Re: (no subject)

 Hi Dmitry,

On Tue, 3 May 2005, Dmitry Naumov wrote:

> Dear VMC developers,
>
> I am adapting Ex03 for my application in which I build geometry via TGeo
> and use vgm for converting it into g4 internally in memory. Some things
> are not yet clear to me:
>
> - naming conventions. My TGeoVolumes have names like: ScintPlateL_1_2
> it seems that G4 does not recongnize when the name contains underscores,
> G4 releases warnings. I modified names to like follows: ScintPlateLX1X2
> and they are recognized, while a warning persists:

 The reason is that underscore is used by default as a special character  in G3toG4 in naming of logical volumes. Even if you don't use g3tog4,  the underscores are still treated as special characters.  You can override this default value with e.g. '%' by applying the command:

 /mcDet/volNameSeparator %

 in g4config.in.
 Then, the underscores should be ok in your volumes names.

> ++++ TG4Warning: ++++
> TG4StepManager::GetCurrentOffPhysicalVolume:
> Volume ScintPlateLX1X2 has not defined mother in the required level.
>

 This warning is issued each time when the depth of the volume  hierarchy is lower then that asked in gMC->CurrentVolOffID(2, copyNo);

• in your case 2. For example, if you have hierarchy of volumes as below: World World/A1 World/A1/B2 you will get these warnings when the current volume is World or A1; only if you are in B2, this call has a good sense and will return the Id of World.

> - When the event is generated I see with G4 OpenGL viewer my detector and
> tracks
> inside it. That viewer does not look too nice and I would like to use root
> TGeo
> package as a viewer. The detector can be viweved without any problems, however
> I would like to fetch G4 generated tracks and draw them with TGeo "viewer".
> What
> is the way these tracks can be accessed and drawn?
>

  There is no way to draw directly G4 tracks via TGeo,   as the tracks are not interfaced between the two programs.   Besides OpenGL, you can use other Geant4 tools,   such as Dawn and Wired; see eg:
  http://geant4.slac.stanford.edu/g4cd/January2004/Documentation/Visualization/G4WIREDTutorial/G4WIREDTutorial.html   http://geant4.slac.stanford.edu/g4cd/January2004/Documentation/Visualization/G4DAWNTutorial/G4DAWNTutorial.html

  Or, with TGeo, you can base your display on your hits objects   and draw the hits positions. Andrei, probably, can give you more   hints for this direction.

  Best regards,

  Ivana

-- 
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e-mail:  Ivana.Hrivnacova_at_cern.ch
address: Institut Physique Nucleaire, 91406 Orsay, France
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