DD4hep Meeting February 19th, 2026

Present:     Andre, Juan, Markus, Peter

Apologies: Thomas, Mahmoud

Link to minutes of previous meeting

Merged PRs

• PR1552:        Ensure DD4hep still configures with EDM4hep 1.0 (Thomas)
• PR1564:        Implement optional printout of hit VolumeIDs from Geant4Sensitive (Markus)
• PR1566:        Use the generic podio Reader and Writer to add support for RNTuples (Juan)
• PR1567:        Global reformatting: Replace TAB by spaces (Markus)
• PR1571:        Use Clang 19 instead of 16 in CI (Juan)

Closed PRs, closed issues and fixed problems

• PR1314:          Cylinder segment surface (Armin)
• PR1503:          [WIP] Add flag for fast simulation to MCParticle  (Thomas)
• PR1565:          feat: support ddsim --outputConfig.useRNTuple=true in EDM4hep output (Wouter)
• ISSUE311:      Check MC particle record on demandenhancement (Marko)
                 ===> Stone age issue. Closed due to inactivity
• ISSUE471:      missing MCParticle for particles scattered back into the calorimeter (Frank.G)
                 ===> Stone age issue. Closed due to inactivity
• ISSUE1487:    The test t_DDDigi_sim_test_weighted_deposit_overlay can fail (Juan)
                  ===> Disappeared
• ISSUE1492:     Readout segmentation for multiple cylinders with offset axesquestion
• ISSUE1563:     geoDisplay/geoWebDisplay crashes with ROOT v6.38bug
• ISSUE1569:     Clang-format the codeenhancement (Andre)
• ISSUE1570:     ddsim seg. faults since 2026-02-01 key4hep releasebug (dudarboh)

Pending Problems

• ISSUE1297:  Possible to dump all available readout elements?
                        ==> Possibly a copy of unsolved ISSUE580 from Valentin about enumerating all sensitive cells.
• ISSUE1335:   Uniform random picking of points on detector surfaces for noise studies
                         This problem is linked to #1297 and #580.
• ISSUE1458: XML file vs TGeoStored geometry in GenFit
• ISSUE1501: Bug/Feature: Condense duplicated particle contributions in calorimeter question
• ISSUE1514: How to convert Geant4TrackID into MCParticle Parent ID
• ISSUE1535: How to add new output variables in Hitsquestion (matclim -> DD4SHip)
                        ----> Debugging ongoing
• ISSUE1544:     Feature: additional DetTypes for backward and far detectors (Derek M Anderson)

New issues:

• ISSUE1568:     Sim hits between two sensitive volumes? (alexandertuna)

Pending PR:

• PR1572:        replace compact.xsd location (Andre)

Round Table

Juan:.             NTR
Markus:         NTR
Peter:             NTR
Andre:            NTR

AOB

Next meeting:   March 5th, 2026