By the way, Li Wan-Chiu has written a Ph.D. thesis on the automatic conversion of triangle meshes to rectangular spline surfaces....

Here is the link:

http://alice.loria.fr/php/article.php?pub=../publications/papers/2006/wan_chiu_li_phd_thesis

http://alice.loria.fr/php/article.php?pub=../publications/papers/2006/TOG_pgp

Hope you enjoy,

All the best,

Boatstalker