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vcglib/wrap/igl/smooth_field.h

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/****************************************************************************
* VCGLib o o *
* Visual and Computer Graphics Library o o *
* _ O _ *
* Copyright(C) 2014 \/)\/ *
* 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 SMOOTHER_FIELD_H
#define SMOOTHER_FIELD_H
//eigen stuff
#include <Eigen/Sparse>
//vcg stuff
#include <vcg/complex/algorithms/update/color.h>
#include <vcg/complex/algorithms/update/quality.h>
#include <vcg/complex/algorithms/parametrization/tangent_field_operators.h>
#include <vcg/complex/algorithms/mesh_to_matrix.h>
//igl related stuff
#include <igl/n_polyvector.h>
#include <igl/principal_curvature.h>
#include <igl/igl_inline.h>
#include <igl/copyleft/comiso/nrosy.h>
namespace vcg {
namespace tri {
enum SmoothMethod{SMMiq,SMNPoly};
template <class MeshType>
class FieldSmoother
{
typedef typename MeshType::FaceType FaceType;
typedef typename MeshType::VertexType VertexType;
typedef typename MeshType::ScalarType ScalarType;
typedef typename MeshType::CoordType CoordType;
static void InitQualityByAnisotropyDir(MeshType &mesh)
{
std::vector<ScalarType> QVal;
for (size_t i=0;i<mesh.vert.size();i++)
{
ScalarType N1=fabs(mesh.vert[i].K1());
ScalarType N2=fabs(mesh.vert[i].K2());
QVal.push_back(N1);
QVal.push_back(N2);
}
std::sort(QVal.begin(),QVal.end());
int percUp=int(floor(QVal.size()*0.95+0.5));
ScalarType trimUp=QVal[percUp];
for (size_t i=0;i<mesh.vert.size();i++)
{
ScalarType N1=(mesh.vert[i].K1());
ScalarType N2=(mesh.vert[i].K2());
ScalarType NMax=std::max(N1,N2)/trimUp;
ScalarType NMin=std::min(N1,N2)/trimUp;
if (NMax>1)NMax=1;
if (NMax<-1)NMax=-1;
if (NMin>1)NMin=1;
if (NMin<-1)NMin=-1;
ScalarType CurvAni=(NMax-NMin)/2;
mesh.vert[i].Q()=CurvAni;
}
vcg::tri::UpdateQuality<MeshType>::FaceFromVertex(mesh);
}
static void SetEdgeDirection(FaceType *f,int edge)
{
CoordType dir=f->P0(edge)-f->P1(edge);
dir.Normalize();
ScalarType prod1=fabs(dir*f->PD1());
ScalarType prod2=fabs(dir*f->PD2());
if (prod1>prod2)
{
f->PD1()=dir;
f->PD2()=f->N()^dir;
}else
{
f->PD2()=dir;
f->PD1()=f->N()^dir;
}
}
static void AddSharpEdgesConstraints(MeshType & mesh,
const ScalarType &thr=0.2)
{
for (size_t i=0;i<mesh.face.size();i++)
for (int j=0;j<mesh.face[i].VN();j++)
{
FaceType *f0=&mesh.face[i];
FaceType *f1=f0->FFp(j);
if (f0==f1)continue;
CoordType N0=f0->N();
CoordType N1=f1->N();
if ((N0*N1)>thr)continue;
SetEdgeDirection(f0,j);
f0->SetS();
}
}
static void AddBorderConstraints(MeshType & mesh)
{
for (size_t i=0;i<mesh.face.size();i++)
for (int j=0;j<mesh.face[i].VN();j++)
{
FaceType *f0=&mesh.face[i];
FaceType *f1=f0->FFp(j);
assert(f1!=NULL);
if (f0!=f1)continue;
SetEdgeDirection(f0,j);
f0->SetS();
}
}
static void AddCurvatureConstraints(MeshType & mesh,const ScalarType &thr=0.5)
{
for (size_t i=0;i<mesh.face.size();i++)
if (mesh.face[i].Q()>thr)mesh.face[i].SetS();
}
//hard constraints have selected face
static void CollectHardConstraints( MeshType & mesh,
Eigen::VectorXi &HardI,
Eigen::MatrixXd &HardD,
SmoothMethod SMethod,
int Ndir)
{
//count number of hard constraints
int numS=vcg::tri::UpdateSelection<MeshType>::FaceCount(mesh);
HardI=Eigen::MatrixXi(numS,1);
if ((Ndir==2)||(SMethod==SMMiq))
HardD=Eigen::MatrixXd(numS,3);
else
HardD=Eigen::MatrixXd(numS,6);
//then update them
int curr_index=0;
for (size_t i=0;i<mesh.face.size();i++)
{
if (!mesh.face[i].IsS())continue;
CoordType dir=mesh.face[i].PD1();
dir.Normalize();
HardI(curr_index,0)=i;
HardD(curr_index,0)=dir.X();
HardD(curr_index,1)=dir.Y();
HardD(curr_index,2)=dir.Z();
if ((Ndir==4)&&(SMethod==SMNPoly))
{
dir=mesh.face[i].PD2();
HardD(curr_index,3)=dir.X();
HardD(curr_index,4)=dir.Y();
HardD(curr_index,5)=dir.Z();
}
curr_index++;
}
}
//hard constraints have selected face
static void CollectSoftConstraints( MeshType & mesh,
Eigen::VectorXi &SoftI,
Eigen::MatrixXd &SoftD,
Eigen::VectorXd &SoftW)
{
//count number of soft constraints
int numS=vcg::tri::UpdateSelection<MeshType>::FaceCount(mesh);
numS=mesh.fn-numS;
//allocate eigen matrix
SoftI=Eigen::MatrixXi(numS,1);
SoftD=Eigen::MatrixXd(numS,3);
SoftW=Eigen::MatrixXd(numS,1);
//then update them
int curr_index=0;
for (size_t i=0;i<mesh.face.size();i++)
{
if (mesh.face[i].IsS())continue;
CoordType dir=mesh.face[i].PD1();
dir.Normalize();
SoftI(curr_index,0)=i;
SoftD(curr_index,0)=dir.X();
SoftD(curr_index,1)=dir.Y();
SoftD(curr_index,2)=dir.Z();
SoftW(curr_index,0)=mesh.face[i].Q();
curr_index++;
}
}
static void SmoothMIQ(MeshType &mesh,
Eigen::VectorXi &HardI, //hard constraints index
Eigen::MatrixXd &HardD, //hard directions
Eigen::VectorXi &SoftI, //soft constraints
Eigen::MatrixXd &SoftD, //weight of soft constraints
Eigen::VectorXd &SoftW, //soft directions
ScalarType alpha_soft,
int Ndir)
{
assert((Ndir==2)||(Ndir==4));
Eigen::MatrixXi F;
Eigen::MatrixXd V;
MeshToMatrix<MeshType>::GetTriMeshData(mesh,F,V);
Eigen::MatrixXd output_field;
Eigen::VectorXd output_sing;
igl::copyleft::comiso::nrosy(V,F,HardI,HardD,SoftI,SoftW,SoftD,Ndir,alpha_soft,output_field,output_sing);
//finally update the principal directions
for (size_t i=0;i<mesh.face.size();i++)
{
CoordType dir1;
dir1[0]=output_field(i,0);
dir1[1]=output_field(i,1);
dir1[2]=output_field(i,2);
dir1.Normalize();
CoordType dir2=mesh.face[i].N()^dir1;
dir2.Normalize();
ScalarType Norm1=mesh.face[i].PD1().Norm();
ScalarType Norm2=mesh.face[i].PD2().Norm();
mesh.face[i].PD1()=dir1*Norm1;
mesh.face[i].PD2()=dir2*Norm2;
}
}
static void SmoothNPoly(MeshType &mesh,
Eigen::VectorXi &HardI, //hard constraints index
Eigen::MatrixXd &HardD, //hard directions
int Ndir)
{
assert((Ndir==2)||(Ndir==4));
Eigen::MatrixXi F;
Eigen::MatrixXd V;
MeshToMatrix<MeshType>::GetTriMeshData(mesh,F,V);
Eigen::MatrixXd output_field;
Eigen::VectorXd output_sing;
igl::n_polyvector(V,F,HardI,HardD,output_field);
//finally update the principal directions
for (size_t i=0;i<mesh.face.size();i++)
{
CoordType dir1;
dir1[0]=output_field(i,0);
dir1[1]=output_field(i,1);
dir1[2]=output_field(i,2);
dir1.Normalize();
CoordType dir2=mesh.face[i].N()^dir1;
dir2.Normalize();
ScalarType Norm1=mesh.face[i].PD1().Norm();
ScalarType Norm2=mesh.face[i].PD2().Norm();
mesh.face[i].PD1()=dir1*Norm1;
mesh.face[i].PD2()=dir2*Norm2;
}
}
static void PickRandomDir(MeshType &mesh,
int &indexF,
CoordType &Dir)
{
indexF=rand()%mesh.fn;
FaceType *currF=&mesh.face[indexF];
CoordType dirN=currF->N();
dirN.Normalize();
Dir=CoordType(1,0,0);
if (fabs(Dir*dirN)>0.9)
Dir=CoordType(0,1,0);
if (fabs(Dir*dirN)>0.9)
Dir=CoordType(0,0,1);
Dir=dirN^Dir;
Dir.Normalize();
}
public:
struct SmoothParam
{
//the 90° rotation independence while smoothing the direction field
int Ndir;
//the weight of curvature if doing the smoothing keeping the field close to the original one
ScalarType alpha_curv;
//align the field to border or not
bool align_borders;
//threshold to consider some edge as sharp feature and to use as hard constraint (0, not use)
ScalarType sharp_thr;
//threshold to consider some edge as high curvature anisotropyand to use as hard constraint (0, not use)
ScalarType curv_thr;
//the method used to smooth MIQ or "Designing N-PolyVector Fields with Complex Polynomials"
SmoothMethod SmoothM;
//the number of faces of the ring used ot esteem the curvature
int curvRing;
//this are additional hard constraints
std::vector<std::pair<int,CoordType> > AddConstr;
SmoothParam()
{
Ndir=4;
curvRing=2;
alpha_curv=0.0;
align_borders=false;
SmoothM=SMMiq;
sharp_thr=0.0;
curv_thr=0.4;
}
};
static void SelectConstraints(MeshType &mesh,SmoothParam &SParam)
{
//clear all selected faces
vcg::tri::UpdateFlags<MeshType>::FaceClear(mesh);
//add curvature hard constraints
//ScalarType Ratio=mesh.bbox.Diag()*0.01;
if (SParam.curv_thr>0)
AddCurvatureConstraints(mesh,SParam.curv_thr);///Ratio);
//add alignment to sharp features
if (SParam.sharp_thr>0)
AddSharpEdgesConstraints(mesh,SParam.sharp_thr);
//add border constraints
if (SParam.align_borders)
AddBorderConstraints(mesh);
//aff final constraints
for (int i=0;i<SParam.AddConstr.size();i++)
{
int indexF=SParam.AddConstr[i].first;
CoordType dir=SParam.AddConstr[i].second;
mesh.face[indexF].PD1()=dir;
mesh.face[indexF].PD2()=mesh.face[indexF].N()^dir;
mesh.face[indexF].PD1().Normalize();
mesh.face[indexF].PD2().Normalize();
mesh.face[indexF].SetS();
}
}
static void GloballyOrient(MeshType &mesh)
{
vcg::tri::CrossField<MeshType>::MakeDirectionFaceCoherent(mesh,true);
}
static void InitByCurvature(MeshType & mesh,
unsigned Nring,
bool UpdateFaces=true)
{
tri::RequirePerVertexCurvatureDir(mesh);
Eigen::MatrixXi F;
Eigen::MatrixXd V;
Eigen::MatrixXd PD1,PD2,PV1,PV2;
MeshToMatrix<MeshType>::GetTriMeshData(mesh,F,V);
igl::principal_curvature(V,F,PD1,PD2,PV1,PV2,Nring);
//then copy curvature per vertex
for (size_t i=0;i<mesh.vert.size();i++)
{
mesh.vert[i].PD1()=CoordType(PD1(i,0),PD1(i,1),PD1(i,2));
mesh.vert[i].PD2()=CoordType(PD2(i,0),PD2(i,1),PD2(i,2));
mesh.vert[i].K1()=PV1(i,0);
mesh.vert[i].K2()=PV2(i,0);
}
if (!UpdateFaces)return;
vcg::tri::CrossField<MeshType>::SetFaceCrossVectorFromVert(mesh);
InitQualityByAnisotropyDir(mesh);
}
static void SmoothDirections(MeshType &mesh,
int Ndir,
SmoothMethod SMethod=SMNPoly,
bool HardAsS=true,
ScalarType alphaSoft=0)
{
Eigen::VectorXi HardI; //hard constraints
Eigen::MatrixXd HardD; //hard directions
Eigen::VectorXi SoftI; //soft constraints
Eigen::VectorXd SoftW; //weight of soft constraints
Eigen::MatrixXd SoftD; //soft directions
if (HardAsS)
CollectHardConstraints(mesh,HardI,HardD,SMethod,Ndir);
//collect soft constraints , miw only one that allows for soft constraints
if ((alphaSoft>0)&&(SMethod==SMMiq))
CollectSoftConstraints(mesh,SoftI,SoftD,SoftW);
//add some hard constraints if are not present
int numC=3;
if ((SoftI.rows()==0)&&(HardI.rows()==0))
{
printf("Add Forced Constraints \n");
fflush(stdout);
HardI=Eigen::MatrixXi(numC,1);
if ((Ndir==4)&&(SMethod==SMNPoly))
HardD=Eigen::MatrixXd(numC,6);
else
HardD=Eigen::MatrixXd(numC,3);
for (int i=0;i<numC;i++)
{
CoordType Dir;
int indexF;
PickRandomDir(mesh,indexF,Dir);
HardI(i,0)=indexF;
HardD(i,0)=Dir.X();
HardD(i,1)=Dir.Y();
HardD(i,2)=Dir.Z();
if ((Ndir==4)&&(SMethod==SMNPoly))
{
CoordType Dir1=mesh.face[indexF].N()^Dir;
Dir1.Normalize();
HardD(i,3)=Dir1.X();
HardD(i,4)=Dir1.Y();
HardD(i,5)=Dir1.Z();
}
}
}
//finally smooth
if (SMethod==SMMiq)
SmoothMIQ(mesh,HardI,HardD,SoftI,SoftD,SoftW,alphaSoft,Ndir);
else
{
assert(SMethod==SMNPoly);
SmoothNPoly(mesh,HardI,HardD,Ndir);
}
}
static void SmoothDirections(MeshType &mesh,SmoothParam SParam)
{
//for the moment only cross and line field
//initialize direction by curvature if needed
if ((SParam.alpha_curv>0)||
(SParam.sharp_thr>0)||
(SParam.curv_thr>0))
InitByCurvature(mesh,SParam.curvRing);
SelectConstraints(mesh,SParam);
//then do the actual smooth
SmoothDirections(mesh,SParam.Ndir,SParam.SmoothM,true,SParam.alpha_curv);
}
};
} // end namespace tri
} // end namespace vcg
#endif // SMOOTHER_FIELD_H
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