
So I’ve been out of town on travel and I meant to put this up about your mental ray rendering problem. So as I said before I never use the subNode thing MR gives you to approximate the mesh for rendering. Instead I’ll bring in a lower rez of my mesh in this example it was level 3 for the base to start my rendering on. Already since I’m using a base from the original sculpt I have some silhouette info there so I won’t have to displace to much of the mesh. First I’ll take feature displacement off in the mesh so it won’t cause maya and mental ray to tessellate. This will only push your vertices out depending on the displacement map that you provide which is really all we need. Also I just used an 8-bit displacement texture; it seemed to work just fine.

As for the displacement map texture its self needs the correct alpha gain number so you don’t push the vertices way to out. Usually I get this number from zbrush when it makes my displacement map. But the formula for this goes as this your main number goes into the alpha gain and in the alpha offset is the same number divided by 2 and its always negative.

Here is a quick example I made with this method I like to use. Which by the way its origins come from here Headus Example it goes into much further detail and has examples to download to see the shading networks. This is the lower base mesh which I simply subdivided once in maya with a subdivision node and the poly count is 34,272 polys. The left side is this base level plain on its own, and the right is which the generated normal map, which we can say will deal with all this high-frequency detail we need from the meshes, plus it still uses the displacement map to push out the silhouette to complete the reconstruction of the scuplt. This renders much faster than trying to let maya subdivide the mesh for displacment and captures those really fine details and still gives room to include more bump maps or normal maps if needed for other fine details all handled in the hypergraph shading network.

High rez screen snap for compare. I tried to render it in maya but of course mental ray crashed on me. This sculpt is 548,352 polys, compared to the top 34,272 polys. Your always gonna lose some detail, but not to much.

Screen snap of the shading network, its very simple based shading network, mainly the normal map is capturing the fine detail…