking process can generate a variety of texture maps that help fool the eye into believing the in-game model has more modeled detail than it actually has. The most common of these texture maps are [http://wiki.polycount.com/wiki/Normal_Maps normal maps], and [http://wiki.polycount.com/wiki/AmbientOcclusionMap ambient occlusion maps].<br />
<br />
== Character Examples ==<br />
* [http://www.polycount.com/forum/showthread.php?t=117608 Testing the new DX11 features of ma2013.5], [http://www.youtube.com/watch?v=L5fOwSmSaW8 Youtube timelapse] - Paul Tosca has released the source files for his Nyra character "to help others that might be on the road to becoming game character artists and want to check out the model/textures/psd layout". <br />
* [[Category:Topology]] - Wireframes of meshes used in games. <br />
* [[BaseMesh]] - Low-resolution polygonal models that can be used as the starting point for [[CharacterSculpting|digital sculpting]]. <br />
<br />
== More Information ==<br />
* [[Category:ReferenceAnatomy]]<br />
* [[Category:ReferenceCharacter]]<br />
<br />
[[Category:Discipline]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Category:CharacterCategory:Character2014-08-04T17:54:50Z<p>Dustinbrown: /* Category Character */</p>
<hr />
<div>__NOTOC__<br />
= Category Character =<br />
There are playable and non-playable characters (NPCs). Hero characters, which are typically provided extra visual fidelity, and characters which are deemed less important. There are animals, invented creatures, monsters, minibosses, and final bosses. Basically, if it moves and it isn't part of the environment or the user interface, it's probably a character.<br />
<br />
== Pages in This Category ==<br />
<br />
<br />
== Character Process ==<br />
<br />
Characters for games are usually created as a group effort, involving an Art Director, Concept Artist, and at least one Character Artist. Concept art is almost always used as the starting point because it's a more loose, fast, and efficient way to iterate and find the best character design than 3D.<br />
<br />
For most modern game characters, a high poly model is first created using a combination of modeling and digital sculpting software. These high resolution models are later modeled over, or retopologized, into the game resolution, or low poly model.<br />
<br />
The surface details from the high poly model are transferred to the in-game model using [http://wiki.polycount.com/wiki/Category:Texturing textures] and [http://wiki.polycount.com/wiki/Shaders shaders] though a process called baking. This baking process can generate a variety of texture maps that help fool the eye into believing the in-game model has more modeled detail than it actually has. The most common of these texture maps are [http://wiki.polycount.com/wiki/Normal_Maps normal maps], and [http://wiki.polycount.com/wiki/AmbientOcclusionMap ambient occlusion maps].<br />
<br />
== Character Examples ==<br />
* [http://www.polycount.com/forum/showthread.php?t=117608 Testing the new DX11 features of ma2013.5], [http://www.youtube.com/watch?v=L5fOwSmSaW8 Youtube timelapse] - Paul Tosca has released the source files for his Nyra character "to help others that might be on the road to becoming game character artists and want to check out the model/textures/psd layout". <br />
* [[Category:Topology]] - Wireframes of meshes used in games. <br />
* [[BaseMesh]] - Low-resolution polygonal models that can be used as the starting point for [[CharacterSculpting|digital sculpting]]. <br />
<br />
== More Information ==<br />
* [[Category:ReferenceAnatomy]]<br />
* [[Category:ReferenceCharacter]]<br />
<br />
[[Category:Discipline]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Category:CharacterCategory:Character2014-08-04T17:54:09Z<p>Dustinbrown: /* Character Process */</p>
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<div>__NOTOC__<br />
= Category Character =<br />
All about character art for games. There are playable and non-playable characters (NPCs). Hero characters, which are typically provided extra visual fidelity, and characters which are deemed less important. There are animals, invented creatures, monsters, minibosses, and final bosses. Basically, if it moves and it isn't part of the environment or the user interface, it's probably a character.<br />
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== Pages in This Category ==<br />
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== Character Process ==<br />
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Characters for games are usually created as a group effort, involving an Art Director, Concept Artist, and at least one Character Artist. Concept art is almost always used as the starting point because it's a more loose, fast, and efficient way to iterate and find the best character design than 3D.<br />
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For most modern game characters, a high poly model is first created using a combination of modeling and digital sculpting software. These high resolution models are later modeled over, or retopologized, into the game resolution, or low poly model.<br />
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The surface details from the high poly model are transferred to the in-game model using [http://wiki.polycount.com/wiki/Category:Texturing textures] and [http://wiki.polycount.com/wiki/Shaders shaders] though a process called baking. This baking process can generate a variety of texture maps that help fool the eye into believing the in-game model has more modeled detail than it actually has. The most common of these texture maps are [http://wiki.polycount.com/wiki/Normal_Maps normal maps], and [http://wiki.polycount.com/wiki/AmbientOcclusionMap ambient occlusion maps].<br />
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== Character Examples ==<br />
* [http://www.polycount.com/forum/showthread.php?t=117608 Testing the new DX11 features of ma2013.5], [http://www.youtube.com/watch?v=L5fOwSmSaW8 Youtube timelapse] - Paul Tosca has released the source files for his Nyra character "to help others that might be on the road to becoming game character artists and want to check out the model/textures/psd layout". <br />
* [[Category:Topology]] - Wireframes of meshes used in games. <br />
* [[BaseMesh]] - Low-resolution polygonal models that can be used as the starting point for [[CharacterSculpting|digital sculpting]]. <br />
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== More Information ==<br />
* [[Category:ReferenceAnatomy]]<br />
* [[Category:ReferenceCharacter]]<br />
<br />
[[Category:Discipline]]</div>Dustinbrownhttp://wiki.polycount.com/wiki/Category:CharacterCategory:Character2014-08-04T17:33:27Z<p>Dustinbrown: /* Category Character */</p>
<hr />
<div>__NOTOC__<br />
= Category Character =<br />
All about character art for games. There are playable and non-playable characters (NPCs). Hero characters, which are typically provided extra visual fidelity, and characters which are deemed less important. There are animals, invented creatures, monsters, minibosses, and final bosses. Basically, if it moves and it isn't part of the environment or the user interface, it's probably a character.<br />
<br />
== Pages in This Category ==<br />
<br />
<br />
== Character Process ==<br />
Game characters are usually designed by a [[Category:Concept|Concept Artist]] working with an Art Director or Lead Artist. A concept is a much quicker way to make large changes, helping them discover the optimal character design.<br />
<br />
For most modern game characters, a high resolution model is created with many millions of polygons using a combination of a [[Category:Tools#Main_3D_Software_Packages|3d modeling package]] (i.e. 3ds Max, Maya, Modo) and a [[Category:Tools#A3D_Sculpting_Software|sculpting package]] (ZBrush, Mudbox). These high resolution models are usually modeled over into a low resolution version (a process called [[Category:Tools#Re-Topology_Software|retopologizing]]) or otherwise reduced down to a more usable in-game resolution. <br />
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The high resolution model is usually converted into a [[NormalMap|normal map]], which is a texture that stores not colors but rather mathematical vectors (a math thing that is a direction and distance in 3d space) that indicate what direction each pixel is facing, so effectively each pixel is kind of like a vertex. The "normal" in normal map comes from the term "normalized vector" which is a special kind of vector (a vector whose distance is always 1).<br />
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There are other kinds of [[Category:TextureTypes|texture maps]] that get used, but normal maps are a bit unique in that they are storing information related to the shape, rather than the color or material. Since these are pretty much impossible to accurately paint by hand, as they're a mathematical representation of something, people usually use a high resolution model and "bake" or "project" the normals from the high poly (where each vertex has a discrete normal) down to a texture that can be applied to the low poly.<br />
<br />
== Character Examples ==<br />
* [http://www.polycount.com/forum/showthread.php?t=117608 Testing the new DX11 features of ma2013.5], [http://www.youtube.com/watch?v=L5fOwSmSaW8 Youtube timelapse] - Paul Tosca has released the source files for his Nyra character "to help others that might be on the road to becoming game character artists and want to check out the model/textures/psd layout". <br />
* [[Category:Topology]] - Wireframes of meshes used in games. <br />
* [[BaseMesh]] - Low-resolution polygonal models that can be used as the starting point for [[CharacterSculpting|digital sculpting]]. <br />
<br />
== More Information ==<br />
* [[Category:ReferenceAnatomy]]<br />
* [[Category:ReferenceCharacter]]<br />
<br />
[[Category:Discipline]]</div>Dustinbrown