CGAL users discussion list

[kenichiro yoshimi <>]

Hi,

I am new to CGAL (using CGAL4.4) and trying to tetrahedralize a polyhedron with features. I apply to the attached surface mesh (data/mesh.off) using the following code, but the sharp feature edges are not preserved. 

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#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/Polyhedral_mesh_domain_with_features_3.h>

#include <CGAL/make_mesh_3.h>

// IO

#include <CGAL/IO/Polyhedron_iostream.h>

#include <CGAL/IO/Complex_3_in_triangulation_3_to_vtk.h>

// VTK

#include <vtkSmartPointer.h>

#include <vtkUnstructuredGrid.h>

#include <vtkXMLUnstructuredGridWriter.h>

// STL

#include <string>

// Domain 

typedef CGAL::Exact_predicates_inexact_constructions_kernel K;

typedef CGAL::Polyhedral_mesh_domain_with_features_3<K> Mesh_domain;

// Triangulation

typedef CGAL::Mesh_triangulation_3<Mesh_domain>::type Tr;

typedef CGAL::Mesh_complex_3_in_triangulation_3<

  Tr,Mesh_domain::Corner_index,Mesh_domain::Curve_segment_index> C3t3;

// Criteria

typedef CGAL::Mesh_criteria_3<Tr> Mesh_criteria;

// To avoid verbose function and named parameters call

using namespace CGAL::parameters;

int main()

{

  // Create domain

  Mesh_domain domain("data/mesh.off");

  

  // Get sharp features

  domain.detect_features();

  // Mesh criteria

  Mesh_criteria criteria(facet_angle=25, facet_size=0.3, facet_distance=0.1,

                         cell_radius_edge_ratio=3);

  

  // Mesh generation

  C3t3 c3t3 = CGAL::make_mesh_3<C3t3>(domain, criteria,

                                      lloyd(time_limit=30),

                                      no_exude(),

                                      perturb(sliver_bound=10, time_limit=15));

  // Set tetrahedron size (keep cell_radius_edge_ratio), ignore facets

  Mesh_criteria new_criteria(cell_radius_edge_ratio=3, cell_size=0.4);

  // Mesh refinement

  CGAL::refine_mesh_3(c3t3, domain, new_criteria);

  std::cout << "Mesh refinement\n";

  CGAL::perturb_mesh_3(c3t3, domain, time_limit=15);

  std::cout << "Mesh optimization\n";

  // Output

  //std::ofstream medit_file("out.mesh");

  //c3t3.output_to_medit(medit_file);

  vtkSmartPointer<vtkUnstructuredGrid> output =

    vtkSmartPointer<vtkUnstructuredGrid>::New();

  CGAL::output_c3t3_to_vtk_unstructured_grid(c3t3, output);

  vtkSmartPointer<vtkXMLUnstructuredGridWriter> writer =

    vtkSmartPointer<vtkXMLUnstructuredGridWriter>::New();

  writer->SetFileName("out.vtu");

  writer->SetInputData(output);

  writer->Update();

}

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How can I make mesh nodes forced on feature edges? Any kind of help would be appreciated.

Thanks,

yoshimi

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