View Full Version : Displacement color channel loss

07 July 2010, 09:41 PM
I'm having bizarre problem with a Zbrush mesh rendering in Maya mental ray with a mentalraySubdivApprox node for smoothing for displacement. The more the mesh is subdivided at render time the less of the texture that renders. It seems to crawl in from the edges of the UV, the problem I see is related to scale in maya, as my rig was built at life size (30 feet long) but after retop my mesh came out of Zbrush around 500 times smaller, and rendered perfectly. When the mesh is scaled up and the alpha offset is adjusted to the correct value (500 times larger) the displacement render correctly but the texture gets blown away. I have no idea why. Any suggestion would be great. I have a back end solution, that being geo cache the model and scaling back down for reder time, but that is going to be a real hassle. Thanks in advance for your help.

07 July 2010, 02:47 PM
it might be the CC mesh issue
try reading here

07 July 2010, 06:03 PM
once the CCmesh was turned off, everything rendered perfectly, thanks so much for your help!!

To fix this problem we need to disable this new method of approximation called the CCmesh, by running this MEL command
addAttr -ln “miExportCCMesh” -at bool mentalraySubdivApprox1; where “mentalraySubdivApprox1” is the name of your approximation node.
However this comes with price, the CCmesh is much faster node to render and once you disable it. You will get a hit at render time.


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07 July 2010, 06:03 PM
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