Triangle Remeshing

출처: https://doc.cgal.org/latest/Mesh_3/index.html#Chapter_3D_Mesh_Generation

triangle 로 이루어진 파트가 있을때.. 아래와 같이 CGAL을 이용하여 remshing 가능..

컴파일

% g++ -Wa,-mbig-obj -O2 ./remesh.cpp -lgmp -lmpfr -lgmp

코드

#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>
#include <CGAL/IO/output_to_vtu.h>
// Domain
typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
typedef CGAL::Mesh_polyhedron_3<K>::type Polyhedron;
typedef CGAL::Polyhedral_mesh_domain_with_features_3<K> Mesh_domain;
#ifdef CGAL_CONCURRENT_MESH_3
typedef CGAL::Parallel_tag Concurrency_tag;
#else
typedef CGAL::Sequential_tag Concurrency_tag;
#endif
// Triangulation
typedef CGAL::Mesh_triangulation_3<Mesh_domain,CGAL::Default,Concurrency_tag>::type Tr;
typedef CGAL::Mesh_complex_3_in_triangulation_3<
  Tr,Mesh_domain::Corner_index,Mesh_domain::Curve_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(int argc, char*argv[])
{
  const std::string fname = (argc>1)?argv[1]:CGAL::data_file_path("a.off");
  std::ifstream input(fname);
  Polyhedron polyhedron;
  input >> polyhedron;
  if(input.fail()){
    std::cerr << "Error: Cannot read file " <<  fname << std::endl;
    return EXIT_FAILURE;
  }
  if (!CGAL::is_triangle_mesh(polyhedron)){
    std::cerr << "Input geometry is not triangulated." << std::endl;
    return EXIT_FAILURE;
  }
  // Create domain
  Mesh_domain domain(polyhedron);
  // Get sharp features
  domain.detect_features();
  // Mesh criteria
  Mesh_criteria criteria(edge_size = 1,
                         facet_angle = 25, facet_size = 1, facet_distance = 1);
  // Mesh generation
  C3t3 c3t3 = CGAL::make_mesh_3<C3t3>(domain, criteria);
  // Output the facets of the c3t3 to an OFF file. The facets will not be
  // oriented.
  std::ofstream off_file("out.off");
  c3t3.output_boundary_to_off(off_file);
  return off_file.fail() ? EXIT_FAILURE : EXIT_SUCCESS;
}