Web 3D

http://www.rr-sc.com/forum-313-1.html

http://wenku.baidu.com/view/88d1c99951e79b89680226a2.html?from=rec&pos=1&weight=998&lastweight=529&count=5

1.unity pivot和center

http://www.u3dpro.com/read.php?tid=227