user_data_string picking up primvar data on .1001.exr but not .<UDIM>.exr

[zach-dt6JQ6D]

Hi guys,

We seem to be having this issue where we create a primvar called tex_Diffuse with a full path to a texture and using the <UDIM>  tag it just renders red. But changing it to 1001 works fine. It's like it doesn't know what to do with the <UDIM> tag. 

Anyone else having this problem?

[Stephen.Blair]

I wouldn't expect user data with "<udim>" to work. That will end up as a recursive string token look up in Arnold, like <attr:test> where test="C:\temp\example.<udim>", and that's not supported. You'll have to have the udim separate from the rest of the user data string eg filename="<attr:test>.<udim>" where test=C:\temp\example"

[zach-dt6JQ6D]

Maybe I didn't explain it enough.

In solaris using karma, I am able to attach the following primvar to my prim:
"/jobs/asset/test/texture/color.<UDIM>.exr"

I then access this primvar in the shader to drive the file path for an image node.

When I do the same in arnold, it doesn't seem to expand the <UDIM> token.

I can confirm that using a primvar without the <UDIM> token correctly reads the texture path into my shader, but using <UDIM> in the path causes it to fail

Is there something I need to change to make this work with Arnold? 

[Stephen.Blair]

Do you have an example scene? I don't know how it is exactly set up in your scene, or what happens when it is translated to Arnold.

But prim var = user data in Arnold, and user data with an embedded token won't work. There's no way I could set up Arnold (eg an ass file) to work with that.