1.　　实现深度缓存(z-buffer)算法.

输入数据是简单的多边形网格.

2.　　实现简单的光线跟踪(Ray-tracing)算法.

输入应包含多边形网格(多面体)和圆.

-1. To achieve the depth buffer (z-buffer) algorithm. Input data is a simple polygon mesh. 2. To achieve a simple ray tracing (Ray-tracing) algorithm. Polygon mesh input should be included (polyhedron), and round.