自己写的一个Opengl程序，第一次写，代码很难看~见谅~：L其中用到：从2D到3D的转换，三维漫游，鼠标点击生成树木，3ds的加载和显示，billboard的显示技术-himself wrote a Opengl procedures, the first to write a code standpoint it does not look ~ ~ : L which used : from 2 D to 3-D conversion, 3D roaming, mouse click gen

射线选择演示 通过使用glunproject(), 可以将平面的2D坐标,转换成空间的3D坐标. 所以我们使用glunproject()将鼠标的光标坐标转换成空间的坐标,这样就可以实现鼠标的选取 -ray choice demonstration through the use of glunproject (), can be a 2D plane coordinates, converted into space for the three D coordinates. So w