How to determine relative angle of collision in Box2d

Question

I'm trying to determine the angle during the collision between two box2d bodies in my contact listener (and have failed).

I actually just want to establish whether a collision was simply a glancing blow or a more direct hit - I had hoped to use the relative angle between the two dynamic object (which could be at any angle of rotation and could be polygon or circle) to flag the object for action outside the time step. I guess it would be best to establish the angle at EndContact or PostSolve.

I'm sure this can't be too hard - Box2d must determine this.

Any help greatly appreciated.

Answer 1

Have you checked Ray's tutorial on Collision Detection in Box2d?