CGAL users discussion list

[Dennis Endt <>]

Hi,

this a quite ok Triangulation:


In the other case I have overlapping edges and triangles. That`s a big problem.

This is the other fassade on the back side of the building.

Why is the result so different and how can I avoid this behaviour?

Best
Dennis


Manuel Caroli schrieb:

Hi Dennis,

I don't actually understand what is wrong about that. The triangulation in your picture looks quite ok to me.
Also e.g. in your finite_edge_iterator loop you only get finite edges, so if your triangulation contains only 4 points it is a tetrahedron which consists of 6 edges.

best

Manuel



Dennis Endt wrote:

Here is a Screenshot of that waht CGAL returns.

And here are the points to that fassade:
2585709.716 5703009.266 3.0
2585710.5465 5703008.192 8.0
2585711.377 5703007.118 3.0
2585711.377 5703007.118 0.0
2585709.716 5703009.266 0.0

That not the only case where CGAL returns a wrong number of edges or facets.

What have I to do to get a clean triangulation?

Best,
Dennis

Dennis Endt schrieb:

Hi,

I`ve a problem with the 3D Delaunay Triangulation. I want to triangulate
buildings with multiple fassades. Ech fassade contains of a certain
number of vertices.

That`s my code:
#include <CGAL/Simple_cartesian.h>
#include <CGAL/Filtered_kernel.h>
#include <CGAL/Delaunay_triangulation_3.h>

typedef CGAL::Simple_cartesian<double> SK;
typedef CGAL::Filtered_kernel<SK> FK;
struct K : public FK {};
typedef K::Point_3 Point_3;
typedef K::Triangle_3 Triangle_3;
typedef CGAL::Delaunay_triangulation_3<K> Triangulation;

.
.
.

Triangulation T..... // the Triangulation object of my current fassade

for(Triangulation::Finite_edges_iterator ie = T.finite_edges_begin(); ie
!= T.finite_edges_end(); ie++)
{
    // The problem is, that the number of infinite_edges is too high.
For example the number of vertices is 5, he gives me 9 edges or 4 and he
gives me 6 edges.
}

Why does he gives me so a large number of edges? I would expect 7 or 5
so far. What can I do, about to get a clean and good triangulation of
each of my fassades?

Best,
Dennis
 

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