For a billiards video game where I'm trying to approximate real physics, I have a question. Assume this question deals with the impact of the cue ball and a stationary ball. I'm good with the transfer of lineal momentum from ball to ball, but what happens to the angular momentum of the cue ball during the collision? does it stay with the cue ball or does it also transfer to the object ball? If any of it transfers, what variables would factor in to help determine the amount of momentum transfer. The key word in gameDev physics is 'approximate'. I could actually settle for something like "20 % transfers and is imparted about an axis derived from... & 80% stays with the cue ball but the axis shifts because of..." For my purposes, I do not need to be concerned about momentum/energy losses due to noise or heat 2. A related question; I've been assuming that when any ball hits a bumper, just about all the angular momentum is absorbed by the bumper and as the ball moves away from the bumper, it is sliding with lineal momentum only... while the friction imparts torque over time to increase angular momentum. Does this sound 'approximately' correct?