There are two different projections one can use for a cubemap:
- A planar projection of a rectangular frustum for each side (this is what you get from a GL renderer and what is assumed by
samplerCube). - An equiangular projection (in this case,every texel represents the same area on a sphere).
两种生成天空盒的方式
1 矩形平面的平面投影
2 等角方块投影
