[1208] | 1 | <html> |
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| 2 | <head> |
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| 3 | <title>ADG: Geometry</title> |
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| 4 | </head> |
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| 5 | |
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| 6 | <!-- Changed by: Gabriele Cosmo, 18-Apr-2005 --> |
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| 7 | <!-- $Id: geomReflection.html,v 1.2 2006/06/09 13:57:14 gcosmo Exp $ --> |
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| 8 | <!-- $Name: $ --> |
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| 9 | <body> |
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| 10 | <table WIDTH="100%"><TR> |
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| 11 | <td> |
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| 12 | <a href="../../../../Overview/html/index.html"> |
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| 13 | <IMG SRC="../../../../resources/html/IconsGIF/Overview.gif" ALT="Overview"></a> |
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| 14 | <a href="geometry.html"> |
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| 15 | <IMG SRC="../../../../resources/html/IconsGIF/Contents.gif" ALT="Contents"></a> |
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| 16 | <a href="geomAssembly.html"> |
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| 17 | <IMG SRC="../../../../resources/html/IconsGIF/Previous.gif" ALT="Previous"></a> |
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| 18 | <a href="geomNav.html"> |
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| 20 | </td> |
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| 21 | <td ALIGN="Right"> |
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| 22 | <font SIZE="-1" COLOR="#238E23"> |
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| 23 | <b>Geant4 User's Guide</b> |
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| 24 | <br> |
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| 25 | <b>For Application Developers</b> |
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| 26 | <br> |
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| 27 | <b>Geometry</b> |
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| 28 | </font> |
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| 29 | </td> |
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| 30 | </tr></table> |
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| 31 | <br><br> |
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| 32 | |
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| 33 | <a name="4.1.7"> |
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| 34 | <h2>4.1.7 Reflecting Hierarchies of Volumes</h2></a> |
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| 35 | |
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| 36 | <p> |
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| 37 | Hierarchies of volumes based on <i>CSG</i> or <i>specific</i> solids can be |
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| 38 | reflected by means of the <tt>G4ReflectionFactory</tt> class and |
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| 39 | <tt>G4ReflectedSolid</tt>, which implements a solid that has been shifted |
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| 40 | from its original reference frame to a new 'reflected' one. The reflection |
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| 41 | transformation is applied as a decomposition into rotation and translation |
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| 42 | transformations.<br> |
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| 43 | |
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| 44 | The factory is a singleton object which provides the following methods: |
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| 45 | <pre> |
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| 46 | G4PhysicalVolumesPair Place(const G4Transform3D& transform3D, |
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| 47 | const G4String& name, |
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| 48 | G4LogicalVolume* LV, |
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| 49 | G4LogicalVolume* motherLV, |
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| 50 | G4bool isMany, |
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| 51 | G4int copyNo, |
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| 52 | G4bool surfCheck=false) |
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| 53 | |
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| 54 | G4PhysicalVolumesPair Replicate(const G4String& name, |
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| 55 | G4LogicalVolume* LV, |
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| 56 | G4LogicalVolume* motherLV, |
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| 57 | EAxis axis, |
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| 58 | G4int nofReplicas, |
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| 59 | G4double width, |
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| 60 | G4double offset=0) |
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| 61 | |
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| 62 | G4PhysicalVolumesPair Divide(const G4String& name, |
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| 63 | G4LogicalVolume* LV, |
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| 64 | G4LogicalVolume* motherLV, |
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| 65 | EAxis axis, |
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| 66 | G4int nofDivisions, |
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| 67 | G4double width, |
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| 68 | G4double offset); |
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| 69 | </pre> |
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| 70 | |
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| 71 | The method <tt>Place()</tt> used for placements, evaluates the passed |
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| 72 | transformation. In case the transformation contains a reflection, the |
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| 73 | factory will act as follows: |
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| 74 | <ol> |
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| 75 | <li>Performs the transformation decomposition.</li> |
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| 76 | <li>Creates a new reflected solid and logical volume, or retrieves them |
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| 77 | from a map if the reflected object was already created.</li> |
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| 78 | <li>Transforms the daughters (if any) and place them in the given mother.</li> |
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| 79 | </ol> |
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| 80 | If successful, the result is a pair of physical volumes, where the second |
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| 81 | physical volume is a placement in a reflected mother. Optionally, it is also |
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| 82 | possible to force the overlaps check at the time of placement, by activating |
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| 83 | the <tt>surfCheck</tt> flag. |
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| 84 | <br> |
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| 85 | The method <tt>Replicate()</tt> creates replicas in the given mother. |
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| 86 | If successful, the result is a pair of physical volumes, where the second |
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| 87 | physical volume is a replica in a reflected mother. |
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| 88 | <br> |
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| 89 | The method <tt>Divide()</tt> creates divisions in the given mother. |
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| 90 | If successful, the result is a pair of physical volumes, where the second |
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| 91 | physical volume is a division in a reflected mother. There exists also two |
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| 92 | more variants of this method which may specify or not width or number of |
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| 93 | divisions. |
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| 94 | </p> |
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| 95 | <p> |
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| 96 | <b>Notes</b> |
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| 97 | <ul> |
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| 98 | <li>In order to reflect hierarchies containing divided volumes, |
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| 99 | it is necessary to explicitely instantiate a concrete <i>division</i> |
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| 100 | factory -before- applying the actual reflection: |
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| 101 | (i.e. - <TT>G4PVDivisionFactory::GetInstance();</TT>).</li> |
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| 102 | <li>Reflection of generic parameterised volumes is not possible yet.</li> |
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| 103 | </ul> |
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| 104 | </p> |
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| 105 | |
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| 106 | <p> |
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| 107 | <center> |
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| 108 | <table BORDER=1 CELLPADDING=8> |
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| 109 | <tr><td> |
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| 110 | <pre> |
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| 111 | #include "G4ReflectionFactory.hh" |
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| 112 | |
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| 113 | // Calor placement with rotation |
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| 114 | |
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| 115 | G4double calThickness = 100*cm; |
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| 116 | G4double Xpos = calThickness*1.5; |
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| 117 | G4RotationMatrix* rotD3 = new G4RotationMatrix(); |
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| 118 | rotD3->rotateY(10.*deg); |
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| 119 | |
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| 120 | G4VPhysicalVolume* physiCalor = |
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| 121 | new G4PVPlacement(rotD3, // rotation |
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| 122 | G4ThreeVector(Xpos,0.,0.), // at (Xpos,0,0) |
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| 123 | logicCalor, // its logical volume (defined elsewhere) |
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| 124 | "Calorimeter", // its name |
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| 125 | logicHall, // its mother volume (defined elsewhere) |
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| 126 | false, // no boolean operation |
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| 127 | 0); // copy number |
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| 128 | |
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| 129 | // Calor reflection with rotation |
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| 130 | // |
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| 131 | G4Translate3D translation(-Xpos, 0., 0.); |
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| 132 | G4Transform3D rotation = G4Rotate3D(*rotD3); |
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| 133 | G4ReflectX3D reflection; |
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| 134 | G4Transform3D transform = translation*rotation*reflection; |
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| 135 | |
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| 136 | G4ReflectionFactory::Instance() |
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| 137 | ->Place(transform, // the transformation with reflection |
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| 138 | "Calorimeter", // the actual name |
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| 139 | logicCalor, // the logical volume |
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| 140 | logicHall, // the mother volume |
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| 141 | false, // no boolean operation |
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| 142 | 1, // copy number |
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| 143 | false); // no overlap check triggered |
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| 144 | |
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| 145 | // Replicate layers |
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| 146 | // |
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| 147 | G4ReflectionFactory::Instance() |
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| 148 | ->Replicate("Layer", // layer name |
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| 149 | logicLayer, // layer logical volume (defined elsewhere) |
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| 150 | logicCalor, // its mother |
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| 151 | kXAxis, // axis of replication |
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| 152 | 5, // number of replica |
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| 153 | 20*cm); // width of replica |
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| 154 | </pre> |
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| 155 | </tr></td> |
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| 156 | |
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| 157 | <tr> |
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| 158 | <td ALIGN=center> |
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| 159 | Source listing 4.1.8<br> |
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| 160 | An example of usage of the <tt>G4ReflectionFactory</tt> class. |
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| 161 | </td> |
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| 162 | </tr> |
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| 163 | </table> |
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| 164 | </center> |
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| 165 | |
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| 166 | <hr><a href="../../../../Authors/html/subjectsToAuthors.html"> |
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| 167 | <i>About the authors</a></i> </P> |
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| 168 | |
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| 169 | </body> |
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| 170 | </html> |
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