Imported mesh zaniness.

[system]

In a nutshell, here’s the problem I’m experiencing. When I import into a specific subtool, it appears waaaay above its intended position, scaled a little larger than it should be, and stripped of subdivision levels and polypainting. One thing that is interesting to note, is that when I made a duplicate of the subtool, deleted every subdivision level above the first, and attempted the import, the polypainting remained, and the figure was in the proper place in the proper pose at the proper scale. I also attempted to use the “Freeze Subdivision Levels” button. When I did that, the figure appeared in the proper place, scale, and pose, but when I unchedked the “Freeze Subdivision Levels” button, none of the detail made it onto the figure, and the polypainting looked exactly like it would on subdivision level 1. I even tried exporting the successfully posed low res and frozen subd’d models out and importing them to no avail.

I can only conclude that there’s something weird going on when zbrush tries to update the subdivision levels of that model. I have googled to try to find the problem, and I’ve also searched here to no avail. I’ve tried every combination of importing, exporting and re-importing/exporting that I could think of. I’ve tried resetting transforms and removing history. Nada. What the heck is causing this? I don’t understand what’s going on here. I’m at my wit’s end here.

[DragoCG]

No offense, but your question seems like it’s all over the map. Can you list specifically what you are doing in a bullet point list so we might be able to help you better? I’m not sure what you even mean by “importing into a sub tool” I assume you mean you are importing a previously exported obj of the same polycount that has new uv’s and you are replacing the low poly version of the sub tool. If you are using maya you could just use the goZ function. If you are using UVLayout it should work fine.

If you can really be clear about the steps you are taking and what you are trying to achieve we may be better able to help you better.

[Doug_Jones]

Have you used unify on all the subtools? Are you using another software too or just ZBrush?

[system]

Roger.

Relevant details about the subtool in question: Subtool has a UV layout. Subtool is polypainted. Subtool has five subdivision levels.

Process

• Subtool exported at lowest subdivision level.
• Exported mesh imported into 3DS Max as “single mesh.”
• Mesh posed using biped and “Skin Wrap”
• Posed mesh exported as OBJ using default settings (same thing happens when exporting using the “ZBrush” setting (tried it.))
• Posed mesh imported into previously mentioned subtool (subtool was at its lowest subdivision level).

Expected Result

• Subtool should have updated to reflect pose and position.
  • Subtool should have retained polypainting.
  • Subtool should have retained subdivision levels.

End Result

• Subtool updates to reflect changes in mesh. Pose is correct, but position is off (along Z-axis? Whichever one is “up”.), and it seems slightly larger in scale.
• Subtool somehow lost polypainting.
• Subtool somehow lost subdivision levels.

Notes

• Did not receive error message of any sort upon re-importing the mesh into zBrush.
• Switching to lowest subdivision level, deleting all higher subdivision levels, then importing the posed mesh provided nearly desirable results. The pose, size and position was transferred onto the subtool. However, there were no higher subdivision levels to acquire detail from, so it was kind of pointless - with one small exception (see “Conclusions”).

Attempted Remedies

• Multiple combinations of importing, re-importing, exporting and re-exporting.
• Switching “Freeze Subdivision Levels” on and importing the posed mesh. Pose, position, and polypainting remained, but when the option was switched off, no detail was preserved, and the polypaint looked just as it did on the lowest subdivision level.
• Exporting “successful” low-res, frozen mesh into subtool. Useless. Same as “End Result”.
• Deleting various subdivision levels before import. Failure.
• Resetting transforms in Max before export. Fail.
• Other things that I don’t remember right now. Fail.
• Smacking my computer and screaming obscenities at the top of my lungs. How do you think that worked?

Conclusions

• Seeing as to how removing the subdivision levels before import provided the closest thing to a successful result, I conclude that the problem lies with how the higher subdivision levels were either applied or projected upon import.
• “Freeze Subdivision Levels” seems kind of useless.

Workaround I Found Earlier Today

• Exported all subdivision levels of the tool as separate OBJs
• used a previous version of zBrush to project detail from objs onto a subtool using “Project All”
• imported posed OBJ
• It worked!

Still curious as to why this happened!

[Doug_Jones]

http://www.pixologic.com/docs/index.php/Preferences_Palette#Importexport_Subpalette

[system]

http://www.pixologic.com/docs/index.php/Preferences_Palette#Importexport_Subpalette

The funny thing is that one of the first things I checked was that sub-palette. Nothing had been changed. Additionally, other subtools had imported properly using the same method… Which is why this was so weird.

[Doug_Jones]

I think the world axis is different between ZBrush and Max. I could be wrong.

[system]

In Maya, the default is Y-up. In Max, the default is Z-up. In zBrush, the default seems to be Y-up.

I tried flipping YZ just in case. I’ve attached two images of the result. The first image is what happens when Y and Z ARE flipped. The second image indicates what happens when Y and Z are NOT flipped.

Attachments