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["naresh" <>]

Hi

I have tried to do as you said but it is not showing shape as it should be . 
I  am posting some code here . Please tell me what i am doing wrong


Alpha_shape alpha_shape;

alpha_shape.make_alpha_shape(Points.begin(), Points.end());

alpha_shape.set_alpha(50);



std::list<Facet> facets;

alpha_shape.get_alpha_shape_facets(std::back_inserter(facets), 
Alpha_shape::REGULAR);

std::ofstream outfile;

outfile.open ("test.obj");



for(std::list<Facet>::iterator fit = facets.begin(); fit != facets.end(); 
++fit)

{

const Cell_handle& ch = fit->first;

const int index = fit->second;

const Point3& a = ch->vertex((index+1)&3)->point();

const Point3& b = ch->vertex((index+2)&3)->point();

const Point3& c = ch->vertex((index+3)&3)->point();


outfile << "v " << a.x() << " " << a.y() << " " << a.z() << std::endl;

outfile << "v " << b.x() << " " << b.y() << " " << b.z() << std::endl;

outfile << "v " << c.x() << " " << c.y() << " " << c.z() << std::endl;

}

int count = 0;

for(std::list<Facet>::iterator fit = facets.begin(); fit != facets.end(); 
++fit)

{


int a = count + 0;

int b = count + 1;

int c = count + 2;

count += 3;

outfile << "f " << a << " " << b << " " << c << std::endl;

}

outfile.close();


I hade tried to save wavefront obj file. I have doubt about Faces structure 
that i had saved.

Alex

----- Original Message ----- 
From: "Andreas Fabri" <>
To: 
<>
Sent: Wednesday, March 18, 2009 3:46 PM
Subject: Re: [cgal-discuss] Alpaha shape question


> naresh wrote:
> > Hi
> >  How can i save  Alpha_shape_3 to .off file. ? I want to save 
> > trianglulated shape to off  file .
> >  Is that any way to save it ?
> >  Alex
>
> Hi Alex,
>
> You have to code it by hand, but that shouldn't be too dificult.
>
> print the header with the number of vertices and facets
>
>
> Use a std::map<Vertex_handle, int>, traverse all alpha shape
> vertices, check if they are in the map, and if not, put them in
> there and increment a counter that started at 0.  At the same
> time print the x y z
>
>
> Traverse all alpha shape facets and for the three vertices of the
> facet read the indices from the map   Print   3 i j k
> where "3" indicates that the face has three vertices.
>
> Hope this helps,
>
> andreas
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