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

#include <vtkCompositeInterpolatedVelocityField.h>

Inheritance diagram for vtkCompositeInterpolatedVelocityField:

Collaboration diagram for vtkCompositeInterpolatedVelocityField:

Public Types
typedef vtkAbstractInterpolatedVelocityField	Superclass
Public Member Functions
virtual int	IsA (const char *type)
vtkCompositeInterpolatedVelocityField *	NewInstance () const
void	PrintSelf (ostream &os, vtkIndent indent)
virtual void	AddDataSet (vtkDataSet *dataset)=0

virtual int	GetLastDataSetIndex ()
virtual vtkDataSet *	GetLastDataSet ()
Static Public Member Functions
static int	IsTypeOf (const char *type)
static vtkCompositeInterpolatedVelocityField *	SafeDownCast (vtkObjectBase *o)
Protected Member Functions
virtual vtkObjectBase *	NewInstanceInternal () const
	vtkCompositeInterpolatedVelocityField ()
	~vtkCompositeInterpolatedVelocityField ()
Protected Attributes
int	LastDataSetIndex
vtkCompositeInterpolatedVelocityFieldDataSetsType *	DataSets
Static Protected Attributes
static const double	TOLERANCE_SCALE

Detailed Description

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

vtkCompositeInterpolatedVelocityField 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:: vtkCompositeInterpolatedVelocityField 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 vtkCompositeInterpolatedVelocityField.h.

Member Typedef Documentation

typedef vtkAbstractInterpolatedVelocityField vtkCompositeInterpolatedVelocityField::Superclass

Reimplemented from vtkAbstractInterpolatedVelocityField.

Reimplemented in vtkInterpolatedVelocityField, and vtkCellLocatorInterpolatedVelocityField.

Definition at line 87 of file vtkCompositeInterpolatedVelocityField.h.

Constructor & Destructor Documentation

vtkCompositeInterpolatedVelocityField::vtkCompositeInterpolatedVelocityField ( ) [protected]

vtkCompositeInterpolatedVelocityField::~vtkCompositeInterpolatedVelocityField ( ) [protected]

Member Function Documentation

static int vtkCompositeInterpolatedVelocityField::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 vtkAbstractInterpolatedVelocityField.

Reimplemented in vtkInterpolatedVelocityField, and vtkCellLocatorInterpolatedVelocityField.

virtual int vtkCompositeInterpolatedVelocityField::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 vtkAbstractInterpolatedVelocityField.

Reimplemented in vtkInterpolatedVelocityField, and vtkCellLocatorInterpolatedVelocityField.

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

Reimplemented from vtkAbstractInterpolatedVelocityField.

Reimplemented in vtkInterpolatedVelocityField, and vtkCellLocatorInterpolatedVelocityField.

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

Reimplemented from vtkAbstractInterpolatedVelocityField.

Reimplemented in vtkInterpolatedVelocityField, and vtkCellLocatorInterpolatedVelocityField.

vtkCompositeInterpolatedVelocityField* vtkCompositeInterpolatedVelocityField::NewInstance ( ) const

Reimplemented from vtkAbstractInterpolatedVelocityField.

Reimplemented in vtkInterpolatedVelocityField, and vtkCellLocatorInterpolatedVelocityField.

void vtkCompositeInterpolatedVelocityField::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 vtkAbstractInterpolatedVelocityField.

Reimplemented in vtkInterpolatedVelocityField, and vtkCellLocatorInterpolatedVelocityField.

virtual int vtkCompositeInterpolatedVelocityField::GetLastDataSetIndex ( ) [virtual]

Get the most recently visited dataset and it id. The dataset is used for a guess regarding where the next point will be, without searching through all datasets. When setting the last dataset, care is needed as no reference counting or checks are performed. This feature is intended for custom interpolators only that cache datasets independently.

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

Get the most recently visited dataset and it id. The dataset is used for a guess regarding where the next point will be, without searching through all datasets. When setting the last dataset, care is needed as no reference counting or checks are performed. This feature is intended for custom interpolators only that cache datasets independently.

Reimplemented from vtkAbstractInterpolatedVelocityField.

virtual void vtkCompositeInterpolatedVelocityField::AddDataSet ( vtkDataSet * dataset ) [pure virtual]

Add a dataset for implicit velocity function evaluation. If more than one dataset is added, the evaluation point is searched in all until a match is found. THIS FUNCTION DOES NOT CHANGE THE REFERENCE COUNT OF dataset FOR THREAD SAFETY REASONS.

Implemented in vtkCellLocatorInterpolatedVelocityField, and vtkInterpolatedVelocityField.