CGAL users discussion list

[Gordan Sikic <>]

Andreas Fabri wrote:

> Hello,

Thanks for so swift answer.

> The coordinates must be integers. In your case they are
> all rounded to 0 or 1.

I suppose that you are referring to nef_3 demo...

If I compile and start program with listing included in my previous
post, I will receive different message:

$a.out < cube01.off
CGAL error: assertion violation!
Expr: pe_prev->facet()->plane().
has_on(pe_prev->opposite()->vertex()->point())
File: /usr/local/CGAL/include/CGAL/Nef_3/polyhedron_3_to_nef_3.h
Line: 151
Aborted


Also, if I dump Polyhedron_3 back to the std::cout, all coordinates have
their original values.


Does it mean that converting Polyhedron_3 to Nef_Polyhedron_3 works with
integer coordinates only, regardless of number type used as kernel
definition parameter ?



regards,
Gordan


PS
For brevity, I'll include same listings again:


//main.cpp:
// direct cut'n'paste from xemacs,
// so it should compile without problems
//----------------------cut-----------------
// *read Polyhedron_3 from std::cin,
// *convert it into Nef_Polyhedron_3
//
#include <CGAL/Gmpz.h>
#include <CGAL/Cartesian.h>
#include <CGAL/Homogeneous.h>
#include <CGAL/Extended_homogeneous.h>
#include <CGAL/Nef_polyhedron_3.h>
#include <CGAL/Polyhedron_3.h>
#include <CGAL/IO/Polyhedron_iostream.h>
#include <CGAL/IO/Nef_polyhedron_iostream_3.h>
#include <fstream>

typedef CGAL::Gmpz  NT;
//typedef CGAL::Homogeneous<NT>  SK;
typedef CGAL::Cartesian<double> SK;
typedef CGAL::Extended_homogeneous<NT>  EK;
typedef CGAL::Nef_polyhedron_3<SK>  Nef_polyhedron_S;
//typedef CGAL::Nef_polyhedron_3<EK>  Nef_polyhedron_E;

typedef CGAL::Polyhedron_3<SK>        Polyhedron;

int main() {

  //  debugthread=29;
  Polyhedron P;

  std::cin >> P;

  Nef_polyhedron_S S(P);
  std::cout << S;

}
//----------------cut--------------





#cube01.off:
OFF
8 6 0
# vertices
 -0.1 -0.1  0.1
 -0.1  0.1  0.1
  0.1  0.1  0.1
  0.1 -0.1  0.1
 -0.1 -0.1 -0.1
 -0.1  0.1 -0.1
  0.1  0.1 -0.1
  0.1 -0.1 -0.1
# facets
  4  3 2 1 0
  4  0 1 5 4
  4  6 5 1 2
  4  3 7 6 2
  4  4 7 3 0
  4  4 5 6 7
#------------------------