四面体分析 任意一点是否在体内 体内一点到面距离 任意流向流出面-tetrahedron analysis check if a point in it check which face to exit acccording a velocity vector

实现乒乓球的发射仿真，含有发射球，球桌等仿真。可以控制球速与方向。-The realization of the launch of table tennis simulation, contain ball, table, etc. The simulation. Can control the velocity and direction.