vtkFiniteDifferenceGradientEstimator Class Reference

#include <vtkFiniteDifferenceGradientEstimator.h>

Inheritance diagram for vtkFiniteDifferenceGradientEstimator:

[legend]Collaboration diagram for vtkFiniteDifferenceGradientEstimator:

[legend]List of all members.

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Detailed Description

Use finite differences to estimate gradient.

vtkFiniteDifferenceGradientEstimator is a concrete subclass of vtkEncodedGradientEstimator that uses a central differences technique to estimate the gradient. The gradient at some sample location (x,y,z) would be estimated by:

nx = (f(x-dx,y,z) - f(x+dx,y,z)) / 2*dx; ny = (f(x,y-dy,z) - f(x,y+dy,z)) / 2*dy; nz = (f(x,y,z-dz) - f(x,y,z+dz)) / 2*dz;

This value is normalized to determine a unit direction vector and a magnitude. The normal is computed in voxel space, and dx = dy = dz = SampleSpacingInVoxels. A scaling factor is applied to convert this normal from voxel space to world coordinates.

See also:

vtkEncodedGradientEstimator

Tests:

vtkFiniteDifferenceGradientEstimator (Tests)

Definition at line 46 of file vtkFiniteDifferenceGradientEstimator.h.

virtual void	SetSampleSpacingInVoxels (int)
virtual int	GetSampleSpacingInVoxels ()
static vtkFiniteDifferenceGradientEstimator *	New ()
Public Types
typedef vtkEncodedGradientEstimator	Superclass
Public Member Functions
virtual const char *	GetClassName ()
virtual int	IsA (const char *type)
void	PrintSelf (ostream &os, vtkIndent indent)
Static Public Member Functions
static int	IsTypeOf (const char *type)
static vtkFiniteDifferenceGradientEstimator *	SafeDownCast (vtkObject *o)
Public Attributes
int	SampleSpacingInVoxels
Protected Member Functions
	vtkFiniteDifferenceGradientEstimator ()
	~vtkFiniteDifferenceGradientEstimator ()
void	UpdateNormals (void)

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Member Typedef Documentation

typedef vtkEncodedGradientEstimator vtkFiniteDifferenceGradientEstimator::Superclass

Reimplemented from vtkEncodedGradientEstimator. Definition at line 49 of file vtkFiniteDifferenceGradientEstimator.h.

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Constructor & Destructor Documentation

vtkFiniteDifferenceGradientEstimator::vtkFiniteDifferenceGradientEstimator (   )  [protected]

vtkFiniteDifferenceGradientEstimator::~vtkFiniteDifferenceGradientEstimator (   )  [protected]

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Member Function Documentation

virtual const char* vtkFiniteDifferenceGradientEstimator::GetClassName (   )  [virtual]

Reimplemented from vtkEncodedGradientEstimator.

static int vtkFiniteDifferenceGradientEstimator::IsTypeOf (  const char *  type  )  [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 vtkTypeRevisionMacro found in vtkSetGet.h. Reimplemented from vtkEncodedGradientEstimator.

virtual int vtkFiniteDifferenceGradientEstimator::IsA (  const char *  type  )  [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 vtkTypeRevisionMacro found in vtkSetGet.h. Reimplemented from vtkEncodedGradientEstimator.

static vtkFiniteDifferenceGradientEstimator* vtkFiniteDifferenceGradientEstimator::SafeDownCast (  vtkObject *  o  )  [static]

Reimplemented from vtkEncodedGradientEstimator.

void vtkFiniteDifferenceGradientEstimator::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 vtkEncodedGradientEstimator.

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

Construct a vtkFiniteDifferenceGradientEstimator with a SampleSpacingInVoxels of 1. Reimplemented from vtkObject.

virtual void vtkFiniteDifferenceGradientEstimator::SetSampleSpacingInVoxels (  int   )  [virtual]

Set/Get the spacing between samples for the finite differences method used to compute the normal. This spacing is in voxel units.

virtual int vtkFiniteDifferenceGradientEstimator::GetSampleSpacingInVoxels (   )  [virtual]

Set/Get the spacing between samples for the finite differences method used to compute the normal. This spacing is in voxel units.

void vtkFiniteDifferenceGradientEstimator::UpdateNormals (  void   )  [protected, virtual]

Recompute the encoded normals and gradient magnitudes. Implements vtkEncodedGradientEstimator.

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Member Data Documentation

int vtkFiniteDifferenceGradientEstimator::SampleSpacingInVoxels

Definition at line 60 of file vtkFiniteDifferenceGradientEstimator.h.

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

• dox/VolumeRendering/vtkFiniteDifferenceGradientEstimator.h

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