Light mapping is a technique that allows you to compute illumination and other surface information from an object’s material, and output that information to a texture file that can be used elsewhere in your scene.
XSI uses light mapping in two ways:
• In shaders that use lightmaps internally to store illumination information. For example, the fast subsurface scattering material phenomenon uses a light map to store information about light scattered in an object.
These types of shaders create their lightmaps automatically, and do not give you direct access to the output files. However, they typically provide parameters for controlling the quality of the lightmap.
For more information, see Fast Subsurface Scattering in the Lights and Cameras guide.
• Lightmap shaders, such as the color sampler shader, that write the results of the lightmap computation to an external texture file that you can then reuse in the scene. The Color Sampler shader is described in the next section: Using the Color Sampler Shader.
SOFTIMAGE|XSI v.6.01