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[Sean Hardesty <>]

I was able to compile the polyhedron demo and duplicate the results you described. However, I don't understand how I would test for this in my own program. I generated the .off files I sent from CGAL::Surface_mesh - how do I check whether such an object is a polygon soup (as is done in the demo)?

All of the following look okay:

mesh.is_valid() = 1
CGAL::Polygon_mesh_processing::does_bound_a_volume(mesh) = 1
CGAL::Polygon_mesh_processing::does_self_intersect(mesh) = 0
CGAL::Polygon_mesh_processing::is_outward_oriented(mesh) = 1
CGAL::is_closed(mesh) = 1

I wanted to try something from the polygon soup example, like this

CGAL::Polygon_mesh_processing::is_polygon_soup_a_polygon_mesh

but I haven't been able to figure out how to call that on a CGAL::Surface_mesh object.

    Thanks,

    Sean Hardesty

On Wed, Dec 6, 2017 at 2:24 AM, Sebastien Loriot (GeometryFactory) <> wrote:

When I open you files in the CGAL polyhedron demo, it is telling me that
your meshes are polygon soups (meaning you have non-manifold edges).
If I duplicate those edges to make it a self-intersecting surface
I have the following set of intersecting faces.

Sebastien.

On 12/05/2017 05:22 PM, Sean Hardesty wrote:

I have a collection of meshes that overlap slightly, so I am going through a loop removing overlapping pieces. It works for a while, but eventually I run into trouble. I am calling PMP::corefine_and_compute_difference(CGAL 4.11) on a pair of meshes that satisfy

!CGAL::Polygon_mesh_processing::does_self_intersect
CGAL::Polygon_mesh_processing::does_bound_a_volume

and I get the following:

terminate called after throwing an instance of 'CGAL::Assertion_exception'
   what(): CGAL ERROR: assertion violation!
Expr: hedge!=start
File: /usr/local/include/CGAL/Polygon_mesh_processing/internal/Corefinement/Visitor.h
Line: 663
Aborted (core dumped)

They are fairly small, so I wrote them to .off format and attached them to this message. I am aware from your documentation pages that there can be problems with sequential boolean operations, so I am using the kernel with exact predicates and exact constructions. Maybe the precision in the .off format is inadequate to diagnose the problem. I would be grateful for any help that can be provided.

     Sincerely,
     Sean Hardesty

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