UVs Stuck on Zbrush

Kyle_butler

HI guys.
I'm having a really hard time exporting my pieces from Zbrush to Maya.

I finished my high-res model on zbrush, and I used the uv Master in most of the pieces.
For the ones which the auto mapping wasn't good enough, I would Uv manually on Maya.

So I used GOz -> Visible (when using All, for some reason, many peices where missing when Maya opened).

On this project, since I'm going to use Substance Painter, I decided to work on UDIM. So after manually unfolding I arranged my Uvs on the 1001 - 1020 space.

To my suprise, when I hit the Goz in Zbrush, it restored all my UVs to the 0,1 space.

Weirdly enough all Uvs but the pants, which I had UVed individually before in Maya, and forgot to place on the correct UV space (as you can see). It is as if the Uv information is embedded on the objs and cannot be overwritten.




Then, I tried to export my subtools using Subtool Master->Export visible subtools.

All subtools are exported, but when I export selection in Maya, and Import them back in zbrush, it doesn't recognize the subtools individually.
Instead, it just replaces wherever currently active subtool was selected (on the image shown, the belt).



So I tried  the most inneffcient way possible: exporting each one of the 40+ subtools manually using Tools -> Export. But it still created problems, since it breaks up the model, as such. 


I've read some workarounds this, which involved merging polygroups (I really don't want to do this, especially on the head, since I will create blendshapes later on).

And I can't reduce the number of subtools by merging them and make my life easier, because I'd lose my high res subdivisions.

So I am pretty much stuck inside zbrush and I can't find a way out. 
Can anyone help?

Best Regards,
K

cryrid

By default, polygroups will be split into different OBJ meshes when exporting. To bypass this without merging polygroups, go to Tool: Export and toggle the Grp button. 

Kyle_butler

Thanks for the answer, cryid! Will try to do that! 
As far as the export, is just manual labor, exporting one by one? is that the correct approach? 

musashidan

Zbrush does support UDIMs. It just displays them as overlapped but the multiple UV tiles are, in fact, there. You can use Polygroups>UV groups to assign PGs based on UV tiles.

You should try the .FBX export plugin from ZB. You can export all subtools at once and names/UVs and separate subtools will all be respected.

Kyle_butler

Thanks for the answer, Musashidan! 
I've seen zbrush handling UDIMs, but in this case, I guess something went wrong and it actually reset to the 0,1 sapce, because, once I export the mesh to maya, all the UVs are stacked back together to the 0,1 space.

Your solution on the Fbx is really useful and I'll definitely give it a try!

Also, I've found a script for maya called "mass_obj_exporter" so, it might save some time, since it batches export every object on the scene, instead of you having to manually do, one by one.

Will keep working on the scene!
Thanks guys!