4叉树的实现，用opengl写的。实现的了根据视点渲染地形-4-tree implementation, written with opengl. Implementation of the terrain under the viewpoint rendering

用opengl画的球，按abcd可出现4个不同的图案，网状球体，不透明球体，等等。是本人计算机图形学第一个course work-opengl painting with the ball by abcd, there will be four different designs mesh spherical, opaque sphere, and so on. I was a computer graphics course work