CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

On 10/27/2014 09:51 AM, hiroki shibata wrote:
> first, i am japanease. i am sorry my poor english.
>
> I want to generate FEM mesh by using CGAL. And I want vertices and cell have
> vertex index.
> following is my code.
>
> #include "targetver.h"
> #include <map>
> #include <stdio.h>
> #include <tchar.h>
> #include <CGAL\Exact_predicates_inexact_constructions_kernel.h>
> #include <CGAL\Mesh_triangulation_3.h>
> #include <CGAL\Mesh_complex_3_in_triangulation_3.h>
> #include <CGAL\Mesh_criteria_3.h>
> #include <CGAL\make_mesh_3.h>
> #include <CGAL\Implicit_mesh_domain_3.h>
>
> // Domain
> typedef CGAL::Exact_predicates_inexact_constructions_kernel kernel;
>
>
> typedef kernel::FT FT;
> typedef kernel::Point_3 Point;
> typedef FT (Function)(const Point&);
> typedef CGAL::Implicit_mesh_domain_3<Function,kernel> Mesh_domain;
>         
> // Triangulation
> typedef CGAL::Mesh_triangulation_3<Mesh_domain>::type Tr;
> typedef CGAL::Mesh_complex_3_in_triangulation_3
>   C3t3;
> // Criteria
> typedef CGAL::Mesh_criteria_3
>   Mesh_criteria;
>
>
>
> // To avoid verbose function and named parameters call
> using namespace std;
> using namespace CGAL::parameters;
> // Function
>
> FT sphere_function (const Point& p){
>         return CGAL::squared_distance(p, Point(CGAL::ORIGIN))-1;
> }
> int main()
> {
>         // Domain(Warning: Sphere_3 constructor uses squared radius !)
>         Mesh_domain domain(sphere_function, kernel::Sphere_3(CGAL::ORIGIN, 
> 2.));
>         // Mesh criteria
>         Mesh_criteria criteria(facet_angle=30, facet_size=0.1,
> facet_distance=0.025,
>                 cell_radius_edge_ratio=2, cell_size=0.1);
>         // Mesh generation
>         C3t3 c3t3 = CGAL::make_mesh_3<C3t3>(domain, criteria);
>         // Output
>         std::ofstream medit_file("out.mesh");
>         c3t3.output_to_medit(medit_file);
>
>         Tr tr = c3t3.triangulation();
>         
>         int i=0;
>         std::map<Tr::Vertex_handle , int> Va;
>         for(Tr::Finite_vertices_iterator
> it=tr.finite_vertices_begin();it!=tr.finite_vertices_end();it++)
>         {
>                 Va[it] = i;
>                 i++;
>         }
>         for(C3t3::Cells_in_complex_iterator  
> it=c3t3.cells_in_complex_begin();it !=
> c3t3.cells_in_complex_end();it++)
>         {
>                 i = Va[it->vertex(0)];
>                 *//i is always 0*
>         }
>         return 0;
> }
>
>
> why can not i get the mapped value from "Va" using
> "Cell_in_complex_iterator::vertex(0)" ?.
> "Va" always return "0".
> please help me.

        Tr tr = c3t3.triangulation();

is making a copy of the triangulation.

try:
const Tr& tr = c3t3.triangulation();

Sebastien.

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