Yes, it's a little late for a New in 9 post, but that's what happens when I pretend I'm going to tell you, briefly, anything meaningful about something as gigantic as a rendering engine. After all, it's the sort of thing people write books about.
Said book, by Dwight Atkinson, Canada's funniest Lightworks in Archicad expert, is in the possession of Rill & Decker, or maybe me personally. So if you want to have a look, be my guest.