CGAL users discussion list

[Bueno <>]

Hey, guys.
Thanks for the fast answers.

Sorry for my mistake in replying another message.
I didn`t realize this would be a problem for the list.

I`m using CGAL because this is just the beggining of a bigger project,
including triangulation and big points clouds manipulation.
But I agree with you that I don`t need it for the task of locating points
inside the rectangle.
And, of course, I hoping that CGAL already has a simple way of doing this.
And Yes, I have many many queries to perform on ruge points clouds.

I`m reading documentation of classes like Neighbor_search, Iso_box_d etc.
But I`m not sure if I going to the right way.
I`m starting here:
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Spatial_searching/Chapter_main.html#Subsection_59.1.2

Thanks


Ricardo


--------------------------------------------------
From: "Andreas Fabri" 
<>
Sent: Monday, June 14, 2010 4:13 PM
To: 
<>
Subject: Re: [cgal-discuss] Finding points inside a rectangular region on
space.

> 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