Possible Game Enhancements

This is a pretty advanced Flash game. However, several things can be added or modified that would improve the game even more if they are done well! If you put your mind to it, you can probably come up with a few more important features or effects to make this a more perfect game. Good luck!

Rolling balls In a perfect version of this game, rather than appearing to slide (as they do here) the balls would have some sort of rolling animation that coincided with the direction in which they were rolling.

Angular velocity If you decided that you wanted to do the rolling animations mentioned above, you'd need to know that the physics for rolling balls is different from that of sliding balls. The rotation of a ball is handled using angular velocity that is, angles divided by time. (Think about it: If velocity equals distance per time, so should angular velocity equal angles per time.) We did not cover angular velocity or the moment of inertia for rigid bodies in this book (maybe in the next revision). But in a perfect game of 9-ball, they would be accounted for. These principles also directly apply to the next point.

English English describes the spin put on the cue ball when it is hit off-center. If you put bottom English on the cue ball and hit another ball dead-on, then the cue ball may rebound back toward your stick. Or if you put top English on the cue ball, then it will follow the ball that it just struck. English can help you better position the cue ball after a shot and make shots that would not otherwise be possible. The English on the cue ball affects how it bounces off a cushion and imparts some of its own spin onto every other ball that it touches.

Real friction While the "good-enough" friction used here (and introduced in Chapter 4) looks, well, good enough, it doesn't simulate exactly the look of a real game of pool. In a better version of this game, the friction would look more real. Note also that treating the balls as three-dimensional rolling objects using angular velocity and adding English would not be possible without using real friction.

More sounds A complete and perfect game of 9-ball would include many sounds. You would have soft sounds for balls hitting the cushions, and different sounds for other events, such as the stick hitting the cue ball, the balls getting racked, and a ball being pocketed.