The Essential Guide to Physics for Flash Games, Animation, and Simulations

Collisions and their modeling

Let's begin by defining what we mean by collisions in the context of this book. A collision between two objects is a brief interaction during which they come into contact and exchange forces that then modify their motion. The task of collision resolution is to determine the motion of the two colliding objects immediately after the collision has taken place.

In Part II of the book, you have been used to solving motion problems using forces. This is not how collisions are usually treated. It is very difficult to model the large and brief forces that are exerted during collisions. The way collisions are normally handled is through their effect. We know from Newton’s second law of motion that forces produce changes in ...