XDE Physics Engine
XDE Physics is our interactive physics engine, featuring precise collision detection, multibody and beam dynamics. Possible examples of use are assembly verification, object manipulation and so on. It runs as a process separate from Unity3D and overrides the position and velocities of objects in the scene according to their realistic physical behavior.
XDE allows to animate complex scene with multiple rigid bodies interconnected with mechanical joints very efficiently. XDE Physics offers precise collision handling as well as very accurate simulation of dynamic effects, both at rate compatible with haptic rendering.