
///\file "optical/OpNovice/.README.txt"
///\brief Example OpNovice README page

/*! \page ExampleOpNovice Example OpNovice

This example presently illustrates the following basic concepts, and in
particular (indicated with ***), how to use G4 for optical photon
generation and transport. Other extended example of what is possible
in Geant4 with optical photons can be found at
examples/extended/optical/LXe and wls

\section ExampleOpNovice_s1 main()

 Define Random Number generator initial seed

\section ExampleOpNovice_s2 G4OpticalPhysics

 The G4OpticalPhysics physics class is used. The messenger is the
 G4OpticalParametersMessenger class.

 - Define particles; including - *** G4OpticalPhoton     ***
 - Define processes; including 
   - *** G4Cerenkov          ***
   - *** G4Scintillation     ***
   - *** G4OpAbsorption      ***
   - *** G4OpRayleigh        ***
   - *** G4OpBoundaryProcess ***

 A messenger command allows to define interactively the 
 verbose level and the maximum number of Cerenkov photons per step
 (see for instance OpNovice.in)

\section ExampleOpNovice_s3 G4VUserDetectorConstruction 

 - Define material: Air and Water
 - Define simple G4box geometry
   - *** add G4MaterialPropertiesTable to G4Material       ***
   - *** define G4LogicalSurface(s)                        ***
   - *** define G4OpticalSurface                           ***
   - *** add G4MaterialPropertiesTable to G4OpticalSurface ***

alternatively the Configuration can be read from a gdml file.
The provided gdml file NoviceExample.gdml corresponds to the detector
defined in OpNoviceDetectorConstruction.


\section ExampleOpNovice_s4 G4VUserPrimaryGeneratorAction

 Use G4ParticleGun to shoot a charge particle into a Cerenkov radiator
 
 A messenger command allows to define interactively the polarization of an
 primary optical photon (see for instance optPhoton.mac)
    
\section ExampleOpNovice_s5 G4UserRunAction and G4Run

 - Used to accumulate statistics.

\section ExampleOpNovice_s6 G4UserStackingAction and G4UserEventAction

 Show how to count the number of secondary particles in an event

\section ExampleOpNovice_s7 Visualisation
 
 The Visualization Manager is set in the main().
 The initialisation of the drawing is done via a set of /vis/ commands
 in the macro vis.mac. This macro is automatically read from 
 the main in case of interactive running mode.
 	
 The detector has a default view which is a longitudinal view of the tank. 	
 The tracks are drawn at the end of event, and erased at the end of run.
 
\section ExampleOpNovice_s8 How to start

 - compile and link to generate an executable

   This example handles the program arguments in a new way.
   It can be run with the following optional arguments:
\verbatim
   $ OpNovice  [-g gdmlfile] [-m macro ] [-u UIsession] [-t nThreads]
\endverbatim

   The -t option is available only in multi-threading mode
   and it allows the user to override the Geant4 default number of
   threads. The number of threads can be also set via G4FORCENUMBEROFTHREADS
   environment variable which has the top priority.
 
 - execute OpNovice in 'batch' mode from macro files
\verbatim
   $ OpNovice -m OpNovice.in
\endverbatim

 - execute OpNovice in 'batch' mode from macro files using a gdml file
   to define the geometry
 	$ OpNovice -g NoviceExample.gdml -m OpNovice.in

 - execute OpNovice in 'interactive mode' with visualization
\verbatim
$ OpNovice
....
Idle> type your commands. For instance:
Idle> /control/execute optPhoton.mac
....
Idle> exit
\endverbatim

Macros
------

 The following macros are provided:

 - optPhoton.mac: Shoot optical photons with energy 3 eV
 - OpNovice.in: Shoot positrons with energy 500 keV.
 - gui.mac: Configure the graphical user interface.
 - vis.mac: Configure visualization.

gdml files
----------
NoviceExample.gdml: example gdml file corresponding to
OpNoviceDetectorConstruction
      
*/
