Christoph Hormann wrote:
>
>I had a closer look at your changes and don't really understand the
>meaning of 'Local_BBox'.
>

Local_BBox is the bounding box of an object before a transformation.  The
way that POV-Ray currently produces bounding boxes for transformed objects
is to take the 8 vertices of the untransformed box, transform them, then
find the axis-aligned box that contains all the transformed vertices.  This
can produce a lot of slack space around the object, which you can see by
imagining to transform a long thin cylinder by 45 degrees.

I've added the abilitly to store the bounding box of the object before it
has been transformed.  This allows the tree construction to take advantage
of some more detailed information about the objects in the scene which can
produce a better tree.  For now, I am only using the local box to determine
whether the object should be a member of a cell in the tree - by using a
box/box intersection algorithm.

>BTW the way you implemented the additional statistics is of course not
>the right way(tm) but i'd suggest you wait until the next official
>version before changing this because otherwise you will have to modify
>it twice.
>

How do I implement the statistics in the right way?

Andrew

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