Texture space shaders are a little different from other classes of shader since the contribution that they make to the final intensity of pixels is less obvious. Their effect upon perceived pixel intensities, is indirect rather than direct, since they serve to modify the environment within which color source, reflectance model, transparency source and displacement shaders operate. These latter four shader classes may opt to perform their calculations based upon a two-dimensional coordinate system known as texture space, and it is this coordinate system which is defined by a texture space shader.
Texture space shaders are used to 'wrap' the effects of shaders of other classes around surfaces in predefined ways. Planar, cylindrical and spherical mappings can all be supported.
We provide herewith names and descriptions of texture space shaders:
"arbitrary plane"
A planar mapping of arbitrary orientation.
"auto axis"
Automatic selection from one of the three coordinate axes.
"cylindrical"
A cylindrical projection.
"spherical"
A spherical projection.
"uv"
Texture space derived from the parametric coordinate system.
"x plane"
A planar mapping into constant x.
"y plane"
A planar mapping into constant y.
"z plane"
A planar mapping into constant z.