Not sure whats causing this error. I have 3 subtools and when I merge them it appears that certain seams get sewn together.
I’m using version 2019 Mac, but it also happened in the previous release.
How are you doing the merging? Is the Weld option on?
I’ve tried merging with Weld on and off.
Theses are separate watertight models. I imported the base meshes from Maya LT. I’ve used this workflow many other times without issue, so I’m stumped at the problem with this particular model. I can’t think of what I’m doing differently here.
My only workaround has been to fix the merged UVs in Maya and then reimport to ZBrush, but then if I need to add on another subtool, the seams get sewn together again.
I’ve done Merge Visible, Merging one at a time, Merging with Subtool Master, and with Weld on and off.
I presume that the UVs occupy just one UV tile and that they don’t overlap at all? (One thing that ZBrush doesn’t like is UVs that extend right to the edge of the UV tile, but usually in that case you get horizontal or vertical lines so I don’t think that’s the problem here.)
Could you try this alternative method of merging:
- Import one subtool with UVs.
- In the Tool>Import sub-palette, turn on Add. Leave the other settings as they are.
- Import the second subtool. It will be merged with the first (but without any merged points as I guess that’s what you want with two watertight meshes.)
- Check the UVs.
Let me know if this makes any difference.
The UVs occupy one tile. Some do overlap. I’ve had overlapping UVs before without this issue though.
Your alternate method did work to merge the base mesh models and preserve the UVs.
I ended up importing as one combined model from Maya and Projecting the sculpting and polypainting.
Thank you.
Can you share the two subtools? I’d like to pass the file to the development team so we can find out what is causing the problem.
This is the ZTL I was working with:
Many thanks, though there is only one subtool with that file, and the UVs don’t look anything like what you show above. I get two maps (for two different UV tiles), and one is blank with no apparent UVs. [EDIT: there is only one texture vertex for the head part]
Those images must be from a different file.
Yes, my bad, I muddled the files. It’s been a long day. 
Many thanks for the file. I can reproduce the problem. It is clearly something to do with the calculation of the subdivision levels as if you merge at the lowest subdivision level the UVs are OK.
I’ll pass this along to the developers. If I find out anything useful I’ll let you know.
Thanks for your help!
Hello,
I was just wondering what was the solution for this issue.
I’m having exactly the same problem and I couldn’t find anything online other than this post.