Zbrush UV Master

beefaroni

Hey guys, I've been trying to figure out this problem with UV master for the past few days now and was wondering if you had any insight.

My model has 6 subdivisions. I took the lowest subdivision, exported it, UVed it in 3d-coat and then brought it back to zbrush. The problem begins when I copy the UVs from the low poly mesh back to my original mesh. The UVs get all weird and distorted.

I'd rather stay away from UVing in UV master as there is a lot of control lost when placing seams (especially for games).

Here' an album of some images if it helps.

http://imgur.com/a/fsP2p

JohnnyRaptor

You dont need to use UVMaster for this, you can just import the UVd lowest subdivision mesh back over the lowest subdivision of your unUvd zbrush mesh. ZBrush will automatically add the UVs, update and reproject the details.

beefaroni

Getting some issues with importing over the mesh. The first time it asked to re-project the higher details; however, the mesh became distorted. The second time it just overwrote the mesh leaving me with no higher subdivisions.

JohnnyRaptor

hmm, sounds like your vertex order might have changed.

From the look of the image, with UVMaster, you only have 1 vertex that isnt correctly positioned.

you could just re-export the lowest subd with the problematic UV vertex and fix in your 3d app, and then bring that back as i posted in my original post ?

edit, what version of zbrush you on?

beefaroni

The UV mesh is a bit more distorted than the image leads on. Here are two new images. I have read issues about vertex order on other forums; however, I'm clueless as to what that means.

http://i.imgur.com/vNYk7mJh.png

http://i.imgur.com/ii3zYReh.png

edit: just want to say thank you for the suggestions so far. I'm looking into my models vertex order now. Hopefully that will solve this problem.

edit 2: the original model was 5 objects merged together in zbrush. The objects are the body, r_eye, l_eye, upper_teeth, lower_teeth. When just exporting the body, uving it, and bringing it back to zbrush and copying the UV, there isn't a problem. There still is a problem when trying to UV on the multiple objects. One thing I noticed is that my other objects are not closed polygons. I'm going to give that a shot. The overall goal is to have the body, eyes, and teeth on the same UV map to save UV space and keep the density the same between them all.

cryrid

You'll have better luck if you export the model as one polygroup (group visible) prior to creating the UVs. Otherwise the exported mesh will get split into several parts, which means the vertices are not the same as the original mesh (one vertex at the hip could now be split into 4 vertices to support those groups).

beefaroni

^ A quick test with this method seems promising. I'll update soon.

beefaroni

For anyone running into the same issue that runs into this thread. The main problem was trying to export my object in polygroups to make UVing easier (turning off individual groups). As cryrid said, the model should be one polygroup before export.

1. Model with multiple parts that need to be combined to one part for UV mapping in Zbrush
2. Merge subtools in zbrush (save your separate tools as backup) and go to polygroups > group visible
3. Export model as an .obj file and bring it into UV program of choice
4. UV map (don't separate parts in maya or anything) and then bring it back into zbrush
5. UV master copy UV's

Thank you to all who helped.

cryrid

Step 5 should be redundant as Johny Raptor said. Zbrush can detect the changed UVs and update them on its own (and without a message dialogue)