I did a model of a T-rex using a NURBS to Poly to SubD technique. I made sure that I had NO 5 sided faces. The model is made up of 4 and 3 sided faces. It renders fine with Mayas software renderer but Mental Ray won't touch it. I know the problem has to do with the triangles in my poly model. Once I convert the model to SubD and switch to subdivision level 0 I can see that many of the faces seem disconnected from the rest. I ran a simple test. I took a poly cube and converted it to subD then rendered it with Mental Ray. Everything worked as expected. Next, I took a poly cube and spit one of the faces so that it was now 2 triangles. I converted it to SubD then examined it at subD level O. Just like with my T-rex model, the SubD cube had disconnected faces on the side where I split the quad into 2 triangles. The triangles are causing the problem. When I would try to render a subD that was made by converting a poly with triangles, Mental ray would cause Maya to generate this error: "non-quadrilateral face in base mesh not supported."
Question: Is there anything I can do about this besides trying to find every single triangle in my poly T-rex and eliminating them?
I have tried to use Quadrangulate but it didn't help. I don't want to use a dense poly model for my project but if I can't get the subD to render in Mental Ray then I'm going to have to.
By the way, Here is a link to my site incase you want to see the T-rex that is causing me all this trouble. Morphic Motion