Difference between revisions of "Shaders"

Revision as of 15:20, 6 August 2014

What is a Shader?

A shader is a bit of computer code that is commonly used to describe how a surface will be rendered. It takes some inputs (textures, vertices, view angles, etc.), does some changes to them, then tells the game renderer to render them.

Shaders are typically used for interactive rendering, like in a 3d game, where the view is rendered in real-time at 30 fps (or better). This page is all about these "real-time" shaders, which are optimized to render efficiently, trading performance for less accuracy. "Offline" shaders are used with non-real-time renderers, like mental ray, and have more accurate effects like ray-tracing and sub-pixel filtering, but they are non-interactive (they can take several minutes to render each frame).

Example Shaders

3ds Max Shaders

(in alphabetical order)

• 3ds Max viewport shader by Laurens "Xoliul" Corijn.

More info in the Polycount thread Xoliul's 3DS Max Viewport Shader.

• 3Point Shader by 3 Point Studios

Shader with many options, including near-perfect results for 3ds Max generated normal maps. See the Polycount thread 3Point Shader Lite - Shader material editor and Quality Mode normalmaps for 3ds Max.

• Agusturinn Shader Demo by Wang "RTshaders" Jing.

Shader features: "One UV texture, Two point lights, Diffuse map(include alpha which control transparency), AO(ambient occlusion) map or Lightmap share the same channel, Normal map,Specular map,Specular level map,Gloss map,Emissive map, Two type of Cubemap---One is diffuse cubemap for generating IBL(image based lighting), the other is enviroment cubemap for reflection."

• Ben Cloward Shaders by Ben Cloward.

He has a bunch of HLSL shaders available for normal mapping, ambient occlusion, car paint, skin, etc.

• BRDF shader (3ds Max version) ported by Christoph "CrazyButcher" Kubisch.

Original BRDF shader for Maya by Brice Vandemoortele and Cedric Caillaud. More info in the Polycount thread Free Maya/max cgfx/fx Shader. Update: New version here with many updates, including object-space normal maps, relief mapping, self-shadowing, etc.

• DOTA2 Hero Shader - 3DS & Maya Shader Material by Luigi 'Ace-Angel' Kavijian and Drew 'Drew++' Watts.

Half-Lambert diffuse term with controllable falloff, additive rimlighting, Phong specular, mask support (Dota2 style), all them fancy effects Valve uses!

• ENVO realtime environment shader by Aurel Manea

From the Polycount thread ENVO realtime environment shader for 3d studio max.

• MoP Texture Blender by Paul "MoP" Greveson

This shader uses blendmodulate for vertex blending with per-pixel detail. From the Polycount thread The Snow and Ice of Uncharted2?.

• Paragalis Shader Demo by Wang "RTshaders" Jing.

Shader features: "Post effect, 3dsmax2008/2009 viewport shadowmap, Subsurface scattering, Cubemap Image based lighting, Diffuse(alpha channel control opacity),Normal map,Ao map/Light map,Specular,Specular lever(mask),Gloss etc., Shadermodel 2.x compatible for AMD ATI card."

• SSS Skin Shader by J.I. Styles.

"The aim of this shader is to emulate all the perceptual qualities of realistic skin like translucency (sss), fresnal specular, gloss, oiliness, etc - kludging what I can to produce fast yet realistic looking results."

• TF2 Shader for 3ds Max and Toon/Comic Shader for 3ds Max by Till "Rollin" Maginot.

More info in the Polycount thread TF2 and TOON realtime viewport shader (3ds max).

Maya Shaders

(in alphabetical order)

• BRDF shader for Maya by Brice Vandemoortele and Cedric Caillaud

More info in the Polycount thread Free Maya/max cgfx/fx Shader. Update: New version here with many updates, including object-space normal maps, relief mapping, self-shadowing, etc.

• DOTA2 Hero Shader - 3DS & Maya Shader Material by Luigi 'Ace-Angel' Kavijian and Drew 'Drew++' Watts.

Half-Lambert diffuse term with controllable falloff, additive rimlighting, Phong specular, mask support (Dota2 style), all them fancy effects Valve uses!

• KoddeShader by Kostas "Kodde" Gialitakis

Has several features such as normal mapping, specular, gloss, reflections, ambient cube, parallax, etc. More info in the Polycount thread "KoddeShader", a Maya CGFX shader. Update: Version 2.0 here including updates such as blended normals for skin, cube map mip level parameters for blurring reflections and ambient light, 2-pass transparency support, etc.

• TGA Physically Based Lighting shader by Kostas "Kodde" Gialitakis and Niklas Hansson. Is based around a Physically Based Lighting method of shading where you define materials with albedo, substance and roughness texture rather than diffuse, specular, gloss. Has other features such as cube map based reflections and ambient lighting, normal maps, ambient occlusion, substance based fresnel term which alters reflections and specular, blurred reflections, fully linear shading, energy conserving ambient/reflections, blended normals, etc.
• lcUberShader, lcSkinShader, lcHairShader, lcLitSphere, lcReproject by Leonardo "chronic" Covarrubias

Many techniques and parameters, including normal mapping, specular, ambient env cube, SSS, litspheres, etc.

• Vertex Color BlendMasked CgFX Maya Shader by Amir "choco" Abdaoui and Drew "Drew++" Watts.

More info in the Polycount thread Vertex color BlendMasked cgfx maya shader.

UDK Shaders

• WL-Shader by "TA20"

UDK shaders for cloth, skin, water, glass, foliage, bricks, etc.

Creating Shaders

• Advice with Learning Shader Programming Polycount forum thread
• Material editors vs. Custom shader code Polycount forum thread

Beginner Tutorials

• CG Academy HLSL Shader Creation series by Ben Cloward ($) is an excellent 3-part series on making HLSL shaders for 3ds Max (can easily be transferred to Maya too).
• CGCookie - Introduction to surface shader scripting in Unity by Alex Telford Step by step tutorial with basics of writing for Unity 3.x.
• CGCookie - Noob to pro shader writing for Unity for beginners by Alex Telford Another tutorial by Alex Telford designed for Unity 4.
• Eat3D's "Shader Production - Writing Custom Shaders with CGFX" by Luiz Kruel ($) is anotehr excellent video tutorial that guides you through writing your own shaders, primarily with the CGFX shader language in Maya. DVD release was September 14, 2011.
• Shaders by Ben Cloward These shaders are a bit outdated and there are more up-to-date shaders to learn from, but Ben's shaders are what got many artists started on the path and are still a solid learning resource.
• Shaders by Rob Galanakis (right side of page) Some well-commented shaders that cover a variety of intermediate to advanced topics.
• NormalMap, the Wiki page on normal mapping, provides a comprehensive overview on the subject.
• Ben Cloward's Normal Mapping Tutorial: One of the best sources for people getting into shaders and who want a better understanding of what a normal map is. Covers the basics of lighting, how normal maps work, and the process of creating and applying normal maps.

Intermediate Tutorials

• TF2 Shading in UT3 by Steffen "Neox" "polyphobia" Unger

Shows how the Team Fortress 2 look can be emulated using a shader network in Unreal Engine 3.

• ParallaxMap: different techniques for parallax mapping (offset, parallax occlusion, relief, etc.), with links to the papers detailing them and other related resources.
• Beautiful, yet Friendly: Article by Guillaume Provost, which explains the behind-the-scenes technical aspect of shaders. A must-read when one starts to think about efficiency, math, and hardware.

Advanced Tutorials

Tools

To create and edit shaders, most people use a text editor (like Notepad ++) to write them and a 3d program (a game engine, 3ds Max, Maya, etc.) to view them. For those who are new to shaders the following tools provide a graphical user interface for easier creation.

• FX Composer is NVIDIA's shader authoring toolset.
• GLSL Hacker "is a cross-platform (Windows, Linux and OS X) tool for fast realtime 3D prototyping and coding. It's based on widely used standards such as GLSL (OpenGL Shading Language), Lua or Python. GLSL Hacker has been designed for developers (from newbies to confirmed) and technical 3D artists."
• GLSL Sandbox is a browser-based code editor that shows the output live, right there behind your code. Also has a gallery of neat tricks to steal (ahem, borrow) from.
• mental mill Standard Edition "allows the user to write and edit shader code, and visually debug the shader by interactively inspecting variables while stepping through the code." The more limited Artist Edition is free for personal use, and came bundled with 3ds Max 2010.
• PowerVR SDK lets you live-edit and gives you rough estimates on shader costs. Helps with optimising GL ES2.0 shaders. Works with regular GLSL, too.
• RenderMonkey is AMD's shader authoring toolset.

Shader Tools for 3ds Max

• 3Point Shader Pro "is a toolset for creation and presentation of high-quality real- time materials in the Autodesk 3ds Max™ viewport."
• Shader FX "is a full-featured real-time shader editor for 3ds Max that allows artists with no previous programming experience to build complex HLSL or CG FX shaders, using a graphical schematic interface to wire nodes together." No longer being developed

Shader Tools for Maya

• Maya LT ShaderFX is a node-based shader editor for Maya LT.

Shader Tools for Unity

• Shader Forge "The goal with Shader Forge is to provide an intuitive and visual way of creating shaders in the Unity engine, just like the Material Editor in UDK."
• ShaderFusion is a node-based shader editor for Unity.
• Strumpy Shader Editor another node-based shader editor for Unity.

Shader Tools for Unreal Engine

• Material Editor in UDK

Tech_Artists.Org Wiki

For more info see Portal:Shaders on the Tech Artists Wiki.

These pages need to be ported, see Technical Art:Tech-Artists.Org_Wiki_Conversion.