Introduction

This book is concerned with the subject of collision detection, a broad topic dealing with a seemingly simple problem: detecting if two (or more) objects are intersecting. More specifically, collision detection concerns the problems of determining if, when, and where two objects come into contact. “If”involves establishing a Boolean result, answering the question whether or not the objects intersect. “When”must additionally determine at what time during a movement collision occurred.“Where” establishes how the objects are coming into contact. Roughly, these three types of queries become increasingly more complex to answer in the order given.