100 lines
2.7 KiB
C++
100 lines
2.7 KiB
C++
#include <igl/boundary_facets.h>
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#include <igl/cotmatrix.h>
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#include <igl/invert_diag.h>
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#include <igl/jet.h>
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#include <igl/massmatrix.h>
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#include <igl/min_quad_with_fixed.h>
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#include <igl/readOFF.h>
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#include <igl/opengl/glfw/Viewer.h>
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#include <Eigen/Sparse>
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#include <iostream>
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#include "tutorial_shared_path.h"
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int main(int argc, char *argv[])
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{
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using namespace Eigen;
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using namespace std;
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MatrixXd V;
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MatrixXi F;
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igl::readOFF(TUTORIAL_SHARED_PATH "/cheburashka.off",V,F);
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// Two fixed points
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VectorXi b(2,1);
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// Left hand, left foot
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b<<4331,5957;
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VectorXd bc(2,1);
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bc<<1,-1;
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// Construct Laplacian and mass matrix
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SparseMatrix<double> L,M,Minv,Q;
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igl::cotmatrix(V,F,L);
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igl::massmatrix(V,F,igl::MASSMATRIX_TYPE_VORONOI,M);
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igl::invert_diag(M,Minv);
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// Bi-Laplacian
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Q = L * (Minv * L);
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// Zero linear term
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VectorXd B = VectorXd::Zero(V.rows(),1);
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VectorXd Z,Z_const;
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{
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// Alternative, short hand
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igl::min_quad_with_fixed_data<double> mqwf;
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// Empty constraints
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VectorXd Beq;
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SparseMatrix<double> Aeq;
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igl::min_quad_with_fixed_precompute(Q,b,Aeq,true,mqwf);
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igl::min_quad_with_fixed_solve(mqwf,B,bc,Beq,Z);
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}
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{
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igl::min_quad_with_fixed_data<double> mqwf;
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// Constraint forcing difference of two points to be 0
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SparseMatrix<double> Aeq(1,V.rows());
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// Right hand, right foot
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Aeq.insert(0,6074) = 1;
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Aeq.insert(0,6523) = -1;
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Aeq.makeCompressed();
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VectorXd Beq(1,1);
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Beq(0) = 0;
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igl::min_quad_with_fixed_precompute(Q,b,Aeq,true,mqwf);
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igl::min_quad_with_fixed_solve(mqwf,B,bc,Beq,Z_const);
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}
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// Pseudo-color based on solution
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struct Data{
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MatrixXd C,C_const;
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} data;
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// Use same color axes
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const double min_z = std::min(Z.minCoeff(),Z_const.minCoeff());
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const double max_z = std::max(Z.maxCoeff(),Z_const.maxCoeff());
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igl::jet( Z,min_z,max_z,data.C);
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igl::jet(Z_const,min_z,max_z,data.C_const);
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// Plot the mesh with pseudocolors
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igl::opengl::glfw::Viewer viewer;
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viewer.data().set_mesh(V, F);
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viewer.data().show_lines = false;
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viewer.data().set_colors(data.C);
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viewer.callback_key_down =
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[](igl::opengl::glfw::Viewer& viewer,unsigned char key,int mod)->bool
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{
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if(key == ' ')
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{
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Data & data = *static_cast<Data*>(viewer.callback_key_down_data);
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static bool toggle = true;
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viewer.data().set_colors(toggle?data.C_const:data.C);
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toggle = !toggle;
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return true;
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}else
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{
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return false;
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}
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};
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viewer.callback_key_down_data = &data;
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cout<<
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"Press [space] to toggle between unconstrained and constrained."<<endl;
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viewer.launch();
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}
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