The company's project has passed a milestone, but it is still very busy. When you are busy, there is no loss. For example, when you find that you are stupid, you will derive the Billboard rotating matrix, not only trouble, and the result is not too good, today summed up . Launch
Billboard matrix derive>, show the process, let everyone help me correct the results. Thank you
Because of the trouble of blog. I made PDF. The connection is given here.
http://xreal.51.net/game/bbmatrix.pdf
