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
About the Author
About the Reviewer
Customer Feedback

Solving constraints

In the last section, Integrating Particles, we made our particle class move using Euler Integration. The only force affecting particles was gravity. This means if you were to run the simulation, every particle would fall down without interacting with anything. In this section, we will introduce several unmovable constraints to the world. By the end of the section, particles will bounce around the screen as they hit constraints while falling under the force of gravity.

Our PhysicsSystem currently only supports OBB constraints; however, adding additional constraint types is a trivial task. We will use raycasting to find collision features between a constraint and a particle. Because we modified the raycast for all primitives to return the same data, implementing new constraint types will use very similar code.

Solving constraints is based on Newton's third law of motion:

Every action has an equal and opposite reaction

In this section, we will explore what to do when a particle...