Light sources are supported internally using a similar mechanism to the other shader classes. A light source shader defines which and how much light falls onto a surface.
Examples of light source types are ambient lights (which illuminate all surfaces equally regardless of their orientation), distant lights (which radiate light in a single direction), point lights (which radiate light in all directions), and spot lights (which cast a cone of light from a specified point and in a specific direction).
We provide herewith names and descriptions of light source shaders:
"ambient"
Uniform illumination.
"distant"
Parallel light from a distant source.
"goniometric"
Goniometric (industry standard light fitting data) light source.
"point"
Light from a point source.
"projector"
Projects a supplied image onto illuminated objects.
"sky"
Sky light source for radiosity calculations. Only applicable to users of the Radiosity Processor Module.
"spot"
Light from a spot source contrained to a cone.