ZBrushCentral

Losing my polypaint after a GOZ (Maya)

ZBrush Usage Questions
#1

Hi There,

I’m trying to adjust my UVs in Maya to convert my polypaint information into texture later on. But When I adjust my UVs in Maya and send my tool back to ZBrush, my polypaint sticks to the lowest version of my tool :frowning:

VIDEO when it FAILS

I did reinstall ZBrush (2019.1.2), the GOZ plugin for Maya (2018). I removed the GOZ temp files manually and through the clear cache feature. I saved my tools as ZTL to create a new PRJ. Nothing seems to work :frowning:

You can see a video here from another PRJ file that works fine:
VIDEO when it WORKS

Please HELP :slight_smile:

EDIT 1: When I load the dog or the demohead project, all is working perfectly… (My head is gonna explode!!!)

EDIT 2: It looks like it’s tool related. The demohead or the dog works fine so I copy-pasted them in my scene and they still work fine. If I copy-pasted my ship in the demohead or the dog scene, it still doesn’t work

#2

Hi @Air0ne

Sorry you’re having some trouble here. Thank you for documenting the issue so thoroughly.

I don’t see any issues with unsupported program versions, and the fact that you’ve done this successfully between the two versions before means it’s most likely an issue specific to the tool, not an installation issue.

There aren’t any usage issues that are jumping out at me between the two videos, but I do notice a general difference in the UV layout between the two tools. In the tool that is failing, you’ve got a lot of geometry packed right up against the edge, and this can sometimes cause issues in ZBrush.

Can you try adjusting the layout (of the original mesh before sending it back to Zbrush) to be a bit more loosely distributed like in the successful tool, with a bit of empty space as a buffer between the edge and the UV islands, and see if that works better?

#3

Hi @Spyndel

I tried with an adjusted UVs layout but no success :frowning:

image
image.png1920×1040 214 KB

The UVs were somehow broken but I fixed them! Same result at the end :frowning:

image
image.png1920×1040 238 KB

#4

Just to potentially eliminate some variables, does bypassing GoZ and manually importing the updated UV mesh directly into Zbrush change anything?

So in other words, you would update your UVs in the external program, export the low rez geometry back out as an OBJ, and import that OBJ via the Tool > Import function in ZBrush with the lowest subdivision level of your target tool active. You can use the Tool > UV Map > Morph UV function to check the position of your UV islands to make sure they updated.

This will help us verify if it’s a tool/usuage issue, or possibly a GoZ issue.

#5

Hi @Spyndel,

A while back, I did export my low subdiv version as an OBJ file, update the UVs and then import it back the manual way…

Result: It exports purely my OBJ, without keeping my subdivisions or polypaint information. Do you want my PRJ file to debug?

#6

OBJ files dont store subdivision levels. They only export whatever the active level of geometry is.

You can, though, export the base level geometry of a tool as an obj, open it in an external application, edit the UVs, export it as an OBJ again, then re-import that obj directly into your active target tool in Zbrush with the base subdivision level active. As long as the vertex order is exactly the same between the two meshes, it should update the UVs while leaving your polypaint intact at high subd level.

GoZ simply automates this process.

The testing I’ve done so far shows that should still work, and I havent managed to break my model in a way that replicates your issue exactly. I suggested trying this to rule out any potential issue specific to GoZ.

Unfortunately, I cant debug your file directly, because I don’t own Maya and can’t reproduce your workflow.

Since you can make this work successfully with other models using this process, I have to assume that you know the proper procedure. This again suggests an issue with the tool.

As a test, you might try duplicating your tool, scrapping the UVs , and doing a quick unwrap, keeping in mind the issues I mentioned in my earlier post. If you can get the procedure to work with entirely new UVs, then there was something wrong with your UVs. If it still doesnt work, then there may be an issue with your geometry OR a difference in your procedure with this tool that neither of us is seeing.

#7

@Spyndel

I did scrap my UVs, send it to maya, unwrap again but get the same result… This may suggest a problem with the geo itself :frowning:

#8

Also, I tested it with 3dsmax and the result is the same…Again, everything seems to point the geo :frowning:

Is there a way to clean the geo in ZBrush?

Thx

#9

If you’re comfortable uploading your Ztool (Tool > Save As), I can take a look at it to see if there’s anything weird I can notice. You don’t have to save all the subdivision levels. Delete all but the first 3 or 4 ( in a duplicate file! )to keep file size down.

Otherwise you can always dynamesh it first at sufficient rez to close any holes and remove any weird overlapping geometry, ZRemesh it, subdivide it sufficiently, and project the detail from the original onto the entirely new mesh with different topology. The new mesh will also require UVs if your workflow requires them.

If that still fails, then it’s probably an error in your process with this tool, if it works on other tools as you say.

#10

@Spyndel

Can you just confirm that my problem is a real one… I’m starting to wonder now if it is supposed to work…

When I test with a simple primitive, it doesn’t work either… :confused:

#11

Check your MP :slight_smile:

#12

Well, it’s a real problem for you if something that should be working isn’t working as expected. However, with the information available I can’t determine if it’s an error in your procedure, or an error with GoZ. I am relying on you for information though since I can’t test your workflow directly. If any of the information you’ve given me is incorrect, then my assumptions will be incorrect also.

Why don’t we stick with the pre-made models in ZBrush for testing for the time being. The parametric primitives come with their own sets of concerns, and I don’t know what your level of experience is with these. We don’t need to introduce any new variables right now.

I’ve taken a look at your project file containing the tool. The mesh looks good. I don’t see any issues with the tool other than it is pretty large in the ZBrush worldspace. I don’t think this is a problem, but models that are abnormally small or large in the worldspace can experience strange behavior. If you want to test it, you could try duplicating your subtool, and performing a Tool> Deformation> Unify on the main body subtool. Try working on the resulting smaller mesh to see if anything changes.

Otherwise, the mesh performs as expected when importing UVs. See the attached illustration.

Following this process:

  1. The top image is the geometry of your target mesh with the lowest subdivision level active. The islands to the right represent the UVs the mesh loads with. You can preview these islands with Tool > UV Map > Morph UV.

  2. With the existing mesh active, using the Tool > Import function (and only this function), I import a previously exported base level OBJ with slightly different UVs–two islands were moved. Again, this all has to happen at the lowest SubD level, and the meshes need to be the same except for the UVs. If all goes correctly, there will be no indication anything has happened.

  3. In the bottom image, you can see that now the islands have updated when I morph UV, and the hi-res polypaint is intact when I move up and down subD levels.

UVimport

This is the manual import process I wanted you to try. We need a definitive answer as to whether you can make this work at all, or if it only fails when you try to do it with GoZ. It would also let you make your UV edit and get on with your work.

If it fails when you try to do it manually as well, then I would suspect some sort of export issue with Maya if you hadn’t told me you can make this work with other tools using the same settings.

If you can make it work manually though, then it could be a GoZ issue. That’s something you can repeat and send to Support. Your version of Maya should be supported by GoZ as far as I’m aware.

#13

Hi there,

Here are my comments :slight_smile:

I did scale up the scene to match Marvelous Designer (I had to create cloth for the character). I could try to scale it down but if it works for you, it should work for me…

It WORKS (Check this VIDEO. Last time, I thought it was not working but in fact, as you can see in the video, it’s because the polypaint was hidden - but whyyyy!!! - Anyways… we are progressing…)

Yesterday, I passed the night reinstalling my entire system (win10, Maya 2019, ZBrush 2019.1.2). Everything should work the way it should!

Another workable solution I found so far is the following (which is not really time consuming) :
Once I got the subtool back in ZBrush, I copy its UVs, go back a few times in history (to get my polypaint back) then paste my UVs.

:grey_exclamation::grey_exclamation::grey_exclamation: It looks like, it’s related to the way GOZ works:grey_exclamation::grey_exclamation::grey_exclamation:

I just create a ticket with their support and add the link to this post to it

I would like to thank you for your time. It’s really appreciated :slight_smile:

#14

I forgot to do a follow up

The best way to solve this issue is to COPY the UVs for each subtool who got their polypaint crushed then undo one time and PASTE the UVs

  • you can COPY and PASTE your UVs with UVMASTER