vtkImplicitModeller Class Reference

#include <vtkImplicitModeller.h>

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List of all members.


Detailed Description

compute distance from input geometry on structured point dataset

vtkImplicitModeller is a filter that computes the distance from the input geometry to the points of an output structured point set. This distance function can then be "contoured" to generate new, offset surfaces from the original geometry. An important feature of this object is "capping". If capping is turned on, after the implicit model is created, the values on the boundary of the structured points dataset are set to the cap value. This is used to force closure of the resulting contoured surface. Note, however, that large cap values can generate weird surface normals in those cells adjacent to the boundary of the dataset. Using smaller cap value will reduce this effect.

Another important ivar is MaximumDistance. This controls how far into the volume the distance function is computed from the input geometry. Small values give significant increases in performance. However, there can strange sampling effects at the extreme range of the MaximumDistance.

In order to properly execute and sample the input data, a rectangular region in space must be defined (this is the ivar ModelBounds). If not explicitly defined, the model bounds will be computed. Note that to avoid boundary effects, it is possible to adjust the model bounds (i.e., using the AdjustBounds and AdjustDistance ivars) to strictly contain the sampled data.

This filter has one other unusual capability: it is possible to append data in a sequence of operations to generate a single output. This is useful when you have multiple datasets and want to create a conglomeration of all the data. However, the user must be careful to either specify the ModelBounds or specify the first item such that its bounds completely contain all other items. This is because the rectangular region of the output can not be changed after the 1st Append.

The ProcessMode ivar controls the method used within the Append function (where the actual work is done regardless if the Append function is explicitly called) to compute the implicit model. If set to work in voxel mode, each voxel is visited once. If set to cell mode, each cell is visited once. Tests have shown once per voxel to be faster when there are a lot of cells (at least a thousand?); relative performance improvement increases with addition cells. Primitives should not be stripped for best performance of the voxel mode. Also, if explicitly using the Append feature many times, the cell mode will probably be better because each voxel will be visited each Append. Append the data before input if possible when using the voxel mode. Do not switch between voxel and cell mode between execution of StartAppend and EndAppend.

Further performance improvement is now possible using the PerVoxel process mode on multi-processor machines (the mode is now multithreaded). Each thread processes a different "slab" of the output. Also, if the input is vtkPolyData, it is appropriately clipped for each thread; that is, each thread only considers the input which could affect its slab of the output.

This filter can now produce output of any type supported by vtkImageData. However to support this change, additional sqrts must be executed during the Append step. Previously, the output was initialized to the squared CapValue in StartAppend, the output was updated with squared distance values during the Append, and then the sqrt of the distances was computed in EndAppend. To support different scalar types in the output (largely to reduce memory requirements as an vtkImageShiftScale and/or vtkImageCast could have achieved the same result), we can't "afford" to save squared value in the output, because then we could only represent up to the sqrt of the scalar max for an integer type in the output; 1 (instead of 255) for an unsigned char; 11 for a char (instead of 127). Thus this change may result in a minor performance degradation. Non-float output types can be scaled to the CapValue by turning ScaleToMaximumDistance On.

See also:
vtkSampleFunction vtkContourFilter
Tests:
vtkImplicitModeller (Tests)

Definition at line 101 of file vtkImplicitModeller.h.


Public Types

typedef vtkImageAlgorithm Superclass

Public Member Functions

virtual const char * GetClassName ()
virtual int IsA (const char *type)
void PrintSelf (ostream &os, vtkIndent indent)
double ComputeModelBounds (vtkDataSet *input=NULL)
void StartAppend ()
void Append (vtkDataSet *input)
void EndAppend ()
int ProcessRequest (vtkInformation *, vtkInformationVector **, vtkInformationVector *)
virtual int * GetSampleDimensions ()
virtual void GetSampleDimensions (int data[3])
void SetSampleDimensions (int i, int j, int k)
void SetSampleDimensions (int dim[3])
virtual void SetMaximumDistance (double)
virtual double GetMaximumDistance ()
virtual void SetModelBounds (double, double, double, double, double, double)
virtual void SetModelBounds (double[6])
virtual double * GetModelBounds ()
virtual void GetModelBounds (double data[6])
virtual void SetAdjustBounds (int)
virtual int GetAdjustBounds ()
virtual void AdjustBoundsOn ()
virtual void AdjustBoundsOff ()
virtual void SetAdjustDistance (double)
virtual double GetAdjustDistance ()
virtual void SetCapping (int)
virtual int GetCapping ()
virtual void CappingOn ()
virtual void CappingOff ()
void SetCapValue (double value)
virtual double GetCapValue ()
virtual void SetScaleToMaximumDistance (int)
virtual int GetScaleToMaximumDistance ()
virtual void ScaleToMaximumDistanceOn ()
virtual void ScaleToMaximumDistanceOff ()
virtual void SetProcessMode (int)
virtual int GetProcessMode ()
void SetProcessModeToPerVoxel ()
void SetProcessModeToPerCell ()
const char * GetProcessModeAsString (void)
virtual void SetLocatorMaxLevel (int)
virtual int GetLocatorMaxLevel ()
virtual void SetNumberOfThreads (int)
virtual int GetNumberOfThreads ()
void SetOutputScalarType (int type)
virtual int GetOutputScalarType ()
void SetOutputScalarTypeToFloat ()
void SetOutputScalarTypeToDouble ()
void SetOutputScalarTypeToInt ()
void SetOutputScalarTypeToUnsignedInt ()
void SetOutputScalarTypeToLong ()
void SetOutputScalarTypeToUnsignedLong ()
void SetOutputScalarTypeToShort ()
void SetOutputScalarTypeToUnsignedShort ()
void SetOutputScalarTypeToUnsignedChar ()
void SetOutputScalarTypeToChar ()

Static Public Member Functions

static int IsTypeOf (const char *type)
static vtkImplicitModellerSafeDownCast (vtkObject *o)
static vtkImplicitModellerNew ()

Protected Member Functions

 vtkImplicitModeller ()
 ~vtkImplicitModeller ()
double GetScalarTypeMax (int type)
virtual int RequestInformation (vtkInformation *, vtkInformationVector **, vtkInformationVector *)
virtual int RequestData (vtkInformation *, vtkInformationVector **, vtkInformationVector *)
void StartAppend (int internal)
void Cap (vtkDataArray *s)
virtual int FillInputPortInformation (int, vtkInformation *)

Protected Attributes

vtkMultiThreaderThreader
int NumberOfThreads
int SampleDimensions [3]
double MaximumDistance
double ModelBounds [6]
int Capping
double CapValue
int DataAppended
int AdjustBounds
double AdjustDistance
int ProcessMode
int LocatorMaxLevel
int OutputScalarType
int ScaleToMaximumDistance
int BoundsComputed
double InternalMaxDistance

Member Typedef Documentation

Reimplemented from vtkImageAlgorithm.

Definition at line 104 of file vtkImplicitModeller.h.


Constructor & Destructor Documentation

vtkImplicitModeller::vtkImplicitModeller (  )  [protected]

vtkImplicitModeller::~vtkImplicitModeller (  )  [protected]


Member Function Documentation

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

Reimplemented from vtkImageAlgorithm.

static int vtkImplicitModeller::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 vtkTypeRevisionMacro found in vtkSetGet.h.

Reimplemented from vtkImageAlgorithm.

virtual int vtkImplicitModeller::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 vtkTypeRevisionMacro found in vtkSetGet.h.

Reimplemented from vtkImageAlgorithm.

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

Reimplemented from vtkImageAlgorithm.

void vtkImplicitModeller::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 vtkImageAlgorithm.

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

Construct with sample dimensions=(50,50,50), and so that model bounds are automatically computed from the input. Capping is turned on with CapValue equal to a large positive number.

Reimplemented from vtkAlgorithm.

double vtkImplicitModeller::ComputeModelBounds ( vtkDataSet input = NULL  ) 

Compute ModelBounds from input geometry. If input is not specified, the input of the filter will be used.

virtual int* vtkImplicitModeller::GetSampleDimensions (  )  [virtual]

Set/Get the i-j-k dimensions on which to sample distance function.

virtual void vtkImplicitModeller::GetSampleDimensions ( int  data[3]  )  [virtual]

Set/Get the i-j-k dimensions on which to sample distance function.

void vtkImplicitModeller::SetSampleDimensions ( int  i,
int  j,
int  k 
)

Set/Get the i-j-k dimensions on which to sample distance function.

void vtkImplicitModeller::SetSampleDimensions ( int  dim[3]  ) 

Set/Get the i-j-k dimensions on which to sample distance function.

virtual void vtkImplicitModeller::SetMaximumDistance ( double   )  [virtual]

Set / get the distance away from surface of input geometry to sample. Smaller values make large increases in performance.

virtual double vtkImplicitModeller::GetMaximumDistance (  )  [virtual]

Set / get the distance away from surface of input geometry to sample. Smaller values make large increases in performance.

virtual void vtkImplicitModeller::SetModelBounds ( double  ,
double  ,
double  ,
double  ,
double  ,
double   
) [virtual]

Set / get the region in space in which to perform the sampling. If not specified, it will be computed automatically.

virtual void vtkImplicitModeller::SetModelBounds ( double  [6]  )  [virtual]

Set / get the region in space in which to perform the sampling. If not specified, it will be computed automatically.

virtual double* vtkImplicitModeller::GetModelBounds (  )  [virtual]

Set / get the region in space in which to perform the sampling. If not specified, it will be computed automatically.

virtual void vtkImplicitModeller::GetModelBounds ( double  data[6]  )  [virtual]

Set / get the region in space in which to perform the sampling. If not specified, it will be computed automatically.

virtual void vtkImplicitModeller::SetAdjustBounds ( int   )  [virtual]

Control how the model bounds are computed. If the ivar AdjustBounds is set, then the bounds specified (or computed automatically) is modified by the fraction given by AdjustDistance. This means that the model bounds is expanded in each of the x-y-z directions.

virtual int vtkImplicitModeller::GetAdjustBounds (  )  [virtual]

Control how the model bounds are computed. If the ivar AdjustBounds is set, then the bounds specified (or computed automatically) is modified by the fraction given by AdjustDistance. This means that the model bounds is expanded in each of the x-y-z directions.

virtual void vtkImplicitModeller::AdjustBoundsOn (  )  [virtual]

Control how the model bounds are computed. If the ivar AdjustBounds is set, then the bounds specified (or computed automatically) is modified by the fraction given by AdjustDistance. This means that the model bounds is expanded in each of the x-y-z directions.

virtual void vtkImplicitModeller::AdjustBoundsOff (  )  [virtual]

Control how the model bounds are computed. If the ivar AdjustBounds is set, then the bounds specified (or computed automatically) is modified by the fraction given by AdjustDistance. This means that the model bounds is expanded in each of the x-y-z directions.

virtual void vtkImplicitModeller::SetAdjustDistance ( double   )  [virtual]

Specify the amount to grow the model bounds (if the ivar AdjustBounds is set). The value is a fraction of the maximum length of the sides of the box specified by the model bounds.

virtual double vtkImplicitModeller::GetAdjustDistance (  )  [virtual]

Specify the amount to grow the model bounds (if the ivar AdjustBounds is set). The value is a fraction of the maximum length of the sides of the box specified by the model bounds.

virtual void vtkImplicitModeller::SetCapping ( int   )  [virtual]

The outer boundary of the structured point set can be assigned a particular value. This can be used to close or "cap" all surfaces.

virtual int vtkImplicitModeller::GetCapping (  )  [virtual]

The outer boundary of the structured point set can be assigned a particular value. This can be used to close or "cap" all surfaces.

virtual void vtkImplicitModeller::CappingOn (  )  [virtual]

The outer boundary of the structured point set can be assigned a particular value. This can be used to close or "cap" all surfaces.

virtual void vtkImplicitModeller::CappingOff (  )  [virtual]

The outer boundary of the structured point set can be assigned a particular value. This can be used to close or "cap" all surfaces.

void vtkImplicitModeller::SetCapValue ( double  value  ) 

Specify the capping value to use. The CapValue is also used as an initial distance value at each point in the dataset.

virtual double vtkImplicitModeller::GetCapValue (  )  [virtual]

Specify the capping value to use. The CapValue is also used as an initial distance value at each point in the dataset.

virtual void vtkImplicitModeller::SetScaleToMaximumDistance ( int   )  [virtual]

If a non-floating output type is specified, the output distances can be scaled to use the entire positive scalar range of the output type specified (up to the CapValue which is equal to the max for the type unless modified by the user). For example, if ScaleToMaximumDistance is On and the OutputScalarType is UnsignedChar the distances saved in the output would be linearly scaled between 0 (for distances "very close" to the surface) and 255 (at the specifed maximum distance)... assuming the CapValue is not changed from 255.

virtual int vtkImplicitModeller::GetScaleToMaximumDistance (  )  [virtual]

If a non-floating output type is specified, the output distances can be scaled to use the entire positive scalar range of the output type specified (up to the CapValue which is equal to the max for the type unless modified by the user). For example, if ScaleToMaximumDistance is On and the OutputScalarType is UnsignedChar the distances saved in the output would be linearly scaled between 0 (for distances "very close" to the surface) and 255 (at the specifed maximum distance)... assuming the CapValue is not changed from 255.

virtual void vtkImplicitModeller::ScaleToMaximumDistanceOn (  )  [virtual]

If a non-floating output type is specified, the output distances can be scaled to use the entire positive scalar range of the output type specified (up to the CapValue which is equal to the max for the type unless modified by the user). For example, if ScaleToMaximumDistance is On and the OutputScalarType is UnsignedChar the distances saved in the output would be linearly scaled between 0 (for distances "very close" to the surface) and 255 (at the specifed maximum distance)... assuming the CapValue is not changed from 255.

virtual void vtkImplicitModeller::ScaleToMaximumDistanceOff (  )  [virtual]

If a non-floating output type is specified, the output distances can be scaled to use the entire positive scalar range of the output type specified (up to the CapValue which is equal to the max for the type unless modified by the user). For example, if ScaleToMaximumDistance is On and the OutputScalarType is UnsignedChar the distances saved in the output would be linearly scaled between 0 (for distances "very close" to the surface) and 255 (at the specifed maximum distance)... assuming the CapValue is not changed from 255.

virtual void vtkImplicitModeller::SetProcessMode ( int   )  [virtual]

Specify whether to visit each cell once per append or each voxel once per append. Some tests have shown once per voxel to be faster when there are a lot of cells (at least a thousand?); relative performance improvement increases with addition cells. Primitives should not be stripped for best performance of the voxel mode.

virtual int vtkImplicitModeller::GetProcessMode (  )  [virtual]

Specify whether to visit each cell once per append or each voxel once per append. Some tests have shown once per voxel to be faster when there are a lot of cells (at least a thousand?); relative performance improvement increases with addition cells. Primitives should not be stripped for best performance of the voxel mode.

void vtkImplicitModeller::SetProcessModeToPerVoxel (  )  [inline]

Specify whether to visit each cell once per append or each voxel once per append. Some tests have shown once per voxel to be faster when there are a lot of cells (at least a thousand?); relative performance improvement increases with addition cells. Primitives should not be stripped for best performance of the voxel mode.

Definition at line 192 of file vtkImplicitModeller.h.

void vtkImplicitModeller::SetProcessModeToPerCell (  )  [inline]

Specify whether to visit each cell once per append or each voxel once per append. Some tests have shown once per voxel to be faster when there are a lot of cells (at least a thousand?); relative performance improvement increases with addition cells. Primitives should not be stripped for best performance of the voxel mode.

Definition at line 193 of file vtkImplicitModeller.h.

const char* vtkImplicitModeller::GetProcessModeAsString ( void   ) 

Specify whether to visit each cell once per append or each voxel once per append. Some tests have shown once per voxel to be faster when there are a lot of cells (at least a thousand?); relative performance improvement increases with addition cells. Primitives should not be stripped for best performance of the voxel mode.

virtual void vtkImplicitModeller::SetLocatorMaxLevel ( int   )  [virtual]

Specify the level of the locator to use when using the per voxel process mode.

virtual int vtkImplicitModeller::GetLocatorMaxLevel (  )  [virtual]

Specify the level of the locator to use when using the per voxel process mode.

virtual void vtkImplicitModeller::SetNumberOfThreads ( int   )  [virtual]

Set / Get the number of threads used during Per-Voxel processing mode

virtual int vtkImplicitModeller::GetNumberOfThreads (  )  [virtual]

Set / Get the number of threads used during Per-Voxel processing mode

void vtkImplicitModeller::SetOutputScalarType ( int  type  ) 

Set the desired output scalar type.

virtual int vtkImplicitModeller::GetOutputScalarType (  )  [virtual]

Set the desired output scalar type.

void vtkImplicitModeller::SetOutputScalarTypeToFloat (  )  [inline]

Set the desired output scalar type.

Definition at line 214 of file vtkImplicitModeller.h.

void vtkImplicitModeller::SetOutputScalarTypeToDouble (  )  [inline]

Set the desired output scalar type.

Definition at line 215 of file vtkImplicitModeller.h.

void vtkImplicitModeller::SetOutputScalarTypeToInt (  )  [inline]

Set the desired output scalar type.

Definition at line 216 of file vtkImplicitModeller.h.

void vtkImplicitModeller::SetOutputScalarTypeToUnsignedInt (  )  [inline]

Set the desired output scalar type.

Definition at line 217 of file vtkImplicitModeller.h.

void vtkImplicitModeller::SetOutputScalarTypeToLong (  )  [inline]

Set the desired output scalar type.

Definition at line 219 of file vtkImplicitModeller.h.

void vtkImplicitModeller::SetOutputScalarTypeToUnsignedLong (  )  [inline]

Set the desired output scalar type.

Definition at line 220 of file vtkImplicitModeller.h.

void vtkImplicitModeller::SetOutputScalarTypeToShort (  )  [inline]

Set the desired output scalar type.

Definition at line 222 of file vtkImplicitModeller.h.

void vtkImplicitModeller::SetOutputScalarTypeToUnsignedShort (  )  [inline]

Set the desired output scalar type.

Definition at line 223 of file vtkImplicitModeller.h.

void vtkImplicitModeller::SetOutputScalarTypeToUnsignedChar (  )  [inline]

Set the desired output scalar type.

Definition at line 225 of file vtkImplicitModeller.h.

void vtkImplicitModeller::SetOutputScalarTypeToChar (  )  [inline]

Set the desired output scalar type.

Definition at line 227 of file vtkImplicitModeller.h.

void vtkImplicitModeller::StartAppend (  ) 

Initialize the filter for appending data. You must invoke the StartAppend() method before doing successive Appends(). It's also a good idea to manually specify the model bounds; otherwise the input bounds for the data will be used.

void vtkImplicitModeller::Append ( vtkDataSet input  ) 

Append a data set to the existing output. To use this function, you'll have to invoke the StartAppend() method before doing successive appends. It's also a good idea to specify the model bounds; otherwise the input model bounds is used. When you've finished appending, use the EndAppend() method.

void vtkImplicitModeller::EndAppend (  ) 

Method completes the append process.

int vtkImplicitModeller::ProcessRequest ( vtkInformation ,
vtkInformationVector **  ,
vtkInformationVector  
) [virtual]

see vtkAlgorithm for details

Reimplemented from vtkImageAlgorithm.

double vtkImplicitModeller::GetScalarTypeMax ( int  type  )  [protected]

virtual int vtkImplicitModeller::RequestInformation ( vtkInformation ,
vtkInformationVector **  ,
vtkInformationVector  
) [protected, virtual]

Reimplemented from vtkImageAlgorithm.

virtual int vtkImplicitModeller::RequestData ( vtkInformation request,
vtkInformationVector **  inputVector,
vtkInformationVector outputVector 
) [protected, virtual]

This is called by the superclass. This is the method you should override.

Reimplemented from vtkImageAlgorithm.

void vtkImplicitModeller::StartAppend ( int  internal  )  [protected]

void vtkImplicitModeller::Cap ( vtkDataArray s  )  [protected]

virtual int vtkImplicitModeller::FillInputPortInformation ( int  port,
vtkInformation info 
) [protected, virtual]

Fill the input port information objects for this algorithm. This is invoked by the first call to GetInputPortInformation for each port so subclasses can specify what they can handle.

Reimplemented from vtkImageAlgorithm.


Member Data Documentation

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double vtkImplicitModeller::ModelBounds[6] [protected]

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double vtkImplicitModeller::CapValue [protected]

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

Generated on Wed Jun 3 19:12:01 2009 for VTK by  doxygen 1.5.6