CGAL users discussion list

[Andreas Fabri <>]

On 14/06/2010 21:08, Daniel Duque wrote:
> Hello.
>
> First: you have replied to a previous email, changing the email subject.
> But many email clients will group your email with previous ones - it's
> better to start a new thread.
>
> On to your question: there has been a recent exchange on how to find
> intersections of geometrical objects (rays, segments) with bounding
> boxes, check out the archive. But for this particular case:
>
> > I have a collection of points P in 3D space, and I want to identify
> > every point that
> > is inside some rectangular 3D area in this points cloud.
>
> Do you really need CGAL? I mean, just look at the coordinates of the
> points, and check whether they are inside the box (by "rectangular 3D
> area" you mean "box", right?)

Well, if you only have a single query then this approach is fine.

If you have many queries it might pay off to use a data structure
that allows to perform range queries in poly-logarithmic time.
You might have a look at the CGAL Range and Segment Trees
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/SearchStructures/Chapter_main.html

best regards,

andreas

> Best,
>
> Daniel