C++ GDML Processors

General Information

Latest Release:

Previous releases:

• GDML_2_7_0 - Support for new solids have been added: twisted box, twisted trap, twisted trd and twisted tubs. New feature has been implemented allowing to include GDML files into other GDML files. The mechanism is based on the extension of the 'physvol' element which can now refere to volumes from an external GDML file.
• GDML_2_6_0 - The separate tag for CPPGDML has been droped. Only the common tag GDML_X_Y_Z will be used now for LCG releases of GDMLSchema and CPPGDML. The support for tessellated solids as well as tetrahedra has been added to the Geant4 'reader' and 'writer'. A new (optional) STEPWriter tool has been added to the package allowing the convertion from the intermediate ST-Viewer (CAD visualisation tool) files to GDML. This convertion uses tessellated solids to represent the geometry. In order to build that tool one has to add --enable-build-stepwrt=yes option to the ./configure command.
• CPPGDML_2_4_0 - Support for reflections and divisions has been added. After moving to Geant4.8.0.p01, support for G4Ellipsoid has been enabled.
• CPPGDML_2_3_0 - Implementation of replicas along x, y or z axis has been completed (for the reader as well as for the writer). Major bug in the writer (affecting the precision of generated numbers) has been corrected. Support for G4NistManager has been added.
• CPPGDML_2_2_0 - Same functionality as CPPGDML_2_1_0. An Autoconf-based front end has been added to the build system. A few bug-fixes and cosmetic changes (removed some print-outs) have been also added.
• CPPGDML_2_1_0 - Supports GDMLSchema_2_1_0. This is the first release of C++ GDML processors as an independent package. There are no changes, compared to the previous release (before the reorganization of the package), as far as the functionality is concerned. The build system, however, has been entirely re-writen, and in particular, there are shared libraries which are created now in addition to the static ones. The package contains a common part, application independent and one application specific (Geant4.7.0) binding. The Example directory contains two simple examples illustrating how to write out and read in GDML geometry files.

• Install C++ GDML processors
  The CPPGDML package can be obtained from CVS using the anonymous login:
  cvs -d :pserver:anonymous@simu.cvs.cern.ch:/cvs/simu co -r <version> -d <destination> GDML2/CPPGDML
  where <version> is the tag of the version you want and <destination> is the directory you want to install CPPGDML in (for instance CPPGDML). Note that in order to use the GDML reader, you also need to have GDMLSchema installed. You can refer to Getting started or to LCG build instructions for more information on installing GDML.
• Configure and build
  Since version GDML_2_2_0 there is an Autoconf-based front end for the build system (type ./configure --help for a list of options). Have a look at CPPGDML/README for a short instruction. See CERNConfigure.(c)sh and SLACConfigure.(c)sh for example of usage. For the first-time users a special script (GDMLSetup in CPPGDML directory) has been implemented to guide through the installation procedure.
  Once the configuration is done, in order to build the libraries as well as the executables for the example you only need to issue the 'make' command in the CPPGDML directory.
• Run
  • In order to use the GDMLWriter in your application you need to instanciate the writer class specifying the location of the schema (that location will then be stored in the .gdml file) and the name of the output file

    #include "G4Writer/G4GDMLWriter.h"
    
    G4GDMLWriter g4writer("GDMLSchema/gdml.xsd", "geo.gdml");
    

    In order to create the .gdml file you need to call DumpGeometryInfo method, with the argument being the pointer to the top PhysicalVolume of the geometry tree you want to store

    try
    {
       g4writer.DumpGeometryInfo(g4TopVolume);
    }
    catch(std::logic_error &lerr)
    {
       std::cout << "Caught the exception: "
                 << lerr.what () << std::endl;
    }
    

    Finally, when you build your executable, you need to link with two libraries from CPPGDML: libWriter and libG4Writer (or the global libgdml library containing the whole GDML system).
  • In order to use the GDML processor (reader) in your application you need first to instanciate the SAXProcessor class and configure it, specifying the name of the .gdml file you want to parse

    #include "Saxana/SAXProcessor.h"
    #include "Saxana/ProcessingConfigurator.h"
    
    SAXProcessor sxp;
    ProcessingConfigurator config;
    
    sxp.Initialize();
    config.SetURI( "geo.gdml" );
    config.SetSetupName( "Default" );
    sxp.Configure( &config );
    

    Once that is done, you can call the parser and get the pointer to the top volume of the processed geometry

    sxp.Run();
      
    G4VPhysicalVolume* fWorld =  (G4VPhysicalVolume *)GDMLProcessor::GetInstance()->GetWorldVolume();
    

    Finally, before exiting your program you should call

    sxp.Finalize();
    

    As far as the executable is concerned, it will need to be linked to the following four libraries from CPPGDML: libG4Subscribers, libG4Processor, libG4Evaluator libProcesses and libSaxana (or the global libgdml library containing the entire GDML system).

Code browsers

• GDML Doxygen
• GDML LXR browser

Code Repository

Downloads

• Starting from release GDML_2_6_0, CPPGDML is not available as a separate tarfile. The tarfile containing GDMLSchema and CPPGDML is available from the main GDML web page.
• CPPGDML_2_3_0 tarfile
• CPPGDML_2_2_0 tarfile
• CPPGDML_2_1_0 tarfile