Document for VRMLFile Driver

            Satoshi Tanaka & Yasuhide Sawada
            Fukui University, Japan
            July     29, 1997
	    November 09, 1998 (revised)

<< Abstract >>

  The VRMLFile driver simply generates VRML files, g4.wrl etc,   
  under the current directory where GEANT4 program is invoked. 
  It does not use any network connection to another process.
  It does not require neigher Java nor a VRML viewer.
  It does not depend on neither Unix nor X.

<< No necessity of Java nor VRML viewer >>

  The VRMLFile driver does not require installation of java.
  It does not require installation of a VRML viewer, either.

<< Platform independence of VRMLFile driver >>

  Another important feature is that it is a driver which 
  does not depend of neither Unix nor X, since all 
  it has to do is simply generating VRML files.
  So we will be able to use this driver at NT, too.

<< Assigned names for generated VRML files >>

  Default file name is "g4.wrl".
  If the file of this name already exists  in the current directory, 
  file "g4_2.wrl" is generated.   And similarly, g4_3.wrl, ....

<< How to compile VRMLFile driver >>

 Example:

  % setenv G4VIS_BUILD_VRMLFILE_DRIVER  1
  % setenv G4VIS_USE_VRMLFILE     1
  % gmake 

<< How to use VRMLFile driver >>

  Example:

  % G++-Linux/example2
  .....
  G4> /vis/create_view/new_graphics_system VRMLFile
  G4> /vis/draw/current
  G4> (any drawing commands, e.g., /vis/draw/axes 0 0 0 15000)
  G4> /vis/show/view

  You have to use /vis/show/view to close the generated VRML file.
  Before closing the file, you can accumulate drawing data.

<< How to invoke VRML viewer >>

  Although VRML viewr is not required by the VRMLFile driver,
  you can use your favorite VRML viewer if you hope, and perform visualization.
  Set an environmental variable as follows:

  % setenv G4VRMLFILE_VIEWER  viewer_name

  Then the VRML viewer is automatically invoked inside GEANT4 and
  the generated VRML file (g4.wrl etc) is visualized.