CGAL users discussion list

[D Haley <>]

Hello,

I am having some problems with the CGAL natural neighbour interpolation 
routines, which I am trying to use to compute a scalar field from an 
unstructured point dataset.

I have this working in 2D, as adapted from the documentation, however I would 
like to perform this computation in 3D. My usage of the delaunay 
triangulation compiles in 3D, but the natural neighbour computation does not.

I have the following code, which is wrong,  but there is no documentation (as 
far as I can see...) and  working from the header 
(natural_neighbour_coordinates_3.h) files is proving tricky, as it appears 
there is a different interface. Indeed, I can't seem to get the data types 
and calling sequence right!

If anyone can provide a working snippet (even for only a few points), then I 
can get the data structures right, and this would be very helpful!

Eventually I would like to extend this to 3D  gradient fitting; but may not 
be doing things correctly at the moment...

Thanks.
====
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <CGAL/Delaunay_triangulation_3.h>

#include <CGAL/natural_neighbor_coordinates_3.h>
#include <CGAL/Interpolation_traits_2.h>

#include <CGAL/interpolation_functions.h>

#include <CGAL/ch_graham_andrew.h>

typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
typedef CGAL::Delaunay_triangulation_3<K> DelaunayTriangulation;

bool interpolateNaturalN(const DelaunayTriangulation &dTriangles, 
std::map<K::Point_3, K::FT, K::Less_xyz_3> &scalarMap, K::Point_3 p, float 
&res)
{
        typedef CGAL::Data_access< std::map<K::Point_3, K::FT, K::Less_xyz_3> 
> value_access;
        typedef std::vector< std::pair< K::Point_3, K::FT  > > 
Point_coordinate_vector;


        K::FT norm;    
        Point_coordinate_vector coords;
        CGAL::Triple<std::back_insert_iterator<Point_coordinate_vector>,
                K::FT, bool> 
result=laplace_natural_neighbor_coordinates_3(dTriangles,p,std::back_inserter(coords),norm);

}

====

The above code gives me GCC errors like :

/usr/include/c++/4.4/bits/stl_pair.h: In constructor ‘std::pair<_T1, 
_T2>::pair(const std::pair<_U1, _U2>&) [with _U1 = 
CGAL::CGALi::CC_iterator<CGAL::Compact_container<CGAL::Triangulation_vertex_base_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double>
 >, 
CGAL::Triangulation_ds_vertex_base_3<CGAL::Triangulation_data_structure_3<CGAL::Triangulation_vertex_base_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double>
 >, CGAL::Triangulation_ds_vertex_base_3<void> >, 
CGAL::Triangulation_cell_base_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double>
 >, CGAL::Triangulation_ds_cell_base_3<void> > > > >, 
CGAL::Default_argument>, false>, _U2 = double, _T1 = 
CGAL::Point_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double> > >, _T2 = 
double]’:
/usr/include/CGAL/natural_neighbor_coordinates_3.h:100:   instantiated from 
‘CGAL::Triple<OutputIterator, typename Dt::Geom_traits::FT, bool> 
CGAL::laplace_natural_neighbor_coordinates_3(const Dt&, const typename 
Dt::Geom_traits::Point_3&, OutputIterator, typename Dt::Geom_traits::FT&, 
typename Dt::Cell_handle) [with Dt = 
CGAL::Delaunay_triangulation_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double>
 >, 
CGAL::Triangulation_data_structure_3<CGAL::Triangulation_vertex_base_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double>
 >, CGAL::Triangulation_ds_vertex_base_3<void> >, 
CGAL::Triangulation_cell_base_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double>
 >, CGAL::Triangulation_ds_cell_base_3<void> > > >, OutputIterator = 
std::back_insert_iterator<std::vector<std::pair<CGAL::Point_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double>
 > >, double>, 
std::allocator<std::pair<CGAL::Point_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double>
 > >,
 double> > > >]’
main.cpp:207:   instantiated from here
/usr/include/c++/4.4/bits/stl_pair.h:101: error: no matching function for 
call to ‘CGAL::Point_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double> > 
>::Point_3(const 
CGAL::CGALi::CC_iterator<CGAL::Compact_container<CGAL::Triangulation_vertex_base_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double>
 >, 
CGAL::Triangulation_ds_vertex_base_3<CGAL::Triangulation_data_structure_3<CGAL::Triangulation_vertex_base_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double>
 >, CGAL::Triangulation_ds_vertex_base_3<void> >, 
CGAL::Triangulation_cell_base_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double>
 >, CGAL::Triangulation_ds_cell_base_3<void> > > > >, 
CGAL::Default_argument>, false>&)’
/usr/include/CGAL/Point_3.h:83: note: candidates are: 
CGAL::Point_3<R_>::Point_3(const typename R_::RT&, const typename R_::RT&, 
const typename R_::RT&, const typename R_::RT&) [with R_ = 
CGAL::Filtered_kernel<CGAL::Simple_cartesian<double> >]
/usr/include/CGAL/Point_3.h:75: note:                 
CGAL::Point_3<R_>::Point_3(const typename R_::Kernel_base::Point_3&) [with R_ 
= CGAL::Filtered_kernel<CGAL::Simple_cartesian<double> >]
/usr/include/CGAL/Point_3.h:71: note:                 
CGAL::Point_3<R_>::Point_3(const CGAL::Origin&) [with R_ = 
CGAL::Filtered_kernel<CGAL::Simple_cartesian<double> >]
/usr/include/CGAL/Point_3.h:69: note:                 
CGAL::Point_3<R_>::Point_3() [with R_ = 
CGAL::Filtered_kernel<CGAL::Simple_cartesian<double> >]
/usr/include/CGAL/Point_3.h:40: note:                 
CGAL::Point_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double> > 
>::Point_3(const 
CGAL::Point_3<CGAL::Filtered_kernel<CGAL::Simple_cartesian<double> > >&)