CGTalk - Negative BSP Value

Hamburger

06-19-2009, 06:12 AM

What does it mean when the average BSP depth is in the negative range?

RCI 0.3 info : max depth : 45
RCI 0.3 info : max leaf size : 4122
RCI 0.3 info : average depth : -31
RCI 0.3 info : average leaf size : 6
RCI 0.3 info : leafnodes : 58679257
RCI 0.3 info : bsp size (Kb) : 3249223
RC 0.3 progr: rendering finished
RC 0.3 info : wallclock 0:03:16.40 for rendering
RC 0.3 info : allocated 2242 MB, max resident 5213 MB

Hamburger

06-22-2009, 04:01 AM

silly me, this just happens when FG only mode is on.

cbamber85

06-22-2009, 10:20 AM

This is still confusing the hell out of me, the only way I can see a BSP tree having a negative depth is if the engine is reducing the number of polys on a surface, but that would almost certainly create non-convex geometry - unless you've subdivided very simple geometry a lot!

Hamburger

06-22-2009, 12:40 PM

Well this scene does have billions of polys in it. Most of which are a lot of instances and geo shaders, there is also quite a large ground plane imported in from another application, but I'm not sure why I am getting a negative BSP value either.

Everything is working fine and renders very quick so nothing wrong with the scene, but this was very strange to me, I just want to know what it means too.

That number does change and if it is set to render normal mode and I cancel a render when it's generating final gather tiles I will also get a negative BSP value, so it's not just FG only mode when this happens.