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

Verlet Integration


Earlier in this chapter, we discussed how and why Euler Integration becomes less stable over time. We provided a better way to integrate position, Velocity Verlet Integration. While better than Euler Integration, the new method provided can become unstable too. In this section, we will discuss in detail implementing a more stable integration method: Verlet Integration.

Getting ready

In order to move particles using Verlet Integration, we need to re-implement both the Update and SolveConstraints methods of the Particle class. We need to re-implement these functions in a way that finds the velocity of a particle using the previous and current positions of the particle.

How to do it…

Follow these steps to replace the Euler Integration of the Particle class with Verlet Integration:

  1. Remove the velocity variable from the definition of the Particle class in Particle.h.

  2. Re-implement the Update method of the Particle class in Particle.cpp. This new implementation will perform Verlet...