G4SafetyHelper Class Reference

G4SafetyHelper is a helper class for physics processes which require knowledge of the safety, and the step size for the 'mass' geometry. More...

#include <G4SafetyHelper.hh>

Public Member Functions
	G4SafetyHelper ()
	~G4SafetyHelper ()=default
G4double	CheckNextStep (const G4ThreeVector &position, const G4ThreeVector &direction, const G4double currentMaxStep, G4double &newSafety)
G4double	ComputeSafety (const G4ThreeVector &pGlobalPoint, G4double maxRadius=DBL_MAX)
void	Locate (const G4ThreeVector &pGlobalPoint, const G4ThreeVector &direction)
void	ReLocateWithinVolume (const G4ThreeVector &pGlobalPoint)
void	EnableParallelNavigation (G4bool parallel)
void	InitialiseNavigator ()
G4int	SetVerboseLevel (G4int lev)
G4VPhysicalVolume *	GetWorldVolume ()
void	SetCurrentSafety (G4double val, const G4ThreeVector &pos)
void	InitialiseHelper ()

Detailed Description

G4SafetyHelper is a helper class for physics processes which require knowledge of the safety, and the step size for the 'mass' geometry.

Definition at line 51 of file G4SafetyHelper.hh.

Constructor & Destructor Documentation

G4SafetyHelper()

G4SafetyHelper::G4SafetyHelper

(

)

Constructor and default Destructor.

Definition at line 39 of file G4SafetyHelper.cc.

  : fLastSafetyPosition(0.0,0.0,0.0)
{
}

~G4SafetyHelper()

G4SafetyHelper::~G4SafetyHelper ( )

default

Member Function Documentation

CheckNextStep()

G4double G4SafetyHelper::CheckNextStep	(	const G4ThreeVector &	position,
		const G4ThreeVector &	direction,
		const G4double	currentMaxStep,
		G4double &	newSafety )

Computes the distance in the mass geometry.

Parameters

[in]	position	Point in global coordinates.
[in]	direction	Direction.
[in]	currentMaxStep	Proposed step length to nearest boundary.
[in,out]	newSafety	New safety.

Returns

The linear step for mass geometry.

Definition at line 76 of file G4SafetyHelper.cc.

{  
  // Distance in the Mass geometry
  //
  G4double linstep = fpMassNavigator->CheckNextStep( position,
                                                     direction,
                                                     currentMaxStep,
                                                     newSafety);
  fLastSafetyPosition = position;
  fLastSafety         = newSafety;
 
  // TO-DO: Can replace this with a call to PathFinder 
  //        giving id of Mass Geometry --> this avoid doing the work twice
 
  return linstep;
}

ComputeSafety()

G4double G4SafetyHelper::ComputeSafety	(	const G4ThreeVector &	pGlobalPoint,
		G4double	maxRadius = DBL_MAX )

Computes the safety distance for all geometries.

Parameters

[in]	pGlobalPoint	Point in global coordinates.
[in]	maxRadius	Radius of interest (e.g. maximum displacement). Giving this, one can reduce the average computational cost. If not provided, the real isotropic safety is computed.

Returns

The safety distance for all geometries.

Definition at line 97 of file G4SafetyHelper.cc.

{
  G4double newSafety;
  
  // Only recompute (calling Navigator/PathFinder) if 'position'
  // is  *not* the safety location and has moved 'significantly'
  //
  G4double moveLengthSq = (position-fLastSafetyPosition).mag2();
  if(   (moveLengthSq > 0.0 ) )
  {
    if( !fUseParallelGeometries )
    {
      // Safety for mass geometry
      newSafety = fpMassNavigator->ComputeSafety(position, maxLength, true);
 
      // Only store a 'true' safety - one that was not restricted by maxLength
      if( newSafety < maxLength )
      {
         fLastSafety= newSafety;
         fLastSafetyPosition = position;
      }
    }
    else
    {
      // Safety for all geometries
      newSafety = fpPathFinder->ComputeSafety(position);
 
      fLastSafety= newSafety;
      fLastSafetyPosition = position;
    } 
 
  }
  else
  {
    // return last value if position is not (significantly) changed
    //
    // G4double moveLength = 0;
    // if( moveLengthSq > 0.0 ) { moveLength= std::sqrt(moveLengthSq); }
    newSafety = fLastSafety; // -moveLength;
  }
  
  return newSafety;
}

EnableParallelNavigation()

void G4SafetyHelper::EnableParallelNavigation ( G4bool parallel )

inline

Enables navigation in parallel geometries.

Parameters

[in]

parallel

Flag to have parallel worlds considered. Alternative is to use single (mass) navigator directly.

GetWorldVolume()

G4VPhysicalVolume * G4SafetyHelper::GetWorldVolume ( )

inline

Retrieves the world volume of the mass geometry.

Returns

The pointer to the mass geometry world volume.

InitialiseHelper()

void G4SafetyHelper::InitialiseHelper

(

)

Initialises all data and navigator.

Definition at line 66 of file G4SafetyHelper.cc.

{
  fLastSafetyPosition = G4ThreeVector(0.0,0.0,0.0);
  fLastSafety         = 0.0;
  if (fFirstCall) { InitialiseNavigator(); }
  fFirstCall = false;
}

Referenced by G4ElNeutrinoNucleusProcess::G4ElNeutrinoNucleusProcess(), G4MuNeutrinoNucleusProcess::G4MuNeutrinoNucleusProcess(), G4NeutrinoElectronProcess::G4NeutrinoElectronProcess(), G4TauNeutrinoNucleusProcess::G4TauNeutrinoNucleusProcess(), G4VMscModel::GetParticleChangeForMSC(), and G4VMultipleScattering::PreparePhysicsTable().

InitialiseNavigator()

void G4SafetyHelper::InitialiseNavigator

(

)

Checks for new navigator for tracking, and reinitialises pointer.

Definition at line 45 of file G4SafetyHelper.cc.

{
  fpPathFinder = G4PathFinder::GetInstance();
 
  G4TransportationManager* pTransportMgr= 
    G4TransportationManager::GetTransportationManager();
 
  fpMassNavigator = pTransportMgr->GetNavigatorForTracking(); 
 
  // Check
  //
  G4VPhysicalVolume* worldPV = fpMassNavigator->GetWorldVolume(); 
  if( worldPV == nullptr )
  { 
    G4Exception("G4SafetyHelper::InitialiseNavigator",
                "GeomNav0003", FatalException, 
                "Found that existing tracking Navigator has NULL world"); 
  }
}

Referenced by InitialiseHelper().

Locate()

void G4SafetyHelper::Locate	(	const G4ThreeVector &	pGlobalPoint,
		const G4ThreeVector &	direction )

Locates the point for all geometries.

Parameters

[in]	pGlobalPoint	Point in global coordinates.
[in]	direction	Direction.

Definition at line 178 of file G4SafetyHelper.cc.

{
  if( !fUseParallelGeometries )
  {
    fpMassNavigator->LocateGlobalPointAndSetup(newPosition, &newDirection,
                                               true, false); 
  }
  else
  {
    fpPathFinder->Locate( newPosition, newDirection ); 
  }
}

ReLocateWithinVolume()

void G4SafetyHelper::ReLocateWithinVolume

(

const G4ThreeVector &

pGlobalPoint

)

Relocates the point in the volume of interest.

Parameters

[in]

pGlobalPoint

Point in global coordinates.

Definition at line 143 of file G4SafetyHelper.cc.

{
#ifdef G4VERBOSE
  if( fVerbose > 0 )
  {
    // There is an opportunity - and need - to check whether
    // the proposed move is safe
    G4ThreeVector moveVec = newPosition - fLastSafetyPosition;
    if( moveVec.mag2() > sqr(fLastSafety) )
    {
      // A problem exists - we are proposing to move outside 'Safety Sphere'
      G4ExceptionDescription ed;
      ed << "Unsafe Move> Asked to relocate beyond 'Safety sphere'.  Details: "
         << G4endl;
      ed << " Safety Sphere:  Radius = " << fLastSafety;
      ed << " Center   = " << fLastSafetyPosition << G4endl;
      ed << " New Location :  Move   = " << moveVec.mag();
      ed << " Position = " << newPosition << G4endl;
      G4Exception("G4SafetyHelper::ReLocateWithinVolume",
                  "GeomNav1001", JustWarning, ed);
    }
  }
#endif
   
  if( !fUseParallelGeometries )
  {
    fpMassNavigator->LocateGlobalPointWithinVolume( newPosition ); 
  }
  else
  {
    fpPathFinder->ReLocate( newPosition ); 
  }
}

SetCurrentSafety()

void G4SafetyHelper::SetCurrentSafety ( G4double val, const G4ThreeVector & pos )

inline

Sets the safety value for the given position.

Parameters

[in]	val	The safety value.
[in]	pos	The position.

SetVerboseLevel()

G4int G4SafetyHelper::SetVerboseLevel ( G4int lev )

inline

Verbosity control.

Parameters

[in]

lev

The new verbosity level to enable.

Returns

The old verbosity level.

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The documentation for this class was generated from the following files:

• G4SafetyHelper.hh
• G4SafetyHelper.cc