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create/src/Mod/Mesh/App/Core/CylinderFit.h
2022-11-21 03:24:27 +01:00

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6.9 KiB
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/***************************************************************************
* Copyright (c) 2020 Graeme van der Vlugt *
* *
* 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_CYLINDER_FIT_H
#define MESH_CYLINDER_FIT_H
#include <Eigen/Eigenvalues>
#include "Approximation.h"
// -------------------------------------------------------------------------------
namespace MeshCoreFit {
using Matrix5x5 = Eigen::Matrix<double,5,5,Eigen::RowMajor>;
/**
* Best-fit cylinder for a given set of points.
* Doesn't expect points on any top or bottom end-planes, only points on the side surface
*/
class MeshExport CylinderFit : public MeshCore::Approximation
{
protected:
// Solution 'direction' enumeration
enum SolutionD {solL = 0, // solution L: L is biggest axis component and L = f(M,N)
solM = 1, // solution M: M is biggest axis component and M = f(L,N)
solN = 2 // solution N: N is biggest axis component and N = f(L,M)
};
public:
/**
* Construction
*/
CylinderFit();
/**
* Destruction
*/
~CylinderFit() override;
/**
* Set approximations before calling Fit()
*/
void SetApproximations(double radius, const Base::Vector3d &base, const Base::Vector3d &axis);
/**
* Set approximations before calling Fit(). This version computes the radius
* using the given axis and the existing surface points.
*/
void SetApproximations(const Base::Vector3d &base, const Base::Vector3d &axis);
/**
* Set iteration convergence criteria for the fit if special values are needed.
* The default values set in the constructor are suitable for most uses
*/
void SetConvergenceCriteria(double posConvLimit, double dirConvLimit, double vConvLimit, int maxIter);
/**
* Returns the radius of the fitted cylinder. If Fit() has not been called then zero is returned.
*/
double GetRadius() const;
/**
* Returns the base of the fitted cylinder. If Fit() has not been called the null vector is returned.
*/
Base::Vector3d GetBase() const;
/**
* Returns the axis of the fitted cylinder. If Fit() has not been called the null vector is returned.
*/
Base::Vector3d GetAxis() const;
/**
* Returns the number of iterations that Fit() needed to converge. If Fit() has not been called then zero is returned.
*/
int GetNumIterations() const;
/**
* Fit a cylinder into the given points. If the fit fails FLOAT_MAX is returned.
*/
float Fit() override;
/**
* Returns the distance from the point \a rcPoint to the fitted cylinder. If Fit() has not been
* called FLOAT_MAX is returned.
*/
float GetDistanceToCylinder(const Base::Vector3f &rcPoint) const;
/**
* Returns the standard deviation from the points to the fitted cylinder. If Fit() has not been
* called FLOAT_MAX is returned.
*/
float GetStdDeviation() const;
/**
* Projects the points onto the fitted cylinder.
*/
void ProjectToCylinder();
protected:
/**
* Compute approximations for the parameters using all points using the line fit method
*/
void ComputeApproximationsLine();
/**
* Checks initial parameter values and defines the best solution direction to use
*/
void findBestSolDirection(SolutionD &solDir);
/**
* Compute the mean X-value of all of the points (observed/input surface points)
*/
double meanXObs();
/**
* Compute the mean Y-value of all of the points (observed/input surface points)
*/
double meanYObs();
/**
* Compute the mean Z-value of all of the points (observed/input surface points)
*/
double meanZObs();
/**
* Set up the normal equations
*/
void setupNormalEquationMatrices(SolutionD solDir, const std::vector< Base::Vector3d > &residuals, Matrix5x5 &atpa, Eigen::VectorXd &atpl) const;
/**
* Sets up contributions of given observation to the normal equation matrices.
*/
void setupObservation(SolutionD solDir, const Base::Vector3f &point, const Base::Vector3d &residual, double a[5], double &f0, double &qw, double b[3]) const;
/**
* Computes contribution of the given observation equation on the normal equation matrices
*/
void addObservationU(double a[5], double li, double pi, Matrix5x5 &atpa, Eigen::VectorXd &atpl) const;
/**
* Set the lower part of the normal matrix equal to the upper part
*/
void setLowerPart(Matrix5x5 &atpa) const;
/**
* Compute the residuals and sigma0 and check the residual convergence
*/
bool computeResiduals(SolutionD solDir, const Eigen::VectorXd &x, std::vector< Base::Vector3d > &residuals, double &sigma0, double vConvLimit, bool &vConverged) const;
/**
* Update the parameters after solving the normal equations
*/
bool updateParameters(SolutionD solDir, const Eigen::VectorXd &x);
protected:
Base::Vector3d _vBase; /**< Base vector of the cylinder (point on axis). */
Base::Vector3d _vAxis; /**< Axis of the cylinder. */
double _dRadius; /**< Radius of the cylinder. */
int _numIter; /**< Number of iterations for solution to converge. */
double _posConvLimit; /**< Position and radius parameter convergence threshold. */
double _dirConvLimit; /**< Direction parameter convergence threshold. */
double _vConvLimit; /**< Residual convergence threshold. */
int _maxIter; /**< Maximum number of iterations. */
};
} // namespace MeshCore
#endif // MESH_CYLINDER_FIT_H