Geant4Converter.cpp

//==========================================================================
//  AIDA Detector description implementation 
//--------------------------------------------------------------------------
// Copyright (C) Organisation europeenne pour la Recherche nucleaire (CERN)
// All rights reserved.
//
// For the licensing terms see $DD4hepINSTALL/LICENSE.
// For the list of contributors see $DD4hepINSTALL/doc/CREDITS.
//
// Author     : M.Frank
//
//==========================================================================

// Framework include files
#include <DD4hep/Shapes.h>
#include <DD4hep/Volumes.h>
#include <DD4hep/Plugins.h>
#include <DD4hep/Printout.h>
#include <DD4hep/Detector.h>
#include <DD4hep/DD4hepUnits.h>
#include <DD4hep/PropertyTable.h>
#include <DD4hep/DetectorTools.h>
#include <DD4hep/detail/ShapesInterna.h>
#include <DD4hep/detail/ObjectsInterna.h>
#include <DD4hep/detail/DetectorInterna.h>

#include <DDG4/Geant4Field.h>
#include <DDG4/Geant4Helpers.h>
#include <DDG4/Geant4Converter.h>
#include <DDG4/Geant4UserLimits.h>
#include <DDG4/Geant4AssemblyVolume.h>
#include <DDG4/Geant4PlacementParameterisation.h>
#include "Geant4ShapeConverter.h"

// ROOT includes
#include <TClass.h>
#include <TGeoBoolNode.h>

// Geant4 include files
#include <G4Version.hh>
#include <G4VisAttributes.hh>
#include <G4PVParameterised.hh>
#include <G4ProductionCuts.hh>
#include <G4VUserRegionInformation.hh>

#include <G4Box.hh>
#include <G4Tubs.hh>
#include <G4Ellipsoid.hh>
#include <G4UnionSolid.hh>
#include <G4ReflectedSolid.hh>
#include <G4SubtractionSolid.hh>
#include <G4IntersectionSolid.hh>
#include <G4VSensitiveDetector.hh>

#include <G4Region.hh>
#include <G4Element.hh>
#include <G4Isotope.hh>
#include <G4Material.hh>
#include <G4UserLimits.hh>
#include <G4RegionStore.hh>
#include <G4FieldManager.hh>
#include <G4LogicalVolume.hh>
#include <G4OpticalSurface.hh>
#include <G4ReflectionFactory.hh>
#include <G4LogicalSkinSurface.hh>
#include <G4ElectroMagneticField.hh>
#include <G4LogicalBorderSurface.hh>
#include <G4MaterialPropertiesTable.hh>
#if G4VERSION_NUMBER >= 1040
#include <G4MaterialPropertiesIndex.hh>
#endif
#include <G4ScaledSolid.hh>
#include <CLHEP/Units/SystemOfUnits.h>

// C/C++ include files
#include <iostream>
#include <iomanip>
#include <sstream>
#include <limits>

namespace units = dd4hep;
using namespace dd4hep::sim;
using namespace dd4hep;

namespace {

  static constexpr const double CM_2_MM = (CLHEP::centimeter/dd4hep::centimeter);
  static constexpr const char* GEANT4_TAG_IGNORE = "Geant4-ignore";
  static constexpr const char* GEANT4_TAG_PLUGIN = "Geant4-plugin";
  static constexpr const char* GEANT4_TAG_BIRKSCONSTANT    = "BirksConstant";
  static constexpr const char* GEANT4_TAG_MEE              = "MeanExcitationEnergy";
  static constexpr const char* GEANT4_TAG_ENE_PER_ION_PAIR = "MeanEnergyPerIonPair";

  static std::string indent = "";

  template <typename O, typename C, typename F> void handleRefs(const O* o, const C& c, F pmf) {
    for (typename C::const_iterator i = c.begin(); i != c.end(); ++i) {
      //(o->*pmf)((*i)->GetName(), *i);
      (o->*pmf)("", *i);
    }
  }

  template <typename O, typename C, typename F> void handle(const O* o, const C& c, F pmf) {
    for (typename C::const_iterator i = c.begin(); i != c.end(); ++i) {
      (o->*pmf)((*i)->GetName(), *i);
    }
  }

  template <typename O, typename F> void handleArray(const O* o, const TObjArray* c, F pmf) {
    TObjArrayIter arr(c);
    for(TObject* i = arr.Next(); i; i=arr.Next())
      (o->*pmf)(i);
  }

  template <typename O, typename C, typename F> void handleMap(const O* o, const C& c, F pmf) {
    for (typename C::const_iterator i = c.begin(); i != c.end(); ++i)
      (o->*pmf)((*i).first, (*i).second);
  }

  template <typename O, typename C, typename F> void handleRMap(const O* o, const C& c, F pmf) {
    for (typename C::const_reverse_iterator i = c.rbegin(); i != c.rend(); ++i)  {
      //cout << "Handle RMAP [ " << (*i).first << " ]" << std::endl;
      handle(o, (*i).second, pmf);
    }
  }
  template <typename O, typename C, typename F> void handleRMap_(const O* o, const C& c, F pmf) {
    for (typename C::const_iterator i = c.begin(); i != c.end(); ++i)  {
      const auto& cc = (*i).second;
      for (const auto& j : cc)   {
        (o->*pmf)(j);
      }
    }
  }

  std::string make_NCName(const std::string& in)   {
    std::string res = detail::str_replace(in, "/", "_");
    res = detail::str_replace(res, "#", "_");
    return res;
  }

  bool is_left_handed(const TGeoMatrix* m)   {
    const Double_t* r = m->GetRotationMatrix();
    if ( r )    {
      Double_t det =
        r[0]*r[4]*r[8] + r[3]*r[7]*r[2] + r[6]*r[1]*r[5] -
        r[2]*r[4]*r[6] - r[5]*r[7]*r[0] - r[8]*r[1]*r[3];
      return det < 0e0;
    }
    return false;
  }

  class G4UserRegionInformation : public G4VUserRegionInformation {
  public:
    Region region;
    double threshold;
    bool   storeSecondaries;
    G4UserRegionInformation()
      : threshold(0.0), storeSecondaries(false) {
    }
    virtual ~G4UserRegionInformation() {
    }
    virtual void Print() const {
      if (region.isValid())
        printout(DEBUG, "Region", "Name:%s", region.name());
    }
  };

  std::pair<double,double> g4PropertyConversion(int index)   {
#if G4VERSION_NUMBER >= 1040
    switch(index)  {
    case kRINDEX:                         return std::make_pair(CLHEP::keV/units::keV, 1.0);
    case kREFLECTIVITY:                   return std::make_pair(CLHEP::keV/units::keV, 1.0);
    case kREALRINDEX:                     return std::make_pair(CLHEP::keV/units::keV, 1.0);
    case kIMAGINARYRINDEX:                return std::make_pair(CLHEP::keV/units::keV, 1.0);
    case kEFFICIENCY:                     return std::make_pair(CLHEP::keV/units::keV, 1.0);
    case kTRANSMITTANCE:                  return std::make_pair(CLHEP::keV/units::keV, 1.0);
    case kSPECULARLOBECONSTANT:           return std::make_pair(CLHEP::keV/units::keV, 1.0);
    case kSPECULARSPIKECONSTANT:          return std::make_pair(CLHEP::keV/units::keV, 1.0);
    case kBACKSCATTERCONSTANT:            return std::make_pair(CLHEP::keV/units::keV, 1.0);
    case kGROUPVEL:                       return std::make_pair(CLHEP::keV/units::keV, (CLHEP::m/CLHEP::s)/(units::m/units::s));  // meter/second
    case kMIEHG:                          return std::make_pair(CLHEP::keV/units::keV, CLHEP::m/units::m);
    case kRAYLEIGH:                       return std::make_pair(CLHEP::keV/units::keV, CLHEP::m/units::m);  // ??? says its a length
    case kWLSCOMPONENT:                   return std::make_pair(CLHEP::keV/units::keV, 1.0);
    case kWLSABSLENGTH:                   return std::make_pair(CLHEP::keV/units::keV, CLHEP::m/units::m);
    case kABSLENGTH:                      return std::make_pair(CLHEP::keV/units::keV, CLHEP::m/units::m);
#if G4VERSION_NUMBER >= 1100
    case kWLSCOMPONENT2:                  return std::make_pair(CLHEP::keV/units::keV, 1.0);
    case kWLSABSLENGTH2:                  return std::make_pair(CLHEP::keV/units::keV, CLHEP::m/units::m);
    case kSCINTILLATIONCOMPONENT1:        return std::make_pair(CLHEP::keV/units::keV, units::keV/CLHEP::keV);
    case kSCINTILLATIONCOMPONENT2:        return std::make_pair(CLHEP::keV/units::keV, units::keV/CLHEP::keV);
    case kSCINTILLATIONCOMPONENT3:        return std::make_pair(CLHEP::keV/units::keV, units::keV/CLHEP::keV);
#else
    case kFASTCOMPONENT:                  return std::make_pair(CLHEP::keV/units::keV, 1.0);
    case kSLOWCOMPONENT:                  return std::make_pair(CLHEP::keV/units::keV, 1.0);
#endif
    case kPROTONSCINTILLATIONYIELD:       return std::make_pair(CLHEP::keV/units::keV, units::keV/CLHEP::keV); // Yields: 1/energy
    case kDEUTERONSCINTILLATIONYIELD:     return std::make_pair(CLHEP::keV/units::keV, units::keV/CLHEP::keV);
    case kTRITONSCINTILLATIONYIELD:       return std::make_pair(CLHEP::keV/units::keV, units::keV/CLHEP::keV);
    case kALPHASCINTILLATIONYIELD:        return std::make_pair(CLHEP::keV/units::keV, units::keV/CLHEP::keV);
    case kIONSCINTILLATIONYIELD:          return std::make_pair(CLHEP::keV/units::keV, units::keV/CLHEP::keV);
    case kELECTRONSCINTILLATIONYIELD:     return std::make_pair(CLHEP::keV/units::keV, units::keV/CLHEP::keV);
    default:
      break;
    }
    printout(FATAL,"Geant4Converter", "+++ Cannot convert material property with index: %d", index);
#else
    printout(FATAL,"Geant4Converter", "+++ Cannot convert material property with index: %d [Need Geant4 > 10.03]", index);
#endif
    return std::make_pair(0e0,0e0);
  }

  double g4ConstPropertyConversion(int index)   {
#if G4VERSION_NUMBER >= 1040
    switch(index)   {
    case kSURFACEROUGHNESS:            return CLHEP::m/units::m;                             // Length
    case kISOTHERMAL_COMPRESSIBILITY:  return (CLHEP::m3/CLHEP::keV)/(units::m3/CLHEP::keV); // Volume/Energy
    case kRS_SCALE_FACTOR:             return 1.0;  // ??
    case kWLSMEANNUMBERPHOTONS:        return 1.0;  // ??
    case kWLSTIMECONSTANT:             return CLHEP::second/units::second;                   // Time
    case kMIEHG_FORWARD:               return 1.0;
    case kMIEHG_BACKWARD:              return 1.0;
    case kMIEHG_FORWARD_RATIO:         return 1.0;
    case kSCINTILLATIONYIELD:          return units::keV/CLHEP::keV;                         // Energy
    case kRESOLUTIONSCALE:             return 1.0;
    case kFERMIPOT:                    return CLHEP::keV/units::keV;                         // Energy
    case kDIFFUSION:                   return 1.0;
    case kSPINFLIP:                    return 1.0;
    case kLOSS:                        return 1.0;  // ??
    case kLOSSCS:                      return CLHEP::barn/units::barn;  // ??
    case kABSCS:                       return CLHEP::barn/units::barn;  // ??
    case kSCATCS:                      return CLHEP::barn/units::barn;  // ??
    case kMR_NBTHETA:                  return 1.0;
    case kMR_NBE:                      return 1.0;
    case kMR_RRMS:                     return 1.0;  // ??
    case kMR_CORRLEN:                  return CLHEP::m/units::m;                             // Length
    case kMR_THETAMIN:                 return 1.0;
    case kMR_THETAMAX:                 return 1.0;
    case kMR_EMIN:                     return CLHEP::keV/units::keV;                         // Energy
    case kMR_EMAX:                     return CLHEP::keV/units::keV;                         // Energy
    case kMR_ANGNOTHETA:               return 1.0;
    case kMR_ANGNOPHI:                 return 1.0;
    case kMR_ANGCUT:                   return 1.0;

#if G4VERSION_NUMBER >= 1100
    case kSCINTILLATIONTIMECONSTANT1:  return CLHEP::second/units::second;                   // Time
    case kSCINTILLATIONTIMECONSTANT2:  return CLHEP::second/units::second;                   // Time
    case kSCINTILLATIONTIMECONSTANT3:  return CLHEP::second/units::second;                   // Time
    case kSCINTILLATIONRISETIME1:      return CLHEP::second/units::second;                   // Time
    case kSCINTILLATIONRISETIME2:      return CLHEP::second/units::second;                   // Time
    case kSCINTILLATIONRISETIME3:      return CLHEP::second/units::second;                   // Time
    case kSCINTILLATIONYIELD1:         return 1.0;
    case kSCINTILLATIONYIELD2:         return 1.0;
    case kSCINTILLATIONYIELD3:         return 1.0;
    case kPROTONSCINTILLATIONYIELD1:   return 1.0;
    case kPROTONSCINTILLATIONYIELD2:   return 1.0;
    case kPROTONSCINTILLATIONYIELD3:   return 1.0;
    case kDEUTERONSCINTILLATIONYIELD1: return 1.0;
    case kDEUTERONSCINTILLATIONYIELD2: return 1.0;
    case kDEUTERONSCINTILLATIONYIELD3: return 1.0;
    case kALPHASCINTILLATIONYIELD1:    return 1.0;
    case kALPHASCINTILLATIONYIELD2:    return 1.0;
    case kALPHASCINTILLATIONYIELD3:    return 1.0;
    case kIONSCINTILLATIONYIELD1:      return 1.0;
    case kIONSCINTILLATIONYIELD2:      return 1.0;
    case kIONSCINTILLATIONYIELD3:      return 1.0;
    case kELECTRONSCINTILLATIONYIELD1: return 1.0;
    case kELECTRONSCINTILLATIONYIELD2: return 1.0;
    case kELECTRONSCINTILLATIONYIELD3: return 1.0;
#else
    case kFASTTIMECONSTANT:            return CLHEP::second/units::second;                   // Time
    case kFASTSCINTILLATIONRISETIME:   return CLHEP::second/units::second;                   // Time
    case kSLOWTIMECONSTANT:            return CLHEP::second/units::second;                   // Time
    case kSLOWSCINTILLATIONRISETIME:   return CLHEP::second/units::second;                   // Time
    case kYIELDRATIO:                  return 1.0;
#endif
    default:
      break;
    }
    printout(FATAL,"Geant4Converter", "+++ Cannot convert CONST material property with index: %d", index);
#else
    printout(FATAL,"Geant4Converter", "+++ Cannot convert material property with index: %d [Need Geant4 > 10.03]", index);
#endif
    return 0.0;
  }
}

/// Initializing Constructor
Geant4Converter::Geant4Converter(const Detector& description_ref)
  : Geant4Mapping(description_ref), checkOverlaps(true) {
  this->Geant4Mapping::init();
  m_propagateRegions = true;
  outputLevel = PrintLevel(printLevel() - 1);
}

/// Initializing Constructor
Geant4Converter::Geant4Converter(const Detector& description_ref, PrintLevel level)
  : Geant4Mapping(description_ref), outputLevel(level)  {
  this->Geant4Mapping::init();
  m_propagateRegions = true;
}

/// Standard destructor
Geant4Converter::~Geant4Converter() {
}

/// Handle the conversion of isotopes
void* Geant4Converter::handleIsotope(const std::string& /* name */, const TGeoIsotope* iso) const {
  G4Isotope* g4i = data().g4Isotopes[iso];
  if ( !g4i )  {
    double a_conv = (CLHEP::g / CLHEP::mole);
    g4i = new G4Isotope(iso->GetName(), iso->GetZ(), iso->GetN(), iso->GetA()*a_conv);
    printout(debugElements ? ALWAYS : outputLevel,
             "Geant4Converter", "++ Created G4 Isotope %s from data: Z=%d N=%d A=%.3f [g/mole]",
             iso->GetName(), iso->GetZ(), iso->GetN(), iso->GetA());
    data().g4Isotopes[iso] = g4i;
  }
  return g4i;
}

/// Handle the conversion of elements
void* Geant4Converter::handleElement(const std::string& name, const Atom element) const {
  G4Element* g4e = data().g4Elements[element];
  if ( !g4e ) {
    PrintLevel lvl = debugElements ? ALWAYS : outputLevel;
    if (element->GetNisotopes() > 0) {
      g4e = new G4Element(name, element->GetTitle(), element->GetNisotopes());
      for (int i = 0, n = element->GetNisotopes(); i < n; ++i) {
        TGeoIsotope* iso = element->GetIsotope(i);
        G4Isotope* g4iso = (G4Isotope*)handleIsotope(iso->GetName(), iso);
        g4e->AddIsotope(g4iso, element->GetRelativeAbundance(i));
      }
    }
    else {
      // This adds in Geant4 the natural isotopes, which we normally do not want. We want to steer it outselves.
      double a_conv = (CLHEP::g / CLHEP::mole);
      g4e = new G4Element(element->GetTitle(), name, element->Z(), element->A()*a_conv);
      printout(lvl, "Geant4Converter", "++ Created G4 Isotope %s from data: Z=%d N=%d A=%.3f [g/mole]",
               element->GetName(), element->Z(), element->N(), element->A());
    }
    std::stringstream str;
    str << (*g4e) << std::endl;
    printout(lvl, "Geant4Converter", "++ Created G4 element %s", str.str().c_str());
    data().g4Elements[element] = g4e;
  }
  return g4e;
}

/// Dump material in GDML format to output stream
void* Geant4Converter::handleMaterial(const std::string& name, Material medium) const {
  Geant4GeometryInfo& info = data();
  G4Material*         mat  = info.g4Materials[medium];
  if ( !mat )  {
    PrintLevel    lvl      = debugMaterials ? ALWAYS : outputLevel;
    TGeoMaterial* material = medium->GetMaterial();
    G4State       state    = kStateUndefined;
    double        density  = material->GetDensity() * (CLHEP::gram / CLHEP::cm3);
    if ( density < 1e-25 )
      density = 1e-25;
    switch ( material->GetState() ) {
    case TGeoMaterial::kMatStateSolid:
      state = kStateSolid;
      break;
    case TGeoMaterial::kMatStateLiquid:
      state = kStateLiquid;
      break;
    case TGeoMaterial::kMatStateGas:
      state = kStateGas;
      break;
    default:
    case TGeoMaterial::kMatStateUndefined:
      state = kStateUndefined;
      break;
    }
    printout(lvl,"Geant4Material","+++ Setting up material %s", name.c_str());
    if ( material->IsMixture() )  {
      double A_total = 0.0;
      double W_total = 0.0;
      TGeoMixture* mix = (TGeoMixture*) material;
      int    nElements = mix->GetNelements();
      mat = new G4Material(name, density, nElements, state, 
                           material->GetTemperature(), material->GetPressure());
      for (int i = 0; i < nElements; ++i)  {
        A_total += (mix->GetAmixt())[i];
        W_total += (mix->GetWmixt())[i];
      }
      for (int i = 0; i < nElements; ++i) {
        TGeoElement* e = mix->GetElement(i);
        G4Element* g4e = (G4Element*) handleElement(e->GetName(), Atom(e));
        if (!g4e) {
          printout(ERROR, name, 
                   "Missing element component %s for material %s. A=%f W=%f", 
                   e->GetName(), mix->GetName(), A_total, W_total);
        }
        //mat->AddElement(g4e, (mix->GetAmixt())[i] / A_total);
        mat->AddElement(g4e, (mix->GetWmixt())[i] / W_total);
      }
    }
    else {
      double z = material->GetZ(), a = material->GetA();
      if ( z < 1.0000001 ) z = 1.0;
      if ( a < 0.5000001 ) a = 1.0;
      mat = new G4Material(name, z, a, density, state, 
                           material->GetTemperature(), material->GetPressure());
    }

    std::string plugin_name { };
    double value = 0e0;
    double ionisation_mee = -2e100;
    double ionisation_birks_constant = -2e100;
    double ionisation_ene_per_ion_pair = -2e100;

    /// Attach the material properties if any
    G4MaterialPropertiesTable* tab = 0;
    TListIter propIt(&material->GetProperties());
    for(TObject* obj=propIt.Next(); obj; obj = propIt.Next())  {
      std::string       exc_str;
      TNamed*      named  = (TNamed*)obj;
      TGDMLMatrix* matrix = info.manager->GetGDMLMatrix(named->GetTitle());
      const char*  cptr   = ::strstr(matrix->GetName(), GEANT4_TAG_IGNORE);
      if ( nullptr != cptr )   {
        printout(INFO,name,"++ Ignore property %s [%s]. Not Suitable for Geant4.",
                 matrix->GetName(), matrix->GetTitle());
        continue;
      }
      cptr = ::strstr(matrix->GetTitle(), GEANT4_TAG_IGNORE);
      if ( nullptr != cptr )   {
        printout(INFO,name,"++ Ignore property %s [%s]. Not Suitable for Geant4.",
                 matrix->GetName(), matrix->GetTitle());
        continue;
      }
      Geant4GeometryInfo::PropertyVector* v =
        (Geant4GeometryInfo::PropertyVector*)handleMaterialProperties(matrix);
      if ( nullptr == v )   {
        except("Geant4Converter", "++ FAILED to create G4 material %s [Cannot convert property:%s]",
               material->GetName(), named->GetName());
      }
      if ( nullptr == tab )  {
        tab = new G4MaterialPropertiesTable();
        mat->SetMaterialPropertiesTable(tab);
      }
      int idx = -1;
      try   {
        idx = tab->GetPropertyIndex(named->GetName());
      }
      catch(const std::exception& e)   {
        exc_str = e.what();
        idx = -1;
      }
      catch(...)   {
        idx = -1;
      }
      if ( idx < 0 )   {
        printout(ERROR, "Geant4Converter",
                 "++ UNKNOWN Geant4 Property: %-20s %s [IGNORED]",
                 exc_str.c_str(), named->GetName());
        continue;
      }
      // We need to convert the property from TGeo units to Geant4 units
      auto conv = g4PropertyConversion(idx);
      std::vector<double> bins(v->bins), vals(v->values);
      for(std::size_t i=0, count=bins.size(); i<count; ++i)
        bins[i] *= conv.first, vals[i] *= conv.second;

      G4MaterialPropertyVector* vec =
        new G4MaterialPropertyVector(&bins[0], &vals[0], bins.size());
      tab->AddProperty(named->GetName(), vec);
      printout(lvl, name, "++      Property: %-20s [%ld x %ld] -> %s ",
               named->GetName(), matrix->GetRows(), matrix->GetCols(), named->GetTitle());
      for(std::size_t i=0, count=v->bins.size(); i<count; ++i)
        printout(lvl, name, "  Geant4: %s %8.3g [MeV]  TGeo: %8.3g [GeV] Conversion: %8.3g",
                 named->GetName(), bins[i], v->bins[i], conv.first);
    }

    /// Attach the material properties if any
    TListIter cpropIt(&material->GetConstProperties());
    for(TObject* obj=cpropIt.Next(); obj; obj = cpropIt.Next())  {
      std::string  exc_str;
      Bool_t     err = kFALSE;
      TNamed*  named = (TNamed*)obj;

      const char*  cptr = ::strstr(named->GetName(), GEANT4_TAG_IGNORE);
      if ( nullptr != cptr )   {
        printout(INFO, name, "++ Ignore CONST property %s [%s].",
                 named->GetName(), named->GetTitle());
        continue;
      }
      cptr = ::strstr(named->GetTitle(), GEANT4_TAG_IGNORE);
      if ( nullptr != cptr )   {
        printout(INFO, name,"++ Ignore CONST property %s [%s].",
                 named->GetName(), named->GetTitle());
        continue;
      }
      cptr = ::strstr(named->GetName(), GEANT4_TAG_PLUGIN);
      if ( nullptr != cptr )   {
        printout(INFO, name, "++ Ignore CONST property %s [%s]  --> Plugin.",
                 named->GetName(), named->GetTitle());
        plugin_name = named->GetTitle();
        continue;
      }
      cptr = ::strstr(named->GetName(), GEANT4_TAG_BIRKSCONSTANT);
      if ( nullptr != cptr )   {
        err = kFALSE;
        value = material->GetConstProperty(GEANT4_TAG_BIRKSCONSTANT,&err);
        if ( err == kFALSE ) ionisation_birks_constant = value * (CLHEP::mm/CLHEP::MeV)/(units::mm/units::MeV);
        continue;
      }
      cptr = ::strstr(named->GetName(), GEANT4_TAG_MEE);
      if ( nullptr != cptr )   {
        err = kFALSE;
        value = material->GetConstProperty(GEANT4_TAG_MEE, &err);
        if ( err == kFALSE ) ionisation_mee = value * (CLHEP::MeV/units::MeV);
        continue;
      }
      cptr = ::strstr(named->GetName(), GEANT4_TAG_ENE_PER_ION_PAIR);
      if ( nullptr != cptr )   {
        err = kFALSE;
        value = material->GetConstProperty(GEANT4_TAG_ENE_PER_ION_PAIR,&err);
        if ( err == kFALSE ) ionisation_ene_per_ion_pair = value * (CLHEP::MeV/units::MeV);
        continue;
      }

      err = kFALSE;
      value = info.manager->GetProperty(named->GetTitle(), &err);
      if ( err != kFALSE )   {
        except(name,
               "++ FAILED to create G4 material %s [Cannot convert const property: %s]",
               material->GetName(), named->GetName());
      }
      if ( nullptr == tab )  {
        tab = new G4MaterialPropertiesTable();
        mat->SetMaterialPropertiesTable(tab);
      }
      int idx = -1;
      try   {
        idx = tab->GetConstPropertyIndex(named->GetName());
      }
      catch(const std::exception& e)   {
        exc_str = e.what();
        idx = -1;
      }
      catch(...)   {
        idx = -1;
      }
      if ( idx < 0 )   {
        printout(ERROR, name,
                 "++ UNKNOWN Geant4 CONST Property: %-20s %s [IGNORED]",
                 exc_str.c_str(), named->GetName());
        continue;
      }
      // We need to convert the property from TGeo units to Geant4 units
      double conv = g4ConstPropertyConversion(idx);
      printout(lvl, name, "++      CONST Property: %-20s %g ", named->GetName(), value);
      tab->AddConstProperty(named->GetName(), value * conv);
    }
    //
    // Set Birk's constant if it was supplied in the material table of the TGeoMaterial
    auto* ionisation = mat->GetIonisation();
    std::stringstream str;
    str << (*mat);
    if ( ionisation )   {
      if ( ionisation_birks_constant > 0e0 )   {
        ionisation->SetBirksConstant(ionisation_birks_constant);
      }
      if ( ionisation_mee > -1e100 )   {
        ionisation->SetMeanExcitationEnergy(ionisation_mee);
      }
      if ( ionisation_ene_per_ion_pair > 0e0 )   {
        ionisation->SetMeanEnergyPerIonPair(ionisation_ene_per_ion_pair);
      }
      str << "          log(MEE): " << std::setprecision(4) << ionisation->GetLogMeanExcEnergy();
      if ( ionisation_birks_constant > 0e0 )
        str << "  Birk's constant: " << std::setprecision(4) << ionisation->GetBirksConstant() << " [mm/MeV]";
      if ( ionisation_ene_per_ion_pair > 0e0 )
        str << "  Mean Energy Per Ion Pair: " << std::setprecision(4) << ionisation->GetMeanEnergyPerIonPair()/CLHEP::eV << " [eV]";
    }
    else  {
      str << "          No ionisation parameters availible.";
    }
    printout(lvl, name, "++ Created G4 material %s", str.str().c_str());

    if ( !plugin_name.empty() )    {
      // Call plugin to create extended material if requested
      Detector* det = const_cast<Detector*>(&m_detDesc);
      G4Material* extended_mat = PluginService::Create<G4Material*>(plugin_name, det, medium, mat);
      if ( !extended_mat )   {
        except("G4Cnv::material["+name+"]","++ FATAL Failed to call plugin to create material.");
      }
      mat = extended_mat;
    }
    info.g4Materials[medium] = mat;
  }
  return mat;
}

/// Dump solid in GDML format to output stream
void* Geant4Converter::handleSolid(const std::string& name, const TGeoShape* shape) const {
  G4VSolid* solid = nullptr;
  if ( shape ) {
    if ( nullptr != (solid = data().g4Solids[shape]) )   {
      return solid;
    }
    TClass*    isa = shape->IsA();
    PrintLevel lvl = debugShapes ? ALWAYS : outputLevel;
    if (isa == TGeoShapeAssembly::Class()) {
      // Assemblies have no corresponding 'shape' in Geant4. Ignore the shape translation.
      // It does not harm, since this 'shape' is never accessed afterwards.
      data().g4Solids[shape] = solid = convertShape<TGeoShapeAssembly>(shape);
      return solid;
    }
    else if (isa == TGeoBBox::Class())
      solid = convertShape<TGeoBBox>(shape);
    else if (isa == TGeoTube::Class())
      solid = convertShape<TGeoTube>(shape);
    else if (isa == TGeoTubeSeg::Class())
      solid = convertShape<TGeoTubeSeg>(shape);
    else if (isa == TGeoCtub::Class())
      solid = convertShape<TGeoCtub>(shape);
    else if (isa == TGeoEltu::Class())
      solid = convertShape<TGeoEltu>(shape);
    else if (isa == TwistedTubeObject::Class())
      solid = convertShape<TwistedTubeObject>(shape);
    else if (isa == TGeoTrd1::Class())
      solid = convertShape<TGeoTrd1>(shape);
    else if (isa == TGeoTrd2::Class())
      solid = convertShape<TGeoTrd2>(shape);
    else if (isa == TGeoHype::Class())
      solid = convertShape<TGeoHype>(shape);
    else if (isa == TGeoXtru::Class())
      solid = convertShape<TGeoXtru>(shape);
    else if (isa == TGeoPgon::Class())
      solid = convertShape<TGeoPgon>(shape);
    else if (isa == TGeoPcon::Class())
      solid = convertShape<TGeoPcon>(shape);
    else if (isa == TGeoCone::Class())
      solid = convertShape<TGeoCone>(shape);
    else if (isa == TGeoConeSeg::Class())
      solid = convertShape<TGeoConeSeg>(shape);
    else if (isa == TGeoParaboloid::Class())
      solid = convertShape<TGeoParaboloid>(shape);
    else if (isa == TGeoSphere::Class())
      solid = convertShape<TGeoSphere>(shape);
    else if (isa == TGeoTorus::Class())
      solid = convertShape<TGeoTorus>(shape);
    else if (isa == TGeoTrap::Class())
      solid = convertShape<TGeoTrap>(shape);
    else if (isa == TGeoArb8::Class()) 
      solid = convertShape<TGeoArb8>(shape);
    else if (isa == TGeoPara::Class())
      solid = convertShape<TGeoPara>(shape);
    else if (isa == TGeoTessellated::Class()) 
      solid = convertShape<TGeoTessellated>(shape);
    else if (isa == TGeoScaledShape::Class())  {
      TGeoScaledShape* sh   = (TGeoScaledShape*) shape;
      TGeoShape*       sol  = sh->GetShape();
      if ( sol->IsA() == TGeoShapeAssembly::Class() )  {
        return solid;
      }
      const double*    vals = sh->GetScale()->GetScale();
      G4Scale3D        scal(vals[0], vals[1], vals[2]);
      G4VSolid* g4solid = (G4VSolid*)handleSolid(sol->GetName(), sol);
      if ( scal.xx()>0e0 && scal.yy()>0e0 && scal.zz()>0e0 )
        solid = new G4ScaledSolid(sh->GetName(), g4solid, scal);
      else
        solid = new G4ReflectedSolid(g4solid->GetName()+"_refl", g4solid, scal);
    }
    else if ( isa == TGeoCompositeShape::Class() )   {
      const TGeoCompositeShape* sh = (const TGeoCompositeShape*) shape;
      const TGeoBoolNode* boolean = sh->GetBoolNode();
      TGeoBoolNode::EGeoBoolType oper = boolean->GetBooleanOperator();
      TGeoMatrix* matrix = boolean->GetRightMatrix();
      G4VSolid* left  = (G4VSolid*) handleSolid(name + "_left", boolean->GetLeftShape());
      G4VSolid* right = (G4VSolid*) handleSolid(name + "_right", boolean->GetRightShape());
      
      if (!left) {
        except("Geant4Converter","++ No left Geant4 Solid present for composite shape: %s",name.c_str());
      }
      if (!right) {
        except("Geant4Converter","++ No right Geant4 Solid present for composite shape: %s",name.c_str());
      }

      TGeoShape* ls = boolean->GetLeftShape();
      TGeoShape* rs = boolean->GetRightShape();
      if (strcmp(ls->ClassName(), "TGeoScaledShape") == 0 &&
          strcmp(rs->ClassName(), "TGeoBBox") == 0) {
        if (strcmp(((TGeoScaledShape *)ls)->GetShape()->ClassName(), "TGeoSphere") == 0) {
          if (oper == TGeoBoolNode::kGeoIntersection) {
            TGeoScaledShape* lls = (TGeoScaledShape *)ls;
            TGeoBBox* rrs = (TGeoBBox*)rs;
            double sx     = lls->GetScale()->GetScale()[0];
            double sy     = lls->GetScale()->GetScale()[1];
            double radius = ((TGeoSphere *)lls->GetShape())->GetRmax();
            double dz     = rrs->GetDZ();
            double zorig  = rrs->GetOrigin()[2];
            double zcut2  = dz + zorig;
            double zcut1  = 2 * zorig - zcut2;
            solid = new G4Ellipsoid(name,
                                    sx * radius * CM_2_MM,
                                    sy * radius * CM_2_MM,
                                    radius * CM_2_MM,
                                    zcut1 * CM_2_MM,
                                    zcut2 * CM_2_MM);
            data().g4Solids[shape] = solid;
            return solid;
          }
        }
      }

      if ( matrix->IsRotation() ) {
        G4Transform3D transform;
        g4Transform(matrix, transform);
        if (oper == TGeoBoolNode::kGeoSubtraction)
          solid = new G4SubtractionSolid(name, left, right, transform);
        else if (oper == TGeoBoolNode::kGeoUnion)
          solid = new G4UnionSolid(name, left, right, transform);
        else if (oper == TGeoBoolNode::kGeoIntersection)
          solid = new G4IntersectionSolid(name, left, right, transform);
      }
      else {
        const Double_t *t = matrix->GetTranslation();
        G4ThreeVector transform(t[0] * CM_2_MM, t[1] * CM_2_MM, t[2] * CM_2_MM);
        if (oper == TGeoBoolNode::kGeoSubtraction)
          solid = new G4SubtractionSolid(name, left, right, 0, transform);
        else if (oper == TGeoBoolNode::kGeoUnion)
          solid = new G4UnionSolid(name, left, right, 0, transform);
        else if (oper == TGeoBoolNode::kGeoIntersection)
          solid = new G4IntersectionSolid(name, left, right, 0, transform);
      }
    }

    if ( !solid )
      except("Geant4Converter","++ Failed to handle unknown solid shape: %s of type %s",
             name.c_str(), isa->GetName());
    printout(lvl,"Geant4Converter","++ Successessfully converted shape [%p] of type:%s to %s.",
             solid,isa->GetName(),typeName(typeid(*solid)).c_str());
    data().g4Solids[shape] = solid;
  }
  return solid;
}

/// Dump logical volume in GDML format to output stream
void* Geant4Converter::handleVolume(const std::string& name, const TGeoVolume* volume) const {
  Volume _v(volume);
  Geant4GeometryInfo& info = data();
  PrintLevel lvl = debugVolumes ? ALWAYS : outputLevel;
  Geant4GeometryMaps::VolumeMap::const_iterator volIt = info.g4Volumes.find(volume);
  if ( _v.testFlagBit(Volume::VETO_SIMU) )  {
    printout(lvl, "Geant4Converter", "++ Volume %s not converted [Veto'ed for simulation]",volume->GetName());
    return nullptr;
  }
  else if (volIt == info.g4Volumes.end() ) {
    const char*  vnam = volume->GetName();
    TGeoMedium*  med  = volume->GetMedium();
    Solid        sh   = volume->GetShape();
    bool         is_assembly = sh->IsA() == TGeoShapeAssembly::Class() || volume->IsAssembly();

    printout(lvl, "Geant4Converter", "++ Convert Volume %-32s: %p %s/%s assembly:%s",
             vnam, volume, sh.type(), _v.type(), yes_no(is_assembly));
    if ( is_assembly ) {
      return nullptr;
    }
    Region        reg      = _v.region();
    LimitSet      lim      = _v.limitSet();
    VisAttr       vis      = _v.visAttributes();
    G4Region*     g4region = reg.isValid() ? info.g4Regions[reg] : nullptr;
    G4UserLimits* g4limits = lim.isValid() ? info.g4Limits[lim]  : nullptr;
    G4VSolid*     g4solid  = (G4VSolid*)   handleSolid(sh->GetName(), sh);
    G4Material*   g4medium = (G4Material*) handleMaterial(med->GetName(), Material(med));
    /// Check all pre-conditions
    if ( !g4solid )   {
      except("G4Converter","++ No Geant4 Solid present for volume: %s", vnam);
    }
    else if ( !g4medium )   {
      except("G4Converter","++ No Geant4 material present for volume: %s", vnam);
    }
    else if ( reg.isValid() && !g4region )  {
      except("G4Cnv::volume["+name+"]"," ++ Failed to access Geant4 region %s.", reg.name());
    }
    else if ( lim.isValid() && !g4limits )  {
      except("G4Cnv::volume["+name+"]","++ FATAL Failed to access Geant4 user limits %s.", lim.name());
    }
    else if ( g4limits )   {
      printout(lvl, "Geant4Converter", "++ Volume     + Apply LIMITS settings: %-24s to volume %s.",
               lim.name(), vnam);
    }

    G4LogicalVolume* g4vol = nullptr;
    if ( _v.hasProperties() && !_v.getProperty(GEANT4_TAG_PLUGIN,"").empty() )   {
      Detector* det = const_cast<Detector*>(&m_detDesc); 
      std::string plugin = _v.getProperty(GEANT4_TAG_PLUGIN,"");
      g4vol = PluginService::Create<G4LogicalVolume*>(plugin, det, _v, g4solid, g4medium);
      if ( !g4vol )    {
        except("G4Cnv::volume["+name+"]","++ FATAL Failed to call plugin to create logical volume.");
      }
    }
    else  {
      g4vol = new G4LogicalVolume(g4solid, g4medium, vnam, nullptr, nullptr, nullptr);
    }

    if ( g4limits )   {
      g4vol->SetUserLimits(g4limits);
    }
    if ( g4region )   {
      PrintLevel plevel = (debugVolumes||debugRegions||debugLimits) ? ALWAYS : outputLevel;
      printout(plevel, "Geant4Converter", "++ Volume     + Apply REGION settings: %-24s to volume %s.",
               reg.name(), vnam);
      // Handle the region settings for the world volume seperately.
      // Geant4 does NOT WANT any regions assigned to the workd volume.
      // The world's region is created in the G4RunManagerKernel!
      if ( _v == m_detDesc.worldVolume() )   {
        const char* wrd_nam = "DefaultRegionForTheWorld";
        const char* src_nam = g4region->GetName().c_str();
        auto* world_region  = G4RegionStore::GetInstance()->GetRegion(wrd_nam, false);
        if ( auto* cuts = g4region->GetProductionCuts() )   {
          world_region->SetProductionCuts(cuts);
          printout(plevel, "Geant4Converter",
                   "++ Volume %s Region: %s. Apply production cuts from %s", 
                   vnam, wrd_nam, src_nam);
        }
        if ( auto* lims = g4region->GetUserLimits() )   {
          world_region->SetUserLimits(lims);
          printout(plevel, "Geant4Converter",
                   "++ Volume %s Region: %s. Apply user limits from %s", 
                   vnam, wrd_nam, src_nam);
        }
      }
      else   {
        g4vol->SetRegion(g4region);
        g4region->AddRootLogicalVolume(g4vol);
      }
    }
    G4VisAttributes* g4vattr = vis.isValid()
      ? (G4VisAttributes*)handleVis(vis.name(), vis) : nullptr;
    if ( g4vattr )   {
      g4vol->SetVisAttributes(g4vattr);
    }
    info.g4Volumes[volume] = g4vol;
    printout(lvl, "Geant4Converter",
             "++ Volume     + %s converted: %p ---> G4: %p", vnam, volume, g4vol);
  }
  return nullptr;
}

/// Dump logical volume in GDML format to output stream
void* Geant4Converter::collectVolume(const std::string& /* name */, const TGeoVolume* volume) const {
  Geant4GeometryInfo& info = data();
  Volume              _v(volume);
  Region              reg = _v.region();
  LimitSet            lim = _v.limitSet();
  SensitiveDetector   det = _v.sensitiveDetector();
  bool              world = (volume == m_detDesc.worldVolume().ptr());

  if ( !world )   {
    if ( lim.isValid() )
      info.limits[lim].insert(volume);
    if ( reg.isValid() )
      info.regions[reg].insert(volume);
    if ( det.isValid() )
      info.sensitives[det].insert(volume);
  }
  return (void*)volume;
}

/// Dump volume placement in GDML format to output stream
void* Geant4Converter::handleAssembly(const std::string& name, const TGeoNode* node) const {
  TGeoVolume* mot_vol = node->GetVolume();
  PrintLevel lvl = debugVolumes ? ALWAYS : outputLevel;
  if ( mot_vol->IsA() != TGeoVolumeAssembly::Class() )    {
    return nullptr;
  }
  Volume _v(mot_vol);
  if ( _v.testFlagBit(Volume::VETO_SIMU) )  {
    printout(lvl, "Geant4Converter", "++ AssemblyNode %s not converted [Veto'ed for simulation]",node->GetName());
    return nullptr;
  }
  Geant4GeometryInfo& info = data();
  Geant4AssemblyVolume* g4 = info.g4AssemblyVolumes[node];
  if ( g4 )  {
    printout(ALWAYS, "Geant4Converter", "+++ Assembly: **** : Re-using existing assembly: %s",node->GetName());
  }
  if ( !g4 )  {
    g4 = new Geant4AssemblyVolume();
    for(Int_t i=0; i < mot_vol->GetNdaughters(); ++i)   {
      TGeoNode*     dau     = mot_vol->GetNode(i);
      TGeoVolume*   dau_vol = dau->GetVolume();
      TGeoMatrix*   tr      = dau->GetMatrix();
      G4Transform3D transform;

      g4Transform(tr, transform);
      if ( is_left_handed(tr) )   {
        G4Scale3D     scale;
        G4Rotate3D    rot;
        G4Translate3D trans;
        transform.getDecomposition(scale, rot, trans);
        printout(debugReflections ? ALWAYS : lvl, "Geant4Converter",
                 "++ Placing reflected ASSEMBLY. dau:%s to mother %s "
                 "Tr:x=%8.1f y=%8.1f z=%8.1f   Scale:x=%4.2f y=%4.2f z=%4.2f",
                 dau_vol->GetName(), mot_vol->GetName(),
                 transform.dx(), transform.dy(), transform.dz(),
                 scale.xx(), scale.yy(), scale.zz());
      }

      if ( dau_vol->IsA() == TGeoVolumeAssembly::Class() )  {
        Geant4GeometryMaps::AssemblyMap::iterator ia = info.g4AssemblyVolumes.find(dau);
        if ( ia == info.g4AssemblyVolumes.end() )  {
          printout(FATAL, "Geant4Converter", "+++ Invalid child assembly at %s : %d  parent: %s child:%s",
                   __FILE__, __LINE__, name.c_str(), dau->GetName());
          delete g4;
          return nullptr;
        }
        g4->placeAssembly(dau, (*ia).second, transform);
        printout(lvl, "Geant4Converter", "+++ Assembly: AddPlacedAssembly : dau:%s "
                 "to mother %s Tr:x=%8.3f y=%8.3f z=%8.3f",
                 dau_vol->GetName(), mot_vol->GetName(),
                 transform.dx(), transform.dy(), transform.dz());
      }
      else   {
        Geant4GeometryMaps::VolumeMap::iterator iv = info.g4Volumes.find(dau_vol);
        if ( iv == info.g4Volumes.end() )  {
          printout(FATAL,"Geant4Converter", "+++ Invalid child volume at %s : %d  parent: %s child:%s",
                   __FILE__, __LINE__, name.c_str(), dau->GetName());
          except("Geant4Converter", "+++ Invalid child volume at %s : %d  parent: %s child:%s",
                 __FILE__, __LINE__, name.c_str(), dau->GetName());
        }
        g4->placeVolume(dau,(*iv).second, transform);
        printout(lvl, "Geant4Converter", "+++ Assembly: AddPlacedVolume : dau:%s "
                 "to mother %s Tr:x=%8.3f y=%8.3f z=%8.3f",
                 dau_vol->GetName(), mot_vol->GetName(),
                 transform.dx(), transform.dy(), transform.dz());
      }
    }
    info.g4AssemblyVolumes[node] = g4;
  }
  return g4;
}

/// Dump volume placement in GDML format to output stream
void* Geant4Converter::handlePlacement(const std::string& name, const TGeoNode* node) const {
  Geant4GeometryInfo& info = data();
  PrintLevel lvl = debugPlacements ? ALWAYS : outputLevel;
  Geant4GeometryMaps::PlacementMap::const_iterator g4it = info.g4Placements.find(node);
  G4VPhysicalVolume* g4 = (g4it == info.g4Placements.end()) ? 0 : (*g4it).second;
  TGeoVolume* vol = node->GetVolume();
  Volume _v(vol);

  if ( _v.testFlagBit(Volume::VETO_SIMU) )  {
    printout(lvl, "Geant4Converter", "++ Placement %s not converted [Veto'ed for simulation]",node->GetName());
    return nullptr;
  }
  //g4 = nullptr;
  if ( !g4 ) {
    TGeoVolume* mot_vol = node->GetMotherVolume();
    TGeoMatrix* tr = node->GetMatrix();
    if ( !tr ) {
      except("Geant4Converter",
             "++ Attempt to handle placement without transformation:%p %s of type %s vol:%p",
             node, node->GetName(), node->IsA()->GetName(), vol);
    }
    else if (nullptr == vol) {
      except("Geant4Converter", "++ Unknown G4 volume:%p %s of type %s ptr:%p",
             node, node->GetName(), node->IsA()->GetName(), vol);
    }
    else {
      int           copy               = node->GetNumber();
      bool          node_is_reflected  = is_left_handed(tr);
      bool          node_is_assembly   = vol->IsA() == TGeoVolumeAssembly::Class();
      bool          mother_is_assembly = mot_vol ? mot_vol->IsA() == TGeoVolumeAssembly::Class() : false;
      G4Transform3D transform;
      Geant4GeometryMaps::VolumeMap::const_iterator volIt = info.g4Volumes.find(mot_vol);

      g4Transform(tr, transform);
      if ( mother_is_assembly )   {
        //
        // Mother is an assembly:
        // Nothing to do here, because:
        // -- placed volumes were already added before in "handleAssembly"
        // -- imprint cannot be made, because this requires a logical volume as a mother
        //
        printout(lvl, "Geant4Converter", "+++ Assembly: **** : dau:%s "
                 "to mother %s Tr:x=%8.3f y=%8.3f z=%8.3f",
                 vol->GetName(), mot_vol->GetName(),
                 transform.dx(), transform.dy(), transform.dz());
        return nullptr;
      }
      G4Scale3D        scale;
      G4Rotate3D       rot;
      G4Translate3D    trans;
      transform.getDecomposition(scale, rot, trans);
      if ( node_is_assembly )   {
        //
        // Node is an assembly:
        // Imprint the assembly. The mother MUST already be transformed.
        //
        printout(lvl, "Geant4Converter", "++ Assembly: makeImprint: dau:%-12s %s in mother %-12s "
                 "Tr:x=%8.1f y=%8.1f z=%8.1f   Scale:x=%4.2f y=%4.2f z=%4.2f",
                 node->GetName(), node_is_reflected ? "(REFLECTED)" : "",
                 mot_vol ? mot_vol->GetName() : "<unknown>",
                 transform.dx(), transform.dy(), transform.dz(),
                 scale.xx(), scale.yy(), scale.zz());
        Geant4AssemblyVolume* ass = (Geant4AssemblyVolume*)info.g4AssemblyVolumes[node];
        Geant4AssemblyVolume::Chain chain;