it's like the principle of modeling subdivision surfaces, but the model output nurbs, kotoroya can easily finish in moi
http://www.youtube.com/watch?v=F2qDjS5bOpw
http://www.youtube.com/watch?v=V5fOsZ83pac
http://www.youtube.com/watch?v=EhxnNt6BJeo
http://www.youtube.com/watch?v=NtA5v7OrUO8
http://www.youtube.com/watch?v=_iJWNtXwc7c
http://www.youtube.com/watch?v=WfOKbxfbGC0
http://www.youtube.com/watch?v=hk0u7f137PU