 CGAL 5.1 - Polygon Mesh Processing

Functions to compute the distance between meshes, between a mesh and a point set and between a point set and a mesh.

## Functions

template<class PointOutputIterator , class TriangleMesh , class NamedParameters >
PointOutputIterator CGAL::Polygon_mesh_processing::sample_triangle_mesh (const TriangleMesh &tm, PointOutputIterator out, const NamedParameters &np)
generates points on tm and outputs them to out; the sampling method is selected using named parameters. More...

template<class PointOutputIterator , class TriangleRange , class PointRange , class NamedParameters >
PointOutputIterator CGAL::Polygon_mesh_processing::sample_triangle_soup (const PointRange &points, const TriangleRange &triangles, PointOutputIterator out, const NamedParameters &np)
generates points on a triangle soup and puts them to out; the sampling method is selected using named parameters. More...

template<class Concurrency_tag , class TriangleMesh , class NamedParameters1 , class NamedParameters2 >
double CGAL::Polygon_mesh_processing::approximate_Hausdorff_distance (const TriangleMesh &tm1, const TriangleMesh &tm2, const NamedParameters1 &np1, const NamedParameters2 &np2)
computes the approximate Hausdorff distance from tm1 to tm2 by returning the distance of the farthest point from tm2 amongst a sampling of tm1 generated with the function sample_triangle_mesh() with tm1 and np1 as parameter. More...

template<class Concurrency_tag , class TriangleMesh , class NamedParameters1 , class NamedParameters2 >
double CGAL::Polygon_mesh_processing::approximate_symmetric_Hausdorff_distance (const TriangleMesh &tm1, const TriangleMesh &tm2, const NamedParameters1 &np1, const NamedParameters2 &np2)
computes the approximate symmetric Hausdorff distance between tm1 and tm2. More...

template<class Concurrency_tag , class TriangleMesh , class PointRange , class NamedParameters >
double CGAL::Polygon_mesh_processing::max_distance_to_triangle_mesh (const PointRange &points, const TriangleMesh &tm, const NamedParameters &np)
returns the distance to tm of the point from points that is the furthest from tm. More...

template<class TriangleMesh , class PointRange , class NamedParameters >
double CGAL::Polygon_mesh_processing::approximate_max_distance_to_point_set (const TriangleMesh &tm, const PointRange &points, const double precision, const NamedParameters &np)
returns an approximation of the distance between points and the point lying on tm that is the farthest from points More...

## ◆ approximate_Hausdorff_distance()

template<class Concurrency_tag , class TriangleMesh , class NamedParameters1 , class NamedParameters2 >
 double CGAL::Polygon_mesh_processing::approximate_Hausdorff_distance ( const TriangleMesh & tm1, const TriangleMesh & tm2, const NamedParameters1 & np1, const NamedParameters2 & np2 )

#include <CGAL/Polygon_mesh_processing/distance.h>

computes the approximate Hausdorff distance from tm1 to tm2 by returning the distance of the farthest point from tm2 amongst a sampling of tm1 generated with the function sample_triangle_mesh() with tm1 and np1 as parameter.

A parallel version is provided and requires the executable to be linked against the Intel TBB library. To control the number of threads used, the user may use the tbb::task_scheduler_init class. See the TBB documentation for more details.

Template Parameters
 Concurrency_tag enables sequential versus parallel algorithm. Possible values are Sequential_tag, Parallel_tag, and Parallel_if_available_tag. TriangleMesh a model of the concepts EdgeListGraph and FaceListGraph NamedParameters1 a sequence of Named Parameters for tm1 NamedParameters2 a sequence of Named Parameters for tm2
Parameters
 tm1 the triangle mesh that will be sampled tm2 the triangle mesh to compute the distance to np1 an optional sequence of Named Parameters forwarded to sample_triangle_mesh() np2 an optional sequence of Named Parameters among the ones listed below
Optional Named Parameters
 a property map associating points to the vertices of tm2 Type: a class model of ReadablePropertyMap with boost::graph_traits::vertex_descriptor as key type and Point_3 as value type Default: boost::get(CGAL::vertex_point, tm2) Extra: If this parameter is omitted, an internal property map for CGAL::vertex_point_t must be available in TriangleMesh.

The function CGAL::parameters::all_default() can be used to indicate to use the default values for np1 and specify custom values for np2.

Examples:
Polygon_mesh_processing/hausdorff_distance_remeshing_example.cpp.

## ◆ approximate_max_distance_to_point_set()

template<class TriangleMesh , class PointRange , class NamedParameters >
 double CGAL::Polygon_mesh_processing::approximate_max_distance_to_point_set ( const TriangleMesh & tm, const PointRange & points, const double precision, const NamedParameters & np )

#include <CGAL/Polygon_mesh_processing/distance.h>

returns an approximation of the distance between points and the point lying on tm that is the farthest from points

Template Parameters
 PointRange a range of Point_3, model of Range. TriangleMesh a model of the concept FaceListGraph NamedParameters a sequence of Named Parameters
Parameters
 tm a triangle mesh points a range of points precision for each triangle of tm, the distance of its farthest point from points is bounded. A triangle is subdivided into sub-triangles so that the difference of its distance bounds is smaller than precision. precision must be strictly positive to avoid infinite loops. np an optional sequence of Named Parameters among the ones listed below
Optional Named Parameters
 a property map associating points to the vertices of tm Type: a class model of ReadablePropertyMap with boost::graph_traits::vertex_descriptor as key type and Point_3 as value type Default: boost::get(CGAL::vertex_point, tm) Extra: If this parameter is omitted, an internal property map for CGAL::vertex_point_t must be available in TriangleMesh. an instance of a geometric traits class Type: a class model of PMPDistanceTraits Default: a CGAL Kernel deduced from the point type, using CGAL::Kernel_traits Extra: The geometric traits class must be compatible with the vertex point type.
Examples:
Poisson_surface_reconstruction_3/poisson_reconstruction_example.cpp.

## ◆ approximate_symmetric_Hausdorff_distance()

template<class Concurrency_tag , class TriangleMesh , class NamedParameters1 , class NamedParameters2 >
 double CGAL::Polygon_mesh_processing::approximate_symmetric_Hausdorff_distance ( const TriangleMesh & tm1, const TriangleMesh & tm2, const NamedParameters1 & np1, const NamedParameters2 & np2 )

#include <CGAL/Polygon_mesh_processing/distance.h>

computes the approximate symmetric Hausdorff distance between tm1 and tm2.

It returns the maximum of approximate_Hausdorff_distance(tm1, tm2, np1, np2) and approximate_Hausdorff_distance(tm2, tm1, np2, np1).

## ◆ max_distance_to_triangle_mesh()

template<class Concurrency_tag , class TriangleMesh , class PointRange , class NamedParameters >
 double CGAL::Polygon_mesh_processing::max_distance_to_triangle_mesh ( const PointRange & points, const TriangleMesh & tm, const NamedParameters & np )

#include <CGAL/Polygon_mesh_processing/distance.h>

returns the distance to tm of the point from points that is the furthest from tm.

Template Parameters
 PointRange a range of Point_3, model of Range. Its iterator type is RandomAccessIterator. TriangleMesh a model of the concepts EdgeListGraph and FaceListGraph NamedParameters a sequence of Named Parameters
Parameters
 points the range of points of interest tm the triangle mesh to compute the distance to np an optional sequence of Named Parameters among the ones listed below
Optional Named Parameters
 a property map associating points to the vertices of tm Type: a class model of ReadablePropertyMap with boost::graph_traits::vertex_descriptor as key type and Point_3 as value type Default: boost::get(CGAL::vertex_point, tm) Extra: If this parameter is omitted, an internal property map for CGAL::vertex_point_t must be available in TriangleMesh. an instance of a geometric traits class Type: a class model of PMPDistanceTraits Default: a CGAL Kernel deduced from the point type, using CGAL::Kernel_traits Extra: The geometric traits class must be compatible with the vertex point type.

## ◆ sample_triangle_mesh()

template<class PointOutputIterator , class TriangleMesh , class NamedParameters >
 PointOutputIterator CGAL::Polygon_mesh_processing::sample_triangle_mesh ( const TriangleMesh & tm, PointOutputIterator out, const NamedParameters & np )

#include <CGAL/Polygon_mesh_processing/distance.h>

generates points on tm and outputs them to out; the sampling method is selected using named parameters.

Template Parameters
 TriangleMesh a model of the concepts EdgeListGraph and FaceListGraph PointOutputIterator a model of OutputIterator holding objects of the same point type as the value type of the point type associated to the mesh tm, i.e. the value type of the vertex point map property map, if provided, or the value type of the internal point property map otherwise NamedParameters a sequence of Named Parameters
Parameters
 tm the triangle mesh to be sampled out output iterator to be filled with sample points np an optional sequence of Named Parameters among the ones listed below
Optional Named Parameters
 a property map associating points to the vertices of tm Type: a class model of ReadablePropertyMap with boost::graph_traits::vertex_descriptor as key type and Point_3 as value type Default: boost::get(CGAL::vertex_point, tm) Extra: If this parameter is omitted, an internal property map for CGAL::vertex_point_t must be available in TriangleMesh. an instance of a geometric traits class Type: a class model of PMPDistanceTraits Default: a CGAL Kernel deduced from the point type, using CGAL::Kernel_traits Extra: The geometric traits class must be compatible with the vertex point type. If true is passed, points are generated in a random and uniform way on the surface of tm, and/or on edges of tm. Type: Boolean Type: true Extra: For faces, the number of sample points is the value passed to the named parameter number_of_points_on_faces. If not set, the value passed to the named parameter number_of_points_per_area_unit is multiplied by the area of tm to get the number of sample points. If none of these parameters is set, the number of points sampled is num_vertices(tm). For edges, the number of the number of sample points is the value passed to the named parameter number_of_points_on_edges. If not set, the value passed to the named parameter number_of_points_per_distance_unit is multiplied by the sum of the length of edges of tm to get the number of sample points. If none of these parameters is set, the number of points sampled is num_vertices(tm). If true is passed, points are generated on a grid in each triangle, with a minimum of one point per triangle. Type: Boolean Default: false Extra: The distance between two consecutive points in the grid is that of the length of the smallest non-null edge of tm or the value passed to the named parameter grid_spacing. Edges are also split using the same distance, if requested. if true is passed, points are generated randomly in each triangle and/or on each edge. Type: Boolean Default: false Extra: For faces, the number of points per triangle is the value passed to the named parameter number_of_points_per_face. If not set, the value passed to the named parameter number_of_points_per_area_unit is used to pick a number of points per face proportional to the triangle area with a minimum of one point per face. If none of these parameters is set, 2 divided by the square of the length of the smallest non-null edge of tm is used as if it was passed to number_of_points_per_area_unit. For edges, the number of points per edge is the value passed to the named parameter number_of_points_per_edge. If not set, the value passed to the named parameter number_of_points_per_distance_unit is used to pick a number of points per edge proportional to the length of the edge with a minimum of one point per face. If none of these parameters is set, 1 divided by the length of the smallest non-null edge of tm is used as if it was passed to number_of_points_per_distance_unit. If true is passed, the vertices of tm are part of the sample. Type: Boolean Default: true If true is passed, edges of tm are sampled. Type: Boolean Default: true If true is passed, faces of tm are sampled. Type: Boolean Default: true a value used as the grid spacing for the grid sampling method Type: double Default: the length of the shortest, non-degenerate edge of tm a value used for the random sampling method as the number of points to pick exclusively on edges Type: unsigned int Default: num_vertices(tm) or a value based on nb_points_per_distance_unit, if it is defined a value used for the random sampling method as the number of points to pick on the surface Type: unsigned int Default: num_vertices(tm) or a value based on nb_points_per_area_unit, if it is defined a value used for the random sampling and the Monte Carlo sampling methods to respectively determine the total number of points on edges and the number of points per edge Type: double Default: 1 divided by the length of the shortest, non-degenerate edge of tm a value used by the Monte-Carlo sampling method as the number of points per edge to pick Type: unsigned int Default: 0 a value used for the random sampling and the Monte Carlo sampling methods to respectively determine the total number of points inside faces and the number of points per face Type: double Default: 2 divided by the squared length of the shortest, non-degenerate edge of tm a value used by the Monte-Carlo sampling method as the number of points per face to pick Type: unsigned int Default: 0
CGAL::Polygon_mesh_processing::sample_triangle_soup()

## ◆ sample_triangle_soup()

template<class PointOutputIterator , class TriangleRange , class PointRange , class NamedParameters >
 PointOutputIterator CGAL::Polygon_mesh_processing::sample_triangle_soup ( const PointRange & points, const TriangleRange & triangles, PointOutputIterator out, const NamedParameters & np )

#include <CGAL/Polygon_mesh_processing/distance.h>

generates points on a triangle soup and puts them to out; the sampling method is selected using named parameters.

Template Parameters
 PointRange a model of the concept RandomAccessContainer whose value type is the point type. TriangleRange a model of the concept RandomAccessContainer whose value_type is itself a model of the concept RandomAccessContainer whose value_type is an unsigned integral value. PointOutputIterator a model of OutputIterator holding objects of the same type as PointRange's value type NamedParameters a sequence of Named Parameters
Parameters
 points the points of the soup triangles a TriangleRange containing the triangles of the soup to be sampled out output iterator to be filled with sample points np an optional sequence of Named Parameters among the ones listed below
Optional Named Parameters
 an instance of a geometric traits class Type: a class model of PMPDistanceTraits Default: a CGAL Kernel deduced from the point type, using CGAL::Kernel_traits Extra: The geometric traits class must be compatible with the point range's point type. If true is passed, points are generated in a random and uniform way over the triangles of the soup. Type: Boolean Type: true Extra: The number of sample points is the value passed to the named parameter number_of_points_on_faces. If not set, the value passed to the named parameter number_of_points_per_area_unit is multiplied by the area of the soup to get the number of sample points. If none of these parameters is set, the number of points sampled is points.size(). If true is passed, points are generated on a grid in each triangle, with a minimum of one point per triangle. Type: Boolean Default: false Extra: The distance between two consecutive points in the grid is that of the length of the smallest non-null edge of the soup or the value passed to the named parameter grid_spacing. if true is passed, points are generated randomly in each triangle. Type: Boolean Default: false Extra: The number of points per triangle is the value passed to the named parameter number_of_points_per_face. If not set, the value passed to the named parameter number_of_points_per_area_unit is used to pick a number of points per face proportional to the triangle area with a minimum of one point per face. If none of these parameters is set, the number of points per area unit is set to 2 divided by the square of the length of the smallest non-null edge of the soup. If true is passed, the points of points are part of the sample. Type: Boolean Default: true If true is passed, faces of the soup are sampled. Type: Boolean Default: true a value used as the grid spacing for the grid sampling method Type: double Default: the length of the shortest, non-degenerate edge of the soup a value used for the random sampling method as the number of points to pick on the surface Type: unsigned int Default: points.size() or a value based on nb_points_per_area_unit, if it is defined a value used by the Monte-Carlo sampling method as the number of points per face to pick Type: unsigned int Default: 0 a value used for the random sampling and the Monte Carlo sampling methods to respectively determine the total number of points inside faces and the number of points per face Type: double Default: 2 divided by the squared length of the shortest, non-degenerate edge of the soup
Attention
Contrary to sample_triangle_mesh(), this method does not allow to sample edges.
CGAL::Polygon_mesh_processing::sample_triangle_mesh()