ZBrushCentral

Help with transfering UVs from one mesh to another

ZBrush Usage Questions
#1

Hi everyone. Alright, so I have a high resolution mesh in zBrush, and one that is a lower poly count, but UVed. Can anyone help me out by telling me how I could go about transfering the UVs from the low poly mesh to the high poly one?

Thanks a lot!

-ND

#2
  1. just export you high poly mesh make a mental note of the polycount

2.next load your low polymesh
3.suddivided the low polymesh to the same polycount as the hi res mesh
4. Now while the low poly is SELECTED import the Hi res mesh into the subdivided low poly mesh

Done
Now your UVS are on the High Poly

#3

hey,
garycrump,

Thank you very much for your info and NextDesign for the question. I tried step by step this but it doesn’t want at all keep the low poly mesh UVW. As soon the the high poly mesh is imported into the low one when I go to uvw check its the original one from the high poly instead the low poly uvw one.

any other ideas how to make this work

Kindest regards,

  • Bushidou
#4

follow steps above as stated.

  1. Now export the low res mesh with UVS.
    7.Now go back and select the HI res new subdivided model you just made follwing steps. At the Hi setting hit store morph button.
    (This will capture and store all the details of the hi res version.)
  2. Now drop down subdivision to the low res poly count.
    9.Now while it is still selected inport the low res version with UVS
    in it’s place.
    10.Subdivide this back up to polysount of Hi res model and set the morph back 100%.

Done. Your Hi res model returns with all the detail and it has the UVs of the lo res model.

#5

Hi, thanks for your quick response! However, it just occured to me that when I was UVing the base mesh, the high res was already done, I cut up the mesh to make it easier to work with, such as hands, head, etc. However, this renamed the verticies meaning that I can’t just transfer the UV’s. When I tried to bring it into ZBrush, I tried to use the morph functionality to copy the UV’s, but, as the verts are now in a different sequence, messed up. Does your way care about the vert ID’s? Sorry, but I can’t try it at the moment, I’m not at work.

Thanks man for your help!

#6

If you change the mesh it will not work. The solution is if you have a 3d program that will transfer UVS to one model to another then you could transfer it to the low res of the new Hi res model you made and follow steps above.

#7

hi garycrump,

Thanks for taking the time to reply, I tried every step you mentioned but still with no result

to make sure that I did every step right here what I did

1.exported my high poly model (5 times divided) as .obj
2. creating a new document by deselecting the active model tool then imported my low mesh with the righ UVW
3. diveded the lowpoly (5 times)
4. imported the high poly model I exported in step 1

(the UVW are the one from the high polymodel)

  1. Now export the low res mesh with UVS.

This step is a bit wondering. How to export the low mesh again, I think I did something wrong here so I tried many things here .

a. exported the low poly model with uvw and no divedes. Following again the steps bellow
b. hit the Uvs button from tool > texture then exported. Following again the steps bellow
c. set down the divedes to 1 then exported this new model I just created from this steps.

  1. set up the divedes to 5 then go to Tool > Morph Target > Hit Store MT
  2. drop down subdivision to the low res poly count (1 divide)
  3. imported the obj from step 6 by trying the a, b and c
  4. subdiveded to 5 then set the morph to 100

nothing happens, ctr+z
set project morph to 100, mesh change but it doesn’t have the original form, and looks like is made from extuded squares with holes

tried a few hours in row but same result, did I made something wrong?

#8

Hi!

i had the same problem over and over again. Messed up meshes in the higher subdivs after reimport a lowpoly version with new uvw coordinates.

i think i got the solution:

i presume you export the lowpoly version out of zbrush into your favourit 3d app (in my case: 3dsmax) and then fix your uvws - export it back as obj and reimport into zbrush into the highpoly version.

the fractal mesh problems in zbrush are the result of small changes in the topology that happens during the exchange between zbrush - 3d app - zbrush.

Solution for 3dsmax (should be similiar in other 3d apps):

-reset max

Import
during the obj import dialog in max you have to choose the following settings:

  • Single
    checked - rotate model
    checked - Texture coordinates
    checked - Normals
    UNCHECKED - unify <— ! this causes the problems! it modifies your topology!
    checked - Obj smooth groups
    Vertex scale 1,0
    unchecked - Center Pivot

the “use materials” doesnt matter

UVW fixing / Creation
-now convert the model into “editable poly”
-use the unwrap UVW modifier to fix your uvws or create new one

!dont change ANYthing in the topology of your model!

Export
then you can “export selected” your model with following setting:

group by: object
(materials are ignored)
checked - rotate model
Faces: Polygons
checked - Texture coordinates
checked - Normals
checked - Smooth groups
Vertex scale 1,0

of Digits: 6

UNCHECKED - Compress numbers <-- this would change
UNCHECKED - Relative vertex numbers <-- your topology! ->BAD!

Back in ZBrush

-load your zbrushed model with all the details.
-go to subdivision step 1
-import the lowpoly obj with the new UVWs.
-you can then go to the higher subdivs again. and everything should be fine.

If you make the smallest change in your model. during import or export, it wont work!! just try every combination in the import and export settings and make sure your obj is just changing the uvw coordinates!

I don’t know if there are other people who already found a solution…
ZBrush rocks

Greetz

PS: i have another problem with multiple UV Sets and the ZMapper. if i try to create a normal map for one UV Group, the zmapper just creates randompixels and displays a messed up mesh. Any suggestions?