As usual... come up with an idea and someone else has already done it! :-) (Which is good in this case as I don't want to design, test and build these things) <http://www.homestead-products.com/simtree.htm> -- "The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ: <http://www.xmission.com/~legalize/book/> Pilgrimage: Utah's annual demoparty <http://pilgrimage.scene.org>