Book Image

Learning LibGDX Game Development- Second Edition

Book Image

Learning LibGDX Game Development- Second Edition

Overview of this book

Table of Contents (21 chapters)
Learning LibGDX Game Development Second Edition
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

A few basic concepts


Now, we will explore some basic ideas behind the vast Bullet library in the next sections.

Understanding rigid bodies

Rigid bodies are the basic building block of all physics simulations. Like in the real world, a rigid body has some properties such as mass, position, velocity, inertia as well as motion states, and so on. The rigid body is assumed to be solid and thus incapable of being deformed by the exerting forces.

Static, dynamic, and kinematic rigid bodies

There are three different types of objects in Bullet. They are as follows:

  • Dynamic (moving) rigid bodies:

    • Positive mass

    • On every simulation frame, the dynamic world will update its world transform

  • Static rigid bodies:

    • Zero mass

    • Cannot move or collide

  • Kinematic rigid bodies:

    • Zero mass

    • They can be animated by the user, but there will be only one-way interaction and dynamic objects will be pushed away, however there is no influence from dynamics objects

Collision shapes

Like graphical meshes, collision shapes allow collision of...