Susbtance painter stretches materials on object with UDIM tiles

[freedomfries]

I have a fairly simple shell shaped object that I tried to apply a substance material to. The material is set to tri-linear projection, with only 1 repeat, although this does not matter.

I get unexpected seams and stretching on parts of the model, for no apparent reason. This model has 9 UDIMS, all on the bottom row. As you can see, part of a UDIM has the material applying correctly, and some parts stretch horribly.

The object works fine in Zbrush, and Mudbox, and Maya, giving no such artifacts. Only substance seems to be unable to properly make it work. I tried importing as FBX, or OBJ, same issues. I tried applying a different material, same issue. I checked the UV's in Maya. They don't overlap, they are not flipped, they don't extend over the tile edges.

Also, creating a paint layer and trying to paint across the surface repeats the stroke on every UDIM tile, rather than painting across the tiles. And when I try to export the textures, it only exports the first UDIM.... Is this some kind of bug?

Any suggestions would be greatly appreciated.

[CAGameDEV]

Currently you cannot paint across UDIMs, so if you're using UDIMs it would create a texture set per UDIM tile.

Can you upload your low poly mesh?

[freedomfries]

Thank you for your response! Here's the mesh.

http://www.cookingwithlasers.com/files/Top1.fbx

I'm guessing this also applies to projections in materials, right? No projections across multiple UDIMS? I tested this out by laying all my UV's from the original model into 1 tile, at 0,1, and the material now works as expected, no smearing. Here's the object with new UV's.

http://www.cookingwithlasers.com/files/Top1b.fbx

I have been using Substance painter occasionally for about a year now, and did not realize this was an issue. It's quite limiting for production of high resolution assets.

Is there a workaround? I purchased substance for this personal project, because I was hoping to use the large library of rock type materials to create a fly over of an asteroid, at close up. There has to be seamless textures and displacement, so I'm not sure I can break this geometry into smaller pieces.

It's disappointing. Maybe I'll need to turn to Mari, which has no such limitation, as far as I know.

[CAGameDEV]

Currently for UDIMs you need to do the following:





You most likely did not check the box on project creation which is why your 2D view is showing more UVs beyond your 0-1.

Until Painter allows painting across UDIMs you'll have to work per texture set. I personally avoid working in UDIMs for single pieces until painting across is available because working texture set to texture requires too much touch up for blending in. It works fine if you're splitting whole parts, but not if you cut up a single piece and want to paint across due to the clean up which I prefer to avoid.

[freedomfries]

Yeah I  was hoping to use a material to create a high resolution rock texture. I split the UV's into UDIMs after dertermining my resolution need. Thing is, it has to be seamless. So I guess I'll have to find another workflow. But I really appreciate your explanation of things.