Re: bounding volume hierarchy/space partition

Hi Broli,

broli schrieb:
> I have an object which is converted into triangular mesh. I have found
> the AABB of the entire object So I would like to know what bounding
> volume hierarchy/ space partition methods are possible. I would also
> like to know if it would have been easier with a bounding sphere ?
> What are the BV hierarchy/space partition methods in case of boundary
> sphere ? 

In general BV's are used for collision detection or visibility checks. 
BV may affect the decision process of your algorithm about splitting the 
space enclosed of the BV.

I looked up BSP trees but I could not understand how they
> choose the splitting planes. I came across codes for BSP in graphics
> gems.

BSP doesn't oblige you to a specific way how to choose the splitting
plane.

Usually the splitting plane is chosen like this:

Choose a triangle out of your triangular mesh (your set of triangles) 
which splits all other triangles in two subsets with about the same 
size. Do this until your subsets contains a single triangle at leaf.

example:

Triangle findBestSplitter(TriangleSet set) {
   for all triangles in set do with t {
     use t as spliting plane and generate two triangle subsets

     if (my decision function says all right) {
        return t as the best splitter
     }
   }	
}


regards,
Andreas Schüle