CGAL users discussion list

[Andreas Fabri <>]

Have a look at this example

https://doc.cgal.org/latest/Polygon_mesh_processing/Polygon_mesh_processing_2polygon_soup_example_8cpp-example.html#a3

On 5/29/2018 11:54 AM, sergio campo wrote:

Thanks for your answer. But how It can be detected before corret it?

Sergio

On Tue, May 29, 2018 at 11:03 AM, Andreas Fabri <> wrote:

The orientation of the triangles is not coherent.

You have for examples 2 triangles with an edge going from vertex 0 to vertex 1

You should read a polygon soup and call the function if it can be oriented

andreas

On 5/29/2018 10:56 AM, sergio wrote:

I'm implementing algorithms to detect(Only detection of error, not
correction) if mesh has errors like self-intersection, wrong oriented
normals, etc.
Using scan_OFF with a *.off file it always has result "operator(): input
error: file format is not in OFF."
Why 

// kernel
typedef CGAL::Exact_predicates_inexact_constructions_kernel Kernel;

// polyhedron
typedef CGAL::Polyhedron_3<Kernel> Polyhedron;

int main(int argc, char* argv[])
{
  const char* filename = (argc > 1) ? argv[1] : "tetrahedron-piramide.off";
  std::ifstream input(filename);
  
  Mesh mesh;
  if (!input || !(input >> mesh) || !CGAL::is_triangle_mesh(mesh))
  {
    std::cerr << "Not a valid input file." << std::endl;
    return 1;
  }
  
  Polyhedron M;     // a typical definition of a Polyhedron (see other
examples)
  scan_OFF(input, M, true);                   // read OFF file in verbose
mode
  assert(input);                       // input fails iff mesh is not
manifold
  return 0;
}

This is a simple mesh and I think it does not have errors. Added file 
tetrahedron-piramide.off
<http://cgal-discuss.949826.n4.nabble.com/file/t375958/tetrahedron-piramide.off> 
.

Thanks in advance



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Sent from: http://cgal-discuss.949826.n4.nabble.com/

-- 
Andreas Fabri, PhD
Chief Officer, GeometryFactory
Editor, The CGAL Project

phone: +33.492.954.912    skype: andreas.fabri

-- 
Andreas Fabri, PhD
Chief Officer, GeometryFactory
Editor, The CGAL Project

phone: +33.492.954.912    skype: andreas.fabri