added computation of the per-vertex directions and values of curvature using a quadric fitting method

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Paolo Cignoni 2009-11-05 09:55:43 +00:00
parent 5ef3e2ca50
commit ad4ad4026c
1 changed files with 319 additions and 0 deletions

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/****************************************************************************
* 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. *
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****************************************************************************/
/****************************************************************************
****************************************************************************/
#ifndef VCGLIB_UPDATE_CURVATURE_FITTING
#define VCGLIB_UPDATE_CURVATURE_FITTING
#include <vcg/space/index/grid_static_ptr.h>
#include <vcg/math/base.h>
#include <vcg/math/matrix.h>
#include <vcg/simplex/face/topology.h>
#include <vcg/simplex/face/pos.h>
#include <vcg/simplex/face/jumping_pos.h>
#include <vcg/container/simple_temporary_data.h>
#include <vcg/complex/trimesh/update/normal.h>
#include <vcg/complex/trimesh/point_sampling.h>
#include <vcg/complex/trimesh/append.h>
#include <vcg/complex/intersection.h>
#include <vcg/complex/trimesh/inertia.h>
#include <vcg/math/matrix33.h>
#include <vcg/Eigen/Core>
#include <vcg/Eigen/QR>
#include <vcg/Eigen/LU>
namespace vcg {
namespace tri {
/// \ingroup trimesh
/// \headerfile curvature_fitting.h vcg/complex/trimesh/update/curvature_fitting.h
/// \brief Computation of per-vertex directions and values of curvature.
/**
This class is used to compute the per-vertex directions and values of curvature using a quadric fitting method.
*/
template <class MeshType>
class UpdateCurvatureFitting
{
public:
typedef typename MeshType::FaceType FaceType;
typedef typename MeshType::FacePointer FacePointer;
typedef typename MeshType::FaceIterator FaceIterator;
typedef typename MeshType::VertexIterator VertexIterator;
typedef typename MeshType::VertContainer VertContainer;
typedef typename MeshType::VertexType VertexType;
typedef typename MeshType::VertexPointer VertexPointer;
typedef typename MeshType::VertexPointer VertexTypeP;
typedef vcg::face::VFIterator<FaceType> VFIteratorType;
typedef typename MeshType::CoordType CoordType;
typedef typename CoordType::ScalarType ScalarType;
class Quadric
{
public:
Quadric(double av, double bv, double cv, double dv, double ev)
{
a() = av;
b() = bv;
c() = cv;
d() = dv;
e() = ev;
}
double& a() { return data[0];}
double& b() { return data[1];}
double& c() { return data[2];}
double& d() { return data[3];}
double& e() { return data[4];}
double data[5];
double evaluate(double u, double v)
{
return a*u*u + b*u*v + c*v*v + d*u + e*v;
}
double du(double u, double v)
{
return 2.0*a()*u + b()*v + d();
}
double dv(double u, double v)
{
return 2.0*c()*v + b()*u + e();
}
double duv(double u, double v)
{
return b();
}
double duu(double u, double v)
{
return 2.0*a();
}
double dvv(double u, double v)
{
return 2.0*c();
}
static Quadric fit(vector<CoordType> VV)
{
assert(VV.size() >= 5);
Eigen::MatrixXf A(VV.size(),5);
Eigen::MatrixXf b(VV.size(),1);
Eigen::MatrixXf sol(VV.size(),1);
for(unsigned int c=0; c < VV.size(); ++c)
{
double u = VV[c].X();
double v = VV[c].Y();
double n = VV[c].Z();
A(c,0) = u*u;
A(c,1) = u*v;
A(c,2) = v*v;
A(c,3) = u;
A(c,4) = v;
b[c] = n;
}
sol = ((A.transpose()*A).inverse()*A.transpose())*b;
return Quadric(sol[0],sol[1],sol[2],sol[3],sol[4]);
}
};
static CoordType project(VertexType* v, VertexType* vp)
{
return vp->P() - (v->N() * ((vp->P() - v->P()) * v->N()));
}
static vector<CoordType> computeReferenceFrames(VertexTypeP vi)
{
vcg::face::VFIterator<FaceType> vfi(vi);
int i = (vfi.I()+1)%3;
VertexTypeP vp = vfi.F()->V(i);
CoordType x = (project(&*vi,vp) - vi->P()).Normalize();
assert(fabs(x * vi->N()) < 0.1);
vector<CoordType> res(3);
res[0] = x;
res[1] = (vi->N() ^ res[0]).Normalize();
res[2] = (vi->N())/(vi->N()).Norm();
return res;
}
static set<CoordType> getSecondRing(VertexTypeP v)
{
set<VertexTypeP> ris;
set<CoordType> coords;
vcg::face::VFIterator<FaceType> vvi(v);
for(;!vvi.End();++vvi)
{
vcg::face::VFIterator<FaceType> vvi2(vvi.F()->V((vvi.I()+1)%3));
for(;!vvi2.End();++vvi2)
{
ris.insert(vvi2.F()->V((vvi2.I()+1)%3));
}
}
for(typename set<VertexTypeP>::iterator it = ris.begin(); it != ris.end(); ++it)
coords.insert((*it)->P());
return coords;
}
static Quadric fitQuadric(VertexTypeP v, vector<CoordType>& ref)
{
set<CoordType> ring = getSecondRing(v);
if (ring.size() < 5)
return Quadric(1,1,1,1,1);
vector<CoordType> points;
typename set<CoordType>::iterator b = ring.begin();
typename set<CoordType>::iterator e = ring.end();
while(b != e)
{
// vtang non e` il v tangente!!!
CoordType vTang = *b - v->P();
double x = vTang * ref[0];
double y = vTang * ref[1];
double z = vTang * ref[2];
points.push_back(CoordType(x,y,z));
++b;
}
return Quadric::fit(points);
}
static void computeCurvature(MeshType & m)
{
assert(VertexType::HasVFAdjacency());
assert(FaceType::HasFFAdjacency());
assert(FaceType::HasFaceNormal());
UpdateTopology<MeshType>::VertexFace(m);
vcg::tri::UpdateNormals<MeshType>::PerVertexAngleWeighted(m);
vcg::tri::UpdateNormals<MeshType>::NormalizeVertex(m);
VertexIterator vi;
for(vi = m.vert.begin(); vi!=m.vert.end(); ++vi )
{
vector<CoordType> ref = computeReferenceFrames(&*vi);
Quadric q = fitQuadric(&*vi,ref);
double a = q.a();
double b = q.b();
double c = q.c();
double d = q.d();
double e = q.e();
double E = 1.0 + d*d;
double F = d*e;
double G = 1.0 + e*e;
CoordType n = CoordType(-d,-e,1.0).Normalize();
vi->N() = ref[0] * n[0] + ref[1] * n[1] + ref[2] * n[2];
double L = 2.0 * a * n.Z();
double M = b * n.Z();
double N = 2 * c * n.Z();
// ----------------- Eigen stuff
Eigen::Matrix2d m;
m << L*G - M*F, M*E-L*F, M*E-L*F, N*E-M*F;
m = m / (E*G-F*F);
Eigen::SelfAdjointEigenSolver<Eigen::Matrix2d> eig(m);
Eigen::Vector2d c_val = eig.eigenvalues();
Eigen::Matrix2d c_vec = eig.eigenvectors();
c_val = -c_val;
CoordType v1, v2;
v1[0] = c_vec[0];
v1[1] = c_vec[1];
v1[2] = 0;
v2[0] = c_vec[2];
v2[1] = c_vec[3];
v2[2] = 0;
v1 = v1.Normalize();
v2 = v2.Normalize();
v1 = v1 * c_val[0];
v2 = v2 * c_val[1];
CoordType v1global = ref[0] * v1[0] + ref[1] * v1[1] + ref[2] * v1[2];
CoordType v2global = ref[0] * v2[0] + ref[1] * v2[1] + ref[2] * v2[2];
v1global.Normalize();
v2global.Normalize();
if (c_val[0] > c_val[1])
{
(*vi).PD1() = v1global;
(*vi).PD2() = v2global;
(*vi).K1() = c_val[0];
(*vi).K2() = c_val[1];
}
else
{
(*vi).PD1() = v2global;
(*vi).PD2() = v1global;
(*vi).K1() = c_val[1];
(*vi).K2() = c_val[0];
}
// ---- end Eigen stuff
}
}
};
}
}
#endif