CGAL users discussion list

[Sean Hardesty <>]

I am trying to use CGAL 4.11 to compute the difference of two meshes, using this example as a model (the relevant part of my program is essentially the same):

https://doc.cgal.org/latest/Polygon_mesh_processing/Polygon_mesh_processing_2corefinement_difference_remeshed_8cpp-example.html

Although it works for some meshes, I often get the following error message upon calling PMP::corefine_and_compute_difference:

 sorry, this triangulation does not deal with
 intersecting constraints
terminate called after throwing an instance of 'CGAL::Assertion_exception'
  what():  CGAL ERROR: assertion violation!
Expr: false
File: /usr/local/include/CGAL/Constrained_triangulation_2.h
Line: 853
Aborted (core dumped)

I quickly get confused trying to follow through the code from PMP::corefine_and_compute_difference to instantiation of a Constrained_triangulation_2. Documentation for Constrained_triangulation_2 clearly states how to change the tag specifying how intersecting constraints are to be handled, but I see nothing similar for the corefinement functions. How does a user of the corefinement functions go about specifying this apparently essential information?

    Thanks,

    Sean Hardesty