Files
igl/external/lim/LGARAP_LIMSolver3D.cpp
T
schuellc 52e7231cee Added new serialize function
Modified xml serialization
Updated Embree ray intersection checks
Updateded LIM
Various bug fixes
2015-01-28 15:41:51 +01:00

242 lines
7.0 KiB
C++

// Copyright 2013 - Christian Schüller 2013, schuellc@inf.ethz.ch
// Interactive Geometry Lab - ETH Zurich
#include "LGARAP_LIMSolver3D.h"
#include "TetrahedronMesh.h"
#include "igl/svd3x3/svd3x3.h"
#define IGL_HEADER_ONLY
#include "igl/cotmatrix_entries.h"
LGARAP_LIMSolver3D::LGARAP_LIMSolver3D()
{
}
LGARAP_LIMSolver3D::~LGARAP_LIMSolver3D()
{
}
int LGARAP_LIMSolver3D::Solve()
{
computeLocalStep();
return LIMSolver3D::Solve();
}
void LGARAP_LIMSolver3D::computeLocalStep()
{
const int numVertices = mesh->InitalVertices->rows();
const int numTets = mesh->Tetrahedra->rows();
Eigen::MatrixXd uu, CovMat;
Eigen::Matrix3d rot;
Eigen::Matrix<double,6,6> cc;
cc.fill(0);
uu.resize(6,3);
CovMat.resize(3,3);
Eigen::Vector3d u[4];
R.resize(9*numTets);
// local step: Compute best rigid transformations
for (int t=0;t<numTets;t++)
{
Eigen::Matrix<int,4,1> indices = mesh->Tetrahedra->row(t);
for(int i=0;i<4;i++)
u[i] = mesh->DeformedVertices->row(indices[i]);
for(int i=0;i<6;i++)
uu.row(i) = u[TetEdgeVertices[i][1]] - u[TetEdgeVertices[i][0]];
for(int i=0;i<6;i++)
cc(i,i) = CotanWeights(t,i);
CovMat = RestPoseEdges.block<3,6>(3*t,0) * cc * uu;
Eigen::Matrix3f A = CovMat.cast<float>();
Eigen::Matrix<float,3,3> U, Vt;
Eigen::Matrix<float,3,1> S;
igl::svd3x3(A, U, S, Vt);
rot = (Vt * U.transpose()).cast<double>();
const int idx = 9*t;
for(int x=0;x<3;x++)
for(int y=0;y<3;y++)
R(idx+x*3+y) = rot(y,x);
}
}
void LGARAP_LIMSolver3D::debugOutput(std::stringstream& info)
{
std::cout << "AR: " << info.str() << "\n";
}
void LGARAP_LIMSolver3D::prepareProblemData(std::vector<int>& hessRowIdx, std::vector<int>& hessColIdx)
{
const int numVertices = mesh->InitalVertices->rows();
const int numTets = mesh->Tetrahedra->rows();
CotanWeights.resize(numTets,6);
igl::cotmatrix_entries(*mesh->InitalVertices,*mesh->Tetrahedra,CotanWeights);
// Create matrices L, K
Eigen::SparseMatrix<double> B, tempL, tempK, restV;
tempL.resize(numVertices,numVertices);
tempK.resize(3*numTets,numVertices);
std::vector<Eigen::Triplet<double> > LTriplets, BTriplets, KTriplets, VTriplets;
for(int t=0;t<numTets;t++)
{
B.resize(numVertices,6);
restV.resize(numVertices,3);
BTriplets.clear();
VTriplets.clear();
Eigen::Matrix<int,4,1> indices = mesh->Tetrahedra->row(t);
for(int i=0;i<6;i++)
{
int vIdx0 = indices(TetEdgeVertices[i][0]);
int vIdx1 = indices(TetEdgeVertices[i][1]);
// Create incident matrix B_i for i'th triangle
BTriplets.push_back(Eigen::Triplet<double>(vIdx0,i,1));
BTriplets.push_back(Eigen::Triplet<double>(vIdx1,i,-1));
// Create 3D tet rest pose vertex matrix
Eigen::Vector3d v0 = mesh->InitalVertices->row(vIdx0);
Eigen::Vector3d v1 = mesh->InitalVertices->row(vIdx1);
VTriplets.push_back(Eigen::Triplet<double>(vIdx0,0,v0(0)));
VTriplets.push_back(Eigen::Triplet<double>(vIdx0,1,v0(1)));
VTriplets.push_back(Eigen::Triplet<double>(vIdx0,2,v0(2)));
VTriplets.push_back(Eigen::Triplet<double>(vIdx1,0,v1(0)));
VTriplets.push_back(Eigen::Triplet<double>(vIdx1,1,v1(1)));
VTriplets.push_back(Eigen::Triplet<double>(vIdx1,2,v1(2)));
// cotangent gives not cot but multiple of opposite edge length l: l/6*cot
CotanWeights(t,i) = CotanWeights(t,i)*6/(v1-v0).norm();
}
B.setFromTriplets(BTriplets.begin(),BTriplets.end());
restV.setFromTriplets(VTriplets.begin(),VTriplets.end());
// cotangent weights
Eigen::SparseMatrix<double> Cm(6,6);
for(int i=0;i<6;i++)
Cm.insert(i,i) = CotanWeights(t,i);
// Create B*C*B'
Eigen::SparseMatrix<double> BCBT = B*Cm*B.transpose();
// Stack up K temp matrix
Eigen::SparseMatrix<double> tempK = restV.transpose()*BCBT/3.0;
for (int k=0;k<tempK.outerSize();++k)
{
for (Eigen::SparseMatrix<double>::InnerIterator it(tempK,k);it;++it)
{
KTriplets.push_back(Eigen::Triplet<double>(3*t+it.row(),it.col(),it.value()));
}
}
// Sum up L temp matrix
for (int k=0;k<BCBT.outerSize();++k)
{
for (Eigen::SparseMatrix<double>::InnerIterator it(BCBT,k);it;++it)
{
int row = 3*it.row();
int col = 3*it.col();
LTriplets.push_back(Eigen::Triplet<double>(row,col,it.value()));
LTriplets.push_back(Eigen::Triplet<double>(row+1,col+1,it.value()));
LTriplets.push_back(Eigen::Triplet<double>(row+2,col+2,it.value()));
}
}
}
// Create L matrix
L.resize(numVariables,numVariables);
L.setFromTriplets(LTriplets.begin(), LTriplets.end());
// Create K matrix
tempK.setFromTriplets(KTriplets.begin(),KTriplets.end());
K.resize(tempK.rows()*3,tempK.cols()*3);
KTriplets.clear();
for (int k=0;k<tempK.outerSize();++k)
{
for (Eigen::SparseMatrix<double>::InnerIterator it(tempK,k);it;++it)
{
int row = 3*it.row();
int col = 3*it.col();
KTriplets.push_back(Eigen::Triplet<double>(row,col,it.value()));
KTriplets.push_back(Eigen::Triplet<double>(row+1,col+1,it.value()));
KTriplets.push_back(Eigen::Triplet<double>(row+2,col+2,it.value()));
}
}
K.setFromTriplets(KTriplets.begin(), KTriplets.end());
RestPoseEdges.resize(3*numTets,6);
Eigen::Vector3d p[4];
for (int t=0;t<numTets;t++)
{
Eigen::Matrix<int,4,1> indices = mesh->Tetrahedra->row(t);
for(int i=0;i<4;i++)
p[i] = mesh->InitalVertices->row(indices[i]);
for(int i=0;i<6;i++)
RestPoseEdges.block<3,1>(3*t,i) = p[TetEdgeVertices[i][1]] - p[TetEdgeVertices[i][0]];
}
for (int k=0;k<L.outerSize();++k)
{
for (Eigen::SparseMatrix<double>::InnerIterator it(L,k);it;++it)
{
int row = it.row();
int col = it.col();
// std::sort for upper triangule matrix
if(row <= col)
{
hessRowIdx.push_back(row);
hessColIdx.push_back(col);
}
}
}
// compute constant energy bias for restpose
int numVariables = numVertices*3;
Eigen::Matrix<double,Eigen::Dynamic,1> restPose(numVariables);
for(int n=0;n<numVertices;n++)
{
for(int i=0;i<3;i++)
restPose[n*3+i] = mesh->InitalVertices->coeff(n,i);
}
constantEnergyPart = 0.5*restPose.transpose()*L*restPose;
}
double LGARAP_LIMSolver3D::computeFunction(const Eigen::Matrix<double,Eigen::Dynamic,1>& x)
{
// ARAP global step energy
double xTLx = x.transpose()*L*x;
double KTRx = R.transpose()*K*x;
return 0.5*xTLx - KTRx + constantEnergyPart;
}
void LGARAP_LIMSolver3D::computeGradient(const Eigen::Matrix<double,Eigen::Dynamic,1>& x, Eigen::Matrix<double,Eigen::Dynamic,1>& grad)
{
// ARAP global step
grad = L*x - K.transpose()*R;
}
void LGARAP_LIMSolver3D::computeHessian(const Eigen::Matrix<double,Eigen::Dynamic,1>& x, const Eigen::Matrix<double*,Eigen::Dynamic,1>& hess)
{
// ARAP global step
int numElem = 0;
for (int k=0;k<L.outerSize();++k)
{
for (Eigen::SparseMatrix<double>::InnerIterator it(L,k);it;++it)
{
if(it.row() <= it.col())
*hess[numElem++] = it.value();
}
}
}