Summary

Animation provides a fourth dimension, time, in addition to the three dimensions of X, Y, and Z coordinates. Animation approaches presented in this chapter underlay applications of many types including games, scientific visualization, and the user interface effects of Cocoa Touch. Almost all animations result from changing coordinate systems over time. That’s true whether moving objects around in a scene, pointing spotlights, spinning textures, or walking around a dungeon maze with a first-person point of view. Changing vertex attributes produces animation such as the waving flag examples in this chapter, but frequently changing vertex data should be avoided for optimal performance.

Chapter 7 and Chapter 8, “Special Effects,” extend the SceneModel and SceneAnimatedMesh classes introduced in this chapter. Models are essential for most 3D applications because the alternative, hard-coded vertex data rapidly becomes unwieldy. Chapter 7 explores more sophisticated models than the bumper car, rink, and can light used in this chapter. Chapter 8 demonstrates several techniques that produce compelling visual illusions with minimal run-time processing.