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

How rotations work


A three-dimensional rotation can be expressed as three individual rotations, one around the X Axis, one around the Y Axis, and one around the Z Axis. The smallest matrix we can use to store this type of rotation is a 3 X 3 matrix. When storing rotation in a larger 4 X 4 matrix, we store rotations in its upper 3 X 3 sub-matrix.

The 3 X 3 Rotation Matrix is composed of three vectors that represent each axis of the coordinate system of the matrix. These vectors are called the basis vectors. The basis vectors are stored row or column wise depending on the major of the matrix. We use a 3 X 3 matrix to store three-dimensional rotation data; it is not the only function of a 3 X 3 matrix. We will discuss different uses of 3 X 3 matrices later in the book:

The orientation of this 3 X 3 matrix can be expressed by some combination of yaw, pitch, and roll. Yaw represents rotation around the objects, local Perpendicular Axis, the Y-Axis. Pitch is the rotation around the object's local...