Geant4 Cross Reference (Editor's cut) |
1 G3toG4 2 ------ 3 4 G3toG4 is the Geant4 facility to convert Geant3 geometries into Geant4. 5 This is done in two stages. 6 7 First, the user supplies a Geant3 .rz file containing the initialization 8 data structures. An executable, rztog4, reads this file and produces an 9 ascii ("call list") file containing instructions on how to build the 10 geometry. The source code for this is fortran. 11 12 Second, a call list interpreter (G4BuildGeom.cc) reads these instructions 13 and builds the geometry in the user's G4 client code. 14 15 Two examples of how to use the call list interpreter are supplied in 16 examples/extended/g3tog4: 17 - the first example, cltog4, is a simple example which simply invokes the 18 call list interpreter method G4BuildGeom from G3toG4DetectorConstruction 19 class, builds the geometry and exits. 20 - the second example, clGeometry, is more complete and is patterned after 21 the novice G4 examples. It also invokes the call list interpreter, but 22 in addition, allows the geometry to be visualized and particles to be 23 tracked. Currently, G3toG4 does not provide a method for scoring hits 24 in G4. 25 26 To build these examples, especially the one involving visualization, the 27 user must have one or more of the following environment variables set: 28 29 setenv G4VIS_BUILD_<driver>_DRIVER 30 setenv G4VIS_USE_<driver> 31 32 where the G4-supported drivers are listed in source/visualization/README. 33 34 To use the freeware Mesa API, you must have the environment variable 35 OGLHOME defined to point to the directory containing the Mesa lib/ directory 36 specific to your platform. 37 38 To compile and build the G3toG4 libraries, simply type 39 40 gmake 41 42 from the top-level G3toG4 directory. 43 44 To build the converter executable "rztog4", simply type 45 46 gmake bin 47 48 To make everything, simply type: 49 50 gmake global 51 52 To remove all G3toG4 libraries, executables and .d files, simply type 53 54 gmake clean 55 56 the implementation (April 1999) 57 ---------------------------------------- 58 - PGON, PCON are built using the CSG classes G4Polycone and G4Polyhedra. 59 - G3 MANY feature has not been tested. 60 - GsROTM is fully implemented and supports rotations and mirror reflections 61 - GSPOSP implemented via individual logical volumes for each instantiation 62 (G4PVIndexed doesn't exist yet) 63 - GSDV* routines for dividing volumes implemented, using 64 G4PVReplicas, G4PVParametrised 65 - GSROTM is implemented 66 - hits are not implemented. Hit code is do-nothing. (It is 67 coded up, but hit class references are commented out.) 68 The digits+hits code has to be updated before G3toG4's 69 hit code can be activated. 70 - GSPART has to be updated. 71 - Usage of magnetic field class has to be turned on. 72 73 the implementation (February 2001) 74 ---------------------------------------- 75 - Supported shapes: all G3 shapes except for 76 "HYPE", "GTRA", "CTUB" 77 - G3 MANY feature is not supported. 78 - GSDV* routines for dividing volumes implemented, using 79 G4PVReplicas, for shapes: 80 "BOX", "TUBE", "TUBS", "PARA" - all axes; 81 "CONE", "CONS" - axes 2, 3; 82 "TRD1", "TRD2", "TRAP" - axis 3; 83 "PGON", "PCON" - axis 2; 84 "PARA" -axis 1; axis 2,3 for a special case 85 Unsupported shapes: 86 "SPHE", "ELTU", "HYPE", "GTRA", "CTUB" 87 88 the implementation (November 2001) 89 ---------------------------------------- 90 - Support for G3 MANY feature: 91 92 MANY positions are resolved in G3toG4MANY function, 93 which has to be processed before G3toG4BuildTree 94 (it is not called by default). 95 In order to resolve MANY user code has to provide 96 additional info using G4gsbool(G4String volName, G4String manyVolName) 97 function) for all overlapping volumes. Daughters of 98 overlapping volumes are then resolved automatically 99 and should not be specified via Gsbool. 100 101 Limitation: a volume with a MANY position can have only this 102 one position; if more than one position is needed a new volume 103 has to be defined (gsvolu) for each position. 104 105 See History file for modification history.