void make_FOPI_target(string targetmat="carbon",bool draw = false,
		      TString outpath="", TString fileName="") {
  if(fileName.EqualTo("")){
    fileName="FOPI_TARGET.root";
  }
    
  std::cout<<std::endl<<std::endl<<std::endl<<std::endl<<std::endl;
  //gROOT->Macro("$VMCWORKDIR/gconfig/rootlogon.C");

  //----------------------- INIT --------------------------------------

  //get geometry definitions:
  FairGeoLoader* loader = new FairGeoLoader("TGeo", "FairGeoLoader");
  FairGeoBuilder* builder = loader->getGeoBuilder();

  FairGeoInterface* geoIFC = loader->getGeoInterface();
  TString workdir = gSystem->Getenv("VMCWORKDIR");
  
  geoIFC->setMediaFile(workdir+"/geometry/media_pnd.geo");
  geoIFC->readMedia();
  //geoIFC->print();
  FairGeoMedia* media = geoIFC->getMedia();
  TGeoManager* geoMan = (TGeoManager*) gROOT->FindObject("FAIRGeom");
  geoMan->Print();
  std::cout<<" --------------------------------------------- "<<std::endl;
  gGeoManager->Print();

  //------------------ LOAD MATERIALS ----------------------------------
  

  FairGeoMedium *CbmMediumCopper      = media->getMedium("copper");
  FairGeoMedium *CbmMediumCarbon      = media->getMedium("carbon");
  FairGeoMedium *CbmMediumLead        = media->getMedium("lead");

  builder->createMedium(CbmMediumCopper);
  builder->createMedium(CbmMediumCarbon);
  builder->createMedium(CbmMediumLead);

  
  gROOT->Macro("$FOPI2ROOT/fopigeometry/FopiMedia.C");
  

  // ------------------ DEFINE GEO -------------------------------------

  TGeoVolume* top = new TGeoVolumeAssembly("TARGET");
  TGeoVolumeAssembly* topAss = new TGeoVolumeAssembly("TARGET");

  TGeoVolumeAssembly* target= new TGeoVolumeAssembly("TARGET");
  
  target->Print();
  gROOT->LoadMacro("$FOPI2ROOT/fopigeometry/Target.C");
  Target(target,targetmat);
  target->Print();
  geoMan->SetTopVolume(topAss);


  TGeoTranslation * trans1=new TGeoTranslation(0.,0.,0);

  topAss->AddNode(target,0,trans1);
  top->AddNode(topAss, 0);

  TGeoVoxelFinder* voxels = top->GetVoxels();
  if (voxels) { voxels->SetNeedRebuild(); }
   
  geoMan->CloseGeometry();  
  
  if(draw){
    TEveManager::Create();

    TEveGeoTopNode* meh = new TEveGeoTopNode(geoMan, geoMan->GetTopNode());
    gEve->AddGlobalElement(meh);

    gEve->Redraw3D(kTRUE);
  }

  TFile* outfile;
  if(outpath.EqualTo("")) 
    outfile = new TFile("$VMCWORKDIR/geometry/"+fileName, "recreate");
  else {
    TString finalOut = outpath;
    if(!finalOut.EndsWith("/"))
      finalOut.Append("/");
    finalOut.Append(fileName);
    outfile = new TFile(finalOut, "recreate");
  }
  
  outfile->cd();
  top->Write();
  outfile->Close();
  delete outfile;
  std::cout<<"/n/n/n/n/n"<<std::endl<<std::endl<<std::endl<<std::endl;
}