>> If you have some insane isosurface object, it's going to take forever 
>> to trace it no matter what bounding algorithm you use.
> 
> 
> Not necessarily but creating a tight fitting bounding (no matter if 
> using BVH or BSP) is difficult for arbitrary isosurfaces.

I once wrote my own system for splitting an isosurface into a grid of 
"chunks", so POV-Ray would only sample the function near its surface. I 
had constant problems avoiding holes in the surface! :-\

> Concerning which method is 'better' - that quite definitely depends on 
> the scene.

Really? I find that supprising. (And one immediately wanders which kinds 
of scene each one is "best" at...)

> And note in POV-Ray the BVH method is combined with Vista 
> and Light buffers which can speed up things quite a lot in some cases.

Indeed - but it only accelerates camera rays and shadow rays. As soon as 
you have any reflection or refraction on your scene (or a weird camera 
for that matter) these speedups can't help you.

Post a reply to this message