The PolychordCollapse class provides methods to semplify a quad mesh, by collapsing the polychords. More...

#include <polygon_polychord_collapse.h>

Classes
class	LinkConditions
	The LinkCondition class provides a tool to check if a polychord satisfies the link conditions. More...
struct	PC_Chord
	The PC_Chord struct identifies a coord of a polychord passing through a quad. More...
class	PC_Chords
	The PC_Chords class gives efficient access to each coord (relative to a face). More...
Public Types
typedef PolyMeshType::CoordType	CoordType
typedef PolyMeshType::FaceIterator	FaceIterator
typedef PolyMeshType::FacePointer	FacePointer
typedef PolyMeshType::FaceType	FaceType
enum	PC_ResultCode { PC_SUCCESS = 0x000, PC_NOTMANIF = 0x001, PC_NOTQUAD = 0x002, PC_NOLINKCOND = 0x004, PC_SINGSIDEA = 0x008, PC_SINGSIDEB = 0x010, PC_SINGBOTH = 0x020, PC_SELFINTERSECT = 0x040, PC_NOMOREMANIF = 0x080, PC_VOID = 0x100, PC_OTHER = 0x100 }
	The PC_ResultCode enum codifies the result type of a polychord collapse operation. More...
typedef PolyMeshType::VertexIterator	VertexIterator
typedef PolyMeshType::VertexPointer	VertexPointer
typedef PolyMeshType::VertexType	VertexType
Static Public Member Functions
static PC_ResultCode	CheckPolychordFindStartPosition (const vcg::face::Pos< FaceType > &pos, vcg::face::Pos< FaceType > &startPos, const bool checkSing=true)
	CheckPolychordFindStartPosition checks if it's a collapsable polychord.
static void	CollapseAllPolychords (PolyMeshType &mesh, const bool checkSing=true)
	CollapseAllPolychords finds and collapses all the polychords.
static PC_ResultCode	CollapsePolychord (PolyMeshType &mesh, const vcg::face::Pos< FaceType > &pos, const unsigned long mark, PC_Chords &chords, LinkConditions &linkConditions, const bool checkSing=true)
	CollapsePolychord performs all checks and then collapses the polychord.
static void	FindPolychords (PolyMeshType &mesh, std::deque< vcg::face::Pos< FaceType > > &polychords, const bool loopsOnly=false)
	FindPolychords lists all the valid polychords starting position of a mesh.
static bool	IsPolychordSelfIntersecting (const PolyMeshType &mesh, const vcg::face::Pos< FaceType > &startPos, const PC_Chords &chords, const unsigned long mark)
	IsPolychordSelfIntersecting checks if the input polychord intersects itself.
static bool	IsVertexAdjacentToAnyNonManifoldEdge (const vcg::face::Pos< FaceType > &pos)
	IsVertexAdjacentToAnyNonManifoldEdge checks if a vertex is adjacent to any non-manifold edge.
static void	MarkPolychords (const PolyMeshType &mesh, const vcg::face::Pos< FaceType > &startPos, PC_Chords &chords, const unsigned long mark)
	CheckConsistent checks for consistency. ONLY FOR DEBUG.
static void	SplitPolychord (PolyMeshType &mesh, vcg::face::Pos< FaceType > &pos, const size_t n, std::vector< FacePointer * > &facesToUpdate, std::vector< VertexPointer * > &verticesToUpdate)
	SplitPolychord splits a polychord into n polychords by inserting all the needed faces.
static void	SplitPolychord (PolyMeshType &mesh, vcg::face::Pos< FaceType > &pos, const size_t n)
	SplitPolychord splits a polychord into n polychords by inserting all the needed faces.
static void	VisitPolychord (const PolyMeshType &mesh, const vcg::face::Pos< FaceType > &startPos, PC_Chords &chords, const unsigned long mark, const PC_ResultCode q)
	VisitPolychord updates the information of a polychord.
static bool	WillPolychordBeManifold (const PolyMeshType &mesh, const vcg::face::Pos< FaceType > &startPos, PC_Chords &chords, const unsigned long mark)
	WillPolychordBeManifold checks whether a polychord starting at startPos would cause non-manifoldness if it was collapsed.

Detailed Description

template<typename PolyMeshType>
class vcg::tri::PolychordCollapse< PolyMeshType >

The PolychordCollapse class provides methods to semplify a quad mesh, by collapsing the polychords.

This class is an implementation of a method very similar to that for mesh semplification proposed by Daniels et al. in "Quadrilateral mesh simplification", see http://www.cs.utah.edu/~jdaniels/research/asia2008_qms.htm The main function is PolychordCollapse::CollapsePolychord() which deletes all the quadrilateral faces in a polychord. The polychords that can be collapsed in this case are those forming a closed loop (a ring) or that start and end to mesh borders. A way to preserve the structure of the singularities is also provided. The convenient method PolychordCollapse::CollapseAllPolychords() finds and collapses all the polychords on a mesh. The input mesh should be polygonal, i.e. it should have the vcg::face::PolyInfo component. Even though a generic triangle mesh can be given, actually the class does not perform any collapsing operation since it sees only triangles, in fact it does not consider faux edges.

Definition at line 57 of file polygon_polychord_collapse.h.

Member Typedef Documentation

template<typename PolyMeshType >

typedef PolyMeshType::CoordType vcg::tri::PolychordCollapse< PolyMeshType >::CoordType

Definition at line 59 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

typedef PolyMeshType::FaceIterator vcg::tri::PolychordCollapse< PolyMeshType >::FaceIterator

Definition at line 65 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

typedef PolyMeshType::FacePointer vcg::tri::PolychordCollapse< PolyMeshType >::FacePointer

Definition at line 64 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

typedef PolyMeshType::FaceType vcg::tri::PolychordCollapse< PolyMeshType >::FaceType

Definition at line 63 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

typedef PolyMeshType::VertexIterator vcg::tri::PolychordCollapse< PolyMeshType >::VertexIterator

Definition at line 62 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

typedef PolyMeshType::VertexPointer vcg::tri::PolychordCollapse< PolyMeshType >::VertexPointer

Definition at line 61 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

typedef PolyMeshType::VertexType vcg::tri::PolychordCollapse< PolyMeshType >::VertexType

Definition at line 60 of file polygon_polychord_collapse.h.

Member Enumeration Documentation

template<typename PolyMeshType >

enum vcg::tri::PolychordCollapse::PC_ResultCode

The PC_ResultCode enum codifies the result type of a polychord collapse operation.

Enumerator:

PC_SUCCESS
PC_NOTMANIF
PC_NOTQUAD
PC_NOLINKCOND
PC_SINGSIDEA
PC_SINGSIDEB
PC_SINGBOTH
PC_SELFINTERSECT
PC_NOMOREMANIF
PC_VOID
PC_OTHER

Definition at line 70 of file polygon_polychord_collapse.h.

Member Function Documentation

template<typename PolyMeshType >

static PC_ResultCode vcg::tri::PolychordCollapse< PolyMeshType >::CheckPolychordFindStartPosition	(	const vcg::face::Pos< FaceType > &	pos,
		vcg::face::Pos< FaceType > &	startPos,
		const bool	checkSing = `true`
	)		`[inline, static]`

CheckPolychordFindStartPosition checks if it's a collapsable polychord.

Parameters:

pos	Input The starting position.
startPos	Output the new starting position (in case of borders).
checkSing	true if singularities on both sides are not allowed.

Returns:: PC_SUCCESS if it's a collapsable polychord, otherwise the code for the cause (startPos is on it).

Definition at line 1581 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

static void vcg::tri::PolychordCollapse< PolyMeshType >::CollapseAllPolychords	(	PolyMeshType &	mesh,
		const bool	checkSing = `true`
	)		`[inline, static]`

CollapseAllPolychords finds and collapses all the polychords.

Parameters:

mesh	The input polygonal mesh (it SHOULD have the vcg::face::PolyInfo component).
checkSing	true if singularities on both sides of a polychord are not allowed.

Definition at line 860 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

static PC_ResultCode vcg::tri::PolychordCollapse< PolyMeshType >::CollapsePolychord	(	PolyMeshType &	mesh,
		const vcg::face::Pos< FaceType > &	pos,
		const unsigned long	mark,
		PC_Chords &	chords,
		LinkConditions &	linkConditions,
		const bool	checkSing = `true`
	)		`[inline, static]`

CollapsePolychord performs all checks and then collapses the polychord.

Warning:: This function deletes faces and vertices by calling vcg::tri::Allocator<PolyMeshType>::DeleteFace() and vcg::tri::Allocator<PolyMeshType>::DeleteVertex(). The object PC_Chords chords is used to track the polychords, and it has got a size proportional to that of the mesh face container. If you actually delete faces and vertices by calling vcg::tri::Allocator<PolyMeshType>::CompactFaceVector() and vcg::tri::Allocator<PolyMeshType>::CompactVertexVector() after this function, object PC_Chords chords then is not valid any more, so you MUST rearrange it by calling PC_Chords.Reset(). For the same reason, you MUST rearrange LinkConditions linkConditions by calling LinkConditions.Resize(). However, for efficiency, you SHOULD compact vertex and face containers at the end of all your polychord collapsing operations, without having to rearrange chords and linkConditions. The function CollapseAllPolychords() does this for you.

Note:: Vertex flags, face flags, FF adjacency and FV adjacency are required. Not anything else. Such components are automatically updated here. If the mesh has other components that may be affected by this editing, you should update them later by yourself.

Parameters:

mesh	The polygonal mesh used for getting the face index and deleting the faces (it SHOULD have the vcg::face::PolyInfo component).
pos	Position of the polychord.
mark	Mark for the current polychord.
chords	Vector of chords.
linkConditions	Link conditions checker.
checkSing	true if singularities on both sides are not allowed.

Returns:: A PC_ResultCode resulting from checks or PC_SUCCESS if the collapse has been performed.

Definition at line 638 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

static void vcg::tri::PolychordCollapse< PolyMeshType >::FindPolychords	(	PolyMeshType &	mesh,
		std::deque< vcg::face::Pos< FaceType > > &	polychords,
		const bool	loopsOnly = `false`
	)		`[inline, static]`

FindPolychords lists all the valid polychords starting position of a mesh.

Parameters:

mesh	The input mesh.
polychords	The container of results.
loopsOnly	true if closed polychords only must be listed, false for all polychords.

Definition at line 903 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

static bool vcg::tri::PolychordCollapse< PolyMeshType >::IsPolychordSelfIntersecting	(	const PolyMeshType &	mesh,
		const vcg::face::Pos< FaceType > &	startPos,
		const PC_Chords &	chords,
		const unsigned long	mark
	)		`[inline, static]`

IsPolychordSelfIntersecting checks if the input polychord intersects itself.

Warning:: Don't call this function without being sure that it's a polychord (i.e. call CheckPolychordFindStartPoint() before calling IsPolychordSelfIntersecting().

Parameters:

mesh	The mesh used for getting the face index.
startPos	The starting position.
chords	The vector of chords.
mark	The current mark, used to identify quads already visited.

Returns:: true if it intersects itself, false otherwise.

Definition at line 1777 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

static bool vcg::tri::PolychordCollapse< PolyMeshType >::IsVertexAdjacentToAnyNonManifoldEdge ( const vcg::face::Pos< FaceType > & pos ) [inline, static]

IsVertexAdjacentToAnyNonManifoldEdge checks if a vertex is adjacent to any non-manifold edge.

Parameters:

pos	The starting position.

Returns:: true if adjacent to non-manifold edges, false otherwise.

Definition at line 1754 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

static void vcg::tri::PolychordCollapse< PolyMeshType >::MarkPolychords	(	const PolyMeshType &	mesh,
		const vcg::face::Pos< FaceType > &	startPos,
		PC_Chords &	chords,
		const unsigned long	mark
	)		`[inline, static]`

CheckConsistent checks for consistency. ONLY FOR DEBUG.

Parameters:

mesh

Returns:: MarkPolychords marks the chords of the polychord starting at startPos.

Parameters:

mesh	The input mesh.
startPos	The starting position.
chords	The vector of chords.
mark	The current mark, used to identify quads already visited.

Definition at line 590 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

static void vcg::tri::PolychordCollapse< PolyMeshType >::SplitPolychord	(	PolyMeshType &	mesh,
		vcg::face::Pos< FaceType > &	pos,
		const size_t	n,
		std::vector< FacePointer * > &	facesToUpdate,
		std::vector< VertexPointer * > &	verticesToUpdate
	)		`[inline, static]`

SplitPolychord splits a polychord into n polychords by inserting all the needed faces.

Parameters:

mesh	is the input polygonal mesh.
pos	is a position into the polychord (not necessarily the starting border). It will be updated with changes.
n	is the number of polychords to replace the input one.
facesToUpdate	is a vector of face pointers to be updated after re-allocation.
verticesToUpdate	is a vector of vertex pointers to be updated after re-allocation.

Definition at line 979 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

static void vcg::tri::PolychordCollapse< PolyMeshType >::SplitPolychord	(	PolyMeshType &	mesh,
		vcg::face::Pos< FaceType > &	pos,
		const size_t	n
	)		`[inline, static]`

SplitPolychord splits a polychord into n polychords by inserting all the needed faces.

Parameters:

mesh	is the input polygonal mesh.
pos	is a position into the polychord (not necessarily the starting border). It will be updated with changes.
n	is the number of polychords to replace the input one.

Definition at line 1568 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

static void vcg::tri::PolychordCollapse< PolyMeshType >::VisitPolychord	(	const PolyMeshType &	mesh,
		const vcg::face::Pos< FaceType > &	startPos,
		PC_Chords &	chords,
		const unsigned long	mark,
		const PC_ResultCode	q
	)		`[inline, static]`

VisitPolychord updates the information of a polychord.

Parameters:

mesh	The mesh used for getting the face index.
startPos	The starting position.
chords	The vector of chords.
mark	The mark.
q	The visiting type.

Definition at line 1701 of file polygon_polychord_collapse.h.

template<typename PolyMeshType >

static bool vcg::tri::PolychordCollapse< PolyMeshType >::WillPolychordBeManifold	(	const PolyMeshType &	mesh,
		const vcg::face::Pos< FaceType > &	startPos,
		PC_Chords &	chords,
		const unsigned long	mark
	)		`[inline, static]`

WillPolychordBeManifold checks whether a polychord starting at startPos would cause non-manifoldness if it was collapsed.

Note:: VisitPolychord() should be called before this method.

Parameters:

mesh	The input mesh.
startPos	The starting Pos.
chords	The vector of chords.
mark	The current mark, used to identify quads already visited.

Returns:: true if manifoldness remains, false otherwise.

Definition at line 1841 of file polygon_polychord_collapse.h.

The documentation for this class was generated from the following file:

polygon_polychord_collapse.h

Classes

Public Types

Static Public Member Functions

Detailed Description

template<typename PolyMeshType> class vcg::tri::PolychordCollapse< PolyMeshType >

Member Typedef Documentation

Member Enumeration Documentation

Member Function Documentation

template<typename PolyMeshType>
class vcg::tri::PolychordCollapse< PolyMeshType >