ZBrushCentral

UV Seams Issue

ZBrush Usage Questions
#1

Hi guys,

I’m having an issue with my UV seams showing up back in modo when displacing. I’ve tried using both AUV and GUV and I get the same result. My workflow is as follows:

  • Created box in modo (5x5)
  • Exported as obj
  • Import to ZBrush
  • Subdivide up to lvl 7
  • Sculpt
  • Lower back to lvl 1
  • Make 2048x2048 texture
  • AUV Tiles
  • Delete texture
  • Displacement map (2048, Adaptive, Smooth On)
  • Export lvl 1 mesh as obj (Qud, Mrg)
  • Import lvl 1 mesh into Modo
  • Apply disp map to it (setting range from -100% to 100%)
  • Turn up displacement distance (to about 3m)
  • Render

This is the results I’m getting:

render.jpg

It looks like the issue is with the UVs.

Any suggestions? This is driving me crazy!

(BTW, the ZBrush work is in Windows, not Mac)

Attachments

dispMap.jpg

UV.jpg

#2

You’ve identified the issue discussed in this thread: http://www.zbrushcentral.com/zbc/showthread.php?t=64630

At the moment, there is no simple mac-based work around.

(The issue seems to be with with the displacement map generator–the UV’s appear valid, but the matching algorithm and smoothing across the model’s polygon boundaries at Level 1 doesn’t seem to be working right.)

-K

#3

I know about the Mac issue with this, but I did this ZBrush work on Windows, not Mac. The screenshot of the Mac is with modo, but the ZBrush work was all Windows based.

As far as I know, the Windows version of ZBrush shouldn’t be having these issues too, correct?

#4

It looks like the edge overpainting is overlapping, which is causing seams. Try using Multi Displacement 3 and reduce the value for seam overpainting.

Also make sure that there’s no texture filtering or antialiasing active in your renderer.

#5

Thanks for the reply aurick.

Can you give any insight into why I’m getting these black and white flaws around the edges in the displacement map?

floor_front_left.jpg

#6

It has to do with calculating the seam overpainting using 3D data to generate a 2D result. Those artifacts should be outside the actual UV’s and not appear in the actual render.

If you use Multi Displacement 3 to generate the map you can adjust the Border value from it’s default value of 8 down to 0. This isn’t recommended, though, due to the fact that your map would have no margin for error when you take it to your renderer.

#7

So why is it not outside of the actual UVs? Or rather, why is it showing up in my render?

I haven’t been using MD3, would it help? I’m not sure what would be the best settings for exporting to modo. So far, I’ve just been using the Displacement drop down, setting the DPres to whatever size I need and turning on Adaptive and Smooth. I then flip V on the map before exporting it from the alpha palette. Any insight on the correct settings for MD3?

If the border issue is still there, should I lower the border value?