ZBrushCentral

Zbrush Blender (re-topo) workflow and UV

ZBrush Usage Questions
#1

All Essentially I am looking for a work flow on exporting the polypainted maps from Zbrush…What I have tried (and failed) so far is to:

  1. Create base mesh in blender. Export as OBJ
  2. Edit mesh in Zbrush. Do a bit of polypainting. Create the high poly
  3. Export OBJ. Retopo in Blender to create the low poly. UV unwrap

After this if I want to edit the high poly again in Zbrush, is there any way I can copy the UV from the low poly into the high poly mesh in Zbrush?

Or am I following an incorrect work flow? If you have to use Zbrush for modelling and an external app like Blender for retopo to finally a low poly and maps based on the high poly how do you go about it?

Cheers

#2

Hey Sansalterego, if I understand correctly, it show be straight forward.

Append the base mesh with the UV’s into the high-poly mesh tool list.
With the low res mesh selected, under Zplugins, navigate to UV master, and click ‘Use Existing UV Seems’.
Then click on the ‘Copy UVs’ button below it.

Select your high poly mesh and then click the ‘Paste UVs’ button in UV Master.

If the copy UVs button is greyed out for the low res mesh, click flatten, and then unflatten, it should appear.

For retopo, have you tried using Zremesher, it will get you about 95% of the way, then some minor tweaks should be suffice for a great low res base mesh.

For knocking out high res UV’d Texture Maps, polypaint your mesh at the highest sub div.
When satisfied, go to the Tool menu > UV Map > set your desired map size.
Then down to > Texture Map > Create > New from Polypaint

Then click Clone Texture and go over to the Texture Tab, and click Export.

You can then further texture these maps in photoshop as needed.

Hope this helps ~ cheers)

#3

Bangers, will be possible to copy UVs in Zbrush when both models have unrelated topology? I was under the impression that the only way to do it in Zbrush was if he subdivide the low poly version in Zbrush and projects the detail and the polypaint of the high res model onto the newly subdivided low res version.

#4

Bangers, Thanks for your reply. Unfortunately it didn’t work :frowning: I tried the following steps as you as specified.

  1. Imported the low poly UV mapped OBJ file
  2. Save it as a Ztool
  3. Loaded the high res Ztool
  4. Appended the low res tool to the hi res
  5. Selected the low res sub tool, ensure that ‘Use existing uv seams’ are on and copied UV (p.s. if I flatten this I can see the correct UV map)
  6. Selected the hi-res subtool
  7. Pasted the UV…But when I unflatten this all I am getting is a grid pattern…

I can try ZRemesher but used to doing manual re-topo in Blender. I was hoping that other folks might also be doing the re top in external programs and importing the UV back to Zbrush…

Thanks for your help!

#5

I guess that if you want simply to transfer the polypaint and the normal maps to the new topology you can do it in any external program, as xnormal, substance painter and designer etc. Zbrush only can do it if they have the same topology.

If you want to do further polypaint in Zbrush there is no problem using those external programs. The same if you want to do superficial geometry details. If you do something more structural you will need to sync manually the shape of your low res version.

In general is simpler to do the low res version using the Zbrush tools as it simplify the problem, if you can accept the compromise that the topology tools in Zbrush mean. About the UVs once done the topology doesn’t matter what program you use.

#6

Quote Altea:

Bangers, will be possible to copy UVs in Zbrush when both models have unrelated topology? I was under the impression that the only way to do it in Zbrush was if he subdivide the low poly version in Zbrush and projects the detail and the polypaint of the high res model onto the newly subdivided low res version.
:+1:

Altea you’re right, I wasn’t thinking, but as you said, quite easy to rectify if you duplicate the low res and sub div then project.

Sansalterego, sorry I should have realised they were different tolologies, but as Altea explaind, relatively fast to fix.

#7

Thanks Altea and Bangers. Will try the topology tools in Zbrush