CGAL users discussion list

[Query Cgal <>]

Hi.

Thank you for your reply.

Finally, I have tried with the following code to use the incident_facets function.

int main(array<System::String ^> ^args)
{
    Delaunay_triangulation Dt;

    Dt.insert(Point(0,0,0));
    Dt.insert(Point(10,0,0));
    Dt.insert(Point(5,10,0));
    Dt.insert(Point(8,8,0));
    Dt.insert(Point(-3, -20, 0));
    Dt.insert(Point(-5,10,0));


    Finite_vertices_iterator start = Dt.finite_vertices_begin();

    vector<Delaunay_triangulation::Facet> f;

    Dt.incident_facets(start, back_inserter(f));

}

However, when it has "System.NullReferenceException'
May I ask is it due to the nature of the points that I have inserted into the triangulation?

I am using CGAL-3.3.1 and Visual C++ 2005
And I am using the triangulation with the following declaration.
Thank you very much for your help.



typedef CGAL::Cartesian<double> Rep_class;
typedef CGAL::Vector_3<Rep_class> Vector;
typedef CGAL::Point_3<Rep_class> Point_3;

typedef CGAL::Object CGAL_object;



template < class GT, class Vb = CGAL::Triangulation_vertex_base_3<GT> >
class Vertex_base_for_ssr
  : public Vb
{
public:
  typedef typename Vb::Vertex_handle  Vertex_handle;
  typedef typename Vb::Cell_handle    Cell_handle;
  typedef typename Vb::Point          Point;

  template < class TDS2 >
  struct Rebind_TDS {
    typedef typename Vb::template Rebind_TDS<TDS2>::Other  Vb2;
    typedef Vertex_base_for_ssr<GT, Vb2>                        Other;
  };


  Vector surface_normal;
  vector<Vertex_base_for_ssr<GT, Vb> *> neighbor_vertex_handle;
  double fifth_nearest_dist;


  int surface_label;
  bool is_safe;



  Vertex_base_for_ssr() : Vb()
  {
      surface_label = -1;
      is_safe = false;
  }

  Vertex_base_for_ssr(const Point& p)
    : Vb(p)
  {
      coordinate[0] = p.x();
      coordinate[1] = p.y();
      coordinate[2] = p.z();
      surface_label = -1;
      is_safe = false;
  }


  Vertex_base_for_ssr(const Point& p, Cell_handle c)
    : Vb(p, c)
  {
      surface_label = -1;
      is_safe = false;
  }

  void set_surface_normal(double x_i, double y_i, double z_i)
  {
      surface_normal = Vector(x_i, y_i, z_i);
  }

  Vector get_surface_normal()
  {
     return surface_normal;
  }

  Point get_point()
  {
      return Vb::point();
  }

  double coordinate[3];

  void set_coordiante()
  {
     coordinate[0] = point().x();
     coordinate[1] = point().y();
     coordinate[2] = point().z();
  }
};

typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
typedef CGAL::Triangulation_data_structure_3<Vertex_base_for_ssr<K> > Tds;
typedef CGAL::Delaunay_triangulation_3<K, Tds> Delaunay_triangulation;





--- 2009年3月21日 星期六，naresh <> 寫道﹕


    寄件人: naresh <>
    主題: Re: [cgal-discuss] incident_facets function of a Delaunay triangulation
    收件人:
    日期: 2009 3 21 星期六 下午 1:47

    
    Hi
    
    >>In fact, I am dealing with a 3D triangulation (sorry that I forgot to mention that it is 3D in the >>previous post.)
    >>and therefore, I cannot use Facet since Facet is not represented in 3D triangulation.
    >>So, what should I do to use incident_facets() of a 3D triangulation.
    
    I donot know which triangulation are you using. for simple triangulation here there you can define Facet easily . here is code.
    try to modifiy with ur code
    
    typedef CGAL::Exact_predicates_inexact_constructions_kernel K;

    typedef CGAL::Triangulation_3<K> Triangulation;

    typedef Triangulation::Facet Facet;

    If there is still confusion post some code . But i will not able reply today because saturday now and i am off. :)   I can reply on monday.

    

    Hope this helps

    Alex

    
    
    
    

        ----- Original Message -----
        From: Query Cgal
        To:
        Sent: Saturday, March 21, 2009 6:46 PM
        Subject: Re: [cgal-discuss] incident_facets function of a Delaunay triangulation

        THank you for your reply.

        In fact, I am dealing with a 3D triangulation (sorry that I forgot to mention that it is 3D in the previous post.)
        and therefore, I cannot use Facet since Facet is not represented in 3D triangulation.
        So, what should I do to use incident_facets() of a 3D triangulation.

        Thank you



        --- 2009年3月21日 星期六，naresh <> 寫道﹕


            寄件人: naresh <>
            主題: Re: [cgal-discuss] incident_facets function of a Delaunay triangulation
            收件人:
            日期: 2009 3 21 星期六 下午 1:07

            
            Hi
            
            I think you should try like this
            
            typedef Trianluation_2::Facet Facet;   // something here that you had used in ur programme may different i had showed only example
            
            vector<Facet> f;
            Dt.incident_facets(start, back_inserter(f));
            
            

                ----- Original Message -----
                From: Query Cgal
                To:
                Sent: Saturday, March 21, 2009 5:45 PM
                Subject: [cgal-discuss] incident_facets function of a Delaunay triangulation

                Hi, I have tried to use the function below

                template <class OutputIterator>
                OutputIterator     t.incident_facets ( Vertex_handle v, OutputIterator facets)

                   
                    Copies all Facets incident to v to the output iterator facets. Returns the resulting output iterator.
                Precondition:      t..dimension() >1 , v Vertex_handle(), t.is_vertex(v)..
                
                When I tried to used it in the following way but it didn't work,

                vector<Finite_facets_iterator> f;
                Dt.incident_facets(start, back_inserter(f));

                May I ask in what other way should I use the Output iterator then ?

                Thank you







                Yahoo!香港提供網上安全攻略，教你如何防範黑客!了解更多


        Yahoo!香港提供網上安全攻略，教你如何防範黑客!了解更多

---

Yahoo!香港提供網上安全攻略，教你如何防範黑客!了解更多