In the game engine, how do you lock an object's translation while letting it freely rotate?
I've got a record with grooves, with random noise added to all vertices in the z direction.
The needle/arm should drop into a groove on the record, and be free to rotate about the end of the arm as the grove moves up and down.
If I lock the x/y/z translations of the arm, it doesn't move at all. I don't understand why this doesn't simply lock the pivot point, and give me the desired affect.