It seems UDIMs and MaterialX don't mix...

Development Rendering
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1

We are starting production on a TV Series in Unreal and as such starting testing out ingesting our assets and shaders.

I’ve figured out, after a lot of hair pulling :slight_smile: , that if the images in my MaterialX uses UDIMs, 80% of the textures won’t import, giving me a generic “Unable to retrieve the payload from the source file”.

For the 20% of textures that import, they import wrong, using only the first image from the UDIM set. Even though Virtual Textures are on. Drag and dropping the same texture in, imports fine, with all UDIMS being found.

If I remove the “.1001” from both the filename and MaterialX, then everything imports without any error.

I’m not sure if this was a known issue, as we are brand new to Unreal :sweat_smile:

This is a real bummer, as we had really hoped to use UDIMs :expressionless:

2

I saw a post made 18 days ago about the same issue, but with USD.
This is a serious bug, as UDIM a very much needed for Productions.

I’ve written my own exporter/importer for MaterialX for Both Maya and Blender.
Had I known of this issue, I would have instead built an importer for Unreal, forgoing MatX completly :expressionless: … This would have been more flexible too :man_facepalming:

I guess I’ll have to look into that.

3

Hello @FranckyB1, there is not yet UDIM support for MaterialX.

Do you have a couple of samples of mtlx + texture files you could share with us?