Functions to repair polygon soups and polygon meshes.

Functions
template<typename PolygonMesh >
bool	CGAL::Polygon_mesh_processing::is_non_manifold_vertex (typename boost::graph_traits< PolygonMesh >::vertex_descriptor v, const PolygonMesh &pm)
	returns whether a vertex of a polygon mesh is non-manifold. More...

template<typename PolygonMesh , typename OutputIterator >
OutputIterator	CGAL::Polygon_mesh_processing::non_manifold_vertices (const PolygonMesh &pm, OutputIterator out)
	collects the non-manifold vertices (if any) present in the mesh. More...

template<typename PolygonMesh , typename NamedParameters >
std::size_t	CGAL::Polygon_mesh_processing::duplicate_non_manifold_vertices (PolygonMesh &pm, const NamedParameters &np)
	duplicates all the non-manifold vertices of the input mesh. More...

template<class PolygonMesh , class NamedParameters >
void	CGAL::Polygon_mesh_processing::merge_duplicated_vertices_in_boundary_cycle (typename boost::graph_traits< PolygonMesh >::halfedge_descriptor h, PolygonMesh &pm, const NamedParameters &np)
	merges identical vertices around a cycle of boundary edges. More...

template<class PolygonMesh , class NamedParameters >
void	CGAL::Polygon_mesh_processing::merge_duplicated_vertices_in_boundary_cycles (PolygonMesh &pm, const NamedParameters &np)
	extracts boundary cycles and merges the duplicated vertices of each cycle. More...

template<typename PolygonMesh , typename PointRange , typename PolygonRange , typename NamedParameters >
void	CGAL::Polygon_mesh_processing::polygon_mesh_to_polygon_soup (const PolygonMesh &mesh, PointRange &points, PolygonRange &polygons, const NamedParameters &np)
	adds the vertices and faces of a mesh into a (possibly non-empty) polygon soup. More...

template<typename PolygonRange >
bool	CGAL::Polygon_mesh_processing::is_polygon_soup_a_polygon_mesh (const PolygonRange &polygons)
	returns `true` if the soup of polygons defines a valid polygon mesh that can be handled by `CGAL::Polygon_mesh_processing::polygon_soup_to_polygon_mesh()`. More...

template<typename PolygonMesh , typename PointRange , typename PolygonRange , typename NamedParameters_PS , typename NamedParameters_PM >
void	CGAL::Polygon_mesh_processing::polygon_soup_to_polygon_mesh (const PointRange &points, const PolygonRange &polygons, PolygonMesh &out, const NamedParameters_PS &np_ps, const NamedParameters_PM &np_pm)
	builds a polygon mesh from a soup of polygons. More...

template<class PolygonMesh >
std::size_t	CGAL::Polygon_mesh_processing::remove_isolated_vertices (PolygonMesh &pmesh)
	removes the isolated vertices from any polygon mesh. More...

template<typename TriangleMesh , typename NamedParameters >
std::size_t	CGAL::Polygon_mesh_processing::remove_connected_components_of_negligible_size (TriangleMesh &tmesh, const NamedParameters &np)
	removes connected components whose area or volume is under a certain threshold value. More...

template<typename PointRange , typename PolygonRange >
std::size_t	CGAL::Polygon_mesh_processing::remove_isolated_points_in_polygon_soup (PointRange &points, PolygonRange &polygons)
	removes the isolated points from a polygon soup. More...

template<typename PointRange , typename PolygonRange , typename NamedParameters >
std::size_t	CGAL::Polygon_mesh_processing::merge_duplicate_points_in_polygon_soup (PointRange &points, PolygonRange &polygons, const NamedParameters &np)
	merges the duplicate points in a polygon soup. More...

template<typename PointRange , typename PolygonRange , typename NamedParameters >
std::size_t	CGAL::Polygon_mesh_processing::merge_duplicate_polygons_in_polygon_soup (const PointRange &points, PolygonRange &polygons, const NamedParameters &np)
	merges the duplicate polygons in a polygon soup. More...

template<typename PointRange , typename PolygonRange , typename NamedParameters >
void	CGAL::Polygon_mesh_processing::repair_polygon_soup (PointRange &points, PolygonRange &polygons, const NamedParameters &np)
	cleans a given polygon soup through various repairing operations. More...

template<typename PolygonMesh , typename NamedParameters >
bool	CGAL::Polygon_mesh_processing::is_degenerate_edge (typename boost::graph_traits< PolygonMesh >::edge_descriptor e, const PolygonMesh &pm, const NamedParameters &np)
	checks whether an edge is degenerate. More...

template<typename EdgeRange , typename TriangleMesh , typename OutputIterator , typename NamedParameters >
OutputIterator	CGAL::Polygon_mesh_processing::degenerate_edges (const EdgeRange &edges, const TriangleMesh &tm, OutputIterator out, const NamedParameters &np)
	collects the degenerate edges within a given range of edges. More...

template<typename TriangleMesh , typename OutputIterator , typename NamedParameters >
OutputIterator	CGAL::Polygon_mesh_processing::degenerate_edges (const TriangleMesh &tm, OutputIterator out, const NamedParameters &np)
	calls the function `degenerate_edges()` with the range: `edges(tm)`. More...

template<typename TriangleMesh , typename NamedParameters >
bool	CGAL::Polygon_mesh_processing::is_degenerate_triangle_face (typename boost::graph_traits< TriangleMesh >::face_descriptor f, const TriangleMesh &tm, const NamedParameters &np)
	checks whether a triangle face is degenerate. More...

template<typename FaceRange , typename TriangleMesh , typename OutputIterator , typename NamedParameters >
OutputIterator	CGAL::Polygon_mesh_processing::degenerate_faces (const FaceRange &faces, const TriangleMesh &tm, OutputIterator out, const NamedParameters &np)
	collects the degenerate faces within a given range of faces. More...

template<typename TriangleMesh , typename OutputIterator , typename NamedParameters >
OutputIterator	CGAL::Polygon_mesh_processing::degenerate_faces (const TriangleMesh &tm, OutputIterator out, const NamedParameters &np)
	calls the function `degenerate_faces()` with the range: `faces(tm)`. More...

template<typename TriangleMesh , typename NamedParameters >
boost::graph_traits< TriangleMesh >::halfedge_descriptor	CGAL::Polygon_mesh_processing::is_needle_triangle_face (typename boost::graph_traits< TriangleMesh >::face_descriptor f, const TriangleMesh &tm, const double threshold, const NamedParameters &np)
	checks whether a triangle face is needle. More...

template<typename TriangleMesh , typename NamedParameters >
boost::graph_traits< TriangleMesh >::halfedge_descriptor	CGAL::Polygon_mesh_processing::is_cap_triangle_face (typename boost::graph_traits< TriangleMesh >::face_descriptor f, const TriangleMesh &tm, const double threshold, const NamedParameters &np)
	checks whether a triangle face is a cap. More...

template<typename PolygonMesh , typename NamedParameters >
std::size_t	CGAL::Polygon_mesh_processing::stitch_boundary_cycle (const typename boost::graph_traits< PolygonMesh >::halfedge_descriptor h, PolygonMesh &pmesh, const NamedParameters &np)
	stitches together, whenever possible, two halfedges belonging to the boundary cycle described by the halfedge `h`. More...

template<typename BorderHalfedgeRange , typename PolygonMesh , typename NamedParameters >
std::size_t	CGAL::Polygon_mesh_processing::stitch_boundary_cycles (const BorderHalfedgeRange &boundary_cycle_representatives, PolygonMesh &pmesh, const NamedParameters &np)
	stitches together, whenever possible, two halfedges belonging to the same boundary cycle. More...

template<typename PolygonMesh , typename HalfedgePairsRange >
std::size_t	CGAL::Polygon_mesh_processing::stitch_borders (PolygonMesh &pmesh, const HalfedgePairsRange &hedge_pairs_to_stitch)
	stitches together border halfedges in a polygon mesh. More...

template<typename BorderHalfedgeRange , typename PolygonMesh , typename NamedParameters >
std::size_t	CGAL::Polygon_mesh_processing::stitch_borders (const BorderHalfedgeRange &boundary_cycle_representatives, PolygonMesh &pmesh, const NamedParameters &np)
	Same as the other overload, but the pairs of halfedges to be stitched are automatically found amongst all border halfedges. More...

Function Documentation

◆ degenerate_edges() [1/2]

template<typename EdgeRange , typename TriangleMesh , typename OutputIterator , typename NamedParameters >

OutputIterator CGAL::Polygon_mesh_processing::degenerate_edges	(	const EdgeRange &	edges,
		const TriangleMesh &	tm,
		OutputIterator	out,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/shape_predicates.h>

collects the degenerate edges within a given range of edges.

Template Parameters

EdgeRange	a model of `Range` with value type `boost::graph_traits<TriangleMesh>::edge_descriptor`
TriangleMesh	a model of `HalfedgeGraph`
NamedParameters	a sequence of Named Parameters

Parameters

edges	a subset of edges of `tm`
tm	a triangle mesh
out	an output iterator in which the degenerate edges are written
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<TriangleMesh>::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: The traits class must provide the nested type Point_3, and the nested functor Equal_3 to check whether two points are identical.
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.

◆ degenerate_edges() [2/2]

template<typename TriangleMesh , typename OutputIterator , typename NamedParameters >

OutputIterator CGAL::Polygon_mesh_processing::degenerate_edges	(	const TriangleMesh &	tm,
		OutputIterator	out,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/shape_predicates.h>

calls the function degenerate_edges() with the range: edges(tm).

See above for the comprehensive description of the parameters.

◆ degenerate_faces() [1/2]

template<typename FaceRange , typename TriangleMesh , typename OutputIterator , typename NamedParameters >

OutputIterator CGAL::Polygon_mesh_processing::degenerate_faces	(	const FaceRange &	faces,
		const TriangleMesh &	tm,
		OutputIterator	out,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/shape_predicates.h>

collects the degenerate faces within a given range of faces.

Template Parameters

FaceRange	a model of `Range` with value type `boost::graph_traits<TriangleMesh>::face_descriptor`
TriangleMesh	a model of `FaceGraph`
NamedParameters	a sequence of Named Parameters

Parameters

faces	a subset of faces of `tm`
tm	a triangle mesh
out	an output iterator in which the degenerate faces are put
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<TriangleMesh>::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: The traits class must provide the nested type Point_3, and the nested functor Collinear_3 to check whether three points are collinear.
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.

◆ degenerate_faces() [2/2]

template<typename TriangleMesh , typename OutputIterator , typename NamedParameters >

OutputIterator CGAL::Polygon_mesh_processing::degenerate_faces	(	const TriangleMesh &	tm,
		OutputIterator	out,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/shape_predicates.h>

calls the function degenerate_faces() with the range: faces(tm).

See above for the comprehensive description of the parameters.

◆ duplicate_non_manifold_vertices()

template<typename PolygonMesh , typename NamedParameters >

std::size_t CGAL::Polygon_mesh_processing::duplicate_non_manifold_vertices	(	PolygonMesh &	pm,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/manifoldness.h>

duplicates all the non-manifold vertices of the input mesh.

Template Parameters

PolygonMesh	a model of `HalfedgeListGraph` and `MutableHalfedgeGraph`
NamedParameters	a sequence of Named Parameters

Parameters

pm	the surface mesh to be repaired
np	an optional sequence of Named Parameters among the ones listed below

Optional Named Parameters

a property map associating points to the vertices of pm
Type: a class model of ReadWritePropertyMap with boost::graph_traits<PolygonMesh>::vertex_descriptor as key type and Point_3 as value type
Default: boost::get(CGAL::vertex_point, pm)
Extra: If this parameter is omitted, an internal property map for CGAL::vertex_point_t must be available in PolygonMesh.

a property map containing the constrained-or-not status of each vertex of pm.
Type: a class model of ReadWritePropertyMap with boost::graph_traits<PolygonMesh>::vertex_descriptor as key type and bool as value type. It must be default constructible.
Default: a default property map where no vertex is constrained
Extra: put(vcm, v, true) will be called for each duplicated vertices, as well as the original non-manifold vertex in the input mesh.

an output iterator to collect the duplicated vertices
Type: a model of OutputIterator with value type std::vector<vertex_descriptor>
Default: unused
Extra: The first vertex of each vector is a non-manifold vertex of the input mesh, followed by the new vertices that were created to fix the given non-manifold configuration.

Returns: the number of vertices created.

Examples:: Polygon_mesh_processing/manifoldness_repair_example.cpp.

◆ is_cap_triangle_face()

template<typename TriangleMesh , typename NamedParameters >

boost::graph_traits<TriangleMesh>::halfedge_descriptor CGAL::Polygon_mesh_processing::is_cap_triangle_face	(	typename boost::graph_traits< TriangleMesh >::face_descriptor	f,
		const TriangleMesh &	tm,
		const double	threshold,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/shape_predicates.h>

checks whether a triangle face is a cap.

A triangle is said to be a cap if one of the its angles is close to 180 degrees.

Template Parameters

TriangleMesh	a model of `FaceGraph`
NamedParameters	a sequence of Named Parameters

Parameters

f	a triangle face of `tm`
tm	triangle mesh containing `f`
threshold	the cosine of a minimum angle such that if `f` has an angle greater than this bound, it is a cap. The threshold is in range `[-1 0]` and corresponds to an angle between `90` and `180` degrees.
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<TriangleMesh>::vertex_descriptor as key type and Point_3 as value type
Default: boost::get(CGAL::vertex_point, tm)

an instance of a geometric traits class
Type: The traits class must provide the nested type Point_3, the nested functors Compute_squared_distance_3, Construct_vector_3, and Compute_scalar_product_3.
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.

Returns: the halfedge opposite of the largest angle if the face is a cap, and a null halfedge otherwise.

◆ is_degenerate_edge()

template<typename PolygonMesh , typename NamedParameters >

bool CGAL::Polygon_mesh_processing::is_degenerate_edge	(	typename boost::graph_traits< PolygonMesh >::edge_descriptor	e,
		const PolygonMesh &	pm,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/shape_predicates.h>

checks whether an edge is degenerate.

An edge is considered degenerate if the geometric positions of its two extremities are identical.

Template Parameters

PolygonMesh	a model of `HalfedgeGraph`
NamedParameters	a sequence of Named Parameters

Parameters

e	an edge of `pm`
pm	polygon mesh containing `e`
np	an optional sequence of Named Parameters among the ones listed below

Optional Named Parameters

a property map associating points to the vertices of pm
Type: a class model of ReadablePropertyMap with boost::graph_traits<PolygonMesh>::vertex_descriptor as key type and Point_3 as value type
Default: boost::get(CGAL::vertex_point, pm)

an instance of a geometric traits class
Type: The traits class must provide the nested type Point_3, and the nested functor Equal_3 to check whether two points are identical.
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.

See also: degenerate_edges()

Returns: true if the edge e is degenerate, false otherwise.

◆ is_degenerate_triangle_face()

template<typename TriangleMesh , typename NamedParameters >

bool CGAL::Polygon_mesh_processing::is_degenerate_triangle_face	(	typename boost::graph_traits< TriangleMesh >::face_descriptor	f,
		const TriangleMesh &	tm,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/shape_predicates.h>

checks whether a triangle face is degenerate.

A triangle face is considered degenerate if the geometric positions of its vertices are collinear.

Template Parameters

TriangleMesh	a model of `FaceGraph`
NamedParameters	a sequence of Named Parameters

Parameters

f	a triangle face of `tm`
tm	a triangle mesh containing `f`
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<TriangleMesh>::vertex_descriptor as key type and Point_3 as value type
Default: boost::get(CGAL::vertex_point, tm)

an instance of a geometric traits class
Type: The traits class must provide the nested type Point_3, and the nested functor Collinear_3 to check whether three points are aligned.
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.

See also: degenerate_faces()

Returns: true if the face f is degenerate, false otherwise.

◆ is_needle_triangle_face()

template<typename TriangleMesh , typename NamedParameters >

boost::graph_traits<TriangleMesh>::halfedge_descriptor CGAL::Polygon_mesh_processing::is_needle_triangle_face	(	typename boost::graph_traits< TriangleMesh >::face_descriptor	f,
		const TriangleMesh &	tm,
		const double	threshold,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/shape_predicates.h>

checks whether a triangle face is needle.

A triangle is said to be a needle if its longest edge is much longer than its shortest edge.

Template Parameters

TriangleMesh	a model of `FaceGraph`
NamedParameters	a sequence of Named Parameters

Parameters

f	a triangle face of `tm`
tm	triangle mesh containing `f`
threshold	a bound on the ratio of the longest edge length and the shortest edge length
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<TriangleMesh>::vertex_descriptor as key type and Point_3 as value type
Default: boost::get(CGAL::vertex_point, tm)

an instance of a geometric traits class
Type: The traits class must provide the nested type FT, and the nested functor Compute_squared_distance_3.
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.

Returns: the shortest halfedge if the triangle face is a needle, and a null halfedge otherwise. If the face contains degenerate edges, a halfedge corresponding to one of these edges is returned.

◆ is_non_manifold_vertex()

template<typename PolygonMesh >

bool CGAL::Polygon_mesh_processing::is_non_manifold_vertex	(	typename boost::graph_traits< PolygonMesh >::vertex_descriptor	v,
		const PolygonMesh &	pm
	)

#include <CGAL/Polygon_mesh_processing/manifoldness.h>

returns whether a vertex of a polygon mesh is non-manifold.

Template Parameters

PolygonMesh a model of HalfedgeListGraph

Parameters

v	a vertex of `pm`
pm	a triangle mesh containing `v`

Warning: This function has linear runtime with respect to the size of the mesh.

See also: duplicate_non_manifold_vertices()

Returns: true if the vertex is non-manifold, false otherwise.

Examples:: Polygon_mesh_processing/manifoldness_repair_example.cpp.

◆ is_polygon_soup_a_polygon_mesh()

template<typename PolygonRange >

bool CGAL::Polygon_mesh_processing::is_polygon_soup_a_polygon_mesh ( const PolygonRange & polygons )

#include <CGAL/Polygon_mesh_processing/polygon_soup_to_polygon_mesh.h>

returns true if the soup of polygons defines a valid polygon mesh that can be handled by CGAL::Polygon_mesh_processing::polygon_soup_to_polygon_mesh().

It checks that each edge has at most two incident faces and such an edge is visited in opposite direction along the two face boundaries, no polygon has twice the same vertex, and the polygon soup describes a manifold surface. This function does not require a range of points as an argument since the check is purely topological. To each vertex of the mesh is associated an index that is used in the description of the boundaries of the polygons provided in polygons.

Template Parameters

PolygonRange a model of the concept RandomAccessContainer whose value_type is a model of the concept RandomAccessContainer whose value_type is std::size_t.

Parameters

polygons each element in the range describes a polygon using the indices of the vertices.

See also: orient_polygon_soup()

Examples:: Polygon_mesh_processing/orientation_pipeline_example.cpp.

◆ merge_duplicate_points_in_polygon_soup()

template<typename PointRange , typename PolygonRange , typename NamedParameters >

std::size_t CGAL::Polygon_mesh_processing::merge_duplicate_points_in_polygon_soup	(	PointRange &	points,
		PolygonRange &	polygons,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/repair_polygon_soup.h>

merges the duplicate points in a polygon soup.

Note that the index of a point that is merged with another point will thus change in all the polygons that the point appears in.

Template Parameters

PointRange	a model of the concepts `SequenceContainer` and `Swappable` whose value type is the point type.
PolygonRange	a model of the concept `RandomAccessContainer` whose `value_type` is itself a model of the concept `RandomAccessContainer` whose `value_type` is `std::size_t`.
NamedParameters	a sequence of Named Parameters

Parameters

points	points of the soup of polygons
polygons	a vector of polygons. Each element in the vector describes a polygon using the indices of the points in `points`.
np	an optional sequence of Named Parameters among the ones listed below

Optional Named Parameters

an instance of a geometric traits class
Type: The traits class must provide the nested functor Less_xyz_3 to compare lexicographically two points a function Less_xyz_3 less_xyz_3_object().
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.

Returns: the number of removed points

◆ merge_duplicate_polygons_in_polygon_soup()

template<typename PointRange , typename PolygonRange , typename NamedParameters >

std::size_t CGAL::Polygon_mesh_processing::merge_duplicate_polygons_in_polygon_soup	(	const PointRange &	points,
		PolygonRange &	polygons,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/repair_polygon_soup.h>

merges the duplicate polygons in a polygon soup.

Two polygons are duplicate if they share the same vertices in the same order. Note that the first vertex of the polygon does not matter, that is the triangle 0,1,2 is a duplicate of the triangle 2,0,1.

Template Parameters

PointRange	a model of the concept `RandomAccessContainer` whose value type is the point type.
PolygonRange	a model of the concept `SequenceContainer` whose `value_type` is itself a model of the concepts `RandomAccessContainer` and `ReversibleContainer` whose `value_type` is `std::size_t`.
NamedParameters	a sequence of Named Parameters

Parameters

points	points of the soup of polygons
polygons	a vector of polygons. Each element in the vector describes a polygon using the indices of the points in `points`.
np	an optional sequence of Named Parameters among the ones listed below

Optional Named Parameters

an instance of a geometric traits class
Type: The traits class must provide the nested functor Less_xyz_3 to compare lexicographically two points a function Less_xyz_3 less_xyz_3_object().
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.

Parameter to indicate, when multiple polygons are duplicates, whether all the duplicate polygons should be removed or if one (arbitrarily chosen) face should be kept.
Type: Boolean
Default: false

Parameter to indicate if polygon orientation should be taken into account when determining whether two polygons are duplicates, that is, whether e.g. the triangles 0,1,2 and 0,2,1 are duplicates.
Type: Boolean
Default: false

Returns: the number of removed polygons

◆ merge_duplicated_vertices_in_boundary_cycle()

template<class PolygonMesh , class NamedParameters >

void CGAL::Polygon_mesh_processing::merge_duplicated_vertices_in_boundary_cycle	(	typename boost::graph_traits< PolygonMesh >::halfedge_descriptor	h,
		PolygonMesh &	pm,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/merge_border_vertices.h>

merges identical vertices around a cycle of boundary edges.

Template Parameters

PolygonMesh	a model of `FaceListGraph` and `MutableFaceGraph`.
NamedParameters	a sequence of Named Parameters.

Parameters

h	a halfedge that belongs to a boundary cycle.
pm	the polygon mesh which contains the boundary cycle.
np	an optional sequence of Named Parameters among the ones listed below

Optional Named Parameters

a property map associating points to the vertices of pm
Type: a class model of ReadWritePropertyMap with boost::graph_traits<PolygonMesh>::vertex_descriptor as key type and Point_3 as value type
Default: boost::get(CGAL::vertex_point, pm)

◆ merge_duplicated_vertices_in_boundary_cycles()

template<class PolygonMesh , class NamedParameters >

void CGAL::Polygon_mesh_processing::merge_duplicated_vertices_in_boundary_cycles	(	PolygonMesh &	pm,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/merge_border_vertices.h>

extracts boundary cycles and merges the duplicated vertices of each cycle.

Template Parameters

PolygonMesh	a model of `FaceListGraph` and `MutableFaceGraph`.
NamedParameters	a sequence of Named Parameters.

Parameters

pm	the polygon mesh which contains the cycles.
np	an optional sequence of Named Parameters among the ones listed below

Optional Named Parameters

a property map associating points to the vertices of pm
Type: a class model of ReadWritePropertyMap with boost::graph_traits<PolygonMesh>::vertex_descriptor as key type and Point_3 as value type
Default: boost::get(CGAL::vertex_point, pm)

See also: merge_duplicated_vertices_in_boundary_cycle()

◆ non_manifold_vertices()

template<typename PolygonMesh , typename OutputIterator >

OutputIterator CGAL::Polygon_mesh_processing::non_manifold_vertices	(	const PolygonMesh &	pm,
		OutputIterator	out
	)

#include <CGAL/Polygon_mesh_processing/manifoldness.h>

collects the non-manifold vertices (if any) present in the mesh.

A non-manifold vertex v is returned via one incident halfedge h such that target(h, pm) = v for all the umbrellas that v appears in (an umbrella being the set of faces incident to all the halfedges reachable by walking around v using hnext = prev(opposite(h, pm), pm), starting from h).

Template Parameters

PolygonMesh	a model of `HalfedgeListGraph`
OutputIterator	a model of `OutputIterator` holding objects of type `boost::graph_traits<PolygonMesh>::halfedge_descriptor`

Parameters

pm	a triangle mesh
out	the output iterator that collects halfedges incident to `v`

See also: is_non_manifold_vertex(); duplicate_non_manifold_vertices()

Returns: the output iterator.

◆ polygon_mesh_to_polygon_soup()

template<typename PolygonMesh , typename PointRange , typename PolygonRange , typename NamedParameters >

void CGAL::Polygon_mesh_processing::polygon_mesh_to_polygon_soup	(	const PolygonMesh &	mesh,
		PointRange &	points,
		PolygonRange &	polygons,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/polygon_mesh_to_polygon_soup.h>

adds the vertices and faces of a mesh into a (possibly non-empty) polygon soup.

Template Parameters

PolygonMesh	a model of `FaceListGraph`
PointRange	a model of the concepts `RandomAccessContainer` and `BackInsertionSequence` whose value type can be constructed from the point type of the polygon mesh
PolygonRange	a model of the concepts `RandomAccessContainer` and `BackInsertionSequence` whose value type is itself a model of the concepts `RandomAccessContainer` and `BackInsertionSequence` whose value type is `std::size_t`
NamedParameters	a sequence of Named Parameters

Parameters

mesh	the mesh whose faces are being put in the polygon soup
points	points making the polygons of the soup
polygons	each element in the vector describes a polygon using the indices of the points in `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 mesh
Type: a class model of ReadablePropertyMap with boost::graph_traits<PolygonMesh>::vertex_descriptor as key type and Point_3 as value type
Default: boost::get(CGAL::vertex_point, mesh)

Advanced

PolygonRange can also be a model of the concepts RandomAccessContainer and BackInsertionSequence whose value type is an array, but it is the user's responsability to ensure that all faces have the same number of vertices, and that this number is equal to the size of the array.

See also: CGAL::Polygon_mesh_processing::orient_polygon_soup(); CGAL::Polygon_mesh_processing::is_polygon_soup_a_polygon_mesh(); CGAL::Polygon_mesh_processing::polygon_soup_to_polygon_mesh()

◆ polygon_soup_to_polygon_mesh()

template<typename PolygonMesh , typename PointRange , typename PolygonRange , typename NamedParameters_PS , typename NamedParameters_PM >

void CGAL::Polygon_mesh_processing::polygon_soup_to_polygon_mesh	(	const PointRange &	points,
		const PolygonRange &	polygons,
		PolygonMesh &	out,
		const NamedParameters_PS &	np_ps,
		const NamedParameters_PM &	np_pm
	)

#include <CGAL/Polygon_mesh_processing/polygon_soup_to_polygon_mesh.h>

builds a polygon mesh from a soup of polygons.

Precondition: the input polygon soup describes a consistently oriented polygon mesh. This can be checked using the function CGAL::Polygon_mesh_processing::is_polygon_soup_a_polygon_mesh(polygons) .

Template Parameters

PolygonMesh	a model of `MutableFaceGraph`
PointRange	a model of the concept `RandomAccessContainer` whose value type is the point type
PolygonRange	a model of the concept `RandomAccessContainer` whose value type is a model of the concept `RandomAccessContainer` whose value type is `std::size_t`
NamedParameters_PS	a sequence of Named Parameters
NamedParameters_PM	a sequence of Named Parameters

Parameters

points	points of the soup of polygons
polygons	each element in the range describes a polygon using the indices of the points in `points`
out	the polygon mesh to be built
np_ps	an optional sequence of Named Parameters among the ones listed below

Optional Named Parameters

a property map associating points to the elements of the range points
Type: a model of ReadablePropertyMap whose value type is a point type convertible to the point type of the vertex point map associated to the polygon mesh
Default: CGAL::Identity_property_map

Parameters

np_pm an optional sequence of Named Parameters among the ones listed below

Optional Named Parameters

a property map associating points to the vertices of out
Type: a class model of ReadWritePropertyMap with boost::graph_traits<PolygonMesh>::vertex_descriptor as key type and Point_3 as value type
Default: boost::get(CGAL::vertex_point, out)
Extra: If this parameter is omitted, an internal property map for CGAL::vertex_point_t must be available in PolygonMesh.

See also: CGAL::Polygon_mesh_processing::orient_polygon_soup(); CGAL::Polygon_mesh_processing::is_polygon_soup_a_polygon_mesh(); CGAL::Polygon_mesh_processing::polygon_mesh_to_polygon_soup()

Examples:: Polygon_mesh_processing/orient_polygon_soup_example.cpp, Polygon_mesh_processing/orientation_pipeline_example.cpp, and Polygon_mesh_processing/repair_polygon_soup_example.cpp.

◆ remove_connected_components_of_negligible_size()

template<typename TriangleMesh , typename NamedParameters >

std::size_t CGAL::Polygon_mesh_processing::remove_connected_components_of_negligible_size	(	TriangleMesh &	tmesh,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/repair.h>

removes connected components whose area or volume is under a certain threshold value.

Thresholds are provided via Named Parameters. (see below). If thresholds are not provided by the user, default values are computed as follows:

the area threshold is taken as the square of one percent of the length of the diagonal of the bounding box of the mesh.
the volume threshold is taken as the third power of one percent of the length of the diagonal of the bounding box of the mesh.

The area and volume of a connected component will always be positive values (regardless of the orientation of the mesh).

As a consequence of the last sentence, the area or volume criteria can be disabled by passing zero (0) as threshold value.

Template Parameters

TriangleMesh	a model of `FaceListGraph` and `MutableFaceGraph`
NamedParameters	a sequence of Named Parameters

Parameters

tmesh	the triangulated polygon mesh
np	an optional sequence of Named Parameters among the ones listed below

Optional Named Parameters

a property map associating points to the vertices of `tmesh` Type: a class model of `ReadWritePropertyMap` with `boost::graph_traits<TriangleMesh>::vertex_descriptor` as key type and `Point_3` as value type Default: `boost::get(CGAL::vertex_point, tmesh)` 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 `Kernel` 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. Extra: Exact constructions kernels are not supported by this function.
a property map associating to each face of `tmesh` a unique index between `0` and `num_faces(tmesh) - 1` Type: a class model of `ReadablePropertyMap` with `boost::graph_traits<TriangleMesh>::face_descriptor` as key type and `std::size_t` as value type Default: an automatically indexed internal map
a fixed value such that only connected components whose area is larger than this value are kept Type: `geom_traits::FT` Default: 1% of the length of the diagonal of the axis-aligned bounding box of the mesh, squared
a fixed value such that only connected components whose volume is larger than this value are kept (only applies to closed connected components) Type: `geom_traits::FT` Default: 1% of the length of the diagonal of the axis-aligned bounding box of the mesh, cubed Extra: The mesh must be closed.
a property map containing the constrained-or-not status of each edge of `tmesh` Type: a class model of `ReadablePropertyMap` with `boost::graph_traits<TriangleMesh>::edge_descriptor` as key type and `bool` as value type. It must be default constructible. Default: a default property map where no edge is constrained Extra: A constrained edge can be split or collapsed, but not flipped, nor its endpoints moved by smoothing.
If `true`, the mesh will not be altered, but the number of components that would be removed is returned. Type: Boolean Default: `false`
An output iterator to collect the faces that would be removed by the algorithm, when using the "dry run" mode (see parameter `dry_run`) Type: a model of `OutputIterator` with value type `face_descriptor` Default: unused

Returns: the number of connected components removed (ignoring isolated vertices).

◆ remove_isolated_points_in_polygon_soup()

template<typename PointRange , typename PolygonRange >

std::size_t CGAL::Polygon_mesh_processing::remove_isolated_points_in_polygon_soup	(	PointRange &	points,
		PolygonRange &	polygons
	)

#include <CGAL/Polygon_mesh_processing/repair_polygon_soup.h>

removes the isolated points from a polygon soup.

A point is considered isolated if it does not appear in any polygon of the soup.

Template Parameters

PointRange	a model of the concept `SequenceContainer` whose value type is the point type.
PolygonRange	a model of the concept `RandomAccessContainer` whose `value_type` is itself a model of the concept `RandomAccessContainer` whose `value_type` is `std::size_t`.

Parameters

points	points of the soup of polygons
polygons	a vector of polygons. Each element in the vector describes a polygon using the indices of the points in `points`.

Returns: the number of removed isolated points

◆ remove_isolated_vertices()

template<class PolygonMesh >

std::size_t CGAL::Polygon_mesh_processing::remove_isolated_vertices ( PolygonMesh & pmesh )

#include <CGAL/Polygon_mesh_processing/repair.h>

removes the isolated vertices from any polygon mesh.

A vertex is considered isolated if it is not incident to any simplex of higher dimension.

Template Parameters

PolygonMesh a model of FaceListGraph and MutableFaceGraph

Parameters

pmesh the polygon mesh to be repaired

Returns: number of removed isolated vertices

◆ repair_polygon_soup()

template<typename PointRange , typename PolygonRange , typename NamedParameters >

void CGAL::Polygon_mesh_processing::repair_polygon_soup	(	PointRange &	points,
		PolygonRange &	polygons,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/repair_polygon_soup.h>

cleans a given polygon soup through various repairing operations.

More precisely, this function carries out the following tasks, in the same order as they are listed:

merging of duplicate points, using the function CGAL::Polygon_mesh_processing::merge_duplicate_points_in_polygon_soup();
simplification of polygons to remove geometrically identical consecutive vertices;
splitting of "pinched" polygons, that is polygons in which a geometric position appears more than once. The splitting process results in multiple non-pinched polygons;
removal of invalid polygons, that is polygons with fewer than 2 vertices;
removal of duplicate polygons, using the function CGAL::Polygon_mesh_processing::merge_duplicate_polygons_in_polygon_soup();
removal of isolated points, using the function CGAL::Polygon_mesh_processing::remove_isolated_points_in_polygon_soup().

Note that the point and polygon containers will be modified by the repairing operations, and thus the indexation of the polygons will also be changed.

Template Parameters

PointRange	a model of the concepts `SequenceContainer` and `Swappable` and whose value type is the point type.
PolygonRange	a model of the concept `SequenceContainer`. whose `value_type` is itself a model of the concepts `SequenceContainer`, `Swappable`, and `ReversibleContainer` whose `value_type` is `std::size_t`.
NamedParameters	a sequence of Named Parameters

Parameters

points	points of the soup of polygons
polygons	a vector of polygons. Each element in the vector describes a polygon using the indices of the points in `points`.
np	an optional sequence of Named Parameters among the ones listed below

Optional Named Parameters

an instance of a geometric traits class
Type: The traits class must provide the nested functors Less_xyz_3 and Equal_3 to respectivelycompare lexicographically two points and to check if two points are identical. For each functor Foo, a function Foo foo_object() must be provided.
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.

Parameter to indicate, when multiple polygons are duplicates, whether all the duplicate polygons should be removed or if one (arbitrarily chosen) face should be kept.
Type: Boolean
Default: false

Parameter to indicate if polygon orientation should be taken into account when determining whether two polygons are duplicates, that is, whether e.g. the triangles 0,1,2 and 0,2,1 are duplicates.
Type: Boolean
Default: false

Examples:: Polygon_mesh_processing/repair_polygon_soup_example.cpp.

◆ stitch_borders() [1/2]

template<typename PolygonMesh , typename HalfedgePairsRange >

std::size_t CGAL::Polygon_mesh_processing::stitch_borders	(	PolygonMesh &	pmesh,
		const HalfedgePairsRange &	hedge_pairs_to_stitch
	)

#include <CGAL/Polygon_mesh_processing/stitch_borders.h>

stitches together border halfedges in a polygon mesh.

The halfedges to be stitched are provided in hedge_pairs_to_stitch. For each pair p in this vector, p.second and its opposite will be removed from pmesh.

Template Parameters

PolygonMesh	a model of `MutableFaceGraph`
HalfedgePairsRange	a range of `std::pair<boost::graph_traits<PolygonMesh>::halfedge_descriptor, boost::graph_traits<PolygonMesh>::halfedge_descriptor>`, model of `Range`. Its iterator type is `InputIterator`.

Parameters

pmesh	the polygon mesh to be modified by stitching
hedge_pairs_to_stitch	a range of `std::pair` of halfedges to be stitched together

Returns: the number of pairs of halfedges that were stitched.

Examples:: Polygon_mesh_processing/stitch_borders_example.cpp.

◆ stitch_borders() [2/2]

template<typename BorderHalfedgeRange , typename PolygonMesh , typename NamedParameters >

std::size_t CGAL::Polygon_mesh_processing::stitch_borders	(	const BorderHalfedgeRange &	boundary_cycle_representatives,
		PolygonMesh &	pmesh,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/stitch_borders.h>

Same as the other overload, but the pairs of halfedges to be stitched are automatically found amongst all border halfedges.

Two border halfedges h1 and h2 are set to be stitched if the points associated to the source and target vertices of h1 are the same as those of the target and source vertices of h2, respectively.

Template Parameters

BorderHalfedgeRange	a model of `Range` with value type `boost::graph_traits<PolygonMesh>::halfedge_descriptor`
PolygonMesh	a model of `FaceListGraph` and `MutableFaceGraph`
NamedParameters	a sequence of Named Parameters

Parameters

boundary_cycle_representatives	a range of border halfedges, each describing a boundary cycle whose halfedges will be considered for stitching
pmesh	the polygon mesh to be modified by the stitching procedure
np	optional sequence of Named Parameters among the ones listed below

Optional Named Parameters

specifies if the borders should only be stitched only within their own connected component. Type: Boolean Default: `false`
a property map associating to each face of `pmesh` a unique index between `0` and `num_faces(pmesh) - 1` Type: a class model of `ReadablePropertyMap` with `boost::graph_traits<PolygonMesh>::face_descriptor` as key type and `std::size_t` as value type Default: an automatically indexed internal map
a property map associating points to the vertices of `pmesh` Type: a class model of `ReadWritePropertyMap` with `boost::graph_traits<PolygonMesh>::vertex_descriptor` as key type and `Point_3` as value type Default: `boost::get(CGAL::vertex_point, pmesh)` Extra: If this parameter is omitted, an internal property map for `CGAL::vertex_point_t` must be available in `PolygonMesh`.
an instance of a geometric traits class Type: The traits class must provide the nested type `Point_3`, and the nested functors: `Less_xyz_3` to compare lexicographically two points `Equal_3` to check whether two points are identical. For each functor `Foo`, a function `Foo foo_object()` must be provided. 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.

Returns: the number of pairs of halfedges that were stitched.

See also: stitch_boundary_cycle(); stitch_boundary_cycles()

◆ stitch_boundary_cycle()

template<typename PolygonMesh , typename NamedParameters >

std::size_t CGAL::Polygon_mesh_processing::stitch_boundary_cycle	(	const typename boost::graph_traits< PolygonMesh >::halfedge_descriptor	h,
		PolygonMesh &	pmesh,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/stitch_borders.h>

stitches together, whenever possible, two halfedges belonging to the boundary cycle described by the halfedge h.

Two border halfedges h1 and h2 can be stitched if the points associated to the source and target vertices of h1 are the same as those of the target and source vertices of h2, respectively.

Template Parameters

PolygonMesh	a model of `MutableFaceGraph`
NamedParameters	a sequence of Named Parameters

Parameters

h	a border halfedge of the polygon mesh `pmesh`
pmesh	the polygon mesh to be stitched
np	an optional sequence of Named Parameters among the ones listed below

Optional Named Parameters

a property map associating points to the vertices of pm
Type: a class model of ReadWritePropertyMap with boost::graph_traits<PolygonMesh>::vertex_descriptor as key type and Point_3 as value type
Default: boost::get(CGAL::vertex_point, pmesh)
Extra: If this parameter is omitted, an internal property map for CGAL::vertex_point_t must be available in PolygonMesh.

an instance of a geometric traits class
Type: The traits class must provide the nested type Point_3, and the nested functors:
- Less_xyz_3 to compare lexicographically two points
- Equal_3 to check whether two points are identical. For each functor Foo, a function Foo foo_object() must be provided.
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.

Returns: the number of pairs of halfedges that were stitched.

See also: stitch_boundary_cycles(); stitch_borders()

◆ stitch_boundary_cycles()

template<typename BorderHalfedgeRange , typename PolygonMesh , typename NamedParameters >

std::size_t CGAL::Polygon_mesh_processing::stitch_boundary_cycles	(	const BorderHalfedgeRange &	boundary_cycle_representatives,
		PolygonMesh &	pmesh,
		const NamedParameters &	np
	)

#include <CGAL/Polygon_mesh_processing/stitch_borders.h>

stitches together, whenever possible, two halfedges belonging to the same boundary cycle.

Two border halfedges h1 and h2 can be stitched if the points associated to the source and target vertices of h1 are the same as those of the target and source vertices of h2, respectively.

Template Parameters

BorderHalfedgeRange	a model of `Range` with value type `boost::graph_traits<PolygonMesh>::halfedge_descriptor`
PolygonMesh	a model of `MutableFaceGraph`
NamedParameters	a sequence of Named Parameters

Parameters

boundary_cycle_representatives	a range of border halfedges, each describing a boundary cycle of the mesh `pmesh`
pmesh	the polygon mesh to be modified by stitching
np	an optional sequence of Named Parameters among the ones listed below

Optional Named Parameters

a property map associating points to the vertices of pm
Type: a class model of ReadWritePropertyMap with boost::graph_traits<PolygonMesh>::vertex_descriptor as key type and Point_3 as value type
Default: boost::get(CGAL::vertex_point, pmesh)
Extra: If this parameter is omitted, an internal property map for CGAL::vertex_point_t must be available in PolygonMesh.

an instance of a geometric traits class
Type: The traits class must provide the nested type Point_3, and the nested functors:
- Less_xyz_3 to compare lexicographically two points
- Equal_3 to check whether two points are identical. For each functor Foo, a function Foo foo_object() must be provided.
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.

Returns: the number of pairs of halfedges that were stitched.

See also: stitch_boundary_cycle(); stitch_borders()