Changing UVs after polypainting and sculpting in Zbrush 4r6

JakeRay007

Hello,

I made a low poly axe (with multiple parts) in 3ds Max, unwrapped it and imported the same in Zbrush. The axe has multiple sub tools, each unwrapped already. I am now done detailing sculpting and poly painting all the sub tools of the axe. However, I noticed that after doing a test run for generating a combined texture map (by Multimap exporter) of all the sub tools, there were some UV elements which overlapped each other stating the overlaps while I did the unwrapping in 3Ds Max. 
I want to fix the overlaps but I am confused how to apply the poly paint and sculpt details to the same axe, but with the changed UVs. 
P.S: I didn't generate any maps yet. So the model with its sub tools still has the sculpting and poly paint details.

Please help me on what to do here!

DZ_23

Hello,

First fix your UVs in the max. Then enter that to the zbrush file that you already have. (means file that is contain HP sculpted axe with details and paint). If you change your coordinates in the 3ds max then you should overlap each part of axe in the zbrush manually (a little error is ok), if you didn`t change the coordinate and scale then you should be fine.

Now you have a lowpoly axe and a high poly that is painted. so you can easily project the details and paint data to your new  LP axe. (but don`t forget to sub divide the LP axe.)

Probably you will get some errors with paint data (white points) that you can paint them easily again. 

I hope I could help you

Good luck!

JakeRay007

DZ_23 said:

Hello,

First fix your UVs in the max. Then enter that to the zbrush file that you already have. (means file that is contain HP sculpted axe with details and paint). If you change your coordinates in the 3ds max then you should overlap each part of axe in the zbrush manually (a little error is ok), if you didn`t change the coordinate and scale then you should be fine.

Now you have a lowpoly axe and a high poly that is painted. so you can easily project the details and paint data to your new  LP axe. (but don`t forget to sub divide the LP axe.)

Probably you will get some errors with paint data (white points) that you can paint them easily again. 

I hope I could help you

Good luck!

Hello there,
Thanks for your reply. I do get your point of fixing the uvs in Max and then enter the same in the Sculpted high poly mesh, but I don't know how to do that. I don't know the procedure.

Can you guide me as of how to do it via a procedure or help me with a link to a tutorial?

Thanks

JakeRay007

DZ_23 said:

Hello,

First fix your UVs in the max. Then enter that to the zbrush file that you already have. (means file that is contain HP sculpted axe with details and paint). If you change your coordinates in the 3ds max then you should overlap each part of axe in the zbrush manually (a little error is ok), if you didn`t change the coordinate and scale then you should be fine.

Now you have a lowpoly axe and a high poly that is painted. so you can easily project the details and paint data to your new  LP axe. (but don`t forget to sub divide the LP axe.)

Probably you will get some errors with paint data (white points) that you can paint them easily again. 

I hope I could help you

Good luck!

Let me show you the UV changes that I have made. The first one is the original with the uncorrected UVs and the second one is the one with the corrected UVs. This was done in 3Ds Max and the correction in the UVs was also done there. 

Now I want to either transfer the corrected UVs to the High Poly mesh with all the sculpt and poly paint details or do it by any other method, which I don't know

I hope you got the part where I am too stuck to solve.

thomasp

it's perfectly possible to slip in a new set of UVs while preserving sculpt, polypaint and layers in Z as long as the vertex order stays the same - but in my experience with max in it's a particular headache since it manages to mess it up all the time in the OBJ exporter.

if you have access to maya or blender it's not even a problem to do this kind of thing - just export your lowest level from Z, load up the OBJ, apply your UV tweaks (or transfer from another mesh), export to Z and voila. mesh stays the same, UVs change. if you are working with layers and want to keep them you'll have to have the layer set to recording and then import into it while making sure you're on the lowest level.

if you use max for the process it may still work, depending on circumstances but good chance that the vertex order goes out the window by which time Z will inform you about having to reproject. that usually leaves artifacts as mentioned by DZ_23 - and is generally a really undesirable thing because it degrades the original model.

cryrid

Just to append to what Thomasp said, when you export your sculpt from zbrush you either need to do so as a single polygroup, or with polygroup export turned off. Otherwise the export will not have the same vertex order. 

JakeRay007

thomasp said:

it's perfectly possible to slip in a new set of UVs while preserving sculpt, polypaint and layers in Z as long as the vertex order stays the same - but in my experience with max in it's a particular headache since it manages to mess it up all the time in the OBJ exporter.

if you have access to maya or blender it's not even a problem to do this kind of thing - just export your lowest level from Z, load up the OBJ, apply your UV tweaks (or transfer from another mesh), export to Z and voila. mesh stays the same, UVs change. if you are working with layers and want to keep them you'll have to have the layer set to recording and then import into it while making sure you're on the lowest level.

if you use max for the process it may still work, depending on circumstances but good chance that the vertex order goes out the window by which time Z will inform you about having to reproject. that usually leaves artifacts as mentioned by DZ_23 - and is generally a really undesirable thing because it degrades the original model.

cryrid said:

Just to append to what Thomasp said, when you export your sculpt from zbrush you either need to do so as a single polygroup, or with polygroup export turned off. Otherwise the export will not have the same vertex order. 

Actually, I use the plugin called smoothing groups to import the mesh so that I can crease the edges of my mesh according to smoothing groups made in 3Ds Max. If I click on 'Import' from the tools menu or use GoZ while keeping the right sub tool highlighted then that will not crease the particular edges according to smoothing groups. 
That's what I am confused about how do I import the obj of the same object with corrected UVS, apart from using GoZ or Import tool?

JakeRay007

Hi,

I imported the mesh with corrected UVs to the same subtool as the original one (one with the bad UVs but good painting and sculpting details). The, using the UV master, I copied the good UVs from the newly imported mesh and pasted them in the original mesh (one with the bad UVs but good painting and sculpting details)

Thank you all for the help and suggestions!