Getting empty string when trying to get resolvedPath of UDIM path

Community USD
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1

Title says it all, I have a usda file like UsdUVTexture like:

def Shader "bla"
{
     uniform token info:id = "UsdUVTexture"
     asset inputs:file = @udimsfolder/udim_texture_<UDIM>.jpg@
     ....
}

and somewhere in my code i do:

file_attr = usd_texture.GetInput('file')
if file_attr:
     file_path = file_attr.Get().resolvedPath
     texture.filename = file_path
     ....

and no matter if the UDIM path is relative or absolute, I always get an empty string returned by the “.resolvedPath” call. I searched around the archives to see if others came across similar issues and there seem to have been but not quite the same. Is the behavior I am seeing expected/normal?

2

Hi @Quaxo , welcome to the forum.
Unfortunately, the UDIM resolution is left up to the renderer.

USD itself doesn’t have a UDIM resolver so the empty string is due to failed resolution.

If you’re trying to resolve this without a renderer doing it for you, the easiest method is probably querying the raw string and substituting the UDIM token yourself, then asking usd to resolve that.

3

That’s right, and USD will do “the best it can”, i.e. if the authored path is an “anchored path” like
@./udimsfolder/udim_texture_.jpg@ , the returned SdfAssetPath that the UsdAttribute gives you will have already performed the anchoring to the layer’s location for you, so you will get back a different and more complete string than the one that was authored, but the “” will still be there for you to resolve yourself.