其中包含了两份文档，一份是对碰撞的详细分析，在D3D情况下的碰撞检测和碰撞响应，另一份是Direct9的简介，一些基本知识的介绍,Which contains two documents, a collision is a detailed analysis of the circumstances in D3D collision detection and collision response, the other is the Direct9 brief introduction to some basic knowledge