CGAL users discussion list

[Philipp Moeller <>]

moogroo 
<>
 writes:

> I'm trying to use the incremental builder to extract a surface from a 3D
> polyhedron by
> defining a class using the polyhedron incremental builder.
> The class will construct a new surface that is a 1/3 of a polyhedron by
> passing the
> original polyhedron to the constructor.
>
> The code compiles fine, however on executing the code, I receive the error:
>
> terminate called after throwing an instance of 'CGAL::Assertion_exception'
>   what():  CGAL ERROR: assertion violation!
> Expr: check_protocoll == 1
> File: /usr/local/include/CGAL/Polyhedron_incremental_builder_3.h
> Line: 256
> Aborted
>
> I think the error is thrown when I am adding the polyhedron triangles after
> adding the
> points.  I have included my code in the link below:
>
> http://pastebin.com/vWeN3QZ2

The obvious problem is not calling
Polyhedron_incremental_builder_3::end_facet() after the three calls to
add_vertex_to_face. This is what is causing the protocol error. I
haven't really looked the rest of the code but I'm not sure it does what
you expect it to do.