I’ve just discovered that Zbrush allows for multiple displacement maps within an object (say a map for an arm, another for the body etc.) to increase the resolution (it is limited to 4096 per map).
What it does is you lay your UVs out so, say the arms would occupy 0,0 to 1,1, the body would be 1,1 to 1,2 etc. and Zbrush would create separate maps automatically.
I tried Vray’s displacement using a mesh select to define the polys of the 2 groups, but I seem to get a seam with it.
Use a multi-subobject material and 3d displacement instead. Assign different material IDs to the different parts of the object, and make VRayDisplacementMod take the displacement from the object’s material (there is an option for that).
here’s quick one - the most time-consuming bit is laying out the UVs on your original model. I could have used the Auto UV feature in Zbrush, but I prefer to have a UV layout that I can work on in a 2D package if need be.
the main drawback is that obj files don’t preserve multi-subobj IDs or selection sets, so if you export the obj file back to Max you’ll need to redefine the different areas (not a major pain, but worth knowing)
Also, multi-displacement only works for displacement maps (AFAIK) so if you need to get seamless texture maps over the model you’ll need another solution…
Finally, I think the multidisplacement offsets can only be horizontal, as ZB crashed when I tried putting one on the next row down. Hopefully you wouldn’t want to use too many, as it becomes a bit of a chore having many horizontally offset UV sets.
the main drawback is that obj files don’t preserve multi-subobj IDs or selection sets
Actually I checked by reimporting right after exporting and OBJ’s do support multi/sub-object ID’s. The problem lies with Zbrush not reading the OBJ file properly (been playing with the UV Groups button all day trying to make proper polygroups from Max exports).
Nlo - it’s the disease of me going crazy with the projection painting in Zbrush
Zeddicus, I know what I was doing wrong, I hadn’t actually assigned a multi-subj material, although the object itself did have different IDs. If you don’t assign a material then the import/exporter will disregard them.
From what Lightwave users have said, ZB took the named sets, but the exporter definitely doesn’t support them. I’ve e-mailed Harald at HabWare to see if its possible to add this feature, but I haven’t heard anything back yet.
