Iray and teeth

Myds

Hi!  Before I started using Iray, I got in teh habit of using "Dental Plan for Genesis/Genesis2) on my G1+2 figures.  Now that I'm using Iray, their teeth won't show at all.  No teeth, no gums, no inside mouth, just a black hole.  I see people offering settings for better teeth materials, but what if they aren't showing at all?  I can see them in the previews, but mouths jsut render as black holes.

Myds

OK, I finally found a third set of settings that makes them show up.  But I guess what I want to know is, what's the go-to setting if something is too dark (compared to its surroundings) in IRAY?