OverlapFilterCallback should be abstract

[zdimension]

No description provided.

[Inverness]

Echoing this. The NeedsBroadphaseCollision method is also not virtual. Please fix this.

Edit: Also, the Bullet manual suggests overriding btCollisionDispatcher for virtual methods needsCollision(), needsResponse, and dispatchAllCollisionPairs. I don't see virtual methods for any of these in C#.

Could you please verify that those things that should be override-able are properly exposed?

[AndresTraks]

Done in 99d1738.

[AndresTraks]

CollisionDispatcher will take some more time. Making C++ classes inheritable in C# is not very straight-forward.