On products with only Iray materials
Oso3D
Posts: 15,095
People have complained about some products that lack 3DL materials, and I've thought 'you know, unless the materials use specialized shaders, it shouldn't be too hard to go 3DL <> Iray under most circumstances.'
So I've been experimenting.
Here's the Marcoor, converted. All I did was convert Iray > UberShader Base, put the normal maps back (they got wiped in the conversion), set Glossy to 58% and Specular color to 236 gray. I then gave the lights an ambient color.
Now, granted, the Marcoor DOES come with 3DL stuff set up, but this is more a proof of concept.
Also, granted, if you are dealing with a project that has lots of different material zones each with different properties... yeah, that would be annoying.

Comments
I haven't had any problems converting any materials to whichever render engine I'm using. Most of the time I don't even look to see which shaders are on an obj before I decide to use it. It doesn't matter as I can make it work. Granted I don't use 3Delight often, but I am using it currently on my latest render so that I can get a better handle on how it works now that I've learned a ton of stuff since the last time I tried it. And I'm using obj. that only come with Iray materials and had no problems using 3Delight shaders of which I have gotten a ton through all the sales. I haven't ever had a problem getting something to convert to Iray either. I usually just ignore anyone complaining and move on. I just don't see what the big deal is. Like you, I've found it remarkably easy.
Here's another zany attempt... Iray Worlds and http://www.daz3d.com/g3d-da-grass-and-plant-pack... in 3DL!
I like Age of Armor's Subsurface Base Shader. I was experimenting with Dragonfly Hair, and UberShader Base took away the jpgs as well.
I see what you mean, Will, about the maps disappearing with an item with multiple surfaces. Dragonfly Hair has maps on Opacity Strength, Bump Strength, Displacement Strength, Specular Color, and Specular 2 Color, with colors set on each one... and repeat this across 31 surfaces. Lucky for me it comes with 3DL shaders, whew!
However, using AOA's Subsurface Base Shader on Peasant clothes for G3M was rather easy - and the maps didn't disappear.
I've had my eye on some of those really pretty Iray shaders and now I'm seriously considering them. Thanks for this thread - I was looking for a way to convert Iray to 3DL.
they allways get wiped (the normals) also if you use the simple DS Shader preset. Has anyone an Idea why because each of these shaders uber and DS default have normals, so why they get wiped?
you can also use the DS default shader preset and put the normals back (unfortunatelly you have not the option of the strength, for that you have to use the Uber Surface Shader or AoA Uber Surface Shader)
While the label that is displayed in the Surface tab may be the same (I'm not 100% sure that it is) the INTERNAL names are different and only items with the same internal name will be transferred when switching shaders.
Don't tell the PA I said this, and I sort of feel bad, but I actually think that looks way better in 3DL.