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Dr moderator:

 

     It is a very simple test. A 3D box is to be triangulated by dD-Triangulation  algorithm. The finite vertices are the vertices of the box,

but I encountered a serious problem: the tetrahedra in the output file seems to be incorrect.

 

My codes are as follows :

 

      typedef CGAL::Epeck_d< CGAL::Dynamic_dimension_tag> K;

      typedef CGAL::Triangulation<K>          Triangulation;

      typedef Triangulation::Point POINT_t;

      std::vector<POINT_t> points;

      points.reserve(8);

 

         std::vector<std::vector<double>> d_points(8);//the vertices of a 3D-Box

     d_points[0]={1,2,3 };   d_points[1]={-1,2,3 };  d_points[2]={1,-2,3 };  

d_points[3]={-1,-2,3 };  d_points[4]={1,2,-3 };  d_points[5]={-1,2,-3 };  d_points[6]={1,-2,-3 };  d_points[7]={-1,-2,-3 };  

 

      int i;

      for (i = 0; i < 8; ++i)

      {

            points.push_back(POINT_t(3, d_points[i].begin(), d_points[i].end()));

      }

 

      Triangulation t(3);                      

      

      t.insert(points.begin(), points.end());  

 

      assert(t.is_valid());

      std::ofstream ff("D:\\ccc.txt");

      ff << t;

 

 

 The problem 

1. the 2^nd simplex (1234) intersect with 4^th simplex (6523)  ;   and the 5^th simplex(5123) seems not to be a tetrahedra(see the output file below).

 

2. why the order of input finite vertices are changed? As follows, the input order is " d_points[0]={1,2,3 }; d_points[1]={-1,2,3 };...d_points[7]={-1,-2,-3 }; ",

 but the  order in the output file is :

3 1 2 -3

3 1 -2 -3

3 -1 -2 -3

3 1 2 3

3 -1 2 -3

3 1 -2 3

3 -1 -2 3

3 -1 2 3

3 1 2 -3

 

3. The expected results would contain the following tetrahedra, but I can not find them in the output file.

  7 4 6 2

  1 3 2 4

  4 7 3 2

  3 7 4 8

  1 3 4 5

  5 8 3 1

 

 

>>>>The results in the output file are as follows:   

3

8

3 1 2 -3

3 1 -2 -3

3 -1 -2 -3

3 1 2 3

3 -1 2 -3

3 1 -2 3

3 -1 -2 3

3 -1 2 3

3 1 2 -3

 

18

 6 7 3 4

 1 2 3 4//mistake

 0 2 1 4

 6 5 2 3//mistake

 5 1 2 3//mistake

 7 0 3 4

 0 1 5 3

 0 1 2 5

 2 6 3 4

 0 5 6 3

 0 5 2 6

 8 1 3 4

 2 0 6 4

 6 0 7 4

 6 0 3 7

 0 8 3 4

 0 1 8 4

 0 1 3 8

 5 8 13 14

 8 11 2 4

 1 16 12 7

 4 8 9 10

 1 3 6 7

 15 0 13 14

 4 9 17 7

 4 10 6 2

 0 1 12 3

 3 14 6 10

 3 12 9 7

 1 15 16 17

 13 8 2 10

 5 0 12 14

 5 0 13 9

 11 5 16 17

 11 15 2 17

 11 15 16 6

                                                                                                                                   Thanks for help! 

                                                                                                                                           Best regards,

 

                                                                                                                                                      Liu

 

 

 

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