ZBrushCentral

Subdiving kills UV map

ZBrush Usage Questions
#1

Hello!

I want to polypaint a rose using Lightbox / polypaint.

The rose model is low poly, has only 1 subdivision level and is UVed:

uvs1.jpg

The UVs are nice and intact:

uvs2.jpg

However, I noticed that after UVing, the model got another subdivision level. I can now click the “Higher” button.
Why would the “Higher” button now be available?

When I click “Higher” and then click “Morph UV” again, the UV map looks strange:

uvs3.jpg

This is the same effect that I see when I then subdivide in order to polypaint from Lightbox at high resolution.

How should I handle this situation?

Should I simply ignore the broken UV map and paint using the broken UV map, then export the texture map and delete the higher subdivision levels (as I only needed them for the polypainting)?

Thank you for the help!

Attachments

uvs1.jpg

uvs2.jpg

uvs3.jpg

#2

If you subdivide after you made the UV map, you change the point order of the mesh and your UV map is no longer valid. You would subdivide your mesh first to as high as you are going to go, then create the UV map on the lowest subdivision level.

edit: disregard this statement. wrong answer.

#3

If you subdivide after you made the UV map, you change the point order of the mesh and your UV map is no longer valid

Very suspicious statement, take it for granted…

Same result in morph UVs can get if dynamic subdiv on.

But there’s warning when turning that on, default. Or?

#4

Subdividing doesn’t alter the vertex order as the base level itself is left completely unchanged. You can load in a simple lowpoly cube with UVs, subdivide it to a few million polygons, and sculpt/paint on it without any issues (this was sort of the old workflow afterall).

What we’re seeing here is simply the result of trying to Morph UVs when the Dynamic Subdivision Preview is active (which it is, based on that geometry subpallete and lack of SDiv slider). The dynamic subdivision preview contains polygons that not accounted for in the UVs (because they are just for preview don’t technically exist on the actual model), hence the gaps. The good news is that because this is just a preview it isn’t actually affecting the UVs. Turn off Dynamic Subdivision and the UVs will preview (and export) just fine.

#5

Yes, I agree. Brain fart on my part. Sorry.

#6

Thank you!

Turning off “Geometry->Dynamic Subdiv” did it.