Mudbox and UDIMs / by Xuan Prada

When you’re going to texture an asset which already have a displacement map, probably you’ll want to apply that displacement to your mesh before start the painting process.

In my pipeline, I usually apply the displacement map in Mudbox and then I export the high resolution mesh to Mari.

The problem here is that Mudbox doesn’t allow you to work with displacement maps and multiple UV shells.

I tried below to find a solution for this problem.

  • Check your UV mapping in Maya.
  • I’m using these simple displacement maps here.
  • One map for each UV shell.
  • Export as .Obj
  • Open in Mudbox and subdivide.
  • Go to maps -> sculpt model using displacement map.
  • Select your mesh and your displacement map.

As you’ll realize, Mudbox doesn’t allow you to choose different maps for each UV shell which means that Mudbox will be able only to sculpt using the displacement map for U0-1 V1-0 coordinates. Big problem.

The way which I’ve found to solve this problem is:

  • Go back to Maya.
  • Select your mesh and open de UV Texture Editor.
  • Select one of the UV shells which is outside of the default U0-1 V1-0 range.
  • Open the script editor and type -> polyEditUV -u -1 -v 0 ;
  • You’ll notice that the second UV shell is placed in the default UV shell but was moved 1 exact position. Then your displacement texture  will match perfectly.
  • Export again as .obj
  • Now you’ll can use your displacement map in Mudbox without problem.
  • Repeat the process for each UV shell.
  • Commands to move UV shells 1 exact position.

Move left -> polyEditUV -u -1 -v 0 ;

Move right -> polyEditUV -u 1 -v 0 ;

Move up -> polyEditUV -u 0 -v 1 ;

Move down -> polyEditUV -u 0 -v -1 ;