DD4hep Developers Meeting

→ Europe/Zurich
zoom

zoom

Andre Sailer (CERN), Markus Frank (CERN)
Description

Please Join DD4hep developer's meeting via Zoom

Zoom Meeting ID
68917133930
Host
Andre Sailer
Useful links
Join via phone
Zoom URL

DD4hep Meeting October 22nd, 2026

Present:      Andre, Juan, Markus, Peter

Apologies:  Thomas



Link to minutes of previous meeting

Merged PRs

  • PR1663:  Geant4Output2EDM4hep: get run from worker context (Andre)
       ---> Access to context for run parameters
  • PR1676:  build(deps): bump cvmfs-contrib/github-action-cvmfs from 5.5 to 5.6dependenciesgithub_actions (BOT)
  • PR1678:  DDSim: outputconfig: fix example for multi-threaded running for user Addressing (Andre)
       ---> Protection to not use shared actions in single threaded mode
  • PR1680:  Use non-deprecated ROOT RVersion header (Juan)
  • PR1681:  DDCAD: remove CSG-based exporter (Juan)
       ---> For now no round trips with CAD volumes anymore 

  • PR1684:  Make vertex consistent for edm4hep reader and hepmc reader
       ---> Use end-vertex for beam particles vertex rather than start-vertex
  • PR1686:  Remove unused variable s_exit_handler_active (Juan)
  • PR1687:  Remove filesystem detection and require GCC 9.1+ (Juan)
       ---> std::file_system always present for gcc 9 and above
  • PR1688:  TestSteppingAction: don't suspend tracks that are already dead (Andre)
       ---> Check track status before suspending
  • PR1689:  correct edm4hep reader for new MDI synchrotron radiation file format (David Lange)
       ---> like PR1684, but for EDM4hepFileReader
  • PR1690:  Preserve state changes on hits when steps are filtered out (Tova Holmes)
      ---> optional processing hook when tracks get rejected
  • PR1691:  fix(HepMC3EventReader): apply the length unit to the primary vertex position (Joshua Beirer)
      ---> add units to event reader when creating vertices
  • PR1694:  CMake: require boost 1.70 so we are sure there is a BoostConfg.cmake file provided (Andre)
      ---> cmake improvement
  • PR1697:  CI: remove config for macOS11 jobs that haven't run in living memory (Andre)
  • PR1698:  Pass nMax to VolSurface::getLines in Surface::getLines (Juan)
       ---> DDRec protection
  • PR1699:  add symmetry=0 for barrel and endcap cylindrical surfaces (Giovanni Marchiori)
       ---> Generic improvement to CaloFaceBarrel/Endcap surfaces

Closed PRs, closed issues and fixed problems


  • PR1685:  GaudiPluginService: find plugins on macOS when DYLD_LIBRARY_PATH is stripped (Federico Meloni)
  • ISSUE1677: Duplication in the events saved in the output file using ddsimbug (Andrea da Vita)
  • ISSUE1679: RPATH baked into DD4hep binaries overrides LD_LIBRARY_PATH, causing wrong-library loads of local key4hep buildbug
      ---> Closed as unplanned

Pending Problems


  • ISSUE1335: Uniform random picking of points on detector surfaces for noise studies
                           This problem is linked to #1297 and #580.
  • ISSUE1458: Possible discrepancy between xml file and geometry converted into root file
  • ISSUE1501: Bug/Feature: Condense duplicated particle contributions in calorimeter question
  • ISSUE1568: Sim hits between two sensitive volumes (Alexander Tuna)
  • ISSUE1633: Decouple DD4hep Readers/Writers into Separate Source and Injection/Build Stagesenhancement (Simon Gardner)
  • ISSUE1643: Non-determinism in hit ordering when multiple detectors share readoutbug (Wouter)

Pending PR:

  • PR1606:   feat: AdePT physics list plugin for e+/e-/gamma offload to GPU [WIP] (Wouter)

  • PR1626:  feat: add support for python geometry plugins (Wouter)
  • PR1658:   [DRAFT POC] Add Arrow IPC stream writer for EDM4hep output (Wouter)
            ---> What is arrow IPC
  • PR1664:   feat: honor DD4HEP_LIBRARY_PATH for plugin search (Wouter)
            ---> MacOS is non-trivial!

Not so new:

  • ISSUE1657: DDG4 reduces the generator status to 16 bits and gives no warning (Marco Meyer-Conde)
       ---> What to do here ?
  • ISSUE1667: LCIO output not writing runParameters (Andre)
  • ISSUE1671: CI: replace macOS brew install with lcgcmake installenhancement (Andre)


New:

  • ISSUE1683: Bug about the thickness in DiskTracker_geo.cppbug (Fangyi Guo)
  • ISSUE1693: Incorrect number of events saved to EOS when running with multithreading (IDEA o1 v4)bug (Andrea da Vita)

 

  • PR1672:  Add cvmfs/LCG-based macOS workflow (Wouter)
  • PR1682:  AssimpWriter: Drop need for rootcsg (Andre)
       ---> PR started, but still problems with assemblies. Problem was always present in rootcsg.
  • PR1692:  fix(Geant4InputHandling): start a tracked parent-less particle at its own production point (Joshua Beirer)
       ---> Does this not do the gun as well ?
  • PR1695:  Fix concurrent DDDigi container combining (Juan)
       ---> Missing locking caused crashes
  • PR1700:  Geant4Action: get event action by name without splitting. (Andre)
  • PR1701:  CI: build and test k4geo against DD4hep (Juan)

  • PR1702   fix(Geant4ParticleHandler): avoid duplicate track-equivalents map at end of event (Wouter)
       ---> memory saving mechanism

Round Table


Andre:            NTR
Juan:              NTR
Markus:         Possibility to create DD4hep descriptions from Geant3 implementations.
                       See presentation here. 
Peter:             NTR


Next meeting:   November 5th, 2026

There are minutes attached to this event. Show them.
    • 15:30 → 15:50
      Around the table 20m