I see over the last year or two there have been several questions relating to the attribute node. I was wondering if there were any plans to implement this feature?
My specific problem is that I need to import .x3d values with colors assigned from another application. Under object data properties, the vertex colors have values under the name "Col". These get assigned with cycles and eevee through the attribute node, but this is not supported with RPR.
I looked at the RPR Lookup node with type Vertex Color, which seemed promising, but this just rendered uniformly black. Looking into rpr_nodes.py the VERTEX_COLOR option in RPRShaderNodeLookup seems to be appropriate, so I'm not sure what's going wrong.