vcglib/vcg/space/fitting3.h

189 lines
4.9 KiB
C++

/****************************************************************************
* 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. *
* *
****************************************************************************/
/****************************************************************************
History
$Log: not supported by cvs2svn $
Revision 1.2 2005/10/13 14:59:57 ganovelli
versione con svd
Revision 1.1 2005/03/14 17:04:24 ganovelli
created
****************************************************************************/
#ifndef __VCGLIB_FITTING3
#define __VCGLIB_FITTING3
#include <vector>
#include <vcg/space/plane3.h>
#include <vcg/math/matrix44.h>
#include <vcg/math/matrix33.h>
#include <vcg/math/lin_algebra.h>
namespace vcg {
template <class S>
bool PlaneFittingPoints( std::vector< Point3<S> > & samples,Plane3<S> &p){
int j;
Matrix44<S> m;m.SetZero();
typename std::vector< Point3<S> > ::iterator i;
Point3<S> c; c.Zero();
for(i = samples.begin(); i != samples.end(); ++i)
c+=*i;
c/=samples.size();
for(i = samples.begin(); i != samples.end(); ++i){
Point3<S> p = (*i)-c;
for(j = 0 ; j < 3;++j)
*(Point3<S>*)&m[j][0] += p * p[j];
}
m[0][3]= m[1][3]=m[2][3]=0.0;
m[3][3]= 1.0;
m[3][0]= m[3][1]=m[3][2]=0.0;
int n;
Matrix44<S> res;
Point4<S> e;
Point3<S> d;
Jacobi(m,e,res,n);
S mx = fabs(e[0]); int mxi=0;
for(j=1; j < 3; ++j) if( (fabs(e[j]) < mx) ) {mx=fabs(e[j]); mxi = j;}
d[0]=res[0][mxi];
d[1]=res[1][mxi];
d[2]=res[2][mxi];
p.SetOffset(c*d/d.Norm());
p.SetDirection(d/d.Norm());
return true;
}
template<class S>
inline double FIT_VExp( const Point3<S> & x, const int i )
{
assert(i>=0);
assert(i<4);
if(i==0) return 1;
else return x[i-1];
}
/** Fitting di piani: trova il piano che meglio approssima
l'insieme di punti dato
*/
template<class S>
bool PlaneFittingPointsOld( std::vector< Point3<S> > & samples, Plane3<S> & p )
{
Point3<S> d;
const int N = 4;
S P[N][N]; // A = s' . s
S U[N][N];
int i,j,k,n;
n = (int)samples.size();
if(n<3)
return false;
//printf("\n p_prima: %f %f %f %f \n",p.Offset(),p.Direction()[0],p.Direction()[1],p.Direction()[2]);
for(i=0;i<N;++i)
{
for(j=i;j<N;++j)
{
P[i][j] = 0;
for(k=0;k<n;++k)
P[i][j] += FIT_VExp(samples[k],i) * FIT_VExp(samples[k],j);
}
for(j=0;j<i;++j)
P[i][j] = P[j][i];
}
//printf("D \n");
//for(i=0;i<N;++i){
// printf("\n");
// for(j=0;j<N;++j)
// printf("%2.3f\t",P[i][j]);
//}
//
Matrix44<S> m;
for(i=0;i<N;++i)
for(j=0;j<N;++j)
m[i][j]=P[i][j];
// Point4<S> s;s.Zero();
//
// s.Normalize();
// printf("\n RES %f %f %f %f \n",s[0],s[1],s[2],s[3]);
//printf("\n GJ \n");
// for(i=0;i<N;++i){
// printf("\n");
// for(j=0;j<N;++j)
// printf("%2.3f\t",m[i][j]);
// }
for(i=0;i<N;++i)
{
U[i][i] = 1.0;
for(j=0;j<i;++j)
U[i][j] = 0.0;
for(j=i+1;j<N;++j)
{
if(P[i][i]==0.0)
return false;
U[i][j] = P[i][j]/P[i][i];
for(k=j;k<N;++k)
P[j][k] -= U[i][j]*P[i][k];
}
}
//printf("\n U \n");
//for(i=0;i<N;++i){
// printf("\n");
// for(j=0;j<N;++j)
// printf("%2.3f\t",U[i][j]);
//}
S norm = Point3<S>(U[1][2]*U[2][3]-U[1][3],-U[2][3],1).Norm();
p.SetDirection(Point3<S>(U[1][2]*U[2][3]-U[1][3],-U[2][3],1));
p.SetOffset(-(U[0][2]*U[2][3]-U[0][3]+U[0][1]*U[1][3]-U[0][1]*U[1][2]*U[2][3])/norm);
//printf("\n p: %f %f %f %f \n",p.Offset(),p.Direction()[0],p.Direction()[1],p.Direction()[2]);
return true;
}
} // end namespace
#endif