表面メッシュからテトラメッシュの作成(CGALライブラリ)

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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_3.h>
#include <CGAL/make_mesh_3.h>
#include <CGAL/refine_mesh_3.h>
 
#include <CGAL/IO/Complex_3_in_triangulation_3_to_vtk.h>
 
#include <vtkSmartPointer.h>
#include <vtkUnstructuredGrid.h>
#include <vtkXMLUnstructuredGridWriter.h>
 
// IO
#include <CGAL/IO/Polyhedron_iostream.h>
 
// Domain
typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
typedef CGAL::Polyhedron_3<K> Polyhedron;
typedef CGAL::Polyhedral_mesh_domain_3<Polyhedron, K> Mesh_domain;
 
// Triangulation
typedef CGAL::Mesh_triangulation_3<Mesh_domain>::type Tr;
typedef CGAL::Mesh_complex_3_in_triangulation_3<Tr> 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 input polyhedron
  Polyhedron polyhedron;
  std::ifstream input("data/surface.off");
  input >> polyhedron;
   
  // Create domain
  Mesh_domain domain(polyhedron);
  
  // Mesh criteria (no cell_size set)
  Mesh_criteria criteria(facet_angle=25, facet_size=0.1, facet_distance=0.008,
                         cell_radius_edge_ratio=3);
  
  // Mesh generation
  C3t3 c3t3 = CGAL::make_mesh_3<C3t3>(domain, criteria, no_perturb(), no_exude());
 
  // Set tetrahedron size (keep cell_radius_edge_ratio), ignore facets
  Mesh_criteria new_criteria(cell_radius_edge_ratio=3, cell_size=0.05);
 
  // Mesh refinement
  CGAL::refine_mesh_3(c3t3, domain, new_criteria);
 
  // Output
  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->SetInput(output);
  writer->Update();
 
  return 0;
}