Bullet 2.78 released

Bullet physics library version 2.78 released.

New in Bullet 2.78

• Fracture and glueing demo that can break or glue child shapes of a btCompoundShape when certain impulse thresholds are exceeded.
  See Bullet/Demos/FractureDemo
• Breakable constraints, based on an applied impulse threshold.
  See Bullet/Demos/ConstraintDemos
• Improved binary .bullet file format with soft body serialization and
  See Bullet/Demos/SerializeDemo
• Polyhedral contact clipping and optional separating axis test (SAT) as alternative to GJK/EPA and incremental contact manifold, for btPolyhedralConvexShape derived shapes such as btConvexHullShape
  See Demos/InternalEdgeDemo
• OpenCL and DirectCompute cloth simulation improvements: GPU kernels for capsule collision detection and OpenCL-OpenGL interop
  See Demos/OpenCLClothDemo and Demos/DX11ClothDemo
• Speculative/predictive contact constraints as a method to perform continuous collision response.