三角形逼近球体演示

原理：先用正三角形逼近绘出20面体，然后递归分割，把每个面分割为4个三角形(递归次数可定),此以来逼近球体。-spherical approximation triangle demonstration tenets : first approximation using regular triangle charted 20 Verses, and then recursive segmentation, each side of the divided four triangles (recursive number may be), since this sphere approximation.