[SciPy-User] SciPy for Computational Geometry

[Lorenzo Isella]

Dear All,
This is admittedly a bit off topic, but I wonder if anybody on the list 
is familiar with this problem (which should belong to computational 
geometry) and is able to point me to an implementation (possibly relying 
on scipy).
Imagine that you are sitting at the origin (0,0,0) of a 3D coordinate 
system and that you are looking at a set of (non-overlapping) spheres 
(all the spheres are identical and with radius R=1).
You ask yourself how many spheres you can see overall.
The result is in general a (positive) real number as one sphere may 
partially eclipse another sphere for an observer in the origin (e.g. if 
one sphere is located at (0,0,5) and the other (0,0.3,10)).
Does anybody know an algorithm to calculate this quantity efficiently?
I have in mind (for now at least) configurations of less that 100 
spheres, so hopefully this should not be too demanding.
I had a look at

http://www.qhull.org/

but I am not 100% sure that this is the way to go.
Any suggestion is appreciated.
Many thanks

Lorenzo