Attribute Objects

Overview

This chapter describes attribute objects (or attributes) and attribute sets. Attributes store information about the characteristics of the materials that make up the objects in a model. For example, you can attach an attribute to a geometric object that specifies the object's color. You can also attach an attribute to part of an object, for example to a vertex of a mesh. QuickDraw 3D provides a wide range of predefined attribute types, and you can define custom attribute types if you wish.

To use this chapter, you should already be familiar with the QuickDraw 3D class hierarchy, described in the chapter "QuickDraw 3D Objects" earlier in this book. To attach attribute sets to geometric objects, you should also be familiar with the routines described in the chapter "Geometric Objects" in this book.

This chapter begins by describing attributes and attribute sets. Then it shows how to create attribute sets and attach them to parts of a model. The section "Attribute Objects Reference" provides a complete description of attributes and attribute sets and of the routines you can use to create and manipulate them.