Add Option to Choose ColorSet for Vertex Color ID Baking (Especially for USD)

[defaultmvep0cmck9ob]

I just spent a long time trying to get vertex colors to import from Maya/Omniverse workflow into painter. The issue ended up being differences in how different applications name their color set for vertex colors. Omniverse was writing to the name "displaycolor",  and Maya used "colorSet1". After some trial and error, painter only accepted "displayColor" with a capital C. I'm sure while USD is still being adopted in more software, applications will have different default color set names, and in advanced pipelines, assets might have multiple color sets for multiple purposes.

I propose that for at least USD import (but ideally all formats) there be an option if Vertex Color is selected in the baker as the source for the ID map, that painter presents a drop down with all the color sets on that object to select from.

This would be very valuable for everyone trying to transition to a USD only pipeline.

As a side note, the vertex colors all came in really dark, even after getting the naming convention correct, not sure what that's about...

[Cyril Dellenbach]

Hi @defaultmvep0cmck9ob,

You're perfectly right. Substance 3D Painter has a new .USD importer since early 2023, but it still has room for improvement, especially considering the growing interest for the format.

For the dark vertex colors issue, would you mind sending me a picture, so I can have a better idea on what's happening?

Best regards,

[RGhost]

Thank you for information! It's helped me much.

[defaultmvep0cmck9ob]

Hey Cyril,

I know this is super old, but I'm still having the issue with newer versions of painter. Here's a screenshot of my two posts on the discord painter-questions room that shows the issue, I have more details there, but can't access discord at work (hence the phone screenshot).

In both you can see the Maya displayColor and on the right, the baked vertex colors in painter.

Note the workaround I've implemented in the top version is to limit my vertex colors to values of .75 or higher. While this works, it greatly reduces the number of colors I have available to use as an ID mask that are 10% different to accomodate the 0.1 default tolerance in the color selection mask.

[defaultmvep0cmck9ob]

After further investigation, it appears that the values saved to USD are linear srgb, and painter doesn't do a transform back to srgb when baking the vertex colors. To show this I made ASCII USD and FBX files and compared the same content.
FBX File:

USD File:

When I import these files back into Maya they have the same color applied, so there's a color transform happening on import/export of the USD which isn't being transformed in Substance Painter.