Working with displacement in mental ray
When we work in zbrush or mudbox, we might need to bring over a displacement map to our model back in Maya. Sometimes when we plug the displacement map into the material of our character, we might end up with undesired results that may not be as nice as what we have in zbrush or mudbox.
To solve that, we need to fire up the approximation editor in the mental ray tab of rendering editors. It is recommended that we use subdivision approximation for organic surfaces like characters and displacement approximation for hard surfaces.
Now all we need is to tweak the settings of the node to get the desired quality at optimum render time!
1) Use spatial method and perhaps fine style for optimum renders.
2) The lower the length (above 0), the smaller the triangles. This works hand in hand with max subdivisions to control quality.
3) For 32bit displacement maps, make sure the tiffFloatReader.mll and openEXRloader.mll plugins are loaded.
4) We might use our displacement map on bump to bring out additional details without affecting rendering time.
5) Don’t ever scale your model in Maya when the displacement is generated.
6) Make sure displacement maps are in linear sRGB if we use color management in render settings.
7) Sometimes we need vector displacement maps if we have curvature coming out of a low-res geometry, which can be generated in zbrush 4r3 or mudbox.