2 - Building Procedural Textures

Abstract

This chapter describes how to construct procedural texture functions. It provides a thorough understanding of the major building blocks of procedural textures and the ways in which they can be combined. One major defining characteristic of a procedural texture is that it is synthetic, generated from a program or model, rather than just a digitized or painted image. However, image textures can be included among procedural textures in a procedural texture language that incorporates image-based texture mapping as one of its primitive operations. Some very nice procedural textures can be based on the procedural combination, modification, or distortion of image textures. One can distinguish two major types of procedural texturing or modeling methods: 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 iso-curve (in 2D) or iso-surface (in 3D) method.