Ooh, where can I get that program?Not off the top of my head. I'm generally a Compulite / Avo guy myself... Well, anything but an ETC Congo really. *shudders*
I'm on an overnight shift tonight (NFL live on C4), so I'll have plenty of time to waste looking stuff up.
EDIT: @Dan has a program called Show Xpress that he sometimes plays about with. It's not the best, but it's free and has a simple "what's it gonna look like" program with it. But it's more for waving beams about than the subtlties of light and shade.