Gabriele CosmoThis G4 Graphics Driver creates a HepRep File suitable for viewing by the WIRED Event Display client. It requires no external packages. The HepRep graphics format is further described at http://heprep.freehep.org Two different drivers are available for either HepRep1 or HepRep2. Driver: HepRepFile ------------------ The version of HepRep produced by this driver is HepRep Version 1. Each call to /vis/viewer/update rewrites the file G4HepRep.xml. View the file using the WIRED Event Display, available from: http://www.slac.stanford.edu/BFROOT/www/Computing/Graphics/Wired/ WIRED can read xml files in zipped format as well as unzipped, so you can save space by applying gzip to the xml file. This will reduce the file to about five percent of its original size. Joseph Perl 9 November 2001 Driver: HepRepXML ----------------- The version of HepRep produced by this driver is HepRep Version 2. It uses ZLIB and ZIPIOS (included in the HepRep driver) to compress the files if necessary. ZLIB and ZIPIOS are included in the zlib and zipios++ include directories and further licensed and described there. HepRep XML files can contain multiple HepRep events/geometries. If the file contains more than one HepRep it is not strictly XML anymore. Files can be written in .heprep.zip .heprep.gz or .heprep format. The .heprep.zip is the default for file output, the .heprep is the default for stdout and stderr. (Optional) To set the filename, where the extension should be .heprep.zip .heprep.gz or .heprep (.zip and .gz will compress), use: /vis/scene/create filename.heprep.zip (Optional) To create separate files for each event, you can set a suffix such as "-0001" to start writing files from filename-0001.heprep.zip to filename-9999.heprep.zip (or up), while "-55-sub" will start write files filename-55-sub.heprep.zip to filename-99-sub.heprep.zip (or up). /vis/heprep/setEventNumberSuffix -0001 (Note: suffix has to contain at least one digit) (Optional) To route the HepRep XML output to stdout (or stderr), by default uncompressed, use: /vis/scene/create stdout To select the driver, where the file if not create by scene is set to G4HepRepOutput.heprep.zip, use: /vis/open HepRepXML (Optional) To write a geometry, use: /vis/viewer/flush (Optional) To signal a change in geometry (to be written with the next event), use: /vis/viewer/refresh To write 10 events (and geometries), use: /run/beamOn 10 (Optional) To accumulate multiple (5) G4 events into one HepRep event, use: /vis/scene/endOfEventAction accumulate /run/beamOn 5 /vis/viewer/update (Optional) To add attributes to each point on a trajectory, use: /vis/heprep/addPointAttributes 1 Be aware that this may increase the size of the output dramatically. (Optional) You may use the commands: /vis/viewer/zoom to set an initial zoom factor /vis/viewer/set/viewpointThetaPhi to set an initial view point /vis/heprep/setCoordinateSystem uvw to change the coordinate system, where uvw can be "xyz", "zxy", ... (Optional) You may decide to write .zip files with events and geometry separated (but linked). This results in a smaller zip file, as the geometry is only written once. Use the command: /vis/heprep/appendGeometry false (Optional) To close the file, remove the SceneHandler, use: /vis/sceneHandler/remove scene-handler-0 View the file using the WIRED Event Display, available from: http://wired.freehep.org Limitations: Only one SceneHandler can exist at any time, connected to a single Viewer. Since the HepRep format is a model rather than a view this is not a real limitation. In WIRED you can create as many views (SceneHandlers) as you like. 27 May 2004 Mark.Donszelmann@slac.stanford.edu