CGAL users discussion list

["Laurent Rineau (CGAL/GeometryFactory)" <>]

On Thursday, January 10, 2019 9:25:39 AM CET Marc Alexa wrote:
> Thank you so much! The code runs fine. But my main problem remains: the
> triangulation in c3t3.triangulation contains more cells than the interior
> triangulation of the object.
> 
> If you add the lines
> 
>     std::cerr << "Number of cells in c3t3: " << c3t3.number_of_cells() <<
> std::endl; std::cerr << "Number of finite cells in t: " <<
> t.number_of_finite_cells() << std::endl;
> 
> to your code you see. this. I had hoped if I take a convex surface there
> would be no difference, because there is no necessity for tetrahedra on the
> outside, but this is still not true. If you create a mesh for a sphere, the
> numbers will still be different.

There is no valid solution to that problem, unless your own `Triangulation_3` 
type keeps a Boolean field for each cell, indicating whether or not the cell 
is part of the mesh.

When the cell converter must be wrote that way:

Cell_converter
{
  Triangulation::Cell operator()(const C3t3::Triangulation::Cell& input_cell) 
const {
      Triangulation::Cell output_cell;
      output_cell.is_in_domain = ( input_cell.subdomain_index() != 0 );
      return output_cell;
  }

  void operator()(const C3t3::Triangulation::Cell&,Triangulation::Cell&) 
const 
{}
};



-- 
Laurent Rineau, PhD
R&D Engineer at GeometryFactory           http://www.geometryfactory.com/
Release Manager of the CGAL Project       http://www.cgal.org/