Hi there! For the last month I can't get my physics engine working, and the problem seems to be with the collision response system. Apparently, bounding volumes "bounce" when they collide, mostly when at some point, all 4 corners collide with a plane. But I don't understand some of the fundamentals... Let's supose that a particle collides with a plane, plastically, with no friction. In this case the impulse, normal to the plane, keeps the particle exactly on the plane, so it slides, without bouncing... When it comes to a rigid body, we apply: v = vt + w X (r-rc) where w is the torque for vt. So basically at the colliding particle r we have vt, which moves the particle exactly to the surface of the plane, and we have w X (r-rc) which also rotatates the particle, above the surface of the plane. So I don't understand ... shouldn't the particle remain ON the surface of the plane, and slide? And what about resting contacts? How do they work?

I recommend looking at the paper of Erin Catto here:

http://www.gphysics.com/files/GDC2006_ErinCatto.zip