Introduction

T he terms Physically Based Animation or Physically Based Modeling are usedinterchangeably. Both imply the use of the principles of physics, usually classical mechanics, to model dynamically evolving phenomena and to capture these

models in the form of simulation algorithms run on a computer. The goal is to pro-

duce a sequence of states of the system as it evolves in time, and to capture this

sequence as a set of images that are played sequentially to depict the motion. An

example is shown in Figure 1.1, showing a ball being tossed into a net and bouncing

away into a second net.