Book Image

Game Physics Cookbook

By : Gabor Szauer
Book Image

Game Physics Cookbook

By: Gabor Szauer

Overview of this book

Physics is really important for game programmers who want to add realism and functionality to their games. Collision detection in particular is a problem that affects all game developers, regardless of the platform, engine, or toolkit they use. This book will teach you the concepts and formulas behind collision detection. You will also be taught how to build a simple physics engine, where Rigid Body physics is the main focus, and learn about intersection algorithms for primitive shapes. You’ll begin by building a strong foundation in mathematics that will be used throughout the book. We’ll guide you through implementing 2D and 3D primitives and show you how to perform effective collision tests for them. We then pivot to one of the harder areas of game development—collision detection and resolution. Further on, you will learn what a Physics engine is, how to set up a game window, and how to implement rendering. We’ll explore advanced physics topics such as constraint solving. You’ll also find out how to implement a rudimentary physics engine, which you can use to build an Angry Birds type of game or a more advanced game. By the end of the book, you will have implemented all primitive and some advanced collision tests, and you will be able to read on geometry and linear Algebra formulas to take forward to your own games!
Table of Contents (27 chapters)
Game Physics Cookbook
Credits
About the Author
Acknowledgements
About the Reviewer
Acknowledgements
www.PacktPub.com
Customer Feedback
Preface
Index

Angular Velocity


With the PhysicsSystem updated, we can now simulate rigidbodies colliding in a linear fashion. This linear collision does not look realistic. To make our simulation more lifelike, we must add Linear Velocity to the rigidbodies. Every object will rotate around its center of mass. To keep the math simple, we assume that the center of mass for every object is at its world position.

In order to rotate an object, we have to store its orientation and understand the forces that affect this orientation. These forces are the Angular Acceleration, Angular Velocity, torque, and the moment of inertia. Each of these topics will be discussed in detail.

Angular Velocity and Acceleration

Angular Velocity is measured in radians per second (). Angular Acceleration is measured in radians per second squared () . Angular Velocity is the first derivative of orientation; Angular Acceleration is the derivative of angular velocity:

We will store angular velocity as a vector. The direction of this...