说明：  Ageia s PhysX(著名的游戏物理库) D3D 9使用演示代码。由于PhysX物理库使用OpenGL代码实现图形着色，从而使许多用DirectX 3D的程序员不能使用/读懂demo代码，这是使用D3D着色引擎重新写的一些demo代码。
(Ageia s PhysX (well-known game physics library) D3D 9 using the demo code. PhysX physics library as a result of the use of OpenGL graphics rendering code so that many use the DirectX 3D programmer can not use/read demo code, which is the use of D3D shaders to re-write some demo code.)