Subdivision of Triangle Surface
https://drive.google.com/file/d/0B9PkXciHrlH5bWRWdU1SMmxQRUU/view?usp=sharing
reference: Andrew Heumann, http://www.grasshopper3d.com/forum/topics/how-to-triangulate-a-triangular-surface?id=2985220%3ATopic%3A663401&page=1#comments








