Someone spilled the paint!
This image contains 100,000 spheres, shown against a checkerboard background.
(The background was computed in an ad-hoc manner, and can be considered to
be the projection of the unit checkerboard far below the xy-plane.)
Bounding box hierarchy
The images below are intended to give some idea of what the bounded-
volume structure looks like. They are computed in only two dimensions,
and are colored so that they are lighter near the root. The leaves are
the darkest squares.
1500 spheres
(That sounds like the title of a cheap science-fiction book!) Notice the
longer, thinner boxes at the right side, which result from the fact that
the first partition splits the boxes very unequally.
2048 spheres
The number of objects is a power of two, so the box structure here is
better. But it is not difficult to see how the tree structure could be
rearranged to improve the locality of the boxes.
