CGAL users discussion list

[Hyungon Kim <>]

Hi Andreas,

I think it is not exact construction problem and also not related to 
regularization.
create_face_objects in Nef2/PM_overlayer.h crashed with example polygons.
And even using exact construct also crashed at same place.

Thanks,
Hyungon Kim

Andreas Fabri wrote:
> Hello,
>
>
> Both, Nef and the Regularizded Boolean operations need exact 
> constructions.
>
> In order to decide which of the two packages is the better choice depends
> on your requirements.  Nef does not regularize, that is it can represent
> isolated points, unbounded faces, open faces, antennas sticking out, etc.
>
> andreas
>
>
>
>  wrote:
> > Hi,
> >
> > Nef_polyhedron_2 boolean operation crushed for some polygons. 
> > However, it is
> > fine when trying General_polygon_set with same polygons. Should I use
> > General_polygon_set instead of Nef_polyhedron_2 even for simple 
> > rectilinear
> > polygon?
> >
> > Thanks,
> > Hyungon Kim
> >
> > #include    <iostream>
> > #include    <list>
> > using namespace std;
> >
> > #include    <CGAL/basic.h>
> > #include    <CGAL/Gmpq.h>
> > #include    <CGAL/Simple_cartesian.h>
> > #include    <CGAL/connect_holes.h>
> > #include    <CGAL/Bounded_kernel.h>
> > #include    <CGAL/Nef_polyhedron_2.h>
> > #include    <CGAL/Polygon_2.h>
> > #include    <CGAL/Polygon_with_holes_2.h>
> > #include    <CGAL/Exact_predicates_inexact_constructions_kernel.h>
> >
> > #include <CGAL/Boolean_set_operations_2.h>
> >
> > typedef CGAL::Simple_cartesian<double>            cgalKernel;
> > typedef CGAL::Bounded_kernel<cgalKernel>        cgalExtKernel;
> >
> > typedef CGAL::Nef_polyhedron_2<cgalExtKernel>        cgalNefPolyhedron;
> >
> > typedef cgalNefPolyhedron::Point            cgalPoint2;
> > typedef CGAL::Polygon_2<cgalKernel>            cgalPolygon2;
> > typedef CGAL::Polygon_with_holes_2<cgalKernel>        
> > cgalPolygonWithHoles2;
> >
> > typedef CGAL::Exact_predicates_inexact_constructions_kernel           
> > cgalExtInextKernel;
> > typedef cgalExtInextKernel::Point_2                       cgalExtPoint2;
> > typedef CGAL::Polygon_2<cgalExtInextKernel>                   
> > cgalExtPolygon2;
> > typedef CGAL::Polygon_with_holes_2<cgalExtInextKernel>               
> > cgalExtPolygonWithHoles2;
> >
> > main()
> > {
> >     vector<cgalPoint2>    P1;
> >     P1.push_back(cgalPoint2(-48690,20167));
> >     P1.push_back(cgalPoint2(-48690,1960));
> >     P1.push_back(cgalPoint2(-42690,-4038));
> >     P1.push_back(cgalPoint2(-42690,-17679));
> >     P1.push_back(cgalPoint2(-17677,-42690));
> >     P1.push_back(cgalPoint2(17679,-42690));
> >     P1.push_back(cgalPoint2(42690,-17677));
> >     P1.push_back(cgalPoint2(42690,-4460));
> >     P1.push_back(cgalPoint2(37690,-4460));
> >     P1.push_back(cgalPoint2(37690,-15613));
> >     P1.push_back(cgalPoint2(15611,-37690));
> >     P1.push_back(cgalPoint2(-15613,-37690));
> >     P1.push_back(cgalPoint2(-37690,-15611));
> >     P1.push_back(cgalPoint2(-37690,-1962));
> >     P1.push_back(cgalPoint2(-43690,4040));
> >     P1.push_back(cgalPoint2(-43690,18103));
> >     P1.push_back(cgalPoint2(-18101,43690));
> >     P1.push_back(cgalPoint2(18103,43690));
> >     P1.push_back(cgalPoint2(43690,18101));
> >     P1.push_back(cgalPoint2(43690,7500));
> >     P1.push_back(cgalPoint2(78690,7500));
> >     P1.push_back(cgalPoint2(78690,12500));
> >     P1.push_back(cgalPoint2(48690,12500));
> >     P1.push_back(cgalPoint2(48690,20169));
> >     P1.push_back(cgalPoint2(20167,48690));
> >     P1.push_back(cgalPoint2(-20169,48690));
> >
> >     vector<cgalPoint2>    P2;
> >     P2.push_back(cgalPoint2(-48690,-1960));
> >     P2.push_back(cgalPoint2(-48690,-9460));
> >     P2.push_back(cgalPoint2(-43690,-9460));
> >     P2.push_back(cgalPoint2(-43690,-4040));
> >     P2.push_back(cgalPoint2(-37690,1962));
> >     P2.push_back(cgalPoint2(-37690,9460));
> >     P2.push_back(cgalPoint2(-42690,9460));
> >     P2.push_back(cgalPoint2(-42690,4038));
> >
> >     cgalNefPolyhedron    N1(P1.begin(), P1.end(),
> > cgalNefPolyhedron::EXCLUDED);
> >     cgalNefPolyhedron    N2(P2.begin(), P2.end(),
> > cgalNefPolyhedron::EXCLUDED);
> >     cgalNefPolyhedron N3 = N1+N2;
> >
> >     /*
> >     cgalPolygon2    POLY1(P1.begin(), P1.end());
> >     cgalPolygon2    POLY2(P2.begin(), P2.end());
> >     cgalPolygonWithHoles2    unionR;
> >     CGAL::join(POLY1, POLY2, unionR);
> >     */
> > }