2 – Building procedural textures

Publisher Summary Texturing is a method of varying the surface properties from point to point in order to give the appearance of surface detail that is not actually present in the geometry of the surface. This chapter describes how to construct procedural texture functions in a variety of ways, starting from very simple textures and eventually moving on to quite elaborate ones. The chapter discusses the major building blocks of procedural textures and the ways in which they can be combined. Two major types of procedural texturing or modeling methods are described: explicit and implicit methods. In explicit methods, the procedure directly generates the points that make up a shape. In implicit methods, the procedure answers a query about a particular point. The most common form of implicit method is the isocurve (in 2D) or isosurface (in 3D) method. In the texturing domain, implicit procedural methods are best for textures that are evaluated during rendering. In both ray tracers and depth buffer renderers, texture samples must be evaluated in an order that is determined by the renderer, not by the texture procedure.