DD4hep Meeting April 10th, 2025

Present: A.Sailer, M.Frank, Peter McKneown

Apologies: A.Tolosa Delgado, T.Madlehner

Link to minutes of previous meeting

Merged PRs

PR1428: CMake: do not build DDEve if ROOT::Eve does not exist
PR1429: UtilityApps: move G__eve dictionary to when we have ROOT::Eve (Andre)
---> PR1428 and PR1429 follow ups of PR1426
PR1432: Clean up header includes
PR1433: Geant4ParticleHandler: do not set vertex bit for particles that were not simulated
PR1437: Geant4TVUserParticleHandler: fix wrong contains check through unit conversion
PR1438: make timeout configurable in g4GraphicalScan
---> Improvement to avoid too long processing times
PR1439: Fix, Optical physics option invokeSD require poststep info only

ISSUE1296: DetectorImp::endDocument() called twice for some geometries?
==> Unsure if it is a problem wrongly configuring multiple xml inputs.
---> No response since August 2024
ISSUE1419: Assigning multiple sensitive volumes to a single readout Idquestion
ISSUE1424: Error with ROOT::Eve when building DD4hep
ISSUE1429: Error with ROOT::Eve when building DD4hep
ISSUE1430: How the signedness affects number of bits in the bitfield?
ISSUE1434: Different behavior in Geant4 particle handlers (TC vs. TV)
---> Unit problem between mm (G4) and cm (TGeo)
ISSUE1435: Make g4GraphicalScan internal timeouts configurable (See PR1438)
ISSUE1436: interpreter information for class dd4hep::sim
---> Question what to load to process DDG4 ROOT files with bare ROOT

ISSUE1199: Persist hepmc vertex status code into output
==> Should we eliminate Geant4EventReaderHepMC
==> Decision: Geant4EventReaderHepMC will be removed
ISSUE1285: Memory Consumption of Sensitive Detectors
==> Should be handled as illustrated in PR1288. Intrinsic problem of the Geant4VolumeManager;
ISSUE1297: Possible to dump all available readout elements?
==> Possibly a copy of unsolved ISSUE580 from Valentin about enumerating all sensitive cells.
ISSUE1319: Problem with regexSensitiveDetector and volume IDs
==> Interesting use case for reg-ex sensitive detectors
having a VolumeMgr equivalent.
ISSUE1320: Replacing a Handle<Segmentation> which contains a MultiSegmentation with the underlying Segmentation
===> Unclear what he really means.
ISSUE1335: Uniform random picking of points on detector surfaces for noise studies
This problem is linked to #1297 and #580.
ISSUE1373: Add GeneratorInfo to EDM4hepReader (Andre)
PR1371: Read edm4hep (Andre)
ISSUE1399: ddsim: Vertices of tau and its decay product not matching the information in the input HEPMC file
---> Apparently Geant4 problem. Andre has submitted a ticket.

PR1240: Add multithreading support to ddsim
PR1304: SurfaceManager: lazily construct surface maps on demand (Leonhard Reichenbach)
PR1314: Cylinder segment surface (Armin Ilg)
PR1370: Feature celeritas integration (Sakib Rahman/EIC)
PR1377: Use canonical variables for the installation locations of libraries and binaries (Andriish)
==> Idea to have an additional DD4HEP_PLUGIN_PATH and remove dd4hep plugins fdrom the LD_LIBRARY_PATH

New Pending PRs and ISSUEs:

ISSUE1431: Unstable particle decays twice in generator and in simulation creating duplicate particles

Andre:       NTR
Markus:    NTR
Peter:        NTR

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Next meeting: April 24th, 2025