ZBrushCentral

problem with reimporting with uv'

ZBrush Usage Questions
#1

Ok here is my problem when i reimport a low subdiv level with layed out uv’s i get some very strange result does anybody know what the problem could be :o

#2

Yep. When you imported your model into your other app to change the UV’s, or when you exported it from that app, one of your settings caused the point order to change. Since every subdivision level is dependent upon the ones below it, the result is a point explosion when you change subdivision levels and that point scrambling propogates to the other levels.

You need to check your import and export settings in your other app to ensure that you don’t do anything to change the point order. For example, in Maya you must set the Create Multiple Objects option to False.

#3

hmm i see i exported both from maya but i don’t see this option from seperate groups. It is still one object when i go to the files not seperate ones like when i export from zbrush and import with maya and it has seperate objects :frowning:

I have tried transfering the properties in maya and it works ok but when i check uv’s in zbrush there are some very small red dots so it looks like it has some overlapping uv’s. But it behaves this way even with the hi res one when i have deleted all uv’s

#4

Hi Pixelsoul

Th option is on the import settings in maya… look for the last option in the import window called Make Multiple Objects, set this to false.

S

#5

Hmm don’t seem to have that either. But when i look at the file it is still one object not several different objects. So I don’t think that is happening, is there anyway to check the point order between the objects?

#6

Set the file type to obj and you will see the option appears.

S

#7

:frowning: It doesn’t work the weird thing is the model comes from mudbox but when i export there a low res version and a highres and import the hires reconstruct the subdiv’s then import the low res again the same thing happens while they both come from the same program. :confused:

#8

Reconstructing the subdivision levels of a hires model will in most cases give you a lowres model with a different vertex order from your original lowres model.

If you need to update the UVs of a reconstructed model you should export subdivision level 1, UV that in your program of choice and then reimport into ZBrush at subdivision level 1.

#9

mmm well i am importing the low res version with uv’s but how can i get the higher detail version in zbrush then with uv’s if i can’t import it :frowning:

#10

I am not sure how to explain it so I will just show the steps needed.

If you want to create a displacement map in ZBrush then forget about the lowres model exported from Mudbox. Instead do the following.

1: Import the high resolution model into ZBrush.
2: Reconstruct the subdivision levels.
3: Export subdivision level 1 as .obj
4: Import the .obj into maya and apply UVs
5: Export from maya as .obj
6: Import .obj into ZBrush at subdivision level 1.
7: Create displacement, texture or normal maps as needed.

Edit: you still need the ‘create multiple objects’ set to false.

If you only need to create a normal map you can use ZMapper to create the normal map based on two different meshes (the low and high resolution models from Mudbox). The ZMapper manual shows the process for comparing two arbitrary models.

#11

This is what i have been doing, but like i said even when i dont change anything and dont import in maya first it has this the lvl 1 and 4 comes straight out of mudbox not even with maya in between the mesh seems to explode :o

#12

:smiley: What I am saying is that the lvl 1 and lvl 4 out of mudbox are not compatible in ZBrush after reconstructing the subdivision levels of the lvl 4 model. You cannot load the lvl 1 model into subdivision level 1 of the zbrush reconstructed lvl 4 model. The vertex order has changed when you reconstructed the subdivision levels.

To change the UVs in ZBrush you will have to export subdivision level 1 of the reconstructed lvl 4 model, reapply/create the UVs in Maya, export from Maya and import back into subdivision level 1 in ZBrush.

#13

But then how to get my model with all the details in zbrush (insert crying smiley here)

#14

Well I guess you could create a displacement map in mudbox, import the lvl 1 model into zbrush and apply the displacement map. The accuracy of the displaced details will depend on the polygon density of your lvl 1 model and the way mudbox subdivides.

To apply displacement to a model do the following:

  1. Import and subdivide the lvl 1 model. Subdivide as many times as your RAM allows you. Draw your model on the canvas and enter edit mode.
  2. Import your displacement map into the Alpha palette and flip it vertically.
  3. Select a texture, any texture.
  4. Turn off Transform > Quick3D and set Tool > Display Properties > DSmooth to 1.
  5. Turn on Tool > Displacement > Mode and play with Tool > Displacement > Intensity until you are happy.
  6. Press Tool > Displacement > Apply DispMap to displace the geometry.

If you do not mind applying new UVs you could also follow the steps from my previous post. They will result in a perfect transfer of detail.

#15

hmm damn guess that would be the only way to lay-ou the damn uv’s again lol maybe it will work good with transfer attribute in maya to copy over the uv’s im going to try this thx :+1:

edit*

Thanks worked a treat :+1: