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create/src/Mod/Mesh/App/Core/Approximation.h

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/***************************************************************************
* Copyright (c) 2005 Imetric 3D GmbH *
* *
* This file is part of the FreeCAD CAx development system. *
* *
* This library is free software; you can redistribute it and/or *
* modify it under the terms of the GNU Library General Public *
* License as published by the Free Software Foundation; either *
* version 2 of the License, or (at your option) any later version. *
* *
* This library 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 Library General Public License for more details. *
* *
* You should have received a copy of the GNU Library General Public *
* License along with this library; see the file COPYING.LIB. If not, *
* write to the Free Software Foundation, Inc., 59 Temple Place, *
* Suite 330, Boston, MA 02111-1307, USA *
* *
***************************************************************************/
#ifndef MESH_APPROXIMATION_H
#define MESH_APPROXIMATION_H
#include <Mod/Mesh/App/WildMagic4/Wm4Vector3.h>
#include <Mod/Mesh/App/WildMagic4/Wm4QuadricSurface.h>
#include <Mod/Mesh/App/WildMagic4/Wm4Eigen.h>
#include <Mod/Mesh/App/WildMagic4/Wm4ImplicitSurface.h>
#include <list>
#include <set>
#include <vector>
#include <Base/Vector3D.h>
#include <Base/Matrix.h>
namespace Wm4
{
/**
* An implicit surface is defined by F(x,y,z) = 0.
* This polynomial surface is actually defined as z = f(x,y) = ax^2 + by^2 + cx + dy + exy + g.
* To use Wm3 routines for implicit surfaces we can write the surface also as F(x,y,z) = f(x,y) - z = 0.
* @author Werner Mayer
*/
template <class Real>
class PolynomialSurface : public ImplicitSurface<Real>
{
public:
PolynomialSurface (const Real afCoeff[6])
{ for (int i=0; i<6; i++) m_afCoeff[i] = afCoeff[i]; }
virtual ~PolynomialSurface () {}
// the function
virtual Real F (const Vector3<Real>& rkP) const
{
return ( m_afCoeff[0]*rkP.X()*rkP.X() +
m_afCoeff[1]*rkP.Y()*rkP.Y() +
m_afCoeff[2]*rkP.X() +
m_afCoeff[3]*rkP.Y() +
m_afCoeff[4]*rkP.X()*rkP.Y() +
m_afCoeff[5]-rkP.Z()) ;
}
// first-order partial derivatives
virtual Real FX (const Vector3<Real>& rkP) const
{ return (Real)(2.0*m_afCoeff[0]*rkP.X() + m_afCoeff[2] + m_afCoeff[4]*rkP.Y()); }
virtual Real FY (const Vector3<Real>& rkP) const
{ return (Real)(2.0*m_afCoeff[1]*rkP.Y() + m_afCoeff[3] + m_afCoeff[4]*rkP.X()); }
virtual Real FZ (const Vector3<Real>& rkP) const
{ return (Real)-1.0; }
// second-order partial derivatives
virtual Real FXX (const Vector3<Real>& rkP) const
{ return (Real)(2.0*m_afCoeff[0]); }
virtual Real FXY (const Vector3<Real>& rkP) const
{ return (Real)(m_afCoeff[4]); }
virtual Real FXZ (const Vector3<Real>& rkP) const
{ return (Real)0.0; }
virtual Real FYY (const Vector3<Real>& rkP) const
{ return (Real)(2.0*m_afCoeff[1]); }
virtual Real FYZ (const Vector3<Real>& rkP) const
{ return (Real)0.0; }
virtual Real FZZ (const Vector3<Real>& rkP) const
{ return (Real)0.0; }
protected:
Real m_afCoeff[6];
};
}
namespace MeshCore {
/**
* Abstract base class for approximation of a geometry to a given set of points.
*/
class MeshExport Approximation
{
public:
/**
* Construction
*/
Approximation();
/**
* Destroys the object and frees any allocated resources.
*/
virtual ~Approximation();
/**
* Add point for the fit algorithm.
*/
void AddPoint(const Base::Vector3f &rcVector);
/**
* Add points for the fit algorithm.
*/
void AddPoints(const std::vector<Base::Vector3f> &rvPointVect);
/**
* Add points for the fit algorithm.
*/
void AddPoints(const std::set<Base::Vector3f> &rsPointSet);
/**
* Add points for the fit algorithm.
*/
void AddPoints(const std::list<Base::Vector3f> &rsPointList);
/**
* Get all added points.
*/
const std::list<Base::Vector3f>& GetPoints() const { return _vPoints; }
/**
* Returns the center of gravity of the current added points.
* @return Base::Vector3f
*/
Base::Vector3f GetGravity() const;
/**
* Determines the number of the current added points.
* @return Number of points
*/
unsigned long CountPoints() const;
/**
* Deletes the inserted points and frees any allocated resources.
*/
void Clear();
/**
* Returns the result of the last fit.
* @return float Quality of the last fit.
*/
float GetLastResult() const;
/**
* Pure virtual function to fit the geometry to the given points. This function
* must be implemented by every subclass.
*/
virtual float Fit() = 0;
/**
* Returns true if Fit() has been called for the current set of points, false otherwise.
*/
bool Done() const;
protected:
/**
* Converts point from Wm4::Vector3 to Base::Vector3f.
*/
static void Convert( const Wm4::Vector3<double>&, Base::Vector3f&);
/**
* Converts point from Base::Vector3f to Wm4::Vector3.
*/
static void Convert( const Base::Vector3f&, Wm4::Vector3<double>&);
/**
* Creates a vector of Wm4::Vector3 elements.
*/
void GetMgcVectorArray( std::vector< Wm4::Vector3<double> >& rcPts ) const;
protected:
std::list< Base::Vector3f > _vPoints; /**< Holds the points for the fit algorithm. */
bool _bIsFitted; /**< Flag, whether the fit has been called. */
float _fLastResult; /**< Stores the last result of the fit */
};
// -------------------------------------------------------------------------------
/**
* Approximation of a plane into a given set of points.
*/
class MeshExport PlaneFit : public Approximation
{
public:
/**
* Construction
*/
PlaneFit();
/**
* Destruction
*/
virtual ~PlaneFit();
Base::Vector3f GetBase() const;
Base::Vector3f GetDirU() const;
Base::Vector3f GetDirV() const;
/**
* Returns the normal of the fitted plane. If Fit() has not been called the null vector is
* returned.
*/
Base::Vector3f GetNormal() const;
/**
* Fit a plane into the given points. We must have at least three non-collinear points
* to succeed. If the fit fails FLOAT_MAX is returned.
*/
float Fit();
/**
* Returns the distance from the point \a rcPoint to the fitted plane. If Fit() has not been
* called FLOAT_MAX is returned.
*/
float GetDistanceToPlane(const Base::Vector3f &rcPoint) const;
/**
* Returns the standard deviation from the points to the fitted plane. If Fit() has not been
* called FLOAT_MAX is returned.
*/
float GetStdDeviation() const;
/**
* Returns the standard deviation from the points to the fitted plane with respect to the orientation
* of the plane's normal. If Fit() has not been called FLOAT_MAX is returned.
*/
float GetSignedStdDeviation() const;
/**
* Projects the points onto the fitted plane.
*/
void ProjectToPlane();
/**
* Get the dimension of the fitted plane.
*/
void Dimension(float& length, float& width) const;
/**
* Returns an array of the transformed points relative to the coordinate system
* of the plane. If this method is called before the plane is computed an empty
* array is returned.
*/
std::vector<Base::Vector3f> GetLocalPoints() const;
protected:
Base::Vector3f _vBase; /**< Base vector of the plane. */
Base::Vector3f _vDirU;
Base::Vector3f _vDirV;
Base::Vector3f _vDirW; /**< Normal of the plane. */
};
// -------------------------------------------------------------------------------
/**
* Approximation of a quadratic surface into a given set of points. The implicit form of the surface
* is defined by F(x,y,z) = a * x^2 + b * y^2 + c * z^2 +
* 2d * x * y + 2e * x * z + 2f * y * z +
* g * x + h * y + * i * z + k
* = 0
* Depending on the parameters (a,..,k) this surface defines a sphere, ellipsoid, cylinder, cone
* and so on.
*/
class MeshExport QuadraticFit : public Approximation
{
public:
/**
* Construction
*/
QuadraticFit() : Approximation() {};
/**
* Destruction
*/
virtual ~QuadraticFit(){};
/**
* Get the quadric coefficients
* @param ulIndex Number of coefficient (0..9)
* @return double value of coefficient
*/
double GetCoeff(unsigned long ulIndex) const;
/**
* Get the quadric coefficients as reference to the
* internal array
* @return const double& Reference to the double array
*/
const double& GetCoeffArray() const;
/**
* Invocation of fitting algorithm
* @return float Quality of fit.
*/
float Fit();
void CalcZValues(double x, double y, double &dZ1, double &dZ2) const;
/**
* Calculate the curvatures of the quadric at a given point.
* @param x X-coordinate
* @param y Y-coordinate
* @param z Z-coordinate
* @param rfCurv0 1. principal curvature
* @param rfCurv1 2. principal curvature
* @param rkDir0 Direction of 1. principal curvature
* @param rkDir1 Direction of 2. principal curvature
* @param dDistance
* @return bool Success = true, otherwise false
*/
bool GetCurvatureInfo(double x, double y, double z,
double &rfCurv0, double &rfCurv1,
Base::Vector3f &rkDir0, Base::Vector3f &rkDir1, double &dDistance);
bool GetCurvatureInfo(double x, double y, double z,
double &rfCurv0, double &rfcurv1);
/**
* Compute form matrix A and calculate Eigenvalues.
* @param dLambda1 Eigenvalue 1
* @param dLambda2 Eigenvalue 2
* @param dLambda3 Eigenvalue 3
* @param clEV1 Eigenvector 1
* @param clEV2 Eigenvector 2
* @param clEV3 Eigenvector 3
*/
void CalcEigenValues(double &dLambda1, double &dLambda2, double &dLambda3,
Base::Vector3f &clEV1, Base::Vector3f &clEV2, Base::Vector3f &clEV3) const;
protected:
double _fCoeff[ 10 ]; /**< Coefficients of the fit */
};
// -------------------------------------------------------------------------------
/**
* This is an 2.5D approach which first determines the bestfit plane of the point set (P_i = (x,y,z), i=1,...,n)
* to get a parametrisation of the points afterwards. The coordinates of the points with respect to the local
* coordinate system of the plane are determined and then a quadratic polynomial function of the form:
* w = f(u,v) = a*u^2 + b*v^2 + c*u*v + d*u + e*v + f
* is determined.
* This approach was developed as an alternative for the 3D approach with quadrics because
* the latter suffers from strange artifacts in planar areas.
*/
class MeshExport SurfaceFit : public PlaneFit
{
public:
/**
* Construction
*/
SurfaceFit();
/**
* Destruction
*/
virtual ~SurfaceFit(){};
bool GetCurvatureInfo(double x, double y, double z, double &rfCurv0, double &rfCurv1,
Base::Vector3f &rkDir0, Base::Vector3f &rkDir1, double &dDistance);
bool GetCurvatureInfo(double x, double y, double z, double &rfCurv0, double &rfcurv1);
float Fit();
double Value(double x, double y) const;
void GetCoefficients(double& a,double& b,double& c,double& d,double& e,double& f) const;
protected:
double PolynomFit();
double _fCoeff[ 10 ]; /**< Ziel der Koeffizienten aus dem Fit */
};
// -------------------------------------------------------------------------------
/**
* Helper class for the quadric fit. Includes the
* partial derivates of the quadric and serves for
* calculation of the quadric properties.
*/
class FunctionContainer
{
public:
/**
* WildMagic library uses function with this interface
*/
typedef double (*Function)(double,double,double);
/**
* The constructor expects an array of quadric coefficients.
* @param pKoef Pointer to the quadric coefficients
* (double [10])
*/
FunctionContainer(const double *pKoef)
{
Assign( pKoef );
pImplSurf = new Wm4::QuadricSurface<double>( dKoeff );
}
/**
* Apply quadric coefficients
* @param pKoef Pointer to the quadric coefficients
* (double [10])
*/
void Assign( const double *pKoef )
{
for (long ct=0; ct < 10; ct++)
dKoeff[ ct ] = pKoef[ ct ];
}
/**
* Destruktor. Deletes the ImpicitSurface instance
* of the WildMagic library
*/
~FunctionContainer(){ delete pImplSurf; }
/**
* Access to the quadric coefficients
* @param idx Index to coefficient
* @return double& coefficient
*/
double& operator[](int idx){ return dKoeff[ idx ]; }
/**
* Redirector to a method of the WildMagic library. Determines
* the principal curvatures and their directions at the given point.
* @param x X-coordinate
* @param y Y-coordinate
* @param z Z-coordinate
* @param rfCurv0 1. principal curvature
* @param rfCurv1 2. principal curvature
* @param rkDir0 direction of 1. principal curvature
* @param rkDir1 direction of 2. principal curvature
* @param dDistance Gives distances from the point to the quadric.
* @return bool Success = true, otherwise false
*/
bool CurvatureInfo(double x, double y, double z,
double &rfCurv0, double &rfCurv1,
Wm4::Vector3<double> &rkDir0, Wm4::Vector3<double> &rkDir1, double &dDistance)
{
return pImplSurf->ComputePrincipalCurvatureInfo( Wm4::Vector3<double>(x, y, z),rfCurv0, rfCurv1, rkDir0, rkDir1 );
}
Base::Vector3f GetGradient( double x, double y, double z ) const
{
Wm4::Vector3<double> grad = pImplSurf->GetGradient( Wm4::Vector3<double>(x, y, z) );
return Base::Vector3f( (float)grad.X(), (float)grad.Y(), (float)grad.Z() );
}
Base::Matrix4D GetHessian( double x, double y, double z ) const
{
Wm4::Matrix3<double> hess = pImplSurf->GetHessian( Wm4::Vector3<double>(x, y, z) );
Base::Matrix4D cMat; cMat.setToUnity();
cMat[0][0] = hess[0][0]; cMat[0][1] = hess[0][1]; cMat[0][2] = hess[0][2];
cMat[1][0] = hess[1][0]; cMat[1][1] = hess[1][1]; cMat[1][2] = hess[1][2];
cMat[2][0] = hess[2][0]; cMat[2][1] = hess[2][1]; cMat[2][2] = hess[2][2];
return cMat;
}
bool CurvatureInfo(double x, double y, double z,
double &rfCurv0, double &rfCurv1)
{
double dQuot = Fz(x,y,z);
double zx = - ( Fx(x,y,z) / dQuot );
double zy = - ( Fy(x,y,z) / dQuot );
double zxx = - ( 2.0f * ( dKoeff[5] + dKoeff[6] * zx * zx + dKoeff[8] * zx ) ) / dQuot;
double zyy = - ( 2.0f * ( dKoeff[5] + dKoeff[6] * zy * zy + dKoeff[9] * zy ) ) / dQuot;
double zxy = - ( dKoeff[6] * zx * zy + dKoeff[7] + dKoeff[8] * zy + dKoeff[9] * zx ) / dQuot;
double dNen = 1 + zx*zx + zy*zy;
double dNenSqrt = (double)sqrt( dNen );
double K = ( zxx * zyy - zxy * zxy ) / ( dNen * dNen );
double H = 0.5f * ( ( 1.0f+zx*zx - 2*zx*zy*zxy + (1.0f+zy*zy)*zxx ) / ( dNenSqrt * dNenSqrt * dNenSqrt ) ) ;
double dDiscr = (double)sqrt(fabs(H*H-K));
rfCurv0 = H - dDiscr;
rfCurv1 = H + dDiscr;
return true;
}
//+++++++++ Quadric +++++++++++++++++++++++++++++++++++++++
double F ( double x, double y, double z )
{
return (dKoeff[0] + dKoeff[1]*x + dKoeff[2]*y + dKoeff[3]*z +
dKoeff[4]*x*x + dKoeff[5]*y*y + dKoeff[6]*z*z +
dKoeff[7]*x*y + dKoeff[8]*x*z + dKoeff[9]*y*z);
}
//+++++++++ 1. derivations ++++++++++++++++++++++++++++++++
double Fx ( double x, double y, double z )
{
return( dKoeff[1] + 2.0f*dKoeff[4]*x + dKoeff[7]*y + dKoeff[8]*z );
}
double Fy ( double x, double y, double z )
{
return( dKoeff[2] + 2.0f*dKoeff[5]*y + dKoeff[7]*x + dKoeff[9]*z );
}
double Fz ( double x, double y, double z )
{
return( dKoeff[3] + 2.0f*dKoeff[6]*z + dKoeff[8]*x + dKoeff[9]*y );
}
//+++++++++ 2. derivations ++++++++++++++++++++++++++++++++
double Fxx( double x, double y, double z )
{
return( 2.0f*dKoeff[4] );
}
double Fxy( double x, double y, double z )
{
return( dKoeff[7] );
}
double Fxz( double x, double y, double z )
{
return( dKoeff[8] );
}
double Fyy( double x, double y, double z )
{
return( 2.0f*dKoeff[5] );
}
double Fyz( double x, double y, double z )
{
return( dKoeff[9] );
}
double Fzz( double x, double y, double z )
{
return( 2.0f*dKoeff[6] );
}
protected:
double dKoeff[ 10 ]; /**< Coefficients of quadric */
Wm4::ImplicitSurface<double> *pImplSurf; /**< Access to the WildMagic library */
private:
/**
* Private construction.
*/
FunctionContainer(){};
};
class MeshExport PolynomialFit : public Approximation
{
public:
/**
* Construction
*/
PolynomialFit();
/**
* Destruction
*/
virtual ~PolynomialFit();
float Fit();
float Value(float x, float y) const;
protected:
float _fCoeff[9];
};
} // namespace MeshCore
#endif // MESH_APPROXIMATION_H