gsSurfMesh Class Reference

Detailed Description

A halfedge data structure for polygonal meshes.

Collaboration diagram for gsSurfMesh:

Classes
class	Base_handle
struct	Edge
class	Edge_container
class	Edge_iterator
class	Edge_property
struct	Face
class	Face_around_vertex_circulator
struct	Face_connectivity
class	Face_container
class	Face_iterator
class	Face_property
struct	Halfedge
class	Halfedge_around_face_circulator
class	Halfedge_around_vertex_circulator
struct	Halfedge_connectivity
class	Halfedge_container
class	Halfedge_iterator
class	Halfedge_property
class	Mesh_property
struct	Vertex
class	Vertex_around_face_circulator
class	Vertex_around_vertex_circulator
struct	Vertex_connectivity
class	Vertex_container
class	Vertex_iterator
class	Vertex_property

Public Types
typedef real_t	Scalar
	Scalar type.

Public Member Functions
Construct, destruct, assignment
	gsSurfMesh ()
	default constructor
	gsSurfMesh (const gsMatrix< Scalar > &pts)
	Constructor from a set of points.
	gsSurfMesh (const gsSurfMesh &rhs)
	copy constructor: copies rhs to *this. performs a deep copy of all properties.
gsSurfMesh &	operator= (const gsSurfMesh &rhs)
	assign rhs to *this. performs a deep copy of all properties.
gsSurfMesh &	assign (const gsSurfMesh &rhs)
	assign rhs to *this. does not copy custom properties.
File IO
bool	read (const std::string &filename)
bool	write (const std::string &filename) const
Add new elements by hand
Vertex	add_vertex (const Point &p)
	add a new vertex with position p
Face	add_face (const std::vector< Vertex > &vertices)
Face	add_triangle (Vertex v1, Vertex v2, Vertex v3)
Face	add_quad (Vertex v1, Vertex v2, Vertex v3, Vertex v4)
Memory Management
unsigned int	vertices_size () const
	returns number of (deleted and valid) vertices in the mesh
unsigned int	halfedges_size () const
	returns number of (deleted and valid)halfedge in the mesh
unsigned int	edges_size () const
	returns number of (deleted and valid)edges in the mesh
unsigned int	faces_size () const
	returns number of (deleted and valid)faces in the mesh
unsigned int	n_vertices () const
	returns number of vertices in the mesh
unsigned int	n_halfedges () const
	returns number of halfedge in the mesh
unsigned int	n_edges () const
	returns number of edges in the mesh
unsigned int	n_faces () const
	returns number of faces in the mesh
unsigned int	empty () const
	returns true iff the mesh is empty, i.e., has no vertices
void	clear ()
	clear mesh: remove all vertices, edges, faces
void	free_memory ()
	remove unused memory from vectors
void	reserve (unsigned int nvertices, unsigned int nedges, unsigned int nfaces)
	reserve memory (mainly used in file readers)
void	garbage_collection ()
	remove deleted vertices/edges/faces
bool	is_deleted (Vertex v) const
bool	is_deleted (Halfedge h) const
bool	is_deleted (Edge e) const
bool	is_deleted (Face f) const
bool	is_valid (Vertex v) const
	return whether vertex v is valid, i.e. the index it stores is within the array bounds.
bool	is_valid (Halfedge h) const
	return whether halfedge h is valid, i.e. the index it stores is within the array bounds.
bool	is_valid (Edge e) const
	return whether edge e is valid, i.e. the index it stores is within the array bounds.
bool	is_valid (Face f) const
	return whether face f is valid, i.e. the index it stores is within the array bounds.
Low-level connectivity
Halfedge	halfedge (Vertex v) const
void	set_halfedge (Vertex v, Halfedge h)
	set the outgoing halfedge of vertex v to h
bool	is_boundary (Vertex v) const
	returns whether v is a boundary vertex
bool	is_isolated (Vertex v) const
	returns whether v is isolated, i.e., not incident to any face
bool	is_manifold (Vertex v) const
	returns whether v is a manifold vertex (not incident to several patches)
Vertex	to_vertex (Halfedge h) const
	returns the vertex the halfedge h points to
Vertex	from_vertex (Halfedge h) const
	returns the vertex the halfedge h emanates from
void	set_vertex (Halfedge h, Vertex v)
	sets the vertex the halfedge h points to to v
Face	face (Halfedge h) const
	returns the face incident to halfedge h
void	set_face (Halfedge h, Face f)
	sets the incident face to halfedge h to f
Halfedge	next_halfedge (Halfedge h) const
	returns the next halfedge within the incident face
void	set_next_halfedge (Halfedge h, Halfedge nh)
	sets the next halfedge of h within the face to nh
Halfedge	prev_halfedge (Halfedge h) const
	returns the previous halfedge within the incident face
Halfedge	opposite_halfedge (Halfedge h) const
	returns the opposite halfedge of h
Halfedge	ccw_rotated_halfedge (Halfedge h) const
Halfedge	cw_rotated_halfedge (Halfedge h) const
Edge	edge (Halfedge h) const
	return the edge that contains halfedge h as one of its two halfedges.
bool	is_boundary (Halfedge h) const
	returns whether h is a boundary halfege, i.e., if its face does not exist.
bool	touches_boundary (Halfedge h) const
	returns whether h touches the boundary, i.e., its opposite is a boundary halfedge.
Halfedge	halfedge (Edge e, unsigned int i) const
	returns the i'th halfedge of edge e. i has to be 0 or 1.
Vertex	vertex (Edge e, unsigned int i) const
	returns the i'th vertex of edge e. i has to be 0 or 1.
Face	face (Edge e, unsigned int i) const
	returns the face incident to the i'th halfedge of edge e. i has to be 0 or 1.
bool	is_boundary (Edge e) const
Halfedge	halfedge (Face f) const
	returns a halfedge of face f
void	set_halfedge (Face f, Halfedge h)
	sets the halfedge of face f to h
bool	is_boundary (Face f) const
	returns whether f is a boundary face, i.e., it one of its edges is a boundary edge.
gsProperty handling
template<class T >
Vertex_property< T >	add_vertex_property (const std::string &name, T t=T())
template<class T >
Halfedge_property< T >	add_halfedge_property (const std::string &name, T t=T())
template<class T >
Edge_property< T >	add_edge_property (const std::string &name, T t=T())
template<class T >
Face_property< T >	add_face_property (const std::string &name, const T t=T())
template<class T >
Mesh_property< T >	add_mesh_property (const std::string &name, const T t=T())
template<class T >
Vertex_property< T >	get_vertex_property (const std::string &name) const
template<class T >
Halfedge_property< T >	get_halfedge_property (const std::string &name) const
template<class T >
Edge_property< T >	get_edge_property (const std::string &name) const
template<class T >
Face_property< T >	get_face_property (const std::string &name) const
template<class T >
Mesh_property< T >	get_mesh_property (const std::string &name) const
template<class T >
Vertex_property< T >	vertex_property (const std::string &name, const T t=T())
template<class T >
Halfedge_property< T >	halfedge_property (const std::string &name, T t=T())
template<class T >
Edge_property< T >	edge_property (const std::string &name, const T t=T())
template<class T >
Face_property< T >	face_property (const std::string &name, const T t=T())
template<class T >
Mesh_property< T >	mesh_property (const std::string &name, const T t=T())
template<class T >
void	rename_vertex_property (Vertex_property< T > &p, std::string newname)
	rename the vertex property p
void	swap_vertex_property (const std::string &name1, const std::string &name2)
	swaps (the values of) two vertex properties of the same type
template<class T >
void	remove_vertex_property (Vertex_property< T > &p)
	remove the vertex property p
template<class T >
void	remove_halfedge_property (Halfedge_property< T > &p)
	remove the halfedge property p
template<class T >
void	remove_edge_property (Edge_property< T > &p)
	remove the edge property p
template<class T >
void	remove_face_property (Face_property< T > &p)
	remove the face property p
template<class T >
void	remove_mesh_property (Mesh_property< T > &p)
	remove the mesh property p
const std::type_info &	get_vertex_property_type (const std::string &name)
const std::type_info &	get_halfedge_property_type (const std::string &name)
const std::type_info &	get_edge_property_type (const std::string &name)
const std::type_info &	get_face_property_type (const std::string &name)
const std::type_info &	get_mesh_property_type (const std::string &name)
std::vector< std::string >	vertex_properties () const
	returns the names of all vertex properties
std::vector< std::string >	halfedge_properties () const
	returns the names of all halfedge properties
std::vector< std::string >	edge_properties () const
	returns the names of all edge properties
std::vector< std::string >	face_properties () const
	returns the names of all face properties
std::vector< std::string >	mesh_properties () const
	returns the names of all mesh properties
void	property_stats () const
	prints the names of all properties
Iterators & Circulators
Vertex_iterator	vertices_begin () const
	returns start iterator for vertices
Vertex_iterator	vertices_end () const
	returns end iterator for vertices
Vertex_container	vertices () const
	returns vertex container for C++11 range-based for-loops
Halfedge_iterator	halfedges_begin () const
	returns start iterator for halfedges
Halfedge_iterator	halfedges_end () const
	returns end iterator for halfedges
Halfedge_container	halfedges () const
	returns halfedge container for C++11 range-based for-loops
Edge_iterator	edges_begin () const
	returns start iterator for edges
Edge_iterator	edges_end () const
	returns end iterator for edges
Edge_container	edges () const
	returns edge container for C++11 range-based for-loops
Face_iterator	faces_begin () const
	returns start iterator for faces
Face_iterator	faces_end () const
	returns end iterator for faces
Face_container	faces () const
	returns face container for C++11 range-based for-loops
Vertex_around_vertex_circulator	vertices (Vertex v) const
	returns circulator for vertices around vertex v
Halfedge_around_vertex_circulator	halfedges (Vertex v) const
	returns circulator for outgoing halfedges around vertex v
Face_around_vertex_circulator	faces (Vertex v) const
	returns circulator for faces around vertex v
Vertex_around_face_circulator	vertices (Face f) const
	returns circulator for vertices of face f
Halfedge_around_face_circulator	halfedges (Face f) const
	returns circulator for halfedges of face f
Higher-level Topological Operations
bool	is_triangle_mesh () const
bool	is_quad_mesh () const
void	triangulate ()
void	triangulate (Face f)
bool	is_collapse_ok (Halfedge h)
void	collapse (Halfedge h)
Vertex	split (Face f, const Point &p)
void	split (Face f, Vertex v)
void	quad_split (Face f, Vertex v, Halfedge s)
Halfedge	split (Edge e, const Point &p)
Halfedge	split (Edge e, Vertex v)
Halfedge	insert_vertex (Edge e, const Point &p)
Halfedge	insert_vertex (Edge e, Vertex v)
Halfedge	insert_vertex (Halfedge h, Vertex v)
Halfedge	insert_edge (Halfedge h0, Halfedge h1)
bool	is_flip_ok (Edge e) const
void	flip (Edge e)
unsigned int	valence (Vertex v) const
unsigned int	valence (Face f) const
	returns the valence of face f (its number of vertices)
unsigned int	face_valence_sum () const
	returns the sum of all valences of faces in the mesh
Halfedge	find_halfedge (Vertex start, Vertex end) const
	find the halfedge from start to end
Edge	find_edge (Vertex a, Vertex b) const
	find the edge (a,b)
void	delete_vertex (Vertex v)
	deletes the vertex v from the mesh
void	delete_edge (Edge e)
	deletes the edge e from the mesh
void	delete_face (Face f)
	deletes the face f from the mesh

Private Types
typedef gsEigen::Vector< Scalar, 3 >	Vec3
	3D vector type

Geometry-related Functions
const Point &	position (Vertex v) const
	position of a vertex (read only)
Point &	position (Vertex v)
	position of a vertex
std::vector< Point > &	points ()
	vector of vertex positions
void	update_face_normals ()
	compute face normals by calling compute_face_normal(Face) for each face.
Normal	compute_face_normal (Face f) const
	compute normal vector of face f.
void	update_vertex_normals ()
	compute vertex normals by calling compute_vertex_normal(Vertex) for each vertex.
Normal	compute_vertex_normal (Vertex v) const
	compute normal vector of vertex v.
Scalar	edge_length (Edge e) const
	compute the length of edge e.
void	cc_subdivide ()
	Catmull-Clark subdivision.
Vertex_property< Point >	cc_limit_points (std::string label="v:limit")
	Compute CC vertex limit positions.
Vertex_property< Point >	cc_limit_normals (std::string label="v:normal", bool normalize=true)
	Compute CC vertex limit normals.
Vertex_property< Point >	cc_limit_tangent_vec (std::string label="v:tanvec", bool normalize=true)
	Compute CC vertex limit tangent.
gsMultiPatch< real_t >	cc_acc3 (bool comp_topology=false) const
	Generate ACC3 biqubic Bezier patches.
gsMultiPatch< real_t >	linear_patches () const
	Generate linear tensor-product patches (possibly merging faces)
Vertex	new_vertex ()
	allocate a new vertex, resize vertex properties accordingly.
Halfedge	new_edge (Vertex start, Vertex end)
	allocate a new edge, resize edge and halfedge properties accordingly.
Face	new_face ()
	allocate a new face, resize face properties accordingly.
void	adjust_outgoing_halfedge (Vertex v)
void	remove_edge (Halfedge h)
	Helper for halfedge collapse.
void	remove_loop (Halfedge h)
	Helper for halfedge collapse.
bool	garbage () const
	are there deleted vertices, edges or faces?

Member Function Documentation

add_edge_property()

template<class T >

Edge_property< T > add_edge_property ( const std::string &  name, T  t = T()  )

inline

add a edge property of type T with name name and default value t. fails if a property named name exists already, since the name has to be unique. in this case it returns an invalid property

add_face()

gsSurfMesh::Face add_face

(

const std::vector< Vertex > &

vertices

)

add a new face with vertex list vertices

See also

add_triangle, add_quad

add_face_property()

template<class T >

Face_property< T > add_face_property ( const std::string &  name, const T  t = T()  )

inline

add a face property of type T with name name and default value t. fails if a property named name exists already, since the name has to be unique. in this case it returns an invalid property

add_halfedge_property()

template<class T >

Halfedge_property< T > add_halfedge_property ( const std::string &  name, T  t = T()  )

inline

add a halfedge property of type T with name name and default value t. fails if a property named name exists already, since the name has to be unique. in this case it returns an invalid property

add_mesh_property()

template<class T >

Mesh_property< T > add_mesh_property ( const std::string &  name, const T  t = T()  )

inline

add a mesh property of type T with name name and default value t. fails if a property named name exists already, since the name has to be unique. in this case it returns an invalid property

add_quad()

gsSurfMesh::Face add_quad	(	Vertex	v1,
		Vertex	v2,
		Vertex	v3,
		Vertex	v4
	)

add a new quad connecting vertices v1, v2, v3, v4

See also

add_triangle, add_face

add_triangle()

gsSurfMesh::Face add_triangle	(	Vertex	v1,
		Vertex	v2,
		Vertex	v3
	)

add a new triangle connecting vertices v1, v2, v3

See also

add_face, add_quad

add_vertex_property()

template<class T >

Vertex_property< T > add_vertex_property ( const std::string &  name, T  t = T()  )

inline

add a vertex property of type T with name name and default value t. fails if a property named name exists already, since the name has to be unique. in this case it returns an invalid property

adjust_outgoing_halfedge()

void adjust_outgoing_halfedge ( Vertex  v )

private

make sure that the outgoing halfedge of vertex v is a boundary halfedge if v is a boundary vertex.

ccw_rotated_halfedge()

Halfedge ccw_rotated_halfedge ( Halfedge  h ) const

inline

returns the halfedge that is rotated counter-clockwise around the start vertex of h. it is the opposite halfedge of the previous halfedge of h.

collapse()

void collapse

(

Halfedge

h

)

Collapse the halfedge h by moving its start vertex into its target vertex. For non-boundary halfedges this function removes one vertex, three edges, and two faces. For boundary halfedges it removes one vertex, two edges and one face.

Attention

This function is only valid for triangle meshes.

Halfedge collapses might lead to invalid faces. Call is_collapse_ok(Halfedge) to be sure the collapse is legal.

The removed items are only marked as deleted. You have to call garbage_collection() to finally remove them.

cw_rotated_halfedge()

Halfedge cw_rotated_halfedge ( Halfedge  h ) const

inline

returns the halfedge that is rotated clockwise around the start vertex of h. it is the next halfedge of the opposite halfedge of h.

edge_property()

template<class T >

Edge_property< T > edge_property ( const std::string &  name, const T  t = T()  )

inline

if an edge property of type T with name name exists, it is returned. otherwise this property is added (with default value t)

face_property()

template<class T >

Face_property< T > face_property ( const std::string &  name, const T  t = T()  )

inline

if a face property of type T with name name exists, it is returned. otherwise this property is added (with default value t)

flip()

void flip

(

Edge

e

)

Flip edge e: Remove edge e and add an edge between the two vertices opposite to edge e of the two incident triangles.

Attention

This function is only valid for triangle meshes.

See also

is_flip_ok(Edge)

get_edge_property()

template<class T >

Edge_property< T > get_edge_property ( const std::string &  name ) const

inline

get the edge property named name of type T. returns an invalid Vertex_property if the property does not exist or if the type does not match.

get_edge_property_type()

const std::type_info & get_edge_property_type ( const std::string &  name )

inline

get the type_info T of edge property named . returns an typeid(void) if the property does not exist or if the type does not match.

get_face_property()

template<class T >

Face_property< T > get_face_property ( const std::string &  name ) const

inline

get the face property named name of type T. returns an invalid Vertex_property if the property does not exist or if the type does not match.

get_face_property_type()

const std::type_info & get_face_property_type ( const std::string &  name )

inline

get the type_info T of face property named . returns an typeid(void) if the property does not exist or if the type does not match.

get_halfedge_property()

template<class T >

Halfedge_property< T > get_halfedge_property ( const std::string &  name ) const

inline

get the halfedge property named name of type T. returns an invalid Vertex_property if the property does not exist or if the type does not match.

get_halfedge_property_type()

const std::type_info & get_halfedge_property_type ( const std::string &  name )

inline

get the type_info T of halfedge property named . returns an typeid(void) if the property does not exist or if the type does not match.

get_mesh_property()

template<class T >

Mesh_property< T > get_mesh_property ( const std::string &  name ) const

inline

get the mesh property named name of type T. returns an invalid Mesh_property if the property does not exist or if the type does not match.

get_mesh_property_type()

const std::type_info & get_mesh_property_type ( const std::string &  name )

inline

get the type_info T of face property named . returns an typeid(void) if the property does not exist or if the type does not match.

get_vertex_property()

template<class T >

Vertex_property< T > get_vertex_property ( const std::string &  name ) const

inline

get the vertex property named name of type T. returns an invalid Vertex_property if the property does not exist or if the type does not match.

get_vertex_property_type()

const std::type_info & get_vertex_property_type ( const std::string &  name )

inline

get the type_info T of vertex property named . returns an typeid(void) if the property does not exist or if the type does not match.

halfedge()

Halfedge halfedge ( Vertex  v ) const

inline

returns an outgoing halfedge of vertex v. if v is a boundary vertex this will be a boundary halfedge.

halfedge_property()

template<class T >

Halfedge_property< T > halfedge_property ( const std::string &  name, T  t = T()  )

inline

if a halfedge property of type T with name name exists, it is returned. otherwise this property is added (with default value t)

insert_edge()

gsSurfMesh::Halfedge insert_edge	(	Halfedge	h0,
		Halfedge	h1
	)

insert edge between the to-vertices v0 of h0 and v1 of h1. returns the new halfedge from v0 to v1.

Attention

h0 and h1 have to belong to the same face

insert_vertex() [1/3]

Halfedge insert_vertex ( Edge  e, const Point &  p  )

inline

Subdivide the edge e = (v0,v1) by splitting it into the two edge (v0,p) and (p,v1). Note that this function does not introduce any other edge or faces. It simply splits the edge. Returns halfedge that points to p.

See also

insert_vertex(Edge, Vertex)

insert_vertex(Halfedge, Vertex)

insert_vertex() [2/3]

Halfedge insert_vertex ( Edge  e, Vertex  v  )

inline

Subdivide the edge e = (v0,v1) by splitting it into the two edge (v0,v) and (v,v1). Note that this function does not introduce any other edge or faces. It simply splits the edge. Returns halfedge that points to p.

See also

insert_vertex(Edge, Point)

insert_vertex(Halfedge, Vertex)

insert_vertex() [3/3]

gsSurfMesh::Halfedge insert_vertex	(	Halfedge	h,
		Vertex	v
	)

Subdivide the edge e = (v0,v1) by splitting it into the two edge (v0,v) and (v,v1). Note that this function does not introduce any other edge or faces. It simply splits the edge. Returns halfedge that points to p.

See also

insert_vertex(Edge, Point)

insert_vertex(Edge, Vertex)

is_boundary()

bool is_boundary ( Edge  e ) const

inline

returns whether e is a boundary edge, i.e., if one of its halfedges is a boundary halfedge.

is_collapse_ok()

bool is_collapse_ok

(

Halfedge

h

)

returns whether collapsing the halfedge h is topologically legal.

Attention

This function is only valid for triangle meshes.

is_deleted() [1/4]

bool is_deleted ( Edge  e ) const

inline

returns whether edge e is deleted

See also

garbage_collection()

is_deleted() [2/4]

bool is_deleted ( Face  f ) const

inline

returns whether face f is deleted

See also

garbage_collection()

is_deleted() [3/4]

bool is_deleted ( Halfedge  h ) const

inline

returns whether halfedge h is deleted

See also

garbage_collection()

is_deleted() [4/4]

bool is_deleted ( Vertex  v ) const

inline

returns whether vertex v is deleted

See also

garbage_collection()

is_flip_ok()

bool is_flip_ok

(

Edge

e

)

const

Check whether flipping edge e is topologically

Attention

This function is only valid for triangle meshes.

See also

flip(Edge)

is_quad_mesh()

bool is_quad_mesh

(

)

const

returns whether the mesh a quad mesh. this function simply tests each face, and therefore is not very efficient.

is_triangle_mesh()

bool is_triangle_mesh

(

)

const

returns whether the mesh a triangle mesh. this function simply tests each face, and therefore is not very efficient.

See also

trianglate(), triangulate(Face)

mesh_property()

template<class T >

Mesh_property< T > mesh_property ( const std::string &  name, const T  t = T()  )

inline

if a mesh property of type T with name name exists, it is returned. otherwise this property is added (with default value t)

quad_split()

void quad_split	(	Face	f,
		Vertex	v,
		Halfedge	s
	)

Quad-split face connecting vertex v, starting from corner s of the face f is assumed to have 8 vertices, and contains halfedge s

read()

bool read

(

const std::string &

filename

)

read mesh from file filename. file extension determines file type.

See also

write(const std::string& filename)

split() [1/4]

Halfedge split ( Edge  e, const Point &  p  )

inline

Split the edge e by first adding point p to the mesh and then connecting it to the two vertices of the adjacent triangles that are opposite to edge e. Returns the halfedge pointing to p that is created by splitting the existing edge e.

Attention

This function is only valid for triangle meshes.

See also

split(Edge, Vertex)

split() [2/4]

gsSurfMesh::Halfedge split	(	Edge	e,
		Vertex	v
	)

Split the edge e by connecting vertex v it to the two vertices of the adjacent triangles that are opposite to edge e. Returns the halfedge pointing to p that is created by splitting the existing edge e.

Attention

This function is only valid for triangle meshes.

See also

split(Edge, Point)

split() [3/4]

Vertex split ( Face  f, const Point &  p  )

inline

Split the face f by first adding point p to the mesh and then inserting edges between p and the vertices of f. For a triangle this is a standard one-to-three split.

See also

split(Face, Vertex)

split() [4/4]

void split	(	Face	f,
		Vertex	v
	)

Split the face f by inserting edges between p and the vertices of f. For a triangle this is a standard one-to-three split.

See also

split(Face, const Point&)

triangulate() [1/2]

void triangulate

(

)

triangulate the entire mesh, by calling triangulate(Face) for each face.

See also

trianglate(Face)

triangulate() [2/2]

void triangulate

(

Face

f

)

triangulate the face f

See also

trianglate()

valence()

unsigned int valence

(

Vertex

v

)

const

returns the valence (number of incident edges or neighboring vertices) of vertex v.

vertex_property()

template<class T >

Vertex_property< T > vertex_property ( const std::string &  name, const T  t = T()  )

inline

if a vertex property of type T with name name exists, it is returned. otherwise this property is added (with default value t)

write()

bool write

(

const std::string &

filename

)

const

write mesh to file filename. file extensions determines file type.

See also

read(const std::string& filename)