OPACS as a visualization environment for Geant4
-------------------------------------------
  The OPACS html address is :

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

  To have OPACS using Geant4 :

  - Install the OPACS v3 by following
    the web installation page.
     For Geant4 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> <edit the setup.csh, setup.sh> to handle your environment.
       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

  - Bring Geant4/source and reconstruct libraries.

  - Bring Geant4/environments/OPACS.

  - Reconstruct Geant4/environments/OPACS :
      UNIX> cd <Geant4>/environments/OPACS/mgr
      UNIX> <edit setup.csh> to handle your environment.
       csh> source setup.csh
       (sh> . ./setup.sh)
      UNIX> make <config>
    ( UNIX> gmake <config> )
    where <config> is a compilation "configuration".
    For example :
      UNIX> make OSF1-cxx
      UNIX> make HP-UX-aCC
    The compilation "configs" are defined in the file :
      mgr/Config.mk
    If the existing "configs" do not match your environment, 
    edit this file. Existing configs are :
      OSF1-cxx
      HP-UX-aCC
      Linux-gxx
      SunOS-CC
    At the end of installation you should
    find in the parallel <config> directory the
    G4o library and the executable :
      EXPO.exe
    Run it by doing :
      UNIX> cd ../usr
      UNIX> ../<config>/EXPO.exe

  As usual, when you have something in an 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...

  The "experiment" EXPO is a very simple example 
 to help starting some Geant4 application working 
 with OPACS. Most of the interactivity is handled 
 in the OPACS/usr/EXPO*odb,osh files.

  NOTE : the app/TEST.cc application is for developer
         testing purpose and is not reconstructed 
         by default.