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[Michael Bieri <>]

Hi,

I attached an image of a mesh. It's a screenshot where you see the top of a block containing two cylinders and another material at the top and bottom. The data is given as a segmented image. I do protect features of the image as given below.

I over and over again observe those relatively large, flat triangles around the phase boundaries as well as along the outer edges. I tried around for hours, but I don't get any grasp where they come from.

I tried all sorts of mesh criteria, combing various of those options:

Mesh_criteria criteria(facet_angle=30, facet_size=cell_size_fct, facet_distance=cell_size_fct, cell_radius_edge_ratio=3, cell_size=cell_size_fct); The cell_size_fct gives a value that seems to correspond to the elements inside the phase, but seems to be ignored in the elements at the boundary.

Where does this strange behavior around the phase and outer boundary come from?

Best regards

Michael

Feature protection snippet:

  std::vector<std::vector<Point_3> > features_inside;

  std::vector<std::vector<Point_3> > polylines_on_bbox;

  CGAL::polylines_to_protect<Point_3, Word_type>(image, polylines_on_bbox,

                                                 features_inside.begin(),

                                                 features_inside.end());

  domain.add_features(polylines_on_bbox.begin(), polylines_on_bbox.end());

Attachment: Screen Shot 2017-09-29 at 16.51.48.png
Description: PNG image