Strange: UV shells were cut into its small pieces after OBJ export

[AlexxCentral]

Hello everybody,

I have an issue, I never had before:

I imported from Maya an OBJ, simply subdivided and simply sculpted it a bit.
But when I export this, my UV shells come back into Maya in small pieces ,
each polygon has it’s own UV shell.
(even with MME or manually doesn’t make a difference)

I am using only a simple 0 to 1 space.
I have well layed out UVs, that don’t touch borders.
It’s a simple OBJ.
I Export with “grp” and “mrg” turned off, like always.
I can see the shells in ZBrush.

When I apply POLYGROUP > Autogroups with UV I get the right shells.

Many thanks…

(ZBrush 4r8, Maya 2017)

IN ZBRUSH Subtool which is exported

AFTER REIMPORT

ORIGINAL OBJ from Maya (opened again in Maya here)

My manual export settings, but also MultiMapExporter makes no difference

[Jack_Niederer]

Try exporting with Mrg turned on in your export settings.

[AlexxCentral]

Hi Jack,

thanks
it worked… Only reason why I switched “MRG” off, because it made trouble often, but in this case the opposite became true
Anyway I do it always like shown before and there must be another hidden reason, but that’s not so important.

[Jack_Niederer]

I know what you mean. I get this sometimes too, it would be interesting to know what triggers it.

[marcus_civis]

Yes, if you are exporting an OBJ with UVs from ZBrush you generally will want to have the Tool>Export>Mrg button on.

[joshuaseaver]

Hi there, I’m experiencing the same problem, and I’m following the suggested workflow for UV Master from zBrush videos using the Demo Head tool. No matter what format I choose (fbx, ma, obj) and what Export setting I use (Mrg, Grp, no Mrg, No Grp, Qud or Tri) it always exports as thousands of individual islands, one per face, though the layout deceptively looks like one shell.
I run a computer lab and this is happening on all the computers in the lab regardless of model. I’ve also tried this on my laptop. Same no matter what. Using 4r7 p3.

[AlexxCentral]

Hi seaverj,
it works for me since I have alwsys MRG on and GRP off!
Did you try that combination?
Did you check your mesh also before (just to make sure it’s not a corrupt mesh).

I’m on 4r8 p2, but I guess this makes not a difference.

[ASERRANO]

I have some similar problem.
Some cuts appears inside the shape of my UV’s when i export from Z.
I have tried export as obj (mrg on, grp on, just one of them, none of them) and as fbx too.
It’s the same subtool and the same polygroup.
I have not an explanation for this