Unity Game Optimization - Third Edition

Understanding the physics engine

Unity technically features two different physics engines: Nvidia's PhysX for 3D physics and the open source project Box2D for 2D physics. However, their implementations are highly abstracted, and from the perspective of the higher-level Unity API that we configure through the main Unity engine, both physics engine solutions operate in a functionally identical fashion.

In either case, the more we understand about Unity's physics engines, the more sense we can make of possible performance enhancements. So, first, we'll cover the theory about how Unity implements these systems.