First version of the implicit smoother

This commit is contained in:
Paolo Cignoni 2014-11-05 15:48:34 +00:00
parent 4dc3c08004
commit d03a5a97d2
2 changed files with 404 additions and 18 deletions

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@ -0,0 +1,304 @@
/****************************************************************************
* VCGLib o o *
* Visual and Computer Graphics Library o o *
* _ O _ *
* Copyright(C) 2004 \/)\/ *
* Visual Computing Lab /\/| *
* ISTI - Italian National Research Council | *
* \ *
* All rights reserved. *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 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 (http://www.gnu.org/licenses/gpl.txt) *
* for more details. *
* *
****************************************************************************/
#ifndef __VCG_IMPLICIT_SMOOTHER
#define __VCG_IMPLICIT_SMOOTHER
#include <eigenlib/Eigen/Sparse>
#include <vcg/complex/algorithms/mesh_to_matrix.h>
#include <vcg/complex/algorithms/update/quality.h>
#include <vcg/complex/algorithms/smooth.h>
#define PENALTY 10000
namespace vcg{
template <class MeshType>
class ImplicitSmoother
{
typedef typename MeshType::FaceType FaceType;
typedef typename MeshType::VertexType VertexType;
typedef typename MeshType::CoordType CoordType;
typedef typename MeshType::ScalarType ScalarType;
typedef typename Eigen::Matrix<ScalarType, Eigen::Dynamic, Eigen::Dynamic> MatrixXm;
MeshType &to_smooth_mesh;
public:
struct FaceConstraint
{
int numF;
std::vector<std::vector<ScalarType> > BarycentricW;
CoordType TargetPos;
ScalarType Weight;
FaceConstraint()
{
numF=-1;
Weight=0;
}
FaceConstraint(int _numF,const std::vector<std::vector<ScalarType> > &_BarycentricW,
const CoordType &_TargetPos,ScalarType _Weight)
{
numF=_numF;
BarycentricW= std::vector<std::vector<ScalarType> > (_BarycentricW.begin(),_BarycentricW.end());
TargetPos=_TargetPos;
Weight=_Weight;
}
};
struct SmoothParam
{
//the amount of smoothness, useful only if we set the mass matrix
ScalarType lambda;
//the use of mass matrix to keep the mesh close to its original position
//(weighted per area distributed on vertices)
bool useMassMatrix;
//this bool is used to fix the border vertices of the mesh or not
bool fixBorder;
//this bool is used to set if cotangent weight is used, this flag to false means uniform laplacian
bool useCotWeight;
//the set of fixed vertices
std::vector<int> FixedV;
//the set of faces for barycentric constraints
std::vector<FaceConstraint> ConstrainedF;
SmoothParam()
{
lambda=0.2;
useMassMatrix=true;
fixBorder=false;
useCotWeight=false;
}
};
private:
// void GetMassMatrix(MeshType &mesh,
// std::vector<std::pair<int,int> > &index,
// std::vector<ScalarType> &entry)
// {
// entry.clear();
// index.clear();
// //calculate area
// vcg::tri::UpdateQuality<MeshType>::FaceArea(mesh);
// //then distribute per vertex
// vcg::tri::UpdateQuality<MeshType>::VertexFromFace(mesh);
// //3, one per coordinate
// index.resize(mesh.vert.size()*3,-1);
// entry.resize(mesh.vert.size()*3,0);
// //store the index and the scalar for the sparse matrix
// for (size_t i=0;i<mesh.vert.size();i++)
// {
// for (size_t j=0;j<3;j++)
// {
// int currI=(i*3)+j;
// index[currI]=currI;
// entry[currI]=mesh.vert[i].Q();
// }
// }
// }
void InitSparse(const std::vector<std::pair<int,int> > &Index,
const std::vector<ScalarType> &Values,
const size_t m,
const size_t n,
Eigen::SparseMatrix<ScalarType>& X)
{
assert(Index.size()==Values.size());
std::vector<Eigen::Triplet<ScalarType> > IJV;
IJV.reserve(Index.size());
for(size_t i= 0;i<Index.size();i++)
{
int row=Index[i].first;
int col=Index[i].second;
ScalarType val=Values[i];
assert(row<m);
assert(col<n);
IJV.push_back(Eigen::Triplet<ScalarType>(row,col,val));
}
X.resize(m,n);
X.setFromTriplets(IJV.begin(),IJV.end());
}
int SystemSize(SmoothParam & SParam)
{
int basic_size=to_smooth_mesh.vert.size();
int constr_size=SParam.ConstrainedF.size();
return (basic_size+constr_size);
}
void CollectHardConstraints(const SmoothParam &SParam,
std::vector<std::pair<int,int> > &IndexC,
std::vector<ScalarType> &WeightC)
{
std::vector<int> To_Fix;
//collect fixed vert
if (SParam.fixBorder)
{
//add penalization constra
for (int i=0;i<to_smooth_mesh.vert.size();i++)
{
if (!to_smooth_mesh.vert[i].IsB())continue;
To_Fix.push_back(i);
}
}
//add additional fixed vertices constraint
To_Fix.insert(To_Fix.end(),SParam.FixedV.begin(),SParam.FixedV.end());
//sort and make them unique
std::sort(To_Fix.begin(),To_Fix.end());
typename std::vector<int>::iterator it= std::unique (To_Fix.begin(), To_Fix.end());
To_Fix.resize( std::distance(To_Fix.begin(),it) );
for (size_t i=0;i<To_Fix.size();i++)
{
for (int j=0;j<3;j++)
{
int IndexV=(i*3)+j;
IndexC.push_back(std::pair<int,int>(IndexV,IndexV));
WeightC.push_back((ScalarType)PENALTY);
}
}
}
public:
//static void Smooth
// static void SmoothLIbIGL(MeshType &mesh,
// ScalarType lambda=0.5)//0.0001)
// {
// Eigen::MatrixXi F;
// Eigen::MatrixXd V,U;
// vcg::tri::MeshToMatrix<MeshType>::GetTriMeshData(mesh,F,V);
// U=V;
// Eigen::SparseMatrix<ScalarType> L,M;
// igl::cotmatrix(V,F,L);
// //compute the mass matrix
// static bool computed=false;
// igl::massmatrix(V,F,igl::MASSMATRIX_TYPE_BARYCENTRIC,M);
// M.setIdentity();
// computed=true;
// //const auto & S = (M - 0.001*L);
// Eigen::SparseMatrix<double> S = (M - lambda*L);
// Eigen::SimplicialLLT<Eigen::SparseMatrix<double > > solver(S);
// assert(solver.info() == Eigen::Success);
// U = solver.solve(M*U).eval();
// // Normalize to unit surface area (important for numerics)
// U.array() /= sqrt(M.diagonal().array().sum());
// //then assing per vertex positions
// printf("smoothed \n");
// fflush(stdout);
// for (size_t i=0;i<mesh.vert.size();i++)
// {
// mesh.vert[i].P().X()=U(i,0);
// mesh.vert[i].P().Y()=U(i,1);
// mesh.vert[i].P().Z()=U(i,2);
// }
// }
void Smooth(SmoothParam &SParam)
{
//the laplacian and the mass matrix
Eigen::SparseMatrix<ScalarType> L,M;
//initialize the mass matrix
std::vector<std::pair<int,int> > IndexM;
std::vector<ScalarType> ValuesM;
//add the entries for mass matrix
if (SParam.useMassMatrix) MeshToMatrix<MeshType>::MassMatrixEntry(to_smooth_mesh,IndexM,ValuesM);
//then also collect hard constraints
//CollectHardConstraints(SParam,IndexM,ValuesM);
//initialize sparse mass matrix
InitSparse(IndexM,ValuesM,to_smooth_mesh.vert.size()*3,to_smooth_mesh.vert.size()*3,M);
//get the entries for laplacian matrix
std::vector<std::pair<int,int> > IndexL;
std::vector<ScalarType> ValuesL;
MeshToMatrix<MeshType>::GetLaplacianMatrix(to_smooth_mesh,IndexL,ValuesL,false);//SParam.useCotWeight);
//initialize sparse laplacian matrix
InitSparse(IndexL,ValuesL,to_smooth_mesh.vert.size()*3,to_smooth_mesh.vert.size()*3,L);
//then solve the system
Eigen::SparseMatrix<ScalarType> S = (M + SParam.lambda*L);
//SimplicialLDLT
Eigen::SimplicialLDLT<Eigen::SparseMatrix<ScalarType > > solver(S);
printf("output %d \n",solver.info());
fflush(stdout);
assert(solver.info() == Eigen::Success);
int size=to_smooth_mesh.vert.size()*3;
MatrixXm V(size,1);
for (size_t i=0;i<to_smooth_mesh.vert.size();i++)
{
int index=i*3;
assert(index<size);
V(index,0)=to_smooth_mesh.vert[i].P().X();
V(index+1,0)=to_smooth_mesh.vert[i].P().Y();
V(index+2,0)=to_smooth_mesh.vert[i].P().Z();
}
V = solver.solve(M*V).eval();
for (size_t i=0;i<to_smooth_mesh.vert.size();i++)
{
int index=i*3;
to_smooth_mesh.vert[i].P().X()=V(index,0);
to_smooth_mesh.vert[i].P().Y()=V(index+1,0);
to_smooth_mesh.vert[i].P().Z()=V(index+2,0);
}
}
ImplicitSmoother(MeshType &_to_smooth_mesh):to_smooth_mesh(_to_smooth_mesh){}
};
}//end namespace vcg
#endif

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@ -25,23 +25,26 @@
#include <vcg/complex/complex.h>
#include <vcg/complex/algorithms/update/topology.h>
#include <vcg/complex/algorithms/update/quality.h>
#include <vcg/complex/algorithms/harmonic.h>
using namespace std;
namespace vcg {
namespace tri {
template < typename TriMeshType >
template < typename MeshType >
class MeshToMatrix
{
// define types
typedef typename TriMeshType::FaceType FaceType;
typedef typename TriMeshType::VertexType VertexType;
typedef typename TriMeshType::CoordType CoordType;
typedef typename TriMeshType::ScalarType ScalarType;
typedef typename MeshType::FaceType FaceType;
typedef typename MeshType::VertexType VertexType;
typedef typename MeshType::CoordType CoordType;
typedef typename MeshType::ScalarType ScalarType;
typedef typename Eigen::Matrix<ScalarType, Eigen::Dynamic, Eigen::Dynamic> MatrixXm;
static void GetTriEdgeAdjacency(const Eigen::MatrixXd& V,
static void GetTriEdgeAdjacency(const MatrixXm& V,
const Eigen::MatrixXi& F,
Eigen::MatrixXi& EV,
Eigen::MatrixXi& FE,
@ -128,13 +131,13 @@ class MeshToMatrix
public:
// return mesh as vector of vertices and faces
static void GetTriMeshData(const TriMeshType &mesh,
static void GetTriMeshData(const MeshType &mesh,
Eigen::MatrixXi &faces,
Eigen::MatrixXd &vert)
MatrixXm &vert)
{
tri::RequireCompactness(mesh);
// create eigen matrix of vertices
vert=Eigen::MatrixXd(mesh.VN(), 3);
vert=MatrixXm(mesh.VN(), 3);
// copy vertices
for (int i = 0; i < mesh.VN(); i++)
@ -151,13 +154,13 @@ public:
}
// return normals of the mesh
static void GetNormalData(const TriMeshType &mesh,
Eigen::MatrixXd &Nvert,
Eigen::MatrixXd &Nface)
static void GetNormalData(const MeshType &mesh,
MatrixXm &Nvert,
MatrixXm &Nface)
{
// create eigen matrix of vertices
Nvert=Eigen::MatrixXd(mesh.VN(), 3);
Nface=Eigen::MatrixXd(mesh.FN(), 3);
Nvert=MatrixXm(mesh.VN(), 3);
Nface=MatrixXm(mesh.FN(), 3);
// per vertices normals
for (int i = 0; i < mesh.VN(); i++)
@ -171,11 +174,11 @@ public:
}
// get face to face adjacency
static void GetTriFFAdjacency(TriMeshType &mesh,
static void GetTriFFAdjacency(MeshType &mesh,
Eigen::MatrixXi &FFp,
Eigen::MatrixXi &FFi)
{
tri::UpdateTopology<TriMeshType>::FaceFace(mesh);
tri::UpdateTopology<MeshType>::FaceFace(mesh);
FFp = Eigen::MatrixXi(mesh.FN(),3);
FFi = Eigen::MatrixXi(mesh.FN(),3);
@ -197,13 +200,13 @@ public:
}
// get edge to face and edge to vertex adjacency
static void GetTriEdgeAdjacency(const TriMeshType &mesh,
static void GetTriEdgeAdjacency(const MeshType &mesh,
Eigen::MatrixXi& EV,
Eigen::MatrixXi& FE,
Eigen::MatrixXi& EF)
{
Eigen::MatrixXi faces;
Eigen::MatrixXd vert;
MatrixXm vert;
GetTriMeshData(mesh,faces,vert);
GetTriEdgeAdjacency(vert,faces,EV,FE,EF);
}
@ -213,6 +216,85 @@ public:
Eigen::Vector3d ret(v[0],v[1],v[2]);
return ret;
}
static void MassMatrixEntry(MeshType &mesh,
std::vector<std::pair<int,int> > &index,
std::vector<ScalarType> &entry)
{
//calculate area
UpdateQuality<MeshType>::FaceArea(mesh);
//then distribute per vertex
UpdateQuality<MeshType>::VertexFromFace(mesh);
std::pair<float,float> minmax=Stat<MeshType>::ComputePerVertexQualityMinMax(mesh);
//store the index and the scalar for the sparse matrix
for (size_t i=0;i<mesh.vert.size();i++)
{
for (size_t j=0;j<3;j++)
{
int currI=(i*3)+j;
index.push_back(std::pair<int,int>(currI,currI));
entry.push_back(mesh.vert[i].Q()/(ScalarType)minmax.second);
}
}
}
static void GetLaplacianEntry(MeshType &mesh,
FaceType &f,
std::vector<std::pair<int,int> > &index,
std::vector<ScalarType> &entry,
bool cotangent)
{
for (int i=0;i<3;i++)
{
ScalarType weight = 1;
if (cotangent)
{
weight=Harmonic<MeshType>::template CotangentWeight<ScalarType>(f,i);
}
//get the index of the vertices
int indexV0=Index(mesh,f.V0(i));
int indexV1=Index(mesh,f.V1(i));
//then assemble the matrix
for (int j=0;j<3;j++)
{
//multiply by 3 and add the component
int currI0=(indexV0*3)+j;
int currI1=(indexV1*3)+j;
index.push_back(std::pair<int,int>(currI0,currI0));
entry.push_back(weight);
index.push_back(std::pair<int,int>(currI0,currI1));
entry.push_back(-weight);
index.push_back(std::pair<int,int>(currI1,currI1));
entry.push_back(weight);
index.push_back(std::pair<int,int>(currI1,currI0));
entry.push_back(-weight);
}
}
}
static void GetLaplacianMatrix(MeshType &mesh,
std::vector<std::pair<int,int> > &index,
std::vector<ScalarType> &entry,
bool cotangent)
{
//store the index and the scalar for the sparse matrix
for (size_t i=0;i<mesh.face.size();i++)
GetLaplacianEntry(mesh,mesh.face[i],index,entry,cotangent);
}
};
} // end namespace tri