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CGAL 4.6.1 - 2D and Surface Function Interpolation
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Functions
3D Surface Neighbor Coordinates Functions
Surface Neighbor and Surface Neighbor Coordinate Computation

The functions surface_neighbor_coordinates_3() compute natural neighbor coordinates for surface points associated to a finite set of sample points issued from the surface.

The coordinates are computed from the intersection of the Voronoi cell of the query point p with the tangent plane to the surface at p. If the sampling is sufficiently dense, the coordinate system meets the properties described in the manual pages and in [2],[5]. The query point p needs to lie inside the convex hull of the projection of the sample points onto the tangent plane at p.

The functions surface_neighbor_coordinates_certified_3() return, in addition, a second Boolean value (the fourth value of the quadruple) that certifies whether or not, the Voronoi cell of p can be affected by points that lie outside the input range, i.e. outside the ball centered on p passing through the furthest sample point from p in the range [first, beyond). If the sample points are collected by a k-nearest neighbor or a range search query, this permits to check whether the neighborhood which has been considered is large enough.

Requirements

  1. Dt is equivalent to the class Delaunay_triangulation_3.
  2. The value type of OutputIterator is equivalent to std::pair<Dt::Point_3, Dt::Geom_traits::FT>, i.e. a pair associating a point and its natural neighbor coordinate.
  3. ITraits is equivalent to the class Voronoi_intersection_2_traits_3<K>.
See Also
CGAL::linear_interpolation()
CGAL::sibson_c1_interpolation()
CGAL::farin_c1_interpolation()
CGAL::Voronoi_intersection_2_traits_3<K>
3D Surface Neighbors Functions

Implementation

This functions construct the regular triangulation of the input points instantiated with Voronoi_intersection_2_traits_3<Kernel> or ITraits if provided. They return the result of the function call PkgInterpolationRegularNeighborCoordinates2 with the regular triangulation and p as arguments.

Functions

template<class OutputIterator , class InputIterator , class Kernel >
CGAL::Triple< OutputIterator,
typename Kernel::FT, bool > 		CGAL::surface_neighbor_coordinates_3 (InputIterator first, InputIterator beyond, const typename Kernel::Point_3 &p, const typename Kernel::Vector_3 &normal, OutputIterator out, const Kernel &K)
 The sample points \( \mathcal{P}\) are provided in the range [first, beyond)`. More...
 
template<class OutputIterator , class InputIterator , class ITraits >
CGAL::Triple< OutputIterator,
typename ITraits::FT, bool > 		CGAL::surface_neighbor_coordinates_3 (InputIterator first, InputIterator beyond, const typename ITraits::Point_2 &p, OutputIterator out, const ITraits &traits)
 the same as above only that the traits class must be instantiated by the user. More...
 
template<class OutputIterator , class InputIterator , class Kernel >
CGAL::Quadruple
< OutputIterator, typename
Kernel::FT, bool, bool > 		CGAL::surface_neighbor_coordinates_certified_3 (InputIterator first, InputIterator beyond, const typename Kernel::Point_3 &p, const typename Kernel::Vector_3 &normal, OutputIterator out, const Kernel &K)
 Similar to the first function. More...
 
template<class OutputIterator , class InputIterator , class Kernel >
CGAL::Quadruple
< OutputIterator, typename
Kernel::FT, bool, bool > 		CGAL::surface_neighbor_coordinates_certified_3 (InputIterator first, InputIterator beyond, const typename Kernel::Point_3 &p, const typename Kernel::FT &max_distance, OutputIterator out, const Kernel &kernel)
 The same as above except that this function takes the maximal distance from p to the points in the range [first, beyond) as additional parameter.
 
template<class OutputIterator , class InputIterator , class ITraits >
CGAL::Quadruple
< OutputIterator, typename
ITraits::FT, bool, bool > 		CGAL::surface_neighbor_coordinates_certified_3 (InputIterator first, InputIterator beyond, const typename ITraits::Point_2 &p, OutputIterator out, const ITraits &traits)
 The same as above only that the traits class must be instantiated by the user and without the parameter max_distance. More...
 
template<class OutputIterator , class InputIterator , class ITraits >
CGAL::Quadruple
< OutputIterator, typename
ITraits::FT, bool, bool > 		CGAL::surface_neighbor_coordinates_certified_3 (InputIterator first, InputIterator beyond, const typename ITraits::Point_2 &p, const typename ITraits::FT &max_distance, OutputIterator out, const ITraits &traits)
 The same as above with the parameter max_distance.
 
template<class Dt , class OutputIterator >
CGAL::Triple< OutputIterator,
typename Dt::Geom_traits::FT,
bool > 		CGAL::surface_neighbor_coordinates_3 (const Dt &dt, const typename Dt::Geom_traits::Point_3 &p, const typename Dt::Geom_traits::Vector_3 &normal, OutputIterator out, typename Dt::Cell_handle start=typename Dt::Cell_handle())
 computes the surface neighbor coordinates with respect to the points that are vertices of the Delaunay triangulation dt. More...
 
template<class Dt , class OutputIterator , class ITraits >
CGAL::Triple< OutputIterator,
typenameDt::Geom_traits::FT,
bool > 		CGAL::surface_neighbor_coordinates_3 (const Dt &dt, const typename Dt::Geom_traits::Point_3 &p, OutputIterator out, const ITraits &traits, typename Dt::Cell_handle start=typename Dt::Cell_handle())
 The same as above only that the parameter traits instantiates the geometric traits class. More...
 

Function Documentation

template<class OutputIterator , class InputIterator , class Kernel >
CGAL::Triple< OutputIterator, typename Kernel::FT, bool > CGAL::surface_neighbor_coordinates_3 ( InputIterator  first,
InputIterator  beyond,
const typename Kernel::Point_3 &  p,
const typename Kernel::Vector_3 &  normal,
OutputIterator  out,
const Kernel &  K 
)

The sample points \( \mathcal{P}\) are provided in the range [first, beyond)`.

The value type of InputIterator is the point type Kernel::Point_3. The tangent plane is defined by the point p and the vector normal. The parameter K determines the kernel type that will instantiate the template parameter of Voronoi_intersection_2_traits_3<K>.

The natural neighbor coordinates for p are computed in the power diagram that results from the intersection of the 3D Voronoi diagram of \( \mathcal{P}\) with the tangent plane. The sequence of point/coordinate pairs that is computed by the function is placed starting at out. The function returns a triple with an iterator that is placed past-the-end of the resulting sequence of point/coordinate pairs, the normalization factor of the coordinates and a Boolean value which is set to true iff the coordinate computation was successful, i.e. if p lies inside the convex hull of the projection of the points \( \mathcal{P}\) onto the tangent plane.

#include <CGAL/surface_neighbor_coordinates_3.h>

Examples:
Interpolation/surface_neighbor_coordinates_3.cpp.
template<class OutputIterator , class InputIterator , class ITraits >
CGAL::Triple< OutputIterator, typename ITraits::FT, bool > CGAL::surface_neighbor_coordinates_3 ( InputIterator  first,
InputIterator  beyond,
const typename ITraits::Point_2 &  p,
OutputIterator  out,
const ITraits &  traits 
)

the same as above only that the traits class must be instantiated by the user.

ITraits must be equivalent to Voronoi_intersection_2_traits_3<K>.

#include <CGAL/surface_neighbor_coordinates_3.h>

template<class Dt , class OutputIterator >
CGAL::Triple< OutputIterator, typename Dt::Geom_traits::FT, bool > CGAL::surface_neighbor_coordinates_3 ( const Dt &  dt,
const typename Dt::Geom_traits::Point_3 &  p,
const typename Dt::Geom_traits::Vector_3 &  normal,
OutputIterator  out,
typename Dt::Cell_handle  start = typename Dt::Cell_handle() 
)

computes the surface neighbor coordinates with respect to the points that are vertices of the Delaunay triangulation dt.

The type Dt must be equivalent to Delaunay_triangulation_3<Gt, Tds>. The optional parameter start is used as a starting place for the search of the conflict zone. It may be the result of the call dt.locate(p). This function instantiates the template parameter ITraits to be Voronoi_intersection_2_traits_3<Dt::Geom_traits>.

This function allows to filter some potential neighbors of the query point p from \( \mathcal{P}\) via its three-dimensional Delaunay triangulation. All surface neighbors of p are necessarily neighbors in the Delaunay triangulation of \( \mathcal{P} \cup \{p\}\).

#include <CGAL/surface_neighbor_coordinates_3.h>

template<class Dt , class OutputIterator , class ITraits >
CGAL::Triple< OutputIterator, typenameDt::Geom_traits::FT, bool > CGAL::surface_neighbor_coordinates_3 ( const Dt &  dt,
const typename Dt::Geom_traits::Point_3 &  p,
OutputIterator  out,
const ITraits &  traits,
typename Dt::Cell_handle  start = typename Dt::Cell_handle() 
)

The same as above only that the parameter traits instantiates the geometric traits class.

Its type ITraits must be equivalent to Voronoi_intersection_2_traits_3<K>.

#include <CGAL/surface_neighbor_coordinates_3.h>

template<class OutputIterator , class InputIterator , class Kernel >
CGAL::Quadruple< OutputIterator, typename Kernel::FT, bool,bool > CGAL::surface_neighbor_coordinates_certified_3 ( InputIterator  first,
InputIterator  beyond,
const typename Kernel::Point_3 &  p,
const typename Kernel::Vector_3 &  normal,
OutputIterator  out,
const Kernel &  K 
)

Similar to the first function.

The additional fourth return value is true if the furthest point in the range [first, beyond) is further away from p than twice the distance from p to the furthest vertex of the intersection of the Voronoi cell of p with the tangent plane defined by (p,normal). It is false otherwise.

#include <CGAL/surface_neighbor_coordinates_3.h>

template<class OutputIterator , class InputIterator , class ITraits >
CGAL::Quadruple< OutputIterator, typename ITraits::FT, bool, bool > CGAL::surface_neighbor_coordinates_certified_3 ( InputIterator  first,
InputIterator  beyond,
const typename ITraits::Point_2 &  p,
OutputIterator  out,
const ITraits &  traits 
)

The same as above only that the traits class must be instantiated by the user and without the parameter max_distance.

ITraits must be equivalent to Voronoi_intersection_2_traits_3<K>.

#include <CGAL/surface_neighbor_coordinates_3.h>