步骤一：创建两个四面体

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步骤二：缝合这两个四面体

发现上面的两个四面体是相离的，我们可以使用方法进行缝合
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步骤三：整体平移

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完整代码

  1. #include <CGAL/Linear_cell_complex_for_generalized_map.h>
  2. #include <iostream>
  3. #include <algorithm>
  5. #ifdef _DEBUG
  6. #include <CGAL/draw_linear_cell_complex.h>
  7. #endif // _DEBUG
  9. typedef CGAL::Linear_cell_complex_for_generalized_map<3> LCC_3;
  10. typedef LCC_3::Dart_handle                Dart_handle;
  11. typedef LCC_3::Point                      Point;
  12. typedef LCC_3::FT                         FT;
  14. //一个仿函数，用于遍历一个体元的所有顶点
  15. // Functor used to display all the vertices of a given volume.
  16. template<class LCC>
  17. struct Display_vol_vertices : public CGAL::cpp98::unary_function<LCC, void>
  18. {
  19.     Display_vol_vertices(const LCC& alcc) :
  20.         lcc(alcc),
  21.         nb_volume(0)
  22.     {}
  24.     void operator() (typename LCC::Dart& d)
  25.     {
  26.         std::cout << "Volume " << ++nb_volume << " : ";
  27.         for (typename LCC::template One_dart_per_incident_cell_range<0, 3>::
  28.             const_iterator it = lcc.template one_dart_per_incident_cell<0, 3>
  29.             (lcc.dart_handle(d)).begin(),
  30.             itend = lcc.template one_dart_per_incident_cell<0, 3>
  31.             (lcc.dart_handle(d)).end();
  32.             it != itend; ++it)
  33.         {
  34.             std::cout << lcc.point(it) << "; ";
  35.         }
  36.         std::cout << std::endl;
  37.     }
  38. private:
  39.     const LCC& lcc;            //线性单元复合体（体模型）
  40.     unsigned int nb_volume;    //该体元对应的索引（第nb_volume+1个体元）
  41. };
  43. int main()
  44. {
  45.     //创建一个线性单元复合体（即体模型）
  46.     LCC_3 lcc;
  48.     std::cout << "==========创建两个四面体==========" << std::endl;
  49.     //创建两个四面体
  50.     // Create two tetrahedra.
  51.     Dart_handle d1 = lcc.make_tetrahedron(Point(-1, 0, 0), Point(0, 2, 0),
  52.         Point(1, 0, 0), Point(1, 1, 2));
  53.     Dart_handle d2 = lcc.make_tetrahedron(Point(0, 2, -1),
  54.         Point(-1, 0, -1),
  55.         Point(1, 0, -1),
  56.         Point(1, 1, -3));
  58.     //通过顶点属性容器上的迭代器，遍历线性单元复合体的所有顶点
  59.     // Display all the vertices of the lcc by iterating on the
  60.     // Vertex_attribute container.
  61.     CGAL::IO::set_ascii_mode(std::cout);
  62.     std::cout << "Vertices: ";
  63.     for (LCC_3::Vertex_attribute_const_range::iterator
  64.         v = lcc.vertex_attributes().begin(),
  65.         vend = lcc.vertex_attributes().end();
  66.         v != vend; ++v)
  67.         std::cout << lcc.point_of_vertex_attribute(v) << "; ";
  68.     std::cout << std::endl;
  70.     //通过darts上的迭代器，遍历体元的所有顶点
  71.     // Display the vertices of each volume by iterating on darts.
  72.     std::for_each(lcc.one_dart_per_cell<3>().begin(),
  73.         lcc.one_dart_per_cell<3>().end(),
  74.         Display_vol_vertices<LCC_3>(lcc));
  76. #ifdef _DEBUG
  77.     CGAL::draw(lcc);
  78. #endif // _DEBUG
  80.     std::cout << "==========缝合两个四面体==========" << std::endl;
  82.     //沿着一个面（两个四面体的公共面）缝合两个四面体
  83.     // 3-Sew the 2 tetrahedra along one facet
  84.     lcc.sew<3>(d1, d2);
  86.     //通过darts上的迭代器，遍历体元的所有顶点
  87.     // Display the vertices of each volume by iterating on darts.
  88.     std::for_each(lcc.one_dart_per_cell<3>().begin(),
  89.         lcc.one_dart_per_cell<3>().end(),
  90.         Display_vol_vertices<LCC_3>(lcc));
  92. #ifdef _DEBUG
  93.     CGAL::draw(lcc);
  94. #endif // _DEBUG
  96.     std::cout << "==========平移操作==========" << std::endl;
  98.     //平移第二个四面体
  99.     // Translate the second tetrahedra by a given vector
  100.     LCC_3::Vector v(3, 1, 1);
  101.     for (LCC_3::One_dart_per_incident_cell_range<0, 3>::iterator
  102.         it = lcc.one_dart_per_incident_cell<0, 3>(d2).begin(),
  103.         itend = lcc.one_dart_per_incident_cell<0, 3>(d2).end();
  104.         it != itend; ++it)
  105.     {
  106.         lcc.point(it) = LCC_3::Traits::Construct_translated_point_3()
  107.             (lcc.point(it), v);
  108.     }
  110.     //通过darts上的迭代器，遍历体元的所有顶点
  111.     // Display the vertices of each volume by iterating on darts.
  112.     std::for_each(lcc.one_dart_per_cell<3>().begin(),
  113.         lcc.one_dart_per_cell<3>().end(),
  114.         Display_vol_vertices<LCC_3>(lcc));
  116.     //检查线性单元复合体是否有效
  117.     // We display the lcc characteristics.
  118.     std::cout << "LCC characteristics: ";
  119.     lcc.display_characteristics(std::cout) << ", valid=" << lcc.is_valid()
  120.         << std::endl;
  122. #ifdef _DEBUG
  123.     CGAL::draw(lcc);
  124. #endif // _DEBUG
  126.     return EXIT_SUCCESS;
  127. }