用了好多公式制作的程序，让程序中的火花也依据万有引力的作用运动。程序简单，但是可以给你许多以后在做小动画时的启示，他们其实并不难。-formula with a lot of the production process for the procedure is also based on gravitation sparks of movement. A simple, but it gave you a lot to do in the future when a small animati