OPACS as a G4 driver
--------------------
 The OPACS html address is :

   http://www.lal.in2p3.fr/OPACS

 To have G4 running with OPACS :

  - Install the OPACS v3 by following
    the web installation page.
     For G4 take the group :
      WoXoXm  if you have MOTIF
      WoXoXaw if you have Xaw
     For example on a UNIX with MOTIF only :
      UNIX> mkdir OPACS
      UNIX> cd    OPACS
      UNIX> ftp ftp.lal.in2p3.fr
      anonymous
      user name
      ftp> cd pub/OPACS/v3
      ftp> bin
      ftp> get WoXoXm.tar.Z
    ( ftp> get WoXoXaw.tar.Z )
      ftp> quit
      UNIX> uncompress WoXoXm.tar.Z
    ( UNIX> uncompress WoXoXaw.tar.Z )
      UNIX> tar xvf WoXoXm.tar
    ( UNIX> tar xvf WoXoXaw.tar )
      UNIX> rm WoXoXm.tar
    ( UNIX> rm WoXoXaw.tar )
      UNIX> cd OPACS/v3
      UNIX> chmod u+x conf.sh    
      UNIX> ./conf.sh
       csh> source setup.csh
       (sh> . ./setup.sh)
      UNIX> make WoXo
    ( UNIX> gmake WoXo )
     At end of installation you should
    be able to build a simple Wo application
    (for exa named Xxx) by doing :
       csh> mkdir tmp
       csh> cd tmp
    with MOTIF :
       csh> onew Xxx
    or with Xaw :
       csh> onew Xxx $WOROOT/usr/template/Xaw/
    then :
       csh> gmake `uname`
       csh> ./Xxx.exe
     The interpreted interface is described 
    in Xxx.odb.
    See OPACS doc for more.

  - Execute OPACS setup script :
       csh> source <OPACS_HOME>/OPACS/v3/setup.csh

  - Set environment variables :
      G4UI_BUILD_WO_SESSION
      G4UI_USE_WO
      G4VIS_BUILD_OPACS_DRIVER
      G4VIS_USE_OPACS
     For example : 
         csh> setenv G4UI_BUILD_WO_SESSION    1
         csh> setenv G4UI_USE_WO              1
         csh> setenv G4VIS_BUILD_OPACS_DRIVER 1
         csh> setenv G4VIS_USE_OPACS          1
     Set G4_OPACS_WIDGET_SET to Xaw if you want 
    to use Athena widget set instead of Motif :
         csh> setenv G4_OPACS_WIDGET_SET Xaw

  - Compile G4 interfaces and visualization modules with
    the upper variables setted.

  - Build visualization/test/test19.

  - example to run test 19 with Xaw G4UI and Xo vis driver :
      csh> source <OPACS_HOME>/OPACS/v3/setup.csh
   (or sh> . <OPACS_HOME>/v3/setup.sh)
      csh> cd .../visualization/test
      csh> G++-Linux/test19 Xaw
    In the little window type :
       continue (and click on ok)
       continue
       /vis~/create_view/new_graphics_system Xo
       /run/beamOn 1 
       continue
    When you have something in the Xo window
   you can manipulate it with :
      Ctrl+button1+move pointer
   on the window. On button3 you have a popup
   menu to do things, like changing "Ctrl" action,
   setting ZBuffer, etc...

  - example to run test19 with Wo G4UI reconstructed 
    with MOTIF :
      csh> source <OPACS_HOME>/OPACS/v3/setup.csh
   (or sh> . <OPACS_HOME>/v3/setup.sh)
      csh> cd .../visualization/test
      csh> HP-UX/test19 Wo
   or with Xaw :
      csh> source <OPACS_HOME>/OPACS/v3/setup.csh
      csh> cd .../visualization/test
      csh> setenv WOENVIRONMENT test19Xaw.odb
      csh> G++-Linux/test19 Wo
  The "Wo" interface to test19 is in test19.odb
 (or test19Xaw.odb). In this file you can 
 find examples of buttons that triggs G4 commands.