Maya hardware and mental ray issues

benopotomus

I seem to have gotten myself into a rather difficult problem with maya and mental ray. I am currently working on a high poly game character using several normal maps. I Have been successful in generating and applying normal maps that look great with maya hardware render. The issue comes into play when I am trying to render the model with mental ray. It seems to flip the normals that are stacked. It seems like there must be a checkbox somewhere that allows it to "fake" the normals like hardware does.



If it's not clear yet these might help

Here's the hardware render



Here's the mentalray render



Some other various renders





I've read that the uv's contain a normal information that has to be flipped as well, but I don't know if maya can do that.

Flipping the normals of the problem polys creates an ugly seam.
Any help is greatly appreciated.
Also, if there is a workaround for this problem in Max 8 I'd like to hear it.

nekked

although its definitely not an elegant solution, when i need to do this i just duplicate the material and assign the new material to all the faces with mirrored uv's. then take your normal map and invert the green channel and use this tweaked normal map on your new material. it should render just fine in mental ray.

alyen

When I have mirrored/copied UVS I tried break it off where there will be a hard edge. That can't always be done with default Maya render, but with your design you can.
The mirrored parts should have been broken where the orange shoulder part is. It would have really hidden/reduce the seams nicely.

Eric Chadwick

Hey, long time no see.

Why not just render in Max 8?

benopotomus

Well heya. I am offically moving everything over to max to render this weekend. Max 8 is proving to be MUCH better.

BeatKitano

Thanx A LOT nekked, i never thought of that, i'm always struggling with mirroring or not when i do normal mapping.