// SPDX-License-Identifier: LGPL-2.1-or-later /*************************************************************************** * 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 #include "Approximation.h" // ------------------------------------------------------------------------------- namespace MeshCoreFit { using Matrix5x5 = Eigen::Matrix; using DoubleArray3 = std::array; using DoubleArray5 = std::array; /** * 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(); /** * 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& 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, DoubleArray5& a, double& f0, double& qw, DoubleArray3& b ) const; /** * Computes contribution of the given observation equation on the normal equation matrices */ void addObservationU(DoubleArray5 a, 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& residuals, double& sigma0, double vConvLimit, bool& vConverged ) const; /** * Update the parameters after solving the normal equations */ bool updateParameters(SolutionD solDir, const Eigen::VectorXd& x); private: Base::Vector3d _vBase; /**< Base vector of the cylinder (point on axis). */ Base::Vector3d _vAxis; /**< Axis of the cylinder. */ double _dRadius {0}; /**< Radius of the cylinder. */ int _numIter {0}; /**< Number of iterations for solution to converge. */ double _posConvLimit {0.0001}; /**< Position and radius parameter convergence threshold. */ double _dirConvLimit {0.000001}; /**< Direction parameter convergence threshold. */ double _vConvLimit {0.001}; /**< Residual convergence threshold. */ int _maxIter {50}; /**< Maximum number of iterations. */ }; } // namespace MeshCoreFit #endif // MESH_CYLINDER_FIT_H