Hierarchies of volumes based on CSG or specific solids can be reflected by means of the G4ReflectionFactory class and G4ReflectedSolid, which implements a solid that has been shifted from its original reference frame to a new 'reflected' one. The reflection transformation is applied as a decomposition into rotation and translation transformations. The factory is a singleton object which provides the following methods: G4PhysicalVolumesPair Place(const G4Transform3D& transform3D, const G4String& name, G4LogicalVolume* LV, G4LogicalVolume* motherLV, G4bool isMany, G4int copyNo, G4bool surfCheck=false) G4PhysicalVolumesPair Replicate(const G4String& name, G4LogicalVolume* LV, G4LogicalVolume* motherLV, EAxis axis, G4int nofReplicas, G4double width, G4double offset=0) G4PhysicalVolumesPair Divide(const G4String& name, G4LogicalVolume* LV, G4LogicalVolume* motherLV, EAxis axis, G4int nofDivisions, G4double width, G4double offset); The method Place() used for placements, evaluates the passed transformation. In case the transformation contains a reflection, the factory will act as follows: Performs the transformation decomposition. Creates a new reflected solid and logical volume, or retrieves them from a map if the reflected object was already created. Transforms the daughters (if any) and place them in the given mother. If successful, the result is a pair of physical volumes, where the second physical volume is a placement in a reflected mother. Optionally, it is also possible to force the overlaps check at the time of placement, by activating the surfCheck flag. The method Replicate() creates replicas in the given mother. If successful, the result is a pair of physical volumes, where the second physical volume is a replica in a reflected mother. The method Divide() creates divisions in the given mother. If successful, the result is a pair of physical volumes, where the second physical volume is a division in a reflected mother. There exists also two more variants of this method which may specify or not width or number of divisions. In order to reflect hierarchies containing divided volumes, it is necessary to explicitely instantiate a concrete division factory -before- applying the actual reflection: (i.e. - G4PVDivisionFactory::GetInstance();). Reflection of generic parameterised volumes is not possible yet. #include "G4ReflectionFactory.hh" // Calor placement with rotation G4double calThickness = 100*cm; G4double Xpos = calThickness*1.5; G4RotationMatrix* rotD3 = new G4RotationMatrix(); rotD3->rotateY(10.*deg); G4VPhysicalVolume* physiCalor = new G4PVPlacement(rotD3, // rotation G4ThreeVector(Xpos,0.,0.), // at (Xpos,0,0) logicCalor, // its logical volume (defined elsewhere) "Calorimeter", // its name logicHall, // its mother volume (defined elsewhere) false, // no boolean operation 0); // copy number // Calor reflection with rotation // G4Translate3D translation(-Xpos, 0., 0.); G4Transform3D rotation = G4Rotate3D(*rotD3); G4ReflectX3D reflection; G4Transform3D transform = translation*rotation*reflection; G4ReflectionFactory::Instance() ->Place(transform, // the transformation with reflection "Calorimeter", // the actual name logicCalor, // the logical volume logicHall, // the mother volume false, // no boolean operation 1, // copy number false); // no overlap check triggered // Replicate layers // G4ReflectionFactory::Instance() ->Replicate("Layer", // layer name logicLayer, // layer logical volume (defined elsewhere) logicCalor, // its mother kXAxis, // axis of replication 5, // number of replica 20*cm); // width of replica