(no subject)

    Dear VMC group,  

I suppose that VMC interface to G3, G4 via root also assumes that a user can
desire to use root visualization of both the detector and the tracks produced. If
this is correct than I think that TGeoTrack is a tool created for visualization of tracks.
I am trying to use it like:

MCApplication::PreTrack()    

    Int_t id = fStack->GetCurrentTrackNumber();     Int_t pdgcode = gMC->TrackPid();
    TLorentzVector position;
    gMC->TrackPosition(position);
    fStack->PreTrack(id, pdgcode, position);

and in
void MCStack::PreTrack(Int_t id, Int_t pdgcode, TLorentzVector position) {

//
//
//

    if (!gGeoManager) Fatal("PreTrack","No gGeoManager");     gGeoManager->AddTrack(id,pdgcode);
    TGeoTrack *newtrack = (TGeoTrack*)gGeoManager->GetTrackOfId(id);     newtrack->AddPoint(position.X(),position.Y(),position.Z(),position.T()); <skip>

Also to update I refer to the track via its Uid. In principle it works but there are however
some things where I am not sure if I use them propely:

1. G4 places and traces all tracks sequentially: 1,2,3,4,...N G3 seems not to follow this rule and it tracks them like: 1,5,12,2,25...

    This forces me to use gGeoManager->GetTrackOfId(id) which is quite time consuming.

    gGeoManager->GetTrack(id) works only for G4 and make crash for G3 because of

    difference in the tracking sequence.

2. When the tracks are drawn I obviuosly need to reset them for the next event. This I do with:

gGeoManager->ClearTracks();
This method deletes all objects from gGeoManager::fTracks For energies of 1 TeV and with hadronic switch on
(in g4config.in /mcPhysics/setHadron 1 if I am not mistaken here) it takes quite a lot of time
to remove all tracks from gGeoManager. Is it an expected behaviour?

Thank you in advance,
Dmitry Received on Wed Jun 01 2005 - 12:55:38 MEST