DGtal 1.3.0
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Functions
curvature-measures-icnc-3d.cpp File Reference
DGtal Examples
#include <iostream>
#include <algorithm>
#include "DGtal/base/Common.h"
#include "DGtal/shapes/SurfaceMesh.h"
#include "DGtal/shapes/SurfaceMeshHelper.h"
#include "DGtal/geometry/meshes/CorrectedNormalCurrentComputer.h"
#include "DGtal/io/writers/SurfaceMeshWriter.h"
#include "DGtal/io/colormaps/GradientColorMap.h"
#include "DGtal/io/colormaps/QuantifiedColorMap.h"

Go to the source code of this file.

Functions

DGtal::GradientColorMap< double > makeColorMap (double min_value, double max_value)
 [curvature-measures-Includes] More...
 
void usage (int argc, char *argv[])
 
int main (int argc, char *argv[])
 

Detailed Description

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Author
Jacques-Olivier Lachaud (jacqu.nosp@m.es-o.nosp@m.livie.nosp@m.r.la.nosp@m.chaud.nosp@m.@uni.nosp@m.v-sav.nosp@m.oie..nosp@m.fr ) Laboratory of Mathematics (CNRS, UMR 5127), University of Savoie, France
Date
2021/10/25

An example file named curvature-measures-icnc-3d.

This file is part of the DGtal library.

Definition in file curvature-measures-icnc-3d.cpp.

Function Documentation

◆ main()

int main ( int  argc,
char *  argv[] 
)

[curvature-measures-Typedefs]

[curvature-measures-Typedefs]

[curvature-measures-SurfaceMesh]

[curvature-measures-SurfaceMesh]

[curvature-measures-CNC]

[curvature-measures-CNC]

[curvature-measures-estimations]

[curvature-measures-estimations]

[curvature-measures-check]

[curvature-measures-check]

[curvature-measures-output]

[curvature-measures-output]

Definition at line 124 of file curvature-measures-icnc-3d.cpp.

125{
126 if ( argc <= 1 )
127 {
128 usage( argc, argv );
129 return 0;
130 }
132 using namespace DGtal;
133 using namespace DGtal::Z3i;
134 typedef SurfaceMesh< RealPoint, RealVector > SM;
135 typedef CorrectedNormalCurrentComputer< RealPoint, RealVector > CNC;
136 typedef SurfaceMeshHelper< RealPoint, RealVector > SMH;
138 // a shape in "torus|lantern|sphere"
139 std::string input = argv[ 1 ];
140 int m = argc > 2 ? atoi( argv[ 2 ] ) : 20; // nb latitude points
141 int n = argc > 3 ? atoi( argv[ 3 ] ) : 20; // nb longitude points
142 double R = argc > 4 ? atof( argv[ 4 ] ) : 0.5; // radius of measuring ball
143
145 SM smesh;
146 double exp_H_min = 0.0;
147 double exp_H_max = 0.0;
148 double exp_G_min = 0.0;
149 double exp_G_max = 0.0;
150 if ( input == "torus" )
151 {
152 const double big_radius = 3.0;
153 const double small_radius = 1.0;
154 smesh = SMH::makeTorus( big_radius, small_radius,
155 RealPoint { 0.0, 0.0, 0.0 }, m, n, 0,
156 SMH::NormalsType::VERTEX_NORMALS );
157 exp_H_min = ( 0.5 / ( small_radius - big_radius ) + 0.5 / small_radius );
158 exp_H_max = ( 0.5 / ( big_radius + small_radius ) + 0.5 / small_radius );
159 exp_G_min = ( 1.0 / ( small_radius - big_radius ) * 1.0 / small_radius );
160 exp_G_max = ( 1.0 / ( big_radius + small_radius ) * 1.0 / small_radius );
161 }
162 else if ( input == "sphere" )
163 {
164 const double radius = 2.0;
165 smesh = SMH::makeSphere( radius, RealPoint { 0.0, 0.0, 0.0 }, m, n,
166 SMH::NormalsType::VERTEX_NORMALS );
167 exp_H_min = 1.0 / radius;
168 exp_H_max = 1.0 / radius;
169 exp_G_min = 1.0 / ( radius * radius );
170 exp_G_max = 1.0 / ( radius * radius );
171 }
172 else if ( input == "lantern" )
173 {
174 const double radius = 2.0;
175 smesh = SMH::makeLantern( radius, 1.0, RealPoint { 0.0, 0.0, 0.0 }, m, n,
176 SMH::NormalsType::VERTEX_NORMALS );
177 exp_H_min = 0.5 / radius;
178 exp_H_max = 0.5 / radius;
179 exp_G_min = 0.0;
180 exp_G_max = 0.0;
181 }
183
185 // builds a CorrectedNormalCurrentComputer object onto the torus/lantern/sphere mesh
186 CNC cnc( smesh );
187 // computes area, mean and Gaussian curvature measures
188 auto mu0 = cnc.computeMu0();
189 auto mu1 = cnc.computeMu1();
190 auto mu2 = cnc.computeMu2();
192
194 // estimates mean (H) and Gaussian (G) curvatures by measure normalization.
195 std::vector< double > H( smesh.nbFaces() );
196 std::vector< double > G( smesh.nbFaces() );
197 for ( auto f = 0; f < smesh.nbFaces(); ++f )
198 {
199 const auto b = smesh.faceCentroid( f );
200 const auto area = mu0.measure( b, R, f );
201 H[ f ] = cnc.meanCurvature ( area, mu1.measure( b, R, f ) );
202 G[ f ] = cnc.GaussianCurvature( area, mu2.measure( b, R, f ) );
203 }
205
207 auto H_min_max = std::minmax_element( H.cbegin(), H.cend() );
208 auto G_min_max = std::minmax_element( G.cbegin(), G.cend() );
209 std::cout << "Expected mean curvatures:"
210 << " min=" << exp_H_min << " max=" << exp_H_max
211 << std::endl;
212 std::cout << "Computed mean curvatures:"
213 << " min=" << *H_min_max.first << " max=" << *H_min_max.second
214 << std::endl;
215 std::cout << "Expected Gaussian curvatures:"
216 << " min=" << exp_G_min << " max=" << exp_G_max
217 << std::endl;
218 std::cout << "Computed Gaussian curvatures:"
219 << " min=" << *G_min_max.first << " max=" << *G_min_max.second
220 << std::endl;
222
224 typedef SurfaceMeshWriter< RealPoint, RealVector > SMW;
225 const auto colormapH = makeQuantifiedColorMap( makeColorMap( -0.625, 0.625 ) );
226 const auto colormapG = makeQuantifiedColorMap( makeColorMap( -0.625, 0.625 ) );
227 auto colorsH = SMW::Colors( smesh.nbFaces() );
228 auto colorsG = SMW::Colors( smesh.nbFaces() );
229 for ( auto i = 0; i < smesh.nbFaces(); i++ )
230 {
231 colorsH[ i ] = colormapH( H[ i ] );
232 colorsG[ i ] = colormapG( G[ i ] );
233 }
234 SMW::writeOBJ( "example-cnc-H", smesh, colorsH );
235 SMW::writeOBJ( "example-cnc-G", smesh, colorsG );
237 return 0;
238}
makeColorMap
DGtal::GradientColorMap< double > makeColorMap(double min_value, double max_value)
[curvature-measures-Includes]
Definition: curvature-measures-icnc-3d.cpp:97
DGtal::Z3i
Z3i this namespace gathers the standard of types for 3D imagery.
DGtal
DGtal is the top-level namespace which contains all DGtal functions and types.
Definition: ClosedIntegerHalfPlane.h:49
DGtal::makeQuantifiedColorMap
QuantifiedColorMap< TColorMap > makeQuantifiedColorMap(TColorMap colormap, int nb=50)
Definition: QuantifiedColorMap.h:113
DGtal::CorrectedNormalCurrentComputer
Aim: Utility class to compute curvature measures induced by (1) a corrected normal current defined by...
Definition: CorrectedNormalCurrentComputer.h:70
DGtal::SurfaceMeshHelper
Aim: An helper class for building classical meshes.
Definition: SurfaceMeshHelper.h:64
DGtal::SurfaceMeshWriter
Aim: An helper class for writing mesh file formats (Waverfront OBJ at this point) and creating a Surf...
Definition: SurfaceMeshWriter.h:65
DGtal::SurfaceMesh
Aim: Represents an embedded mesh as faces and a list of vertices. Vertices may be shared among faces ...
Definition: SurfaceMesh.h:92
RealPoint
Z2i::RealPoint RealPoint
Definition: testAstroid2D.cpp:46

References makeColorMap().

◆ makeColorMap()

DGtal::GradientColorMap< double > makeColorMap ( double  min_value,
double  max_value 
)

[curvature-measures-Includes]

[curvature-measures-Includes]

Definition at line 97 of file curvature-measures-icnc-3d.cpp.

98{
99 DGtal::GradientColorMap< double > gradcmap( min_value, max_value );
100 gradcmap.addColor( DGtal::Color( 0, 0, 255 ) );
101 gradcmap.addColor( DGtal::Color( 0, 255, 255 ) );
102 gradcmap.addColor( DGtal::Color( 255, 255, 255 ) );
103 gradcmap.addColor( DGtal::Color( 255, 255, 0 ) );
104 gradcmap.addColor( DGtal::Color( 255, 0, 0 ) );
105 return gradcmap;
106}
DGtal::Color
Structure representing an RGB triple with alpha component.
Definition: Color.h:68
DGtal::GradientColorMap
Aim: This class template may be used to (linearly) convert scalar values in a given range into a colo...
Definition: GradientColorMap.h:120

References DGtal::GradientColorMap< PValue, PDefaultPreset, PDefaultFirstColor, PDefaultLastColor >::addColor().

Referenced by main().

◆ usage()

void usage ( int  argc,
char *  argv[] 
)

Definition at line 108 of file curvature-measures-icnc-3d.cpp.

109{
110 std::cout << "Usage: " << std::endl
111 << "\t" << argv[ 0 ] << " <shape> <m> <n> <R>" << std::endl
112 << std::endl
113 << "Computation of mean and Gaussian curvatures on a shape, " << std::endl
114 << "using interpolated corrected curvature measures (based " << std::endl
115 << "on the theory of corrected normal currents)." << std::endl
116 << "- builds a <shape> in {torus,lantern,sphere}, with " << std::endl
117 << " <m> latitude points and <n> longitude points." << std::endl
118 << "- <R> is the radius of the measuring balls." << std::endl
119 << "It produces several OBJ files to display mean and" << std::endl
120 << "Gaussian curvature estimation results: `example-cnc-H.obj`" << std::endl
121 << "and `example-cnc-G.obj` as well as the associated MTL file." << std::endl;
122}
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