An abstract class for obtaining the interpolated velocity values at a point. More...

#include <vtkAbstractInterpolatedVelocityField.h>

Inheritance diagram for vtkAbstractInterpolatedVelocityField:

Collaboration diagram for vtkAbstractInterpolatedVelocityField:

Public Types
typedef vtkFunctionSet	Superclass
Public Member Functions
virtual int	IsA (const char *type)
vtkAbstractInterpolatedVelocityField *	NewInstance () const
void	PrintSelf (ostream &os, vtkIndent indent)
virtual vtkDataSet *	GetLastDataSet ()
virtual void	SetLastCellId (vtkIdType c, int dataindex)=0
void	SelectVectors (int fieldAssociation, const char *fieldName)
virtual int	FunctionValues (double x, double f)=0
void	ClearLastCellId ()

virtual void	SetCaching (bool)
virtual bool	GetCaching ()

virtual int	GetCacheHit ()
virtual int	GetCacheMiss ()

virtual vtkIdType	GetLastCellId ()
virtual void	SetLastCellId (vtkIdType c)

virtual char *	GetVectorsSelection ()
virtual int	GetVectorsType ()

virtual void	SetNormalizeVector (bool)
virtual bool	GetNormalizeVector ()

virtual void	CopyParameters (vtkAbstractInterpolatedVelocityField *from)

int	GetLastWeights (double *w)
int	GetLastLocalCoordinates (double pcoords[3])
Static Public Member Functions
static int	IsTypeOf (const char *type)
static vtkAbstractInterpolatedVelocityField *	SafeDownCast (vtkObjectBase *o)
Protected Member Functions
virtual vtkObjectBase *	NewInstanceInternal () const
	vtkAbstractInterpolatedVelocityField ()
	~vtkAbstractInterpolatedVelocityField ()
virtual int	FunctionValues (vtkDataSet ds, double x, double *f)

virtual void	SetVectorsSelection (const char *)

void	FastCompute (vtkDataArray *vectors, double f[3])
bool	InterpolatePoint (vtkPointData *outPD, vtkIdType outIndex)
vtkGenericCell *	GetLastCell ()
Protected Attributes
int	CacheHit
int	CacheMiss
int	WeightsSize
bool	Caching
bool	NormalizeVector
int	VectorsType
char *	VectorsSelection
double *	Weights
double	LastPCoords [3]
vtkIdType	LastCellId
vtkDataSet *	LastDataSet
vtkGenericCell *	Cell
vtkGenericCell *	GenCell
Static Protected Attributes
static const double	TOLERANCE_SCALE
Friends
class	vtkTemporalInterpolatedVelocityField

Detailed Description

An abstract class for obtaining the interpolated velocity values at a point.

vtkAbstractInterpolatedVelocityField acts as a continuous velocity field by performing cell interpolation on the underlying vtkDataSet. This is an abstract sub-class of vtkFunctionSet, NumberOfIndependentVariables = 4 (x,y,z,t) and NumberOfFunctions = 3 (u,v,w). With a brute-force scheme, every time an evaluation is performed, the target cell containing point (x,y,z) needs to be found by calling FindCell(), via either vtkDataSet or vtkAbstractCelllocator's sub-classes (vtkCellLocator & vtkModifiedBSPTree). As it incurs a large cost, one (for vtkCellLocatorInterpolatedVelocityField via vtkAbstractCellLocator) or two (for vtkInterpolatedVelocityField via vtkDataSet that involves vtkPointLocator in addressing vtkPointSet) levels of cell caching may be exploited to increase the performance.

For vtkInterpolatedVelocityField, level #0 begins with intra-cell caching. Specifically if the previous cell is valid and the next point is still in it ( i.e., vtkCell::EvaluatePosition() returns 1, coupled with newly created parametric coordinates & weights ), the function values can be interpolated and only vtkCell::EvaluatePosition() is invoked. If this fails, then level #1 follows by inter-cell search for the target cell that contains the next point. By an inter-cell search, the previous cell provides an important clue or serves as an immediate neighbor to aid in locating the target cell via vtkPointSet:: FindCell(). If this still fails, a global cell location / search is invoked via vtkPointSet::FindCell(). Here regardless of either inter-cell or global search, vtkPointLocator is in fact employed (for datasets of type vtkPointSet only, note vtkImageData and vtkRectilinearGrid are able to provide rapid and robust cell location due to the simple mesh topology) as a crucial tool underlying the cell locator. However, the use of vtkPointLocator makes vtkInterpolatedVelocityField non-robust in cell location for vtkPointSet.

For vtkCellLocatorInterpolatedVelocityField, the only caching (level #0) works by intra-cell trial. In case of failure, a global search for the target cell is invoked via vtkAbstractCellLocator::FindCell() and the actual work is done by either vtkCellLocator or vtkModifiedBSPTree (for datasets of type vtkPointSet only, while vtkImageData and vtkRectilinearGrid themselves are able to provide fast robust cell location). Without the involvement of vtkPointLocator, robust cell location is achieved for vtkPointSet.

Warning:: vtkAbstractInterpolatedVelocityField is not thread safe. A new instance should be created by each thread.

See also:: vtkInterpolatedVelocityField vtkCellLocatorInterpolatedVelocityField vtkGenericInterpolatedVelocityField vtkCachingInterpolatedVelocityField vtkTemporalInterpolatedVelocityField vtkFunctionSet vtkStreamer vtkStreamTracer

Definition at line 84 of file vtkAbstractInterpolatedVelocityField.h.

Member Typedef Documentation

typedef vtkFunctionSet vtkAbstractInterpolatedVelocityField::Superclass

Reimplemented from vtkFunctionSet.

Reimplemented in vtkCompositeInterpolatedVelocityField, vtkInterpolatedVelocityField, vtkCellLocatorInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

Definition at line 87 of file vtkAbstractInterpolatedVelocityField.h.

Constructor & Destructor Documentation

vtkAbstractInterpolatedVelocityField::vtkAbstractInterpolatedVelocityField ( ) [protected]

vtkAbstractInterpolatedVelocityField::~vtkAbstractInterpolatedVelocityField ( ) [protected]

Member Function Documentation

static int vtkAbstractInterpolatedVelocityField::IsTypeOf ( const char * name ) [static]

Return 1 if this class type 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 vtkFunctionSet.

Reimplemented in vtkCompositeInterpolatedVelocityField, vtkInterpolatedVelocityField, vtkCellLocatorInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

virtual int vtkAbstractInterpolatedVelocityField::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 vtkFunctionSet.

Reimplemented in vtkCompositeInterpolatedVelocityField, vtkInterpolatedVelocityField, vtkCellLocatorInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

static vtkAbstractInterpolatedVelocityField* vtkAbstractInterpolatedVelocityField::SafeDownCast ( vtkObjectBase * o ) [static]

Reimplemented from vtkFunctionSet.

Reimplemented in vtkCompositeInterpolatedVelocityField, vtkInterpolatedVelocityField, vtkCellLocatorInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

virtual vtkObjectBase* vtkAbstractInterpolatedVelocityField::NewInstanceInternal ( ) const [protected, virtual]

Reimplemented from vtkFunctionSet.

Reimplemented in vtkCompositeInterpolatedVelocityField, vtkInterpolatedVelocityField, vtkCellLocatorInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

vtkAbstractInterpolatedVelocityField* vtkAbstractInterpolatedVelocityField::NewInstance ( ) const

Reimplemented from vtkFunctionSet.

Reimplemented in vtkCompositeInterpolatedVelocityField, vtkInterpolatedVelocityField, vtkCellLocatorInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

void vtkAbstractInterpolatedVelocityField::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 vtkFunctionSet.

Reimplemented in vtkCompositeInterpolatedVelocityField, vtkAMRInterpolatedVelocityField, vtkInterpolatedVelocityField, and vtkCellLocatorInterpolatedVelocityField.

virtual void vtkAbstractInterpolatedVelocityField::SetCaching ( bool ) [virtual]

Set/Get the caching flag. If this flag is turned ON, there are two levels of caching for derived concrete class vtkInterpolatedVelocityField and one level of caching for derived concrete class vtkCellLocatorInterpolatedVelocityField. Otherwise a global cell location is always invoked for evaluating the function values at any point.

virtual bool vtkAbstractInterpolatedVelocityField::GetCaching ( ) [virtual]

Set/Get the caching flag. If this flag is turned ON, there are two levels of caching for derived concrete class vtkInterpolatedVelocityField and one level of caching for derived concrete class vtkCellLocatorInterpolatedVelocityField. Otherwise a global cell location is always invoked for evaluating the function values at any point.

virtual int vtkAbstractInterpolatedVelocityField::GetCacheHit ( ) [virtual]

Get the caching statistics. CacheHit refers to the number of level #0 cache hits while CacheMiss is the number of level #0 cache misses.

virtual int vtkAbstractInterpolatedVelocityField::GetCacheMiss ( ) [virtual]

Get the caching statistics. CacheHit refers to the number of level #0 cache hits while CacheMiss is the number of level #0 cache misses.

virtual vtkDataSet* vtkAbstractInterpolatedVelocityField::GetLastDataSet ( ) [virtual]

Reimplemented in vtkCompositeInterpolatedVelocityField.

virtual vtkIdType vtkAbstractInterpolatedVelocityField::GetLastCellId ( ) [virtual]

Get/Set the id of the cell cached from last evaluation.

virtual void vtkAbstractInterpolatedVelocityField::SetLastCellId ( vtkIdType c ) [inline, virtual]

Get/Set the id of the cell cached from last evaluation.

Reimplemented in vtkCellLocatorInterpolatedVelocityField, vtkInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

Definition at line 113 of file vtkAbstractInterpolatedVelocityField.h.

virtual void vtkAbstractInterpolatedVelocityField::SetLastCellId	(	vtkIdType	c,
		int	dataindex
	)		`[pure virtual]`

Set the id of the most recently visited cell of a dataset.

Implemented in vtkCellLocatorInterpolatedVelocityField, vtkInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

virtual char* vtkAbstractInterpolatedVelocityField::GetVectorsSelection ( ) [virtual]

Get/Set the name of a spcified vector array. By default it is NULL, with the active vector array for use.

virtual int vtkAbstractInterpolatedVelocityField::GetVectorsType ( ) [virtual]

Get/Set the name of a spcified vector array. By default it is NULL, with the active vector array for use.

void vtkAbstractInterpolatedVelocityField::SelectVectors	(	int	fieldAssociation,
		const char *	fieldName
	)

the association type (see vtkDataObject::FieldAssociations) and the name of the velocity data field

virtual void vtkAbstractInterpolatedVelocityField::SetNormalizeVector ( bool ) [virtual]

Set/Get the flag indicating vector post-normalization (following vector interpolation). Vector post-normalization is required to avoid the 'curve-overshooting' problem (caused by high velocity magnitude) that occurs when Cell-Length is used as the step size unit (particularly the Minimum step size unit). Furthermore, it is required by RK45 to achieve, as expected, high numerical accuracy (or high smoothness of flow lines) through adaptive step sizing. Note this operation is performed (when NormalizeVector TRUE) right after vector interpolation such that the differing amount of contribution of each node (of a cell) to the resulting direction of the interpolated vector, due to the possibly significantly-differing velocity magnitude values at the nodes (which is the case with large cells), can be reflected as is. Also note that this flag needs to be turned to FALSE after vtkInitialValueProblemSolver:: ComputeNextStep() as subsequent operations, e.g., vorticity computation, may need non-normalized vectors.

virtual bool vtkAbstractInterpolatedVelocityField::GetNormalizeVector ( ) [virtual]

Set/Get the flag indicating vector post-normalization (following vector interpolation). Vector post-normalization is required to avoid the 'curve-overshooting' problem (caused by high velocity magnitude) that occurs when Cell-Length is used as the step size unit (particularly the Minimum step size unit). Furthermore, it is required by RK45 to achieve, as expected, high numerical accuracy (or high smoothness of flow lines) through adaptive step sizing. Note this operation is performed (when NormalizeVector TRUE) right after vector interpolation such that the differing amount of contribution of each node (of a cell) to the resulting direction of the interpolated vector, due to the possibly significantly-differing velocity magnitude values at the nodes (which is the case with large cells), can be reflected as is. Also note that this flag needs to be turned to FALSE after vtkInitialValueProblemSolver:: ComputeNextStep() as subsequent operations, e.g., vorticity computation, may need non-normalized vectors.

virtual void vtkAbstractInterpolatedVelocityField::CopyParameters ( vtkAbstractInterpolatedVelocityField * from ) [inline, virtual]

Import parameters. Sub-classes can add more after chaining.

Reimplemented in vtkCellLocatorInterpolatedVelocityField.

Definition at line 154 of file vtkAbstractInterpolatedVelocityField.h.

virtual int vtkAbstractInterpolatedVelocityField::FunctionValues	(	double *	x,
		double *	f
	)		`[pure virtual]`

Evaluate the velocity field f at point (x, y, z).

Implements vtkFunctionSet.

Implemented in vtkCellLocatorInterpolatedVelocityField, vtkInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

void vtkAbstractInterpolatedVelocityField::ClearLastCellId ( ) [inline]

Set the last cell id to -1 to incur a global cell search for the next point.

Definition at line 164 of file vtkAbstractInterpolatedVelocityField.h.

int vtkAbstractInterpolatedVelocityField::GetLastWeights ( double * w )

Get the interpolation weights cached from last evaluation. Return 1 if the cached cell is valid and 0 otherwise.

int vtkAbstractInterpolatedVelocityField::GetLastLocalCoordinates ( double pcoords[3] )

Get the interpolation weights cached from last evaluation. Return 1 if the cached cell is valid and 0 otherwise.

virtual void vtkAbstractInterpolatedVelocityField::SetVectorsSelection ( const char * ) [protected, virtual]

Set the name of a specific vector to be interpolated.

virtual int vtkAbstractInterpolatedVelocityField::FunctionValues	(	vtkDataSet *	ds,
		double *	x,
		double *	f
	)		`[protected, virtual]`

Evaluate the velocity field f at point (x, y, z) in a specified dataset by invoking vtkDataSet::FindCell() to locate the next cell if the given point is outside the current cell. To address vtkPointSet, vtkPointLocator is involved via vtkPointSet::FindCell() in vtkInterpolatedVelocityField for cell location. In vtkCellLocatorInterpolatedVelocityField, this function is invoked just to handle vtkImageData and vtkRectilinearGrid that are not assigned with any vtkAbstractCellLocatot-type cell locator.

Reimplemented in vtkCellLocatorInterpolatedVelocityField, vtkInterpolatedVelocityField, and vtkAMRInterpolatedVelocityField.

void vtkAbstractInterpolatedVelocityField::FastCompute	(	vtkDataArray *	vectors,
		double	f[3]
	)		`[protected]`

If all weights have been computed (parametric coords etc all valid), a scalar/vector can be quickly interpolated using the known weights and the cached generic cell. This function is primarily reserved for use by vtkTemporalInterpolatedVelocityField

bool vtkAbstractInterpolatedVelocityField::InterpolatePoint	(	vtkPointData *	outPD,
		vtkIdType	outIndex
	)		`[protected]`

If all weights have been computed (parametric coords etc all valid), a scalar/vector can be quickly interpolated using the known weights and the cached generic cell. This function is primarily reserved for use by vtkTemporalInterpolatedVelocityField

vtkGenericCell* vtkAbstractInterpolatedVelocityField::GetLastCell ( ) [inline, protected]

If all weights have been computed (parametric coords etc all valid), a scalar/vector can be quickly interpolated using the known weights and the cached generic cell. This function is primarily reserved for use by vtkTemporalInterpolatedVelocityField

Definition at line 218 of file vtkAbstractInterpolatedVelocityField.h.