Angular Momentum in Billiards Video Games

[sh8zen]

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 into 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?

 

[gtoguy97]

1. In the collision between the cue ball and the stationary ball, some of the angular momentum of the cue ball will transfer to the object ball depending on the angle of impact and the masses of both balls. Generally speaking, more angular momentum will be transferred if the angle of impact is shallow, and less angular momentum will be transferred if the angle of impact is steep. Additionally, the mass of the cue ball compared to the object ball will also affect the amount of angular momentum transferred - if the cue ball is much heavier than the object ball, the majority of the angular momentum will remain with the cue ball, whereas if the object ball is much heavier than the cue ball, the majority of the angular momentum will be transferred to the object ball.2. This sounds approximately correct. In the collision between the ball and the bumper, most of the angular momentum will be absorbed by the bumper. The ball will then move away from the bumper with only lineal momentum, and the friction between the ball and the surface will impart a torque over time, increasing its angular momentum.

 

[astrokreng]

I understand your concern with accurately representing real physics in a billiards video game. In terms of angular momentum, it is important to consider the conservation of angular momentum law, which states that the total angular momentum of a system remains constant unless acted upon by an external torque. In the case of a collision between a cue ball and a stationary ball, the angular momentum of the cue ball will be transferred to the object ball, as well as to the entire system as a whole. This transfer of angular momentum will depend on various factors such as the mass and velocity of the balls, the angle of impact, and the elasticity of the collision. The amount of angular momentum transferred can also be affected by external factors such as friction and air resistance.

In terms of the impact of a bumper, it is possible for some of the angular momentum of the ball to be absorbed by the bumper, but it is also likely that some of it will remain with the ball as it continues to move. The friction between the ball and the bumper may also contribute to the increase in angular momentum over time. The exact distribution of angular momentum in this scenario may vary depending on the specific game physics and mechanics, but your approximate understanding seems reasonable.

Overall, it is important to consider all factors and variables when attempting to approximate real physics in a video game. While it may not be possible to perfectly replicate all aspects of real-life physics, a good understanding of the principles involved can help create a more realistic and enjoyable gaming experience.