Game Physics Engine Development, 2nd Edition

8

The M ass

Aggregate

Physics Engine

e’ve now built a mass aggregate physics engine capable of both particle sim-

Wulation and constructions made of many objects connected by rods, cables,

and springs. It’s time to test the engine on some example scenarios.

The engine still has limits; in particular, it can’t describe the way that objects

rotate. We’ll look at ways around this, faking the rotation of objects in terms of mass

aggregates. It is a useful technique for some applications, and can eliminate the need

for more advanced physics.

8.1 Overview of the Engine

The mass aggregate physics engine has three components:

1. The particles themselves keep t