103 lines
2.7 KiB
C++
103 lines
2.7 KiB
C++
// Copyright 2013 - Christian Schüller 2013, schuellc@inf.ethz.ch
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// Interactive Geometry Lab - ETH Zurich
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#include "Laplacian_LIMSolver2D.h"
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#include "TriangleMesh.h"
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#define IGL_HEADER_ONLY
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#include "igl/cotmatrix.h"
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#include "igl/massmatrix.h"
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Laplacian_LIMSolver2D::Laplacian_LIMSolver2D()
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{
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}
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Laplacian_LIMSolver2D::~Laplacian_LIMSolver2D()
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{
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}
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void Laplacian_LIMSolver2D::debugOutput(std::stringstream& info)
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{
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std::cout << "LP: " << info.str() << "\n";
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}
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void Laplacian_LIMSolver2D::prepareProblemData(std::vector<int>& hessRowIdx, std::vector<int>& hessColIdx)
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{
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const int numNodes = mesh->InitalVertices->rows();
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// create sparse laplacian matrix L
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Eigen::SparseMatrix<double> tempL;
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Eigen::SparseMatrix<double> M;
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igl::massmatrix(*mesh->InitalVertices,*mesh->Triangles,igl::MASSMATRIX_TYPE_VORONOI, M);
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igl::cotmatrix(*mesh->InitalVertices, *mesh->Triangles,tempL);
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tempL *= -1;
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// compute inverse of mass matrix
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for (int k=0;k<M.outerSize();++k)
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{
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for (Eigen::SparseMatrix<double>::InnerIterator it(M,k);it;++it)
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{
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it.valueRef() = 1.0/it.value();
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}
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}
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tempL = tempL*M*tempL;
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// Create L matrix
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L.resize(numVariables,numVariables);
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std::vector<Eigen::Triplet<double> > triplets;
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for (int k=0;k<tempL.outerSize();++k)
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{
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for (Eigen::SparseMatrix<double>::InnerIterator it(tempL,k);it;++it)
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{
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int row = 2*it.row();
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int col = 2*it.col();
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triplets.push_back(Eigen::Triplet<double>(row,col,it.value()));
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triplets.push_back(Eigen::Triplet<double>(row+1,col+1,it.value()));
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}
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}
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L.setFromTriplets(triplets.begin(), triplets.end());
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for (int k=0;k<L.outerSize();++k)
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{
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for (Eigen::SparseMatrix<double>::InnerIterator it(L,k);it;++it)
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{
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int row = it.row();
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int col = it.col();
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// std::sort for upper triangule matrix
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if(row <= col)
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{
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hessRowIdx.push_back(row);
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hessColIdx.push_back(col);
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}
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}
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}
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}
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double Laplacian_LIMSolver2D::computeFunction(const Eigen::Matrix<double,Eigen::Dynamic,1>& x)
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{
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// laplacian energy function f(v) = (v-p)'L(v-p)
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Eigen::VectorXd vv0 = x-initialNodes;
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return 0.5 * vv0.transpose() * L * vv0;
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}
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void Laplacian_LIMSolver2D::computeGradient(const Eigen::Matrix<double,Eigen::Dynamic,1>& x, Eigen::Matrix<double,Eigen::Dynamic,1>& grad)
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{
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// laplacian
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grad = L * (x-initialNodes);
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}
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void Laplacian_LIMSolver2D::computeHessian(const Eigen::Matrix<double,Eigen::Dynamic,1>& x, const Eigen::Matrix<double*,Eigen::Dynamic,1>& hess)
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{
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// laplacian
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int numElem = 0;
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for (int k=0;k<L.outerSize();++k)
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{
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for (Eigen::SparseMatrix<double>::InnerIterator it(L,k);it;++it)
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{
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if(it.row() <= it.col())
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*hess[numElem++] = it.value();
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}
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}
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} |