helper class to perform cell tessellation More...

#include <vtkGenericCellTessellator.h>

Inheritance diagram for vtkGenericCellTessellator:

Collaboration diagram for vtkGenericCellTessellator:

Public Types
typedef vtkObject	Superclass

Public Types inherited from vtkObject
typedef vtkObjectBase	Superclass

Public Member Functions
virtual int	IsA (const char *type)

vtkGenericCellTessellator *	NewInstance () const

void	PrintSelf (ostream &os, vtkIndent indent)

virtual void	Initialize (vtkGenericDataSet *ds)=0

void	InitErrorMetrics (vtkGenericDataSet *ds)

void	GetMaxErrors (double *errors)


virtual void	TessellateFace (vtkGenericAdaptorCell cell, vtkGenericAttributeCollection att, vtkIdType index, vtkDoubleArray points, vtkCellArray cellArray, vtkPointData *internalPd)=0


virtual void	Tessellate (vtkGenericAdaptorCell cell, vtkGenericAttributeCollection att, vtkDoubleArray points, vtkCellArray cellArray, vtkPointData *internalPd)=0


virtual void	Triangulate (vtkGenericAdaptorCell cell, vtkGenericAttributeCollection att, vtkDoubleArray points, vtkCellArray cellArray, vtkPointData *internalPd)=0


virtual void	SetErrorMetrics (vtkCollection *someErrorMetrics)

virtual vtkCollection *	GetErrorMetrics ()


virtual int	GetMeasurement ()

virtual void	SetMeasurement (int)

Public Member Functions inherited from vtkObject
vtkObject *	NewInstance () const

virtual void	DebugOn ()

virtual void	DebugOff ()

bool	GetDebug ()

void	SetDebug (bool debugFlag)

virtual void	Modified ()

virtual unsigned long	GetMTime ()

unsigned long	AddObserver (unsigned long event, vtkCommand *, float priority=0.0f)

unsigned long	AddObserver (const char event, vtkCommand , float priority=0.0f)

vtkCommand *	GetCommand (unsigned long tag)

void	RemoveObserver (vtkCommand *)

void	RemoveObservers (unsigned long event, vtkCommand *)

void	RemoveObservers (const char event, vtkCommand )

int	HasObserver (unsigned long event, vtkCommand *)

int	HasObserver (const char event, vtkCommand )

void	RemoveObserver (unsigned long tag)

void	RemoveObservers (unsigned long event)

void	RemoveObservers (const char *event)

void	RemoveAllObservers ()

int	HasObserver (unsigned long event)

int	HasObserver (const char *event)

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, void(T::*callback)(), float priority=0.0f)

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, void(T::callback)(vtkObject , unsigned long, void *), float priority=0.0f)

template<class U , class T >
unsigned long	AddObserver (unsigned long event, U observer, bool(T::callback)(vtkObject , unsigned long, void *), float priority=0.0f)

int	InvokeEvent (unsigned long event, void *callData)

int	InvokeEvent (const char event, void callData)

int	InvokeEvent (unsigned long event)

int	InvokeEvent (const char *event)

Public Member Functions inherited from vtkObjectBase
const char *	GetClassName () const

virtual void	Delete ()

virtual void	FastDelete ()

void	Print (ostream &os)

virtual void	Register (vtkObjectBase *o)

virtual void	UnRegister (vtkObjectBase *o)

void	SetReferenceCount (int)

void	PrintRevisions (ostream &)

virtual void	PrintHeader (ostream &os, vtkIndent indent)

virtual void	PrintTrailer (ostream &os, vtkIndent indent)

int	GetReferenceCount ()

Static Public Member Functions
static int	IsTypeOf (const char *type)

static vtkGenericCellTessellator *	SafeDownCast (vtkObjectBase *o)

Static Public Member Functions inherited from vtkObject
static int	IsTypeOf (const char *type)

static vtkObject *	SafeDownCast (vtkObjectBase *o)

static vtkObject *	New ()

static void	BreakOnError ()

static void	SetGlobalWarningDisplay (int val)

static void	GlobalWarningDisplayOn ()

static void	GlobalWarningDisplayOff ()

static int	GetGlobalWarningDisplay ()

Static Public Member Functions inherited from vtkObjectBase
static int	IsTypeOf (const char *name)

static vtkObjectBase *	New ()

Protected Member Functions
virtual vtkObjectBase *	NewInstanceInternal () const

	vtkGenericCellTessellator ()

	~vtkGenericCellTessellator ()

void	ResetMaxErrors ()

void	SetGenericCell (vtkGenericAdaptorCell *cell)


int	RequiresEdgeSubdivision (double left, double mid, double *right, double alpha)


virtual void	UpdateMaxError (double leftPoint, double midPoint, double *rightPoint, double alpha)

Protected Member Functions inherited from vtkObject
	vtkObject ()

virtual	~vtkObject ()

virtual void	RegisterInternal (vtkObjectBase *, int check)

virtual void	UnRegisterInternal (vtkObjectBase *, int check)

void	InternalGrabFocus (vtkCommand mouseEvents, vtkCommand keypressEvents=NULL)

void	InternalReleaseFocus ()

Protected Member Functions inherited from vtkObjectBase
	vtkObjectBase ()

virtual	~vtkObjectBase ()

virtual void	CollectRevisions (ostream &)

virtual void	ReportReferences (vtkGarbageCollector *)

	vtkObjectBase (const vtkObjectBase &)

void	operator= (const vtkObjectBase &)

Protected Attributes
vtkCollection *	ErrorMetrics

vtkGenericDataSet *	DataSet

int	Measurement

double *	MaxErrors

int	MaxErrorsCapacity

Protected Attributes inherited from vtkObject
bool	Debug

vtkTimeStamp	MTime

vtkSubjectHelper *	SubjectHelper

Protected Attributes inherited from vtkObjectBase
vtkAtomicInt32	ReferenceCount

vtkWeakPointerBase **	WeakPointers

Detailed Description

helper class to perform cell tessellation

vtkGenericCellTessellator is a helper class to perform adaptive tessellation of particular cell topologies. The major purpose for this class is to transform higher-order cell types (e.g., higher-order finite elements) into linear cells that can then be easily visualized by VTK. This class works in conjunction with the vtkGenericDataSet and vtkGenericAdaptorCell classes.

This algorithm is based on edge subdivision. An error metric along each edge is evaluated, and if the error is greater than some tolerance, the edge is subdivided (as well as all connected 2D and 3D cells). The process repeats until the error metric is satisfied.

A significant issue addressed by this algorithm is to insure face compatibility across neigboring cells. That is, diagonals due to face triangulation must match to insure that the mesh is compatible. The algorithm employs a precomputed table to accelerate the tessellation process. The table was generated with the help of vtkOrderedTriangulator; the basic idea is that the choice of diagonal is made by considering the relative value of the point ids.

Definition at line 57 of file vtkGenericCellTessellator.h.

Member Typedef Documentation

typedef vtkObject vtkGenericCellTessellator::Superclass

Definition at line 60 of file vtkGenericCellTessellator.h.

Constructor & Destructor Documentation

vtkGenericCellTessellator::vtkGenericCellTessellator ( )

protected

vtkGenericCellTessellator::~vtkGenericCellTessellator ( )

protected

Member Function Documentation

static int vtkGenericCellTessellator::IsTypeOf ( const char * type )

static

virtual int vtkGenericCellTessellator::IsA ( const char * name )

virtual

Return 1 if this class is the same type of (or a subclass of) the named class. Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h.

Reimplemented from vtkObject.

Reimplemented in vtkSimpleCellTessellator.

static vtkGenericCellTessellator* vtkGenericCellTessellator::SafeDownCast ( vtkObjectBase * o )

static

virtual vtkObjectBase* vtkGenericCellTessellator::NewInstanceInternal ( ) const

protectedvirtual

Reimplemented from vtkObject.

Reimplemented in vtkSimpleCellTessellator.

vtkGenericCellTessellator* vtkGenericCellTessellator::NewInstance ( ) const

void vtkGenericCellTessellator::PrintSelf	(	ostream &	os,
		vtkIndent	indent
	)

virtual

Methods invoked by print to print information about the object including superclasses. Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.

Reimplemented from vtkObject.

Reimplemented in vtkSimpleCellTessellator.

virtual void vtkGenericCellTessellator::TessellateFace	(	vtkGenericAdaptorCell *	cell,
		vtkGenericAttributeCollection *	att,
		vtkIdType	index,
		vtkDoubleArray *	points,
		vtkCellArray *	cellArray,
		vtkPointData *	internalPd
	)

pure virtual

Tessellate a face of a 3D `cell'. The face is specified by the index value. The result is a set of smaller linear triangles in `cellArray' with `points' and point data `internalPd'.

Precondition: cell_exists: cell!=0; valid_dimension: cell->GetDimension()==3; valid_index_range: (index>=0) && (index<cell->GetNumberOfBoundaries(2)); att_exists: att!=0; points_exists: points!=0; cellArray_exists: cellArray!=0; internalPd_exists: internalPd!=0

Implemented in vtkSimpleCellTessellator.

virtual void vtkGenericCellTessellator::Tessellate	(	vtkGenericAdaptorCell *	cell,
		vtkGenericAttributeCollection *	att,
		vtkDoubleArray *	points,
		vtkCellArray *	cellArray,
		vtkPointData *	internalPd
	)

pure virtual

Tessellate a 3D `cell'. The result is a set of smaller linear tetrahedra in `cellArray' with `points' and point data `internalPd'.

Precondition: cell_exists: cell!=0; valid_dimension: cell->GetDimension()==3; att_exists: att!=0; points_exists: points!=0; cellArray_exists: cellArray!=0; internalPd_exists: internalPd!=0

Implemented in vtkSimpleCellTessellator.

virtual void vtkGenericCellTessellator::Triangulate	(	vtkGenericAdaptorCell *	cell,
		vtkGenericAttributeCollection *	att,
		vtkDoubleArray *	points,
		vtkCellArray *	cellArray,
		vtkPointData *	internalPd
	)

pure virtual

Triangulate a 2D `cell'. The result is a set of smaller linear triangles in `cellArray' with `points' and point data `internalPd'.

Precondition: cell_exists: cell!=0; valid_dimension: cell->GetDimension()==2; att_exists: att!=0; points_exists: points!=0; cellArray_exists: cellArray!=0; internalPd_exists: internalPd!=0

Implemented in vtkSimpleCellTessellator.

virtual void vtkGenericCellTessellator::SetErrorMetrics ( vtkCollection * someErrorMetrics )

virtual

Specify the list of error metrics used to decide if an edge has to be splitted or not. It is a collection of vtkGenericSubdivisionErrorMetric-s.

virtual vtkCollection* vtkGenericCellTessellator::GetErrorMetrics ( )

virtual

Specify the list of error metrics used to decide if an edge has to be splitted or not. It is a collection of vtkGenericSubdivisionErrorMetric-s.

virtual void vtkGenericCellTessellator::Initialize ( vtkGenericDataSet * ds )

pure virtual

Initialize the tessellator with a data set `ds'.

Implemented in vtkSimpleCellTessellator.

void vtkGenericCellTessellator::InitErrorMetrics ( vtkGenericDataSet * ds )

Init the error metric with the dataset. Should be called in each filter before any tessellation of any cell.

virtual int vtkGenericCellTessellator::GetMeasurement ( )

virtual

If true, measure the quality of the fixed subdivision.

virtual void vtkGenericCellTessellator::SetMeasurement ( int )

virtual

If true, measure the quality of the fixed subdivision.

void vtkGenericCellTessellator::GetMaxErrors ( double * errors )

Get the maximum error measured after the fixed subdivision.

Precondition: errors_exists: errors!=0; valid_size: sizeof(errors)==GetErrorMetrics()->GetNumberOfItems()

int vtkGenericCellTessellator::RequiresEdgeSubdivision	(	double *	left,
		double *	mid,
		double *	right,
		double	alpha
	)

protected

Does the edge need to be subdivided according to at least one error metric? The edge is defined by its `leftPoint' and its `rightPoint'. `leftPoint', `midPoint' and `rightPoint' have to be initialized before calling RequiresEdgeSubdivision(). Their format is global coordinates, parametric coordinates and point centered attributes: xyx rst abc de... `alpha' is the normalized abscissa of the midpoint along the edge. (close to 0 means close to the left point, close to 1 means close to the right point)

Precondition: leftPoint_exists: leftPoint!=0; midPoint_exists: midPoint!=0; rightPoint_exists: rightPoint!=0; clamped_alpha: alpha>0 && alpha<1; valid_size: sizeof(leftPoint)=sizeof(midPoint)=sizeof(rightPoint) =GetAttributeCollection()->GetNumberOfPointCenteredComponents()+6

virtual void vtkGenericCellTessellator::UpdateMaxError	(	double *	leftPoint,
		double *	midPoint,
		double *	rightPoint,
		double	alpha
	)

protectedvirtual

Update the max error of each error metric according to the error at the mid-point. The type of error depends on the state of the concrete error metric. For instance, it can return an absolute or relative error metric. See RequiresEdgeSubdivision() for a description of the arguments.

Precondition: leftPoint_exists: leftPoint!=0; midPoint_exists: midPoint!=0; rightPoint_exists: rightPoint!=0; clamped_alpha: alpha>0 && alpha<1; valid_size: sizeof(leftPoint)=sizeof(midPoint)=sizeof(rightPoint) =GetAttributeCollection()->GetNumberOfPointCenteredComponents()+6

void vtkGenericCellTessellator::ResetMaxErrors ( )

protected

Reset the maximal error of each error metric. The purpose of the maximal error is to measure the quality of a fixed subdivision.

void vtkGenericCellTessellator::SetGenericCell ( vtkGenericAdaptorCell * cell )

protected

Send the current cell to error metrics. Should be called at the beginning of the implementation of Tessellate(), Triangulate() or TessellateFace()