Bullet is a physics engine which simulates collision detection, soft and rigid body dynamics. It has been used in video games as well as for visual effects in movies. Erwin Coumans, its main author, worked for Sony Computer Entertainment US R&D from 2003 until 2010, for AMD until 2014, and he now works for Google.The Bullet physics library is free and open-source software subject to the terms of the zlib License.