G4VFieldModel Class Reference

#include <G4VFieldModel.hh>

Inheritance diagram for G4VFieldModel:

Public Types
enum	Representation { fullArrow , lightArrow }

Public Member Functions
	G4VFieldModel (const G4String &typeOfField, const G4String &symbol="", const G4VisExtent &extentForField=G4VisExtent(), const std::vector< G4PhysicalVolumesSearchScene::Findings > &pvFindings=std::vector< G4PhysicalVolumesSearchScene::Findings >(), G4int nDataPointsPerHalfScene=10, Representation representation=Representation::fullArrow, G4int arrow3DLineSegmentsPerCircle=6)
virtual	~G4VFieldModel ()
virtual void	DescribeYourselfTo (G4VGraphicsScene &sceneHandler)
Public Member Functions inherited from G4VModel
	G4VModel (const G4ModelingParameters *=0)
virtual	~G4VModel ()
const G4ModelingParameters *	GetModelingParameters () const
const G4String &	GetType () const
virtual G4String	GetCurrentDescription () const
virtual G4String	GetCurrentTag () const
const G4VisExtent &	GetExtent () const
const G4String &	GetGlobalDescription () const
const G4String &	GetGlobalTag () const
void	SetModelingParameters (const G4ModelingParameters *)
void	SetExtent (const G4VisExtent &)
void	SetType (const G4String &)
void	SetGlobalDescription (const G4String &)
void	SetGlobalTag (const G4String &)
virtual G4bool	Validate (G4bool warn=true)

Protected Member Functions
virtual void	GetFieldAtLocation (const G4Field *field, const G4Point3D &position, G4double time, G4Point3D &result) const =0

Additional Inherited Members
Protected Attributes inherited from G4VModel
G4String	fType
G4String	fGlobalTag
G4String	fGlobalDescription
G4VisExtent	fExtent
const G4ModelingParameters *	fpMP

Detailed Description

Definition at line 46 of file G4VFieldModel.hh.

Member Enumeration Documentation

Representation

enum G4VFieldModel::Representation

Enumerator
fullArrow
lightArrow

Definition at line 50 of file G4VFieldModel.hh.

{fullArrow, lightArrow};

Constructor & Destructor Documentation

G4VFieldModel()

G4VFieldModel::G4VFieldModel	(	const G4String &	typeOfField,
		const G4String &	symbol = "",
		const G4VisExtent &	extentForField = G4VisExtent(),
		const std::vector< G4PhysicalVolumesSearchScene::Findings > &	pvFindings = std::vector<G4PhysicalVolumesSearchScene::Findings>(),
		G4int	nDataPointsPerHalfScene = 10,
		Representation	representation = Representation::fullArrow,
		G4int	arrow3DLineSegmentsPerCircle = 6 )

Definition at line 61 of file G4VFieldModel.cc.

: fExtentForField(extentForField)
, fPVFindings(pvFindings)
, fNDataPointsPerMaxHalfExtent(nDataPointsPerMaxHalfExtent)
, fRepresentation(representation)
, fArrow3DLineSegmentsPerCircle(arrow3DLineSegmentsPerCircle)
, fTypeOfField(typeOfField)
, fArrowPrefix(symbol)
{
  fType = "G4"+typeOfField+"FieldModel";
  fGlobalTag = fType;
 
  std::ostringstream oss;
  oss << ':' << fNDataPointsPerMaxHalfExtent
  << ':' << fArrow3DLineSegmentsPerCircle;
  if (fExtentForField == G4VisExtent::GetNullExtent()) {
    oss << " whole scene";
  } else {
    oss
    << ':' << fExtentForField.GetXmin()
    << ':' << fExtentForField.GetXmax()
    << ':' << fExtentForField.GetYmin()
    << ':' << fExtentForField.GetYmax()
    << ':' << fExtentForField.GetZmin()
    << ':' << fExtentForField.GetZmax();
  }
  for (const auto& findings: fPVFindings) {
    oss
    << ',' << findings.fpFoundPV->GetName()
    << ':' << findings.fFoundPVCopyNo;
  }
  if (fRepresentation == Representation::fullArrow) {
    oss << " full arrow";
  } else if (fRepresentation == Representation::lightArrow) {
    oss << " light arrow";
  }
 
  fGlobalDescription = fType + oss.str();
}

~G4VFieldModel()

G4VFieldModel::~G4VFieldModel ( )

virtual

Definition at line 59 of file G4VFieldModel.cc.

{;}

Member Function Documentation

DescribeYourselfTo()

void G4VFieldModel::DescribeYourselfTo ( G4VGraphicsScene & sceneHandler )

virtual

Implements G4VModel.

Definition at line 110 of file G4VFieldModel.cc.

                                                                     {
//  G4cout << "G4VFieldModel::DescribeYourselfTo" << G4endl;
 
  G4TransportationManager* tMgr =
  G4TransportationManager::GetTransportationManager();
  assert(tMgr);
  G4Navigator* navigator = tMgr->GetNavigatorForTracking();
  assert(navigator);
 
  G4FieldManager* globalFieldMgr = tMgr->GetFieldManager();
  const G4Field* globalField = 0;
  const G4String intro = "G4VFieldModel::DescribeYourselfTo: ";
  if (globalFieldMgr) {
    if (globalFieldMgr->DoesFieldExist()) {
      globalField = globalFieldMgr->GetDetectorField();
      if (!globalField) {
        static G4bool warned = false;
        if (!warned) {
          G4warn << intro << "Null global field pointer." << G4endl;
          warned = true;
        }
      }
    }
  } else {
    static G4bool warned = false;
    if (!warned) {
      G4warn << intro << "No global field manager." << G4endl;
      warned = true;
    }
  }
 
  G4VisExtent extent = sceneHandler.GetExtent();
  if (fExtentForField == G4VisExtent::GetNullExtent()) {
    extent = sceneHandler.GetExtent();
  } else {
    extent = fExtentForField;
  }
  const G4double& xMin = extent.GetXmin();
  const G4double& yMin = extent.GetYmin();
  const G4double& zMin = extent.GetZmin();
  const G4double& xMax = extent.GetXmax();
  const G4double& yMax = extent.GetYmax();
  const G4double& zMax = extent.GetZmax();
  const G4double xHalfScene = 0.5 * (xMax - xMin);
  const G4double yHalfScene = 0.5 * (yMax - yMin);
  const G4double zHalfScene = 0.5 * (zMax - zMin);
  const G4double xSceneCentre = 0.5 * (xMax + xMin);
  const G4double ySceneCentre = 0.5 * (yMax + yMin);
  const G4double zSceneCentre = 0.5 * (zMax + zMin);
  const G4double maxHalfScene =
  std::max(xHalfScene,std::max(yHalfScene,zHalfScene));
  if (maxHalfScene <= 0.) {
    G4warn << "Scene extent non-positive." << G4endl;
    return;
  }
 
  // Constants
  const G4double interval = maxHalfScene / fNDataPointsPerMaxHalfExtent;
  const G4int nDataPointsPerXHalfScene = G4int(xHalfScene / interval);
  const G4int nDataPointsPerYHalfScene = G4int(yHalfScene / interval);
  const G4int nDataPointsPerZHalfScene = G4int(zHalfScene / interval);
  const G4int nXSamples = 2 * nDataPointsPerXHalfScene + 1;
  const G4int nYSamples = 2 * nDataPointsPerYHalfScene + 1;
  const G4int nZSamples = 2 * nDataPointsPerZHalfScene + 1;
  const G4int nSamples = nXSamples * nYSamples * nZSamples;
  const G4double arrowLengthMax = 0.8 * interval;
 
  // Working vectors for field values, etc.
  std::vector<G4Point3D> Field(nSamples);          // Initialises to (0,0,0)
  std::vector<G4Point3D> xyz(nSamples);            // Initialises to (0,0,0)
  G4double FieldMagnitudeMax = -std::numeric_limits<G4double>::max();
 
  // Get field values and ascertain maximum field.
  for (G4int i = 0; i < nXSamples; i++) {
    G4double x = xSceneCentre + (i - nDataPointsPerXHalfScene) * interval;
 
    for (G4int j = 0; j < nYSamples; j++) {
      G4double y = ySceneCentre + (j - nDataPointsPerYHalfScene) * interval;
 
      for (G4int k = 0; k < nZSamples; k++) {
        G4double z = zSceneCentre + (k - nDataPointsPerZHalfScene) * interval;
 
        // Calculate indices into working vectors
        const G4int ijk = i * nYSamples * nZSamples + j * nZSamples + k;
    xyz[ijk].set(x,y,z);
 
        G4ThreeVector pos(x,y,z);
 
        // Check if point is in findings
        if (!fPVFindings.empty()) {
          G4bool isInPV = false;
          for (const auto& findings: fPVFindings) {
            G4VPhysicalVolume* pv = findings.fpFoundPV;
            G4int copyNo = findings.fFoundPVCopyNo;
            G4VSolid* solid = pv->GetLogicalVolume()->GetSolid();
            G4PVParameterised* pvParam = dynamic_cast<G4PVParameterised*>(pv);
            if (pvParam) {
              auto* param = pvParam->GetParameterisation();
              solid = param->ComputeSolid(copyNo,pvParam);
              solid->ComputeDimensions(param,copyNo,pvParam);
            }
            // Transform point to local coordinate system
            const auto& transform = findings.fFoundObjectTransformation;
            auto rotation = transform.getRotation();
            auto translation = transform.getTranslation();
            G4ThreeVector lPos = pos; lPos -= translation; lPos.transform(rotation.invert());
            if (solid->Inside(lPos)==kInside) {
              isInPV = true;
              break;
            }
          }
          if (!isInPV) continue;
        }
        // Point is in findings - or there were no findings
 
        // Find volume and field at this location.
        const G4VPhysicalVolume* pPV =
        navigator->LocateGlobalPointAndSetup(pos,0,false,true);
        const G4Field* field = globalField;
        if (pPV) {
          // Get logical volume.
          const G4LogicalVolume* pLV = pPV->GetLogicalVolume();
          if (pLV) {
            // Value for Region, if any, overrides
            G4Region* pRegion = pLV->GetRegion();
            if (pRegion) {
              G4FieldManager* pRegionFieldMgr = pRegion->GetFieldManager();
              if (pRegionFieldMgr) {
                field = pRegionFieldMgr->GetDetectorField();
                // G4cout << "Region with field" << G4endl;
              }
            }
            // 'Local' value from logical volume, if any, overrides
            G4FieldManager* pLVFieldMgr = pLV->GetFieldManager();
            if (pLVFieldMgr) {
              field = pLVFieldMgr->GetDetectorField();
              // G4cout << "Logical volume with field" << G4endl;
            }
          }
        }
 
    G4double time = 0.; // FIXME:  Can we get event time in some way?
 
    // Subclasses will have implemented this for their own field
    GetFieldAtLocation(field, xyz[ijk], time, Field[ijk]);
 
    G4double mag = Field[ijk].mag();
    if (mag > FieldMagnitudeMax) FieldMagnitudeMax = mag;
      } // for (k, z
    }   // for (j, y
  } // for (i, x
 
  if (FieldMagnitudeMax <= 0.) {
    G4warn << "No " << fTypeOfField << " field in this extent." << G4endl;
    return;
  }
 
  for (G4int i = 0; i < nSamples; i++) {
    const G4double Fmag = Field[i].mag();
    const G4double f = Fmag / FieldMagnitudeMax;
    if (f <= 0.) continue;  // Skip zero field locations
 
    G4double red = 0., green = 0., blue = 0., alpha = 1.;
    if (f < 0.5) {  // Linear colour scale: 0->0.5->1 is red->green->blue.
      green = 2. * f;
      red = 2. * (0.5 - f);
    } else {
      blue = 2. * (f - 0.5);
      green = 2. * (1.0 - f);
    }
    const G4Colour arrowColour(red,green,blue,alpha);
 
    // Very small arrows are difficult to see. Better to draw a line.
    G4bool drawAsLine = false;
    switch (fRepresentation) {
      case Representation::fullArrow:
        if (f < 0.1) {
          drawAsLine = true;
        }
        break;
      case Representation::lightArrow:
        drawAsLine = true;
        break;
      default:
        break;
    }
 
    // Head of arrow depends on field direction and strength...
    G4double arrowLength = arrowLengthMax * f;
    // ...but limit the length so it's visible.
    if (f < 0.01) arrowLength = arrowLengthMax * 0.01;
    const G4Point3D head = xyz[i] + arrowLength*Field[i]/Fmag;
 
    if (drawAsLine) {
      G4Polyline FArrowLite;
      G4VisAttributes va(arrowColour);
      va.SetLineWidth(2.);
      FArrowLite.SetVisAttributes(va);
      FArrowLite.push_back(xyz[i]);
      FArrowLite.push_back(head);
      sceneHandler.BeginPrimitives();
      sceneHandler.AddPrimitive(FArrowLite);
      sceneHandler.EndPrimitives();
    } else {
      G4ArrowModel FArrow(xyz[i].x(), xyz[i].y(), xyz[i].z(),
                          head.x(), head.y(), head.z(),
                          arrowLength/5, arrowColour,
                          fArrowPrefix+"Field",
                          fArrow3DLineSegmentsPerCircle);
      FArrow.DescribeYourselfTo(sceneHandler);
    }
  } // for (i, nSamples
}

GetFieldAtLocation()

virtual void G4VFieldModel::GetFieldAtLocation ( const G4Field * field, const G4Point3D & position, G4double time, G4Point3D & result ) const

protectedpure virtual

Implemented in G4ElectricFieldModel, and G4MagneticFieldModel.

Referenced by DescribeYourselfTo().

---

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

• G4VFieldModel.hh
• G4VFieldModel.cc