Trouble applying Iray shader to OBJ
Using a 3rd party OBJ of a crumpled rag, I tried to apply an Iray lace fabric shader, but all I get is a solid, shiny surface instead of a lace pattern. I've never had this issue before. I did try varying the horizontal & vertical tiling by quite a bit, but get the same results every time. The image provided shows a standard primitive plane on the left and the OBJ on the right Top is NVIDIA viewport and bottom is wireframe view.

Comments
Does the OBJ have the Uber base shader applied? If not, you'll need to apply that before the preset.
Yes it does
Is the OBJ UV-Mapped?
The crumpled rag probably isn't UV unwrapped. Which means it cannot properly display any image map, so it will only show a solid color.
A-ha. Thanks - any way to fix this?
I downloaded UVmapper and created a UV for it. Just trying to figure out how to apply it to the object...
Well, I would import the obj into Blender and UV unwrap it there then re export the unwrapped obj out and into DS. Since it's a funny shape, I'd use the Smart UV Project option in Blender.
You don't have to "apply" it. Just re-export the now UV unwrapped object out of that program and import it into DS. then apply the shader as before.
Ah, beautiful, worked like a charm - thanks!
Glad to help.