I've loaded an .obj file into DAZ Studio (Actually the was several .obj files from a free download object) and the one .obj file will not take any iray shader, but all of the others (that were downloaded as a set) will take the iray shaders. Why...and Why Not? I've exported this particular .obj from DAZ and it makes an .mtl file, but that doesn't even seem to matter here. When I apply an iray shader to the object (in DAZ) the object changes color, but it's as if I'm just applying a basic blue or white color to it, as no texturing or bumps or even maps show up.

Any ideas out there?!

I assume you mean the item doesn't show the effect, rather than that the current shader listed at the top of the editor tab of the Surfaces pane doesn't change. Most likely this is because the problem item isn't UV mapped, so DS doesn't know how to vary the effect across the surface - it is possible to make shaders that work by location in 3D space, rather than UVs, but I don't think any of the supplied Iray shaders work that way.

Is it possible to add UV mapping to the obj? If so, is there a tutorial on how to do that?

Yes, but you'd need another application - Hexagon, Blender or the like.

I have a free version of blender. I'll have to look for a tutorial on how to do it. Thanks!

This one starts with the basics:

https://www.youtube.com/watch?v=V6OXSR5Ynyc

Try this one for more complex objects:

https://www.youtube.com/watch?v=scPSP_U858k

(^this one seems to start at the end but give it a few seconds and it'll get back to the start)

Actually, that one looks like a flat plane with a bit cut out - in Blender, try importing the obj, going to the uv-map window, in the 3D-view tap Numpad-7 (so you're looking from above) or whichever view shows it flat. Then use 'project from view' (try to fill the view as much as possible as you want to use as much uv-space as possible. Then export the obj again and see if it works.

Crispycraft posted at 12:20PM Wed, 26 June 2019 - #4354756

I have a free version of blender. I'll have to look for a tutorial on how to do it. Thanks!

There isn't any other version of blender other than free that I know of. It's a public project and open source. ;)

SilentWinter, I was able to apply the UV maps in Blender. You were correct, it took two videos to put the instructions together. Thanks for your help!