OpenGL® Shading Language, Second Edition

Chapter 11. Procedural Texture Shaders

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 an object’s surface. We can use this new freedom to create a wide variety of rendering effects that wouldn’t be possible otherwise.

In the previous chapter, we discussed shaders that achieve their primary effect by reading values from texture memory. This chapter focuses on shaders that do interesting things primarily by means of an algorithm defined by the shader. The results from such a shader are synthesized according to the algorithm rather than being based primarily on precomputed values such as a digitized painting or photograph. This ...