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

Camera object


In order to build engaging physics demos, we need to be able to view a 3D scene in some way. This is where a camera becomes useful. A 3D camera is made up of two matrices, the view matrix and the projection matrix. The view matrix is the inverse of the camera's world transform. The projection matrix transforms vertex data from eye space to NDC space:

The view matrix of a camera should be orthogonal. An orthogonal camera is one whose rotation basis vectors are at right angles from each other. Two vectors that are at a right angle are orthogonal. Orthogonal vectors are perpendicular to each other. The result of the dot product between two perpendicular vectors is zero.

In general, cameras should not have any scale. Because scale is stored within the same components of a 4D matrix as rotation, it is a bad idea to add scale to a camera. Each of the rotation basis vectors we store within our camera will be of unit length. When the rotation basis vectors of an orthogonal matrix are...