ZBrushCentral

ReimportUV with 2 MaterialIDs -> possible bug?

ZBrush Usage Questions
#1

Hello, I used UVLayout to unwrap the UVs on my organic model and wanted to use 2 Texture maps one for the head and the other for the body. The problem with UVLayout is, that it doesn’t support UVGrouping/Polygrouping.

So I went ahead and tried to split the Shells in two MaterialIDs in 3DSMax, which worked well. I exported the model as OBJ for reimport.

The Problem which occured is that when I try to reimport the UVs with 2 MaterialIDs and go back to my highest Subdivision my model gets distorted all over.

Now comes the really strange thing: If I use the exported OBJ from 3DSMax with the 2 Material IDs and collapse them down to one Material ID once again and reimport this to my ZBrush tool and go back to the highest subdivision level, no distortion appears!

I don’t see where I go wrong, is it a known bug or is there a workaround? Is it perhaps even possible to do the MaterialID splitting in ZBrush?

Thanks in advance for your help!

#2

Something that’s happening in Max is changing the point order of the model. It’s possible that changing the material ID’s changes the point order.

How about putting the maps into different UV regions rather than using material ID’s? One map would be in the 0,0 to 1,1 coordinate range, and the other could be in the 1,0 to 2,1 range (for example).

#3

Thanks for the quick answer, I already did that, - but correct me when I’m wrong - wouldn’t the UV coordinates still refer to the same texture then? I’m trying to use a head-texture and a seperate body-texture.

Thanks in advance!

#4

I’m getting really confused, I used Hexagon to assign new “Shading Domains” (that’s what the 3DSMax term “MaterialIDs” are called in Hexagon) which worked great. I checked in 3DSmax and it imported the obj file with 2 Material IDs - one for the Head and one for the Body, so far so good.

I reimported the new UVs into ZBrush and could even go back to highest subdivision with no exploding mesh! Man I was glad - I thought I did it…

… BUT, when I export the mesh from ZBrush again to an obj file, the MaterialIDs/Shading Domains are gone again - aaaargh o.o

Now my question is, is what I try to do even possible for ZBrush, or does it merge every MaterialID/Shading Domain automatically on obj import?

I’m really at the end of the road with my ideas :frowning: please help