I just started playing around with the MR dielectric material. I found a useful tutorial on the web and imported some Rhino meshes I made for the occasion. It didn't work so well. I got frustrated after awhile and took a break. I came back a couple of hours later and tried again without the Rhino meshes, just some spheres created in Maya. To my surprise I had a nice looking glass material on the first try. I plugged in my Rhino meshes again with the shader that worked on the Maya sphere and it was ugly again.
I have a sample image at:
The nested spheres on the left were created in Maya. On the right you see the imported Rhino meshes. What is causing the lack of transparency on the Rhino meshes? I am exporting from Rhino as a mesh in .obj format.