Make Geant4 geometry exception to be just a warning

SimG4Core/Application/interface/ExceptionHandler.h

@@ -18,7 +18,7 @@
 
 class ExceptionHandler : public G4VExceptionHandler {
 public:
-  explicit ExceptionHandler();
+  explicit ExceptionHandler(double th);
   ~ExceptionHandler() override;
 
   int operator==(const ExceptionHandler &right) const { return (this == &right); }
@@ -31,6 +31,9 @@ class ExceptionHandler : public G4VExceptionHandler {
 
   ExceptionHandler(const ExceptionHandler &) = delete;
   ExceptionHandler &operator=(const ExceptionHandler &right) = delete;
+
+private:
+  double m_eth;
 };
 
 #endif

SimG4Core/Application/python/g4SimHits_cfi.py

@@ -85,6 +85,7 @@
     StorePhysicsTables = cms.untracked.bool(False),
     RestorePhysicsTables = cms.untracked.bool(False),
     UseParametrisedEMPhysics = cms.untracked.bool(True),
+    ThresholdForGeometryExceptions = cms.double(0.01),   ## in GeV
     CheckGeometry = cms.untracked.bool(False),
     OnlySDs = cms.vstring('ZdcSensitiveDetector', 'TotemT2ScintSensitiveDetector', 'TotemSensitiveDetector', 'RomanPotSensitiveDetector', 'PLTSensitiveDetector', 'MuonSensitiveDetector', 'MtdSensitiveDetector', 'BCM1FSensitiveDetector', 'EcalSensitiveDetector', 'CTPPSSensitiveDetector', 'BSCSensitiveDetector', 'CTPPSDiamondSensitiveDetector', 'FP420SensitiveDetector', 'BHMSensitiveDetector', 'CastorSensitiveDetector', 'CaloTrkProcessing', 'HcalSensitiveDetector', 'TkAccumulatingSensitiveDetector'),
     G4CheckOverlap = cms.untracked.PSet(

SimG4Core/Application/src/ExceptionHandler.cc

@@ -3,10 +3,13 @@
 
 #include "FWCore/MessageLogger/interface/MessageLogger.h"
 
+#include "G4EventManager.hh"
+#include "G4TrackingManager.hh"
+#include "G4Track.hh"
 #include "globals.hh"
 #include <sstream>
 
-ExceptionHandler::ExceptionHandler() {}
+ExceptionHandler::ExceptionHandler(double th) : m_eth(th) {}
 
 ExceptionHandler::~ExceptionHandler() {}
 
@@ -19,13 +22,43 @@ bool ExceptionHandler::Notify(const char* exceptionOrigin,
   static const G4String ws_banner = "\n-------- WWWW ------- G4Exception-START -------- WWWW -------\n";
   static const G4String we_banner = "\n-------- WWWW -------- G4Exception-END --------- WWWW -------\n";
 
+  const G4Track* track = G4EventManager::GetEventManager()->GetTrackingManager()->GetTrack();
+  double ekin = m_eth;
+
   std::stringstream message;
   message << "*** G4Exception : " << exceptionCode << "\n"
           << "      issued by : " << exceptionOrigin << "\n"
           << description;
 
+  // part of exception happens outside tracking loop
+  if (nullptr != track) {
+    ekin = track->GetKineticEnergy();
+    message << "\n"
+            << "TrackID=" << track->GetTrackID() << " ParentID=" << track->GetParentID() << "  "
+            << track->GetParticleDefinition()->GetParticleName() << "; Ekin(MeV)=" << ekin / CLHEP::MeV
+            << "; time(ns)=" << track->GetGlobalTime() / CLHEP::ns << "; status=" << track->GetTrackStatus()
+            << "\n   position(mm): " << track->GetPosition() << "; direction: " << track->GetMomentumDirection();
+    const G4VPhysicalVolume* vol = track->GetVolume();
+    if (nullptr != vol) {
+      message << "\n   PhysicalVolume: " << vol->GetName() << "; material: " << track->GetMaterial()->GetName();
+    }
+    message << "\n   stepNumber=" << track->GetCurrentStepNumber()
+            << "; stepLength(mm)=" << track->GetStepLength() / CLHEP::mm << "; weight=" << track->GetWeight();
+    const G4VProcess* proc = track->GetCreatorProcess();
+    if (nullptr != proc) {
+      message << "; creatorProcess: " << proc->GetProcessName() << "; modelID=" << track->GetCreatorModelID();
+    }
+  }
+  message << "\n";
+
+  G4ExceptionSeverity localSeverity = severity;
+  G4String code = G4String(*exceptionCode);
+  if (ekin < m_eth && code == "GeomNav0003") {
+    localSeverity = JustWarning;
+  }
+
   std::stringstream ss;
-  switch (severity) {
+  switch (localSeverity) {
     case FatalException:
     case FatalErrorInArgument:
     case RunMustBeAborted:

SimG4Core/Application/src/RunManagerMT.cc

@@ -85,7 +85,8 @@ RunManagerMT::RunManagerMT(edm::ParameterSet const& p)
   m_currentRun = nullptr;
 
   m_kernel = new G4MTRunManagerKernel();
-  G4StateManager::GetStateManager()->SetExceptionHandler(new ExceptionHandler());
+  double th = p.getParameter<double>("ThresholdForGeometryExceptions") * CLHEP::GeV;
+  G4StateManager::GetStateManager()->SetExceptionHandler(new ExceptionHandler(th));
   m_check = p.getUntrackedParameter<bool>("CheckGeometry", false);
 }
 

SimG4Core/Application/src/RunManagerMTWorker.cc

@@ -300,7 +300,8 @@ void RunManagerMTWorker::initializeG4(RunManagerMT* runManagerMaster, const edm:
   }
 
   // Define G4 exception handler
-  G4StateManager::GetStateManager()->SetExceptionHandler(new ExceptionHandler());
+  double th = m_p.getParameter<double>("ThresholdForGeometryExceptions") * CLHEP::GeV;
+  G4StateManager::GetStateManager()->SetExceptionHandler(new ExceptionHandler(th));
 
   // Set the geometry for the worker, share from master
   auto worldPV = runManagerMaster->world().GetWorldVolume();