Adding Bullet physics to a graphics application

Before we conclude the business of this chapter, let's touch on one more topic, which is not a 3D rendering matter but links very closely to our 3D scene implementation. This recipe shows how to animate individual visual objects in our scene graph by using a rigid-body physics simulation library, Bullet (https://github.com/bulletphysics/bullet3).

Getting ready

To compile the Bullet library, we use a custom CMakeLists.txt file, so it is useful to recall the general CMake workflow for third-party libraries covered in Chapter 2, Using Essential Libraries.

The demo application for this recipe can be found in the Chapter9/VK01_Physics folder.

How to do it...

1. To simulate a collection of rigid bodies, we implement the Physics class, which calls the appropriate libBullet methods to create, manage, and update physical objects:

   struct Physics {
     Physics()
     : collisionDispatcher(&collisionConfiguration...