// // ******************************************************************** // * License and Disclaimer * // * * // * The Geant4 software is copyright of the Copyright Holders of * // * the Geant4 Collaboration. It is provided under the terms and * // * conditions of the Geant4 Software License, included in the file * // * LICENSE and available at http://cern.ch/geant4/license . These * // * include a list of copyright holders. * // * * // * Neither the authors of this software system, nor their employing * // * institutes,nor the agencies providing financial support for this * // * work make any representation or warranty, express or implied, * // * regarding this software system or assume any liability for its * // * use. Please see the license in the file LICENSE and URL above * // * for the full disclaimer and the limitation of liability. * // * * // * This code implementation is the result of the scientific and * // * technical work of the GEANT4 collaboration. * // * By using, copying, modifying or distributing the software (or * // * any work based on the software) you agree to acknowledge its * // * use in resulting scientific publications, and indicate your * // * acceptance of all terms of the Geant4 Software license. * // ******************************************************************** // // G4PropagatorInField // // Class description: // // This class performs the navigation/propagation of a particle/track // in a magnetic field. The field is in general non-uniform. // For the calculation of the path, it relies on the class G4ChordFinder. // It utilises an ODE solver (with the Runge-Kutta method) to evolve the // particle, and drives it until the particle has traveled a set distance // or it enters a new volume. // Author: John Apostolakis (CERN), 25 October 1996 // --------------------------------------------------------------------------- #ifndef G4PropagatorInField_hh #define G4PropagatorInField_hh 1 #include "G4Types.hh" #include #include "G4FieldTrack.hh" #include "G4FieldManager.hh" #include "G4VIntersectionLocator.hh" class G4ChordFinder; class G4Navigator; class G4VPhysicalVolume; class G4VCurvedTrajectoryFilter; /** * @brief G4PropagatorInField performs the navigation/propagation of a * particle/track in a magnetic field. The field is in general non-uniform. * For the calculation of the path, it relies on the class G4ChordFinder. * It utilises an ODE solver (with the Runge-Kutta method) to evolve the * particle, and drives it until the particle has traveled a set distance * or it enters a new volume. */ class G4PropagatorInField { public: /** * Constructor and Destructor. */ G4PropagatorInField( G4Navigator* theNavigator, G4FieldManager* detectorFieldMgr, G4VIntersectionLocator* vLocator = nullptr ); ~G4PropagatorInField(); /** * Computes the next geometric Step. * @param[in,out] pFieldTrack Field track to be filled. * @param[in] pCurrentProposedStepLength Current proposed step length. * @param[in,out] pNewSafety New safety. * @param[in] pPhysVol Pointer to the current volume. * @param[in] canRelaxDeltaChord To enable relaxing delta-chord parameter. * @returns Step length. */ G4double ComputeStep( G4FieldTrack& pFieldTrack, G4double pCurrentProposedStepLength, G4double& pNewSafety, G4VPhysicalVolume* pPhysVol = nullptr, G4bool canRelaxDeltaChord = false); /** * Returning the state after the Step. */ inline G4ThreeVector EndPosition() const; inline G4ThreeVector EndMomentumDir() const; inline G4bool IsParticleLooping() const; /** * Returning the relative accuracy for the current Step. */ inline G4double GetEpsilonStep() const; /** * Setting the relative accuracy for the current Step. * The ratio DeltaOneStep()/h_current_step. */ inline void SetEpsilonStep(G4double newEps); /** * Sets (and returns) the correct field manager (global or local), * if it exists. * @note Should be called before ComputeStep is called; * Currently, ComputeStep() will call it, if it has not been called. * @param[in] pCurrentPhysVol Pointer to the current volume. * @returns The pointer to the field manager. */ G4FieldManager* FindAndSetFieldManager(G4VPhysicalVolume* pCurrentPhysVol); /** * Returning the pointer to the chord finder. */ inline G4ChordFinder* GetChordFinder(); /** * Verbosity control. */ G4int SetVerboseLevel( G4int verbose ); inline G4int GetVerboseLevel() const; inline G4int Verbose() const; /** * Enabling check mode for further diagnostics. */ inline void CheckMode(G4bool mode); /** * Accessor/modifier for tracing key parts of ComputeStep(). */ inline void SetVerboseTrace( G4bool enable ); inline G4bool GetVerboseTrace(); /** * Accessor/modifier for controlling the maximum for the number of * substeps that a particle can take. Above this number it is signaled * as 'looping'. */ inline G4int GetMaxLoopCount() const; inline void SetMaxLoopCount( G4int new_max ); /** * Print method, useful mostly for debugging. */ void printStatus( const G4FieldTrack& startFT, const G4FieldTrack& currentFT, G4double requestStep, G4double safety, G4int step, G4VPhysicalVolume* startVolume); /** * Accessor for retrieving the field track. */ inline G4FieldTrack GetEndState() const; /** * Methods to control values for the global field manager. * @deprecated The four methods below are now obsolescent but *for now* * will work. They are being replaced by same-name methods in * G4FieldManager, allowing the specialisation in different volumes. */ inline G4double GetMinimumEpsilonStep() const; // Min for relative accuracy inline void SetMinimumEpsilonStep( G4double newEpsMin ); // of any step inline G4double GetMaximumEpsilonStep() const; inline void SetMaximumEpsilonStep( G4double newEpsMax ); /** * Methods to obtain / change the size of the largest step the method * will undertake. The Reset method uses the world volume's. */ void SetLargestAcceptableStep( G4double newBigDist ); G4double GetLargestAcceptableStep(); void ResetLargestAcceptableStep(); /** * Methods to control extra Multiplier parameter for limiting long steps. */ G4double GetMaxStepSizeMultiplier(); void SetMaxStepSizeMultiplier(G4double vm); /** * Methods to Control minimum 'directional' distance in case of * too-large step. */ G4double GetMinBigDistance(); void SetMinBigDistance(G4double val); /** * Sets the filter that examines & stores 'intermediate' * curved trajectory points. * @note Currently only position is stored. */ void SetTrajectoryFilter(G4VCurvedTrajectoryFilter* filter); /** * Accesses the points which have passed by the filter. * @note Responsibility for deleting the points lies with the client. * This method MUST BE called exactly ONCE per step. */ std::vector* GimmeTrajectoryVectorAndForgetIt() const; /** * Clears the State of this class and its current associates. * @note The current field manager & chord finder will also be called. */ void ClearPropagatorState(); /** * Setter for global field manager. Updates the state. */ inline void SetDetectorFieldManager( G4FieldManager* newGlobalFieldManager ); /** * Toggles & views parameter for using safety to discard unneccesary calls * to the navigator (thus 'optimising' performance). */ inline void SetUseSafetyForOptimization( G4bool ); inline G4bool GetUseSafetyForOptimization(); /** * Intersects the chord from StartPointA to EndPointB and returns * whether an intersection occurred. * @note Safety is changed! */ inline G4bool IntersectChord( const G4ThreeVector& StartPointA, const G4ThreeVector& EndPointB, G4double& NewSafety, G4double& LinearStepLength, G4ThreeVector& IntersectionPoint); /** * Returns if it is the first step in the volume. */ inline G4bool IsFirstStepInVolume(); /** * Returns if it is the last step in the volume. */ inline G4bool IsLastStepInVolume(); /** * Initialises track flags. */ inline void PrepareNewTrack(); /** * Changes or gets the object which calculates the exact intersection * point with the next boundary. */ inline G4VIntersectionLocator* GetIntersectionLocator(); inline void SetIntersectionLocator(G4VIntersectionLocator* pLocator ); /** * Controls the parameter which enables the temporary 'relaxation' which * ensures that chord segments are short enough so that their sagitta is * small than delta-chord parameter. * The Set method increases the value of delta-chord temporarily, doubling * it once the number of iterations substeps reach value of * 'IncreaseChordDistanceThreshold'. It is also doubled again every time * the iteration count reaches a multiple of this value. * @note The delta-chord is reset to its original value at the end of * each call to ComputeStep(). */ inline G4int GetIterationsToIncreaseChordDistance() const; inline void SetIterationsToIncreaseChordDistance(G4int numIters); /** * Accessors. */ inline G4double GetDeltaIntersection() const; inline G4double GetDeltaOneStep() const; /** * Auxiliary methods. * @note Their results can/will change during propagation. */ inline G4FieldManager* GetCurrentFieldManager(); inline G4EquationOfMotion* GetCurrentEquationOfMotion(); /** * Accessor and modifier for navigator. */ inline void SetNavigatorForPropagating(G4Navigator* SimpleOrMultiNavigator); inline G4Navigator* GetNavigatorForPropagating(); /** * Accessors and modifiers for no-zero steps threshold. */ inline void SetThresholdNoZeroStep( G4int noAct, G4int noHarsh, G4int noAbandon ); inline G4int GetThresholdNoZeroSteps( G4int i ); inline G4double GetZeroStepThreshold(); inline void SetZeroStepThreshold( G4double newLength ); /** * Updates the Locator with parameters from this class and from current * field manager. */ void RefreshIntersectionLocator(); protected: /** * Logging methods. */ void PrintStepLengthDiagnostic( G4double currentProposedStepLength, G4double decreaseFactor, G4double stepTrial, const G4FieldTrack& aFieldTrack); void ReportLoopingParticle( G4int count, G4double StepTaken, G4double stepRequest, const char* methodName, const G4ThreeVector& momentumVec, G4VPhysicalVolume* physVol); void ReportStuckParticle(G4int noZeroSteps, G4double proposedStep, G4double lastTriedStep, G4VPhysicalVolume* physVol); private: // ---------------------------------------------------------------------- // DATA Members // ---------------------------------------------------------------------- // ================================================================== // INVARIANTS - Must not change during tracking // ** PARAMETERS ----------- G4int fMax_loop_count = 1000; // Limit for the number of sub-steps taken in one call to ComputeStep G4int fIncreaseChordDistanceThreshold = 100; G4bool fUseSafetyForOptimisation = true; // (false) is less sensitive to incorrect safety // Thresholds for identifying "abnormal" cases - which cause looping // G4int fActionThreshold_NoZeroSteps = 2; // Threshold # - above it act G4int fSevereActionThreshold_NoZeroSteps = 10; // Threshold # to act harshly G4int fAbandonThreshold_NoZeroSteps = 50; // Threshold # to abandon G4double fZeroStepThreshold = 0.0; // Threshold *length* for counting of tiny or 'zero' steps // Parameters related to handling of very large steps which // occur typically in large volumes with vacuum or very thin gas // G4double fLargestAcceptableStep; // Maximum size of a step - for optimization (and to avoid problems) G4double fMaxStepSizeMultiplier = 3; // Multiplier for directional exit distance used as extra long-step limit G4double fMinBigDistance= 100. ; // * CLHEP::mm // Minimum distance added to directional exit distance // ** End of PARAMETERS ----- G4double kCarTolerance; // Geometrical tolerance defining surface thickness G4bool fAllocatedLocator; // Book-keeping // -------------------------------------------------------- // ** Dependent Objects - to which work is delegated G4FieldManager* fDetectorFieldMgr; // The Field Manager of the whole Detector. (default) G4VIntersectionLocator* fIntersectionLocator; // Refines candidate intersection G4VCurvedTrajectoryFilter* fpTrajectoryFilter = nullptr; // The filter encapsulates the algorithm which selects which // intermediate points should be stored in a trajectory. // When it is NULL, no intermediate points will be stored. // Else PIF::ComputeStep must submit (all) intermediate // points it calculates, to this filter. (jacek 04/11/2002) G4Navigator* fNavigator; // Set externally - only by tracking / run manager // // ** End of Dependent Objects ---------------------------- // End of INVARIANTS // ================================================================== // STATE information // ----------------- G4FieldManager* fCurrentFieldMgr; // The Field Manager of the current volume (may be the global) G4bool fSetFieldMgr = false; // Has it been set for the current step? // Parameters of current step // G4double fEpsilonStep; // Relative accuracy of current Step G4FieldTrack End_PointAndTangent; // End point storage G4bool fParticleIsLooping = false; G4int fNoZeroStep = 0; // Count of zero Steps // State used for Optimisation // G4double fFull_CurveLen_of_LastAttempt = -1; G4double fLast_ProposedStepLength = -1; // Previous step information -- for use in adjust step size G4ThreeVector fPreviousSftOrigin; G4double fPreviousSafety = 0.0; // Last safety origin & value: for optimisation G4int fVerboseLevel = 0; G4bool fVerbTracePiF = false; G4bool fCheck = false; // For debugging purposes G4bool fFirstStepInVolume = true; G4bool fLastStepInVolume = true; G4bool fNewTrack = true; }; // Inline methods // #include "G4PropagatorInField.icc" #endif