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

Mesh operations


It's time to implement intersection tests for the mesh object. We want to test the mesh for intersection against all of the primitive shapes we have implemented. The only shapes that we will not test for intersection are points and other meshes.

Getting ready

We are about to implement seven new functions. These functions test for intersection between a mesh and a number of primitives. We will not be performing a mesh to mesh intersection test because it would require looping through the triangle list of each mesh in a nested fashion. This nested loop would become very expensive.

Because most of the functions we are about to implement look the exact same, I will list the full source of MeshRay and MeshAABB here. MeshAABB will contain comments for copy/paste instructions to the rest of the functions being implemented.

How to do it…

Follow these steps to implement intersection tests against meshes:

  1. Declare all mesh operations in Geometry3D.h:

    float MeshRay(const Mesh& mesh, const...