CGAL users discussion list

[Mathieu Brédif <>]

Hello,

Has anyone been able to reproduce my problem?
if I understood correctly, the kernel I use is exact :

typedef CGAL::Gmpz RT;
typedef CGAL::Homogeneous_d<RT> Kernel;
typedef CGAL::Delaunay_d<Kernel> Delaunay_d;

Thus the inifinite recursion looks like a bug or a prerequisite that I
did not checked. For instance, does the "Delaunay_d" class handle
degenerate inputs such as aligned, coplanar or cospherical points?

Also, apart from this problem, and using the current implementation,
what are reasonable numbers of input points in 4D delaunay
triangulation?

Thanks
Mathieu

2009/10/2 Mathieu Brédif 
<>:
> Hi,
>
> I am playing with 4d delaunay triangulations to compute a graph to
> navigate within a 3D+time point cloud, where each 4D point refers to a
> timestamped geolocated panoramic image.
>
> I however stumbled upon a segfault. My code is attached together with
> an ascii file containing the 180 4d points. The insertion of the 180th
> point yields this backtrace in gdb :
>
> #0  0x00002b5b0c59d8b9 in valloc () from /lib/libc.so.6
> #1  0x00002b5b0c59e69a in realloc () from /lib/libc.so.6
> #2  0x00002b5b0be55d0c in __gmp_default_reallocate () from 
> /usr/lib/libgmp.so.3
> #3  0x00002b5b0be6a881 in __gmpz_realloc () from /usr/lib/libgmp.so.3
> #4  0x00002b5b0be67510 in __gmpz_mul () from /usr/lib/libgmp.so.3
> #5  0x0000000000407662 in boost::operator* ()
> #6  0x000000000040bf27 in
> CGAL::Convex_hull_d<CGAL::Homogeneous_d<CGAL::Gmpz,
> CGAL::Linear_algebraHd<CGAL::Gmpz, std::allocator<CGAL::Gmpz> > >
>>::visibility_search ()
> #7  0x000000000040c0d9 in
> CGAL::Convex_hull_d<CGAL::Homogeneous_d<CGAL::Gmpz,
> CGAL::Linear_algebraHd<CGAL::Gmpz, std::allocator<CGAL::Gmpz> > >
>>::visibility_search ()
> [infinite recursion of visibility_search() ]
>
> Am I doing something wrong?
>
> Mathieu Brédif
>
> PS: bug report infos
> Linux 2.6.18-6-amd64 #1 SMP Thu Dec 25 21:08:54 UTC 2008 x86_64 GNU/Linux
> CGAL 3.5-beta1 (same problem occured in 3.4)
> installed with cmake (default options)
>