I am a researcher working in the field of Granular simulations.
We have an existing code with custom collision detection and physics. I am trying to replace the collision detection algorithms with the ones used in Bullet. The strategy I have employed is to add bullet Rigid body pointers as data members of the Particles class (our equivalent of the btRigidBody) in our simulation. I add these btRigidBodies to discrete dynamics world and then find colliding pairs. So when I get contacting bodies from the persistent manifold I know which bullet objects are colliding. But I also want to know which Particles are colliding because our physics engine works with particles and not btRigidBody. I am thinking of using a map with btRigidBody as the key but since we will be operating on a scale of hundreds of millions of particles, it will be very slow. Any help would be appreciated
