Diffusely convolved cube map
A diffusely convolved cube map is simply a blurred-down version of a regular cube map. When a shader adds the cube map to the model's diffuse map the result is similar to global-illumination, except it is extremely efficient performance-wise.
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| Images by Eric Chadwick. | |
Contents
Lys
"Lys is an ultra-fast GPU powered solution that sets the standard for generating Radiance, Irradiance and Specular textures from panoramic, Sphere or 2d cube map cross source textures for use with HDR Image Based Lighting."
AMD Cubemapgen
- Cubemapgen is open-sourced utility for filtering down cube maps.
- Sébastien Lagarde made a modified version for physically based rendering
Cubemapgen Cube Faces
| Cubemapgen | 3ds Max | Maya | CryENGINE 3 | Unity |
| +X | _RT | Left -X | ||
| -X | _LF | Right +X | ||
| +Y | _UP | Top +Y | ||
| -Y | _DN | Bottom -Y | ||
| +Z | _BK | Front (+Z) | ||
| -Z | _FR | Back (-Z) |
| Cubemapgen | 3ds Max | Maya | CryENGINE 3 | Unity |
| c00 | Left -X (180°) | |||
| c01 | Right +X (180°) | |||
| c02 | Top +Y | |||
| c03 | Bottom -Y | |||
| c04 | Back -Z (180°) | |||
| c05 | Front +Z (180°) |
Cubemapgen Custom Meshes
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| Images by Eric Chadwick.]] | |
You can load your own geometry in Cubemapgen using the Load Object button, really helps to see what settings are working well.
You can also load a bitmap for the model using the Load Basemap button. There's a bug right now that causes your Basemap to be mirrored vertically... to fix it pre-flip the bitmap yourself before loading it in Cubemapgen. An Ambient occlusion map map makes a great Basemap, or you can use your Diffuse map.
Editing Cubemaps in Photoshop
If your cube map is in DDS cube format, you'll need the NVIDIA DDS plugin to load and save in Photoshop.
More Information
- Cubemaps Tutorial by CGTextures.com - Tutorial using Nvidia's Photoshop plugin, AMD's CubeMapGen, and Photoshop to convert cubemaps to various layouts.
