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["Santosh Tiwari" <>]

Thanks a lot.

I am able to write the facets now. I am using the following code snippet.

        //write the facets;
        list<Facet> facets;
        as.get_alpha_shape_facets(back_inserter(facets),
Alpha_shape_3::REGULAR);
        cout<<facets.size()<<" boundary facets \n";
        int numFacets = 0;
        for(list<Facet>::const_iterator iter = facets.begin();
iter!=facets.end(); ++iter) {
                cout<<"Facet "<<++numFacets<<endl;
                cout<<(*(iter->first->vertex(1))).point()<<", ";
                cout<<(*(iter->first->vertex(2))).point()<<", ";
                cout<<(*(iter->first->vertex(3))).point()<<endl;
        }

Thanks again. :)

__
Santosh Tiwari




-----Original Message-----
From: Manuel Caroli 
[mailto:]
 
Sent: Sunday, March 09, 2008 6:44 AM
To: 

Subject: Re: [cgal-discuss] CGAL (need help writing the facets to a file)

Hi Santosh,

Santosh Tiwari wrote:
> Hello,
> 
> I am learning to use CGAL.
> 
> I want to output the vertices of a list of Facets on the screen. How do I
do
> it?
> 
> Any help or references would be appreciated. Following is the code
snippet,
> I am using.
The triangulation data structure stores facets only implicitly:
http://www.cgal.org/Manual/3.3/doc_html/cgal_manual/TriangulationDS_3/Chapte
r_main.html
http://www.cgal.org/Manual/3.3/doc_html/cgal_manual/TriangulationDS_3_ref/Co
ncept_TriangulationDataStructure_3.html

Short explanation:
A facet is represented as a pair of a Cell_handle ch of a cell to which 
the facet is incident and an int i such that ch->vertex(i) gives you the 
only vertex that is not incident to the facet (the opposite vertex).
To output the all vertices of the facet f you could do something like
std::cout<<f.first->vertex((f.second+1)%4)<<", "
         <<f.first->vertex((f.second+2)%4)<<", "
         <<f.first->vertex((f.second+3)%4)<<std::endl;

Best

Manuel
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