[math] ConvexHull in 3D

[luc <lu...@spaceroots.org>]

Hi,

Thomas, do you intend to add an implementation of convex hull for 3D?
I need one soon ...

best regards

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
For additional commands, e-mail: dev-help@commons.apache.org

Re: [math] ConvexHull in 3D

[Thomas Neidhart <th...@gmail.com>]

On Mon, Feb 10, 2014 at 4:32 PM, luc <lu...@spaceroots.org> wrote:

> Le 2014-02-10 16:05, Thomas Neidhart a écrit :
>
>  Hi Luc,
>>
>> it is on my queue of things to do.
>> I already started to look at qhull (www.qhull.org) which is under a very
>> permissive license and contains algorithms for convex hull, voronoi and
>> triangulation for arbitrary dimensions.
>>
>
> This seems nice. I did not find the license on the web page (did not
> download
> the source yet).


http://www.qhull.org/COPYING.txt

IMO, it is similar to a Public Domain license, which only requires that the
copyright notices are kept in re-distributed or derived code.


>
>
>> Implementing the other convex hull algorithms were my first steps to get
>> accustomed to geometry algorithms, and my plan was to finally port qhull
>> to
>> java, but this will surely take some time.
>> Focusing on the 3D case for convex hulls should be feasible though,
>> depending on when you need this feature, do you need it to be included in
>> the 3.3 release?
>>
>
> Well, ideally, yes, but this if you have not already started it, I'll have
> an interim solution. The tests I have recently done with enclosing
> spherical
> on the sphere show that due to the phere topology, the Welzl algorithms
> fails
> to find the smallest cap in many cases. So I will remove
> SphericalCapGenerator
> and will implement getEnclosingCap using another trick.
>
> Don't hurry to do it, I have a way to compute the enclosing cap, even if in
> extreme cases it will not be the smallest possible. So this mean I can
> wait after 3.3.
>

No problem, I also do not want to give the impression that I am the only
one who can work on this.
In fact I would be happy to collaborate with others as certainly 3D is not
my main area of expertise ;-)

Thomas

Re: [math] ConvexHull in 3D

[luc <lu...@spaceroots.org>]

Le 2014-02-10 16:05, Thomas Neidhart a écrit :
> Hi Luc,
> 
> it is on my queue of things to do.
> I already started to look at qhull (www.qhull.org) which is under a 
> very
> permissive license and contains algorithms for convex hull, voronoi and
> triangulation for arbitrary dimensions.

This seems nice. I did not find the license on the web page (did not 
download
the source yet).

> 
> Implementing the other convex hull algorithms were my first steps to 
> get
> accustomed to geometry algorithms, and my plan was to finally port 
> qhull to
> java, but this will surely take some time.
> Focusing on the 3D case for convex hulls should be feasible though,
> depending on when you need this feature, do you need it to be included 
> in
> the 3.3 release?

Well, ideally, yes, but this if you have not already started it, I'll 
have
an interim solution. The tests I have recently done with enclosing 
spherical
on the sphere show that due to the phere topology, the Welzl algorithms 
fails
to find the smallest cap in many cases. So I will remove 
SphericalCapGenerator
and will implement getEnclosingCap using another trick.

Don't hurry to do it, I have a way to compute the enclosing cap, even if 
in
extreme cases it will not be the smallest possible. So this mean I can 
wait after 3.3.

Luc

> 
> Thomas
> 
> 
> 
> On Mon, Feb 10, 2014 at 3:05 PM, luc <lu...@spaceroots.org> wrote:
> 
>> Hi,
>> 
>> Thomas, do you intend to add an implementation of convex hull for 3D?
>> I need one soon ...
>> 
>> best regards
>> 
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
>> For additional commands, e-mail: dev-help@commons.apache.org
>> 
>> 

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
For additional commands, e-mail: dev-help@commons.apache.org

Re: [math] ConvexHull in 3D

[Thomas Neidhart <th...@gmail.com>]

Hi Luc,

it is on my queue of things to do.
I already started to look at qhull (www.qhull.org) which is under a very
permissive license and contains algorithms for convex hull, voronoi and
triangulation for arbitrary dimensions.

Implementing the other convex hull algorithms were my first steps to get
accustomed to geometry algorithms, and my plan was to finally port qhull to
java, but this will surely take some time.
Focusing on the 3D case for convex hulls should be feasible though,
depending on when you need this feature, do you need it to be included in
the 3.3 release?

Thomas



On Mon, Feb 10, 2014 at 3:05 PM, luc <lu...@spaceroots.org> wrote:

> Hi,
>
> Thomas, do you intend to add an implementation of convex hull for 3D?
> I need one soon ...
>
> best regards
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
> For additional commands, e-mail: dev-help@commons.apache.org
>
>