Streamline generator. More...

#include <vtkStreamTracer.h>

Inheritance diagram for vtkStreamTracer:

Collaboration diagram for vtkStreamTracer:

Classes
struct	IntervalInformation
Public Types
enum	Units { LENGTH_UNIT = 1, CELL_LENGTH_UNIT = 2 }
enum	Solvers { RUNGE_KUTTA2, RUNGE_KUTTA4, RUNGE_KUTTA45, NONE, UNKNOWN }
enum	ReasonForTermination { OUT_OF_DOMAIN = vtkInitialValueProblemSolver::OUT_OF_DOMAIN, NOT_INITIALIZED = vtkInitialValueProblemSolver::NOT_INITIALIZED, UNEXPECTED_VALUE = vtkInitialValueProblemSolver::UNEXPECTED_VALUE, OUT_OF_LENGTH = 4, OUT_OF_STEPS = 5, STAGNATION = 6 }
enum	{ FORWARD, BACKWARD, BOTH }
enum	{ INTERPOLATOR_WITH_DATASET_POINT_LOCATOR, INTERPOLATOR_WITH_CELL_LOCATOR }
typedef vtkPolyDataAlgorithm	Superclass
Public Member Functions
virtual int	IsA (const char *type)
vtkStreamTracer *	NewInstance () const
void	PrintSelf (ostream &os, vtkIndent indent)
void	SetSourceConnection (vtkAlgorithmOutput *algOutput)
void	SetInterpolatorTypeToDataSetPointLocator ()
void	SetInterpolatorTypeToCellLocator ()
void	SetInterpolatorPrototype (vtkAbstractInterpolatedVelocityField *ivf)
void	SetInterpolatorType (int interpType)

virtual void	SetStartPosition (double, double, double)
virtual void	SetStartPosition (double[3])
virtual double *	GetStartPosition ()
virtual void	GetStartPosition (double &, double &, double &)
virtual void	GetStartPosition (double[3])

void	SetSourceData (vtkDataSet *source)
vtkDataSet *	GetSource ()

void	SetIntegrator (vtkInitialValueProblemSolver *)
virtual vtkInitialValueProblemSolver *	GetIntegrator ()
void	SetIntegratorType (int type)
int	GetIntegratorType ()
void	SetIntegratorTypeToRungeKutta2 ()
void	SetIntegratorTypeToRungeKutta4 ()
void	SetIntegratorTypeToRungeKutta45 ()

virtual void	SetMaximumPropagation (double)
virtual double	GetMaximumPropagation ()

void	SetIntegrationStepUnit (int unit)
int	GetIntegrationStepUnit ()

virtual void	SetInitialIntegrationStep (double)
virtual double	GetInitialIntegrationStep ()

virtual void	SetMinimumIntegrationStep (double)
virtual double	GetMinimumIntegrationStep ()

virtual void	SetMaximumIntegrationStep (double)
virtual double	GetMaximumIntegrationStep ()

virtual void	SetMaximumError (double)
virtual double	GetMaximumError ()

virtual void	SetMaximumNumberOfSteps (vtkIdType)
virtual vtkIdType	GetMaximumNumberOfSteps ()

virtual void	SetTerminalSpeed (double)
virtual double	GetTerminalSpeed ()

virtual void	SetIntegrationDirection (int)
virtual int	GetIntegrationDirection ()
void	SetIntegrationDirectionToForward ()
void	SetIntegrationDirectionToBackward ()
void	SetIntegrationDirectionToBoth ()

virtual void	SetComputeVorticity (bool)
virtual bool	GetComputeVorticity ()

virtual void	SetRotationScale (double)
virtual double	GetRotationScale ()
Static Public Member Functions
static int	IsTypeOf (const char *type)
static vtkStreamTracer *	SafeDownCast (vtkObjectBase *o)
static vtkStreamTracer *	New ()
Protected Member Functions
virtual vtkObjectBase *	NewInstanceInternal () const
	vtkStreamTracer ()
	~vtkStreamTracer ()
virtual vtkExecutive *	CreateDefaultExecutive ()
void	AddInput (vtkDataObject *)
virtual int	RequestData (vtkInformation , vtkInformationVector , vtkInformationVector )
virtual int	FillInputPortInformation (int, vtkInformation *)
void	CalculateVorticity (vtkGenericCell cell, double pcoords[3], vtkDoubleArray cellVectors, double vorticity[3])
void	Integrate (vtkPointData inputData, vtkPolyData output, vtkDataArray seedSource, vtkIdList seedIds, vtkIntArray integrationDirections, double lastPoint[3], vtkAbstractInterpolatedVelocityField func, int maxCellSize, int vecType, const char *vecFieldName, double &propagation, vtkIdType &numSteps)
void	SimpleIntegrate (double seed[3], double lastPoint[3], double stepSize, vtkAbstractInterpolatedVelocityField *func)
int	CheckInputs (vtkAbstractInterpolatedVelocityField &func, int maxCellSize)
void	GenerateNormals (vtkPolyData output, double firstNormal, const char *vecName)
void	ConvertIntervals (double &step, double &minStep, double &maxStep, int direction, double cellLength)
int	SetupOutput (vtkInformation inInfo, vtkInformation outInfo)
void	InitializeSeeds (vtkDataArray &seeds, vtkIdList &seedIds, vtkIntArray &integrationDirections, vtkDataSet source)
Static Protected Member Functions
static double	ConvertToLength (double interval, int unit, double cellLength)
static double	ConvertToLength (IntervalInformation &interval, double cellLength)
Protected Attributes
bool	GenerateNormalsInIntegrate
double	StartPosition [3]
double	TerminalSpeed
double	LastUsedStepSize
double	MaximumPropagation
double	MinimumIntegrationStep
double	MaximumIntegrationStep
double	InitialIntegrationStep
int	IntegrationStepUnit
int	IntegrationDirection
vtkInitialValueProblemSolver *	Integrator
double	MaximumError
vtkIdType	MaximumNumberOfSteps
bool	ComputeVorticity
double	RotationScale
vtkAbstractInterpolatedVelocityField *	InterpolatorPrototype
vtkCompositeDataSet *	InputData
bool	HasMatchingPointAttributes
Static Protected Attributes
static const double	EPSILON
Friends
class	PStreamTracerUtils

Detailed Description

Streamline generator.

vtkStreamTracer is a filter that integrates a vector field to generate streamlines. The integration is performed using a specified integrator, by default Runge-Kutta2.

vtkStreamTracer produces polylines as the output, with each cell (i.e., polyline) representing a streamline. The attribute values associated with each streamline are stored in the cell data, whereas those associated with streamline-points are stored in the point data.

vtkStreamTracer supports forward (the default), backward, and combined (i.e., BOTH) integration. The length of a streamline is governed by specifying a maximum value either in physical arc length or in (local) cell length. Otherwise, the integration terminates upon exiting the flow field domain, or if the particle speed is reduced to a value less than a specified terminal speed, or when a maximum number of steps is completed. The specific reason for the termination is stored in a cell array named ReasonForTermination.

Note that normalized vectors are adopted in streamline integration, which achieves high numerical accuracy/smoothness of flow lines that is particularly guaranteed for Runge-Kutta45 with adaptive step size and error control). In support of this feature, the underlying step size is ALWAYS in arc length unit (LENGTH_UNIT) while the 'real' time interval (virtual for steady flows) that a particle actually takes to trave in a single step is obtained by dividing the arc length by the LOCAL speed. The overall elapsed time (i.e., the life span) of the particle is the sum of those individual step-wise time intervals.

The quality of streamline integration can be controlled by setting the initial integration step (InitialIntegrationStep), particularly for Runge-Kutta2 and Runge-Kutta4 (with a fixed step size), and in the case of Runge-Kutta45 (with an adaptive step size and error control) the minimum integration step, the maximum integration step, and the maximum error. These steps are in either LENGTH_UNIT or CELL_LENGTH_UNIT while the error is in physical arc length. For the former two integrators, there is a trade-off between integration speed and streamline quality.

The integration time, vorticity, rotation and angular velocity are stored in point data arrays named "IntegrationTime", "Vorticity", "Rotation" and "AngularVelocity", respectively (vorticity, rotation and angular velocity are computed only when ComputeVorticity is on). All point data attributes in the source dataset are interpolated on the new streamline points.

vtkStreamTracer supports integration through any type of dataset. Thus if the dataset contains 2D cells like polygons or triangles, the integration is constrained to lie on the surface defined by 2D cells.

The starting point, or the so-called 'seed', of a streamline may be set in two different ways. Starting from global x-y-z "position" allows you to start a single trace at a specified x-y-z coordinate. If you specify a source object, traces will be generated from each point in the source that is inside the dataset.

See also:: vtkRibbonFilter vtkRuledSurfaceFilter vtkInitialValueProblemSolver vtkRungeKutta2 vtkRungeKutta4 vtkRungeKutta45 vtkTemporalStreamTracer vtkAbstractInterpolatedVelocityField vtkInterpolatedVelocityField vtkCellLocatorInterpolatedVelocityField

Examples:: vtkStreamTracer (Examples)

Tests:: vtkStreamTracer (Tests)

Definition at line 102 of file vtkStreamTracer.h.

Member Typedef Documentation

typedef vtkPolyDataAlgorithm vtkStreamTracer::Superclass

Reimplemented from vtkPolyDataAlgorithm.

Reimplemented in vtkTemporalStreamTracer, vtkPTemporalStreamTracer, and vtkPStreamTracer.

Definition at line 105 of file vtkStreamTracer.h.

Member Enumeration Documentation

enum vtkStreamTracer::Units

Enumerator:

LENGTH_UNIT
CELL_LENGTH_UNIT

Reimplemented in vtkTemporalStreamTracer.

Definition at line 144 of file vtkStreamTracer.h.

enum vtkStreamTracer::Solvers

Enumerator:

RUNGE_KUTTA2
RUNGE_KUTTA4
RUNGE_KUTTA45
NONE
UNKNOWN

Definition at line 150 of file vtkStreamTracer.h.

enum vtkStreamTracer::ReasonForTermination

Enumerator:

OUT_OF_DOMAIN
NOT_INITIALIZED
UNEXPECTED_VALUE
OUT_OF_LENGTH
OUT_OF_STEPS
STAGNATION

Definition at line 159 of file vtkStreamTracer.h.

anonymous enum

Enumerator:

FORWARD
BACKWARD
BOTH

Definition at line 258 of file vtkStreamTracer.h.

anonymous enum

Enumerator:

INTERPOLATOR_WITH_DATASET_POINT_LOCATOR
INTERPOLATOR_WITH_CELL_LOCATOR

Definition at line 265 of file vtkStreamTracer.h.

Constructor & Destructor Documentation

vtkStreamTracer::vtkStreamTracer ( ) [protected]

vtkStreamTracer::~vtkStreamTracer ( ) [protected]

Member Function Documentation

static int vtkStreamTracer::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 vtkPolyDataAlgorithm.

Reimplemented in vtkTemporalStreamTracer, vtkPTemporalStreamTracer, and vtkPStreamTracer.

virtual int vtkStreamTracer::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 vtkPolyDataAlgorithm.

Reimplemented in vtkTemporalStreamTracer, vtkPTemporalStreamTracer, and vtkPStreamTracer.

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

Reimplemented from vtkPolyDataAlgorithm.

Reimplemented in vtkTemporalStreamTracer, vtkPTemporalStreamTracer, and vtkPStreamTracer.

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

Reimplemented from vtkPolyDataAlgorithm.

Reimplemented in vtkTemporalStreamTracer, vtkPTemporalStreamTracer, and vtkPStreamTracer.

vtkStreamTracer* vtkStreamTracer::NewInstance ( ) const

Reimplemented from vtkPolyDataAlgorithm.

Reimplemented in vtkTemporalStreamTracer, vtkPTemporalStreamTracer, and vtkPStreamTracer.

void vtkStreamTracer::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 vtkPolyDataAlgorithm.

Reimplemented in vtkTemporalStreamTracer, vtkPTemporalStreamTracer, and vtkPStreamTracer.

static vtkStreamTracer* vtkStreamTracer::New ( ) [static]

Construct object to start from position (0,0,0), with forward integration, terminal speed 1.0E-12, vorticity computation on, integration step size 0.5 (in cell length unit), maximum number of steps 2000, using Runge-Kutta2, and maximum propagation 1.0 (in arc length unit).

Reimplemented from vtkPolyDataAlgorithm.

Reimplemented in vtkTemporalStreamTracer, vtkPTemporalStreamTracer, and vtkPStreamTracer.

virtual void vtkStreamTracer::SetStartPosition	(	double	,
		double	,
		double
	)		`[virtual]`