About Attribute Objects

An attribute object (or, more briefly, an attribute ) is a type of QuickDraw 3D object that determines some of the characteristics of a model, such as the color of objects or parts of objects in the model, the transparency of objects, and so forth. In general, attributes define material properties of the surfaces of objects in a model.

An attribute is defined as an attribute type and some associated data. You apply an attribute to an object by creating an instance of a specific attribute type, defining its data, and then attaching it to the object. QuickDraw 3D defines many types of attributes, including diffuse color, specular color, transparency color, surface normals, and surface tangents.

In general, however, attributes are not applied to objects individually. Instead, you usually create an attribute set, which is a collection of zero or more different attribute types and their associated data. For example, to create a transparent red triangle, you create an attribute set, add both color and transparency attributes to it, and then attach the attribute set to the triangle. An attribute set is of type TQ3AttributeSet , a type of TQ3SetObject .

Types of Attributes and Attribute Sets

Attribute Inheritance

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