/usr/include/vtk-6.3/vtkCurvatures.h is in libvtk6-dev 6.3.0+dfsg1-5.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 | /*=========================================================================
Program: Visualization Toolkit
Module: vtkCurvatures.h
Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
All rights reserved.
See Copyright.txt or http://www.kitware.com/Copyright.htm 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.
=========================================================================*/
// .NAME vtkCurvatures - compute curvatures (Gauss and mean) of a Polydata object
// .SECTION Description
// vtkCurvatures takes a polydata input and computes the curvature of the
// mesh at each point. Four possible methods of computation are available :
//
// Gauss Curvature
// discrete Gauss curvature (K) computation,
// \f$K(vertex v) = 2*PI-\sum_{facet neighbs f of v} (angle_f at v)\f$
// The contribution of every facet is for the moment weighted by \f$Area(facet)/3\f$
// The units of Gaussian Curvature are \f$[1/m^2]\f$
//
// Mean Curvature
// \f$H(vertex v) = average over edges neighbs e of H(e)\f$
// \f$H(edge e) = length(e)*dihedral_angle(e)\f$
// NB: dihedral_angle is the ORIENTED angle between -PI and PI,
// this means that the surface is assumed to be orientable
// the computation creates the orientation
// The units of Mean Curvature are [1/m]
//
// Maximum (\f$k_max\f$) and Minimum (\f$k_min\f$) Principal Curvatures
// \f$k_max = H + sqrt(H^2 - K)\f$
// \f$k_min = H - sqrt(H^2 - K)\f$
// Excepting spherical and planar surfaces which have equal principal curvatures,
// the curvature at a point on a surface varies with the direction one "sets off"
// from the point. For all directions, the curvature will pass through two extrema:
// a minimum (\f$k_min\f$) and a maximum (\f$k_max\f$) which occur at mutually orthogonal
// directions to each other.
//
// NB. The sign of the Gauss curvature is a geometric ivariant, it should be +ve
// when the surface looks like a sphere, -ve when it looks like a saddle,
// however, the sign of the Mean curvature is not, it depends on the
// convention for normals - This code assumes that normals point outwards (ie
// from the surface of a sphere outwards). If a given mesh produces curvatures
// of opposite senses then the flag InvertMeanCurvature can be set and the
// Curvature reported by the Mean calculation will be inverted.
//
// .SECTION Thanks
// Philip Batchelor philipp.batchelor@kcl.ac.uk for creating and contributing
// the class and Andrew Maclean a.maclean@acfr.usyd.edu.au for cleanups and
// fixes. Thanks also to Goodwin Lawlor for contributing patch to calculate
// principal curvatures
//
// .SECTION See Also
//
#ifndef vtkCurvatures_h
#define vtkCurvatures_h
#include "vtkFiltersGeneralModule.h" // For export macro
#include "vtkPolyDataAlgorithm.h"
#define VTK_CURVATURE_GAUSS 0
#define VTK_CURVATURE_MEAN 1
#define VTK_CURVATURE_MAXIMUM 2
#define VTK_CURVATURE_MINIMUM 3
class VTKFILTERSGENERAL_EXPORT vtkCurvatures : public vtkPolyDataAlgorithm
{
public:
vtkTypeMacro(vtkCurvatures,vtkPolyDataAlgorithm);
void PrintSelf(ostream& os, vtkIndent indent);
// Description:
// Construct with curvature type set to Gauss
static vtkCurvatures *New();
// Description:
// Set/Get Curvature type
// VTK_CURVATURE_GAUSS: Gaussian curvature, stored as
// DataArray "Gauss_Curvature"
// VTK_CURVATURE_MEAN : Mean curvature, stored as
// DataArray "Mean_Curvature"
vtkSetMacro(CurvatureType,int);
vtkGetMacro(CurvatureType,int);
void SetCurvatureTypeToGaussian()
{ this->SetCurvatureType(VTK_CURVATURE_GAUSS); }
void SetCurvatureTypeToMean()
{ this->SetCurvatureType(VTK_CURVATURE_MEAN); }
void SetCurvatureTypeToMaximum()
{ this->SetCurvatureType(VTK_CURVATURE_MAXIMUM); }
void SetCurvatureTypeToMinimum()
{ this->SetCurvatureType(VTK_CURVATURE_MINIMUM); }
// Description:
// Set/Get the flag which inverts the mean curvature calculation for
// meshes with inward pointing normals (default false)
vtkSetMacro(InvertMeanCurvature,int);
vtkGetMacro(InvertMeanCurvature,int);
vtkBooleanMacro(InvertMeanCurvature,int);
protected:
vtkCurvatures();
// Usual data generation method
int RequestData(vtkInformation *, vtkInformationVector **, vtkInformationVector *);
// Description:
// discrete Gauss curvature (K) computation,
// cf http://www-ipg.umds.ac.uk/p.batchelor/curvatures/curvatures.html
void GetGaussCurvature(vtkPolyData *output);
// discrete Mean curvature (H) computation,
// cf http://www-ipg.umds.ac.uk/p.batchelor/curvatures/curvatures.html
void GetMeanCurvature(vtkPolyData *output);
//Description:
// Maximum principal curvature \f$k_max = H + sqrt(H^2 -K)\f$
void GetMaximumCurvature(vtkPolyData *input, vtkPolyData *output);
//Description:
// Minimum principal curvature \f$k_min = H - sqrt(H^2 -K)\f$
void GetMinimumCurvature(vtkPolyData *input, vtkPolyData *output);
// Vars
int CurvatureType;
int InvertMeanCurvature;
private:
vtkCurvatures(const vtkCurvatures&); // Not implemented.
void operator=(const vtkCurvatures&); // Not implemented.
};
#endif
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