generally, this chapter will cover using computation in shaders to supply quality versions of what might normally come from large texture maps, complex geometry, or expensive multisampling. however, accessing thexture will not be forbidden. we will occasionally use them as side tables to drive the calculations performed in the shaders.
Procedural Texturing
the fact that we have a full-featured, high-level programming language to express the processing at each fragment means that we can algorithmically compute a pattern on a object’s surface. we can use this freedom to create a wide variety of rendering effects that would not be possible otherwise. we can also algorithmically compute the content of a volume from which a surface is cut away, as in a wood object made from a tree. this can lead to a result superio