I have a simple USDPreviewSurface material, which I want to add a materialvariation to, controlling it's texture file.

My UsdPreviewSurface has a usduvtexture node connected, and file is pointing to a .tif. This works.

As a test, I can change the diffuseColor on the shader by wiring in a float3 primvar in a usdprimvarreader instead of the usdtexture, which I can then modify in the materialvariation node. This also works, I can override the color

But I cant get the same functionality when wiring in a string primvar into the File input of the usdtexture node.

How do I vary the texture file path for a usdtexture node?

thanks

is this a limitation of UsdPreviewSurface I wonder? that 'file' isnt connectable

is the same true for MaterialX