Hi Yo
From having used it for a brief period you need to explode your model down into individual groups and components. Then it will only apply a material to that individual element. Or try putting elements to have a similar material on the same layer. there are ruby plug-ins that that will do this automatically.
Geh4evr-
How have you found the output from the HD version?, i'm trying convince work to buy it. So far using the demo version i can get 1600x900 which is just about sufficient. i believe the HD version goes to 1920x1080.
This software is potential absurdly good, in terms of results and ease of use. but its also a little frustrating as you cant import camera scenes yet. Which seems archaic. But there is a rhino plug in that works from within Rhino, that would be excellent for SU, we should be asking bunkspeed to release something similar for SU.
Many thanks
Matt