"Andrew Clinton" <ajc### [at] uwaterlooca> wrote in
news:pan### [at] uwaterlooca: 

> You're right that it is more specifically defined as a KD-Tree.  It
> would be a fair amount of work at this point to fix all the references
> so I've left it as BSP-tree.  It seems that BSP trees also have a
> third definition and that is that the splitting plane is axis-aligned
> AND it is put in the center of the cell it is splitting.  If there is
> enough interest in the patch I could correct the naming.

If I were you I would change the naming just to make sure to avoid 
confusion when looking for algorithms and insights in the literature.
I noticed that you have also a "competitor" ;-), and that you've already 
discussed a bit on your respective implementations, any thought of 
"merging your results taking the best from both"?

> The scene has very large numbers of overlapping objects (spheres). 
> The tree degenerates a a small number of nodes with very long object
> lists.  The slowdown is probably caused by the large number of object
> bounding boxes that are intersected and then sorted before testing the
> contained objects for intersection.  For scenes like this the BSP tree
> is not a very appropriate data structure (although there are some
> improvements that could be made but possibly at the expense of
> performance on more ordinary scenes). 

Thanks.
That's why it's better to leave to the user the option to tune some 
parameters of the spatial data structure and to choose the old one.

--
Alessandro Falappa

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