In Motion

Abstract

Motion adds life to a computer-generated image — it is possible to animate the individual objects within a scene or alternatively to dynamically update the viewpoint from which the scene is observed. Each virtual object or observer may be assigned its own independent frame of reference defined by a local coordinate system — the local coordinate frames move rigidly through the 3D world by tracking the motion of the associated object or observer. This chapter is principally concerned with describing various coordinate system transformations — the essential topics include:

• managing the simulation of a virtual world

• collision detection

• local-to-world coordinate transformations

• world-to-camera coordinate transformations

• implementing translations and rotations

• pitch, yaw and roll

• basis and anti-basis vector sets