I've been curious about this for a long time, but I never tried to figure out an answer. Now that my scenes are becoming more complex and requiring more time I was wondering if I was missing out on something. Anyway, can someone explain the difference between using 'Optimizations for clustered scenes (BSP)' against 'Optimizations for uniform scenes (grid)'? I keep it on the second option for uniform scenes because it was the default when I first got Bryce a long time ago. Are there advantages to using one or the other? I'd truly appreciate any help anyone can offer. Thanks in advance!

Ummm, it is described in manual. "The BSP algorithm is most efficient when rendering scenes that include clustered or overlapping objects." So Bryce doesn't render every facet of every object, but just those things that are visible. Ditto for optimisation: "Aggressive This is a more extreme version of Minimal mode. It is best used for complex scenes with localized concentrations of objects. If you have imported DXF objects in your scene, this mode will speed up rendering considerably." And yeah, so there are advantages, obviously. In render times. :-)

I abhore manuals. I like to figure things out for myself most of the time. If I can't figure it out my feeling is the explanation I can get from actual people are much more helpful. _

I like to take the manuals to work or something and slam them like a beer, just read it all in one quick sitting. The stuff that doesn't make sense you at least read, and it'll pop out of your head when you need it later. I never read the Bryce 4 or 5 manuals, I think the Bryce 3D manual was the last one I read. Excellent manual, though...

I can understand that. I started to read Bryce 2's manual way back and then I had to stop before my head burst. It's not that confusing. I'm like this mainly because of learning all the specifics for Photoshop about 5 years ago burned me out.