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/*=========================================================================
Program: Visualization Toolkit
Module: vtkFitImplicitFunction.h
Copyright (c) Kitware, Inc.
All rights reserved.
See LICENSE file for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notice for more information.
=========================================================================*/
/**
* @class vtkFitImplicitFunction
* @brief extract points on the surface of an implicit function
*
*
* vtkFitImplicitFunction extract points that are on the surface of an
* implicit function (within some threshold). Implicit functions in VTK are
* any function of the form f(x,y,z)=c, where values c==0 are considered the
* surface of the implicit function. Typical examples of implicit functions
* include planes, spheres, cylinders, cones, etc. plus boolean combinations
* of these functions. In this implementation, a threshold is used to create
* a fuzzy region considered "on" the surface. In essence, this is a very
* poor man's RANSAC algorithm, where the user picks a function on which to
* fit some points. Thus it is possible to use this filter to define a
* proposed model and place it into an optimization loop to best fit it to a
* set of points.
*
* Note that while any vtkPointSet type can be provided as input, the output is
* represented by an explicit representation of points via a
* vtkPolyData. This output polydata will populate its instance of vtkPoints,
* but no cells will be defined (i.e., no vtkVertex or vtkPolyVertex are
* contained in the output). Also, after filter execution, the user can
* request a vtkIdType* map which indicates how the input points were mapped
* to the output. A value of map[i] (where i is the ith input point) less
* than 0 means that the ith input point was removed. (See also the
* superclass documentation for accessing the removed points through the
* filter's second output.)
*
* @warning
* This class has been threaded with vtkSMPTools. Using TBB or other
* non-sequential type (set in the CMake variable
* VTK_SMP_IMPLEMENTATION_TYPE) may improve performance significantly.
*
* @sa
* vtkPointCloudFilter vtkExtractPoints vtkImplicitFunction
*/
#ifndef vtkFitImplicitFunction_h
#define vtkFitImplicitFunction_h
#include "vtkFiltersPointsModule.h" // For export macro
#include "vtkPointCloudFilter.h"
class vtkImplicitFunction;
class vtkPointSet;
class VTKFILTERSPOINTS_EXPORT vtkFitImplicitFunction : public vtkPointCloudFilter
{
public:
//@{
/**
* Standard methods for instantiating, obtaining type information, and
* printing information.
*/
static vtkFitImplicitFunction *New();
vtkTypeMacro(vtkFitImplicitFunction,vtkPointCloudFilter);
void PrintSelf(ostream& os, vtkIndent indent);
//@}
//@{
/**
* Specify the implicit function defining a surface on which points
* are to be extracted.
*/
virtual void SetImplicitFunction(vtkImplicitFunction*);
vtkGetObjectMacro(ImplicitFunction,vtkImplicitFunction);
//@}
//@{
/**
* Specify a threshold value which defines a fuzzy extraction surface.
* Since in this filter the implicit surface is defined as f(x,y,z)=0;
* the extracted points are (-Threshold <= f(x,y,z) < Threshold).
*/
vtkSetClampMacro(Threshold,double,0.0,VTK_FLOAT_MAX);
vtkGetMacro(Threshold,double);
//@}
/**
* Return the MTime taking into account changes to the implicit function.
*/
virtual vtkMTimeType GetMTime();
protected:
vtkFitImplicitFunction();
~vtkFitImplicitFunction();
vtkImplicitFunction *ImplicitFunction;
double Threshold;
// All derived classes must implement this method. Note that a side effect of
// the class is to populate the PointMap. Zero is returned if there is a failure.
virtual int FilterPoints(vtkPointSet *input);
private:
vtkFitImplicitFunction(const vtkFitImplicitFunction&) VTK_DELETE_FUNCTION;
void operator=(const vtkFitImplicitFunction&) VTK_DELETE_FUNCTION;
};
#endif
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