something like the following works nice for me: //apply friction to the balls for (int i =0; i<balls.length; i++) { balls[i].update(); balls[i].isInHole(); } whiteBall.update(); https://github.com/Code-Bullet/Pool_AI/blob/f2eb2e03b2b6f2f0f5e35e163e83ceec8ef402d0/PoolAI/Player.pde#L51