void FopiGeom()
{   
   //--- Definition of a simple geometry
   gSystem->Load("libGeom");
   new TGeoManager("genfitGeom", "GENFIT geometry");
   gROOT->Macro("FopiMedia.C");
   
   gROOT->Macro("Cavb.C");
   gROOT->Macro("Magnet.C");
   
   gROOT->Macro("Helitron.C");
   gROOT->Macro("Plawa.C"); 
   gROOT->Macro("Zer.C");   

   gROOT->Macro("CDC.C");
   gROOT->Macro("Pbar.C");
   gROOT->Macro("RPC.C");
   
   gROOT->Macro("TPC.C");             
   //gROOT->Macro("Silvio.C"); 
   gROOT->Macro("Target.C");
   // gROOT->Macro("Body.C"); 

   gGeoManager->SetTopVolume(CAVB);
   //--- close the geometry
   gGeoManager->CloseGeometry();
   
   //--- draw the ROOT box
   gGeoManager->SetVisLevel(3);


   CAVB->Draw();  
   TVirtualViewer3D *viewer3D = gPad->GetViewer3D("ogl");
   TGLViewer *glviewer = (TGLViewer *)viewer3D;
   //   glviewer->SetCurrentCamera(TGLViewer::kCameraPerspXOY);
   glviewer->CurrentCamera().RotateRad(0.0, TMath::Pi()/3);
   glviewer->CurrentCamera().RotateRad(-TMath::Pi()/16,0.0);
   glviewer->CurrentCamera().Dolly(50, 0, 0); 

   //glviewer->GetClipSet()->SetClipType(2);
   //if (gPad) gPad->GetViewer3D("ogl"); 
   
   TFile *outfile = TFile::Open("FopiGeom_S339.root","RECREATE");
   gGeoManager->Write();
   outfile->Close();   
}