[ REQ 5265]: 3-D Geometry Stuff

[SVLAD at delphi.com]

I've been looking for some efficient  algorithms for
determining if a point is inside of a polygon in 3-D space.
More broadly, I am working on an oct-tree and I want to be able
to efficiently find all 2-D (or 3-D) geometric objects within a
defined region.  My  approach is to determine which octants an
object covers (kind of like gridding it) and make entries for
the object in each octant.

 Do you have or know where I could find such algorithms, or
even better, if someone has already implemented this
oct-tree/object gridding scheme?

Thanks, I appreciate any help you can provide.

Rick Harding
svlad at delphi.com