Learning LibGDX Game Development- Second Edition

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: