DD4hep Developers Meeting

Thursday 18 Sept 2025, 15:30 → 16:00 Europe/Zurich

zoom

Andre Sailer (CERN), Markus Frank (CERN)

Please Join DD4hep developer's meeting via Zoom

DD4hep Meeting September 18th, 2025

Present:    Andre, Juan, Markus, Peter

Apologies: --

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Link to minutes of previous meeting

Merged PRs

• PR1491:  Remove an include of a folder that does not exist in ClientTests (Juan)
• PR1493:  Add warning message about unreliable material scans (Markus)
• PR1494:  CI: mac: drop cmake, already installed (Andre)
• PR1495:  fix: avoid double deduce/open for HEPMC3FileReader when not ReaderAscii (Wouter)
• PR1496:  fix: Remove logging of constants (name and ptr) in checkOverlaps.py (Wouter)

Closed PRs, closed issues and fixed problems

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• ISSUE1490:  Discrepancy in Material Encountered by graphicalScan and g4MaterialScan Commandsbug
                        ---> Required warning about tessellated surfaces
• ISSUE1469: Memory leak in Compact2Objects / Detector concerning Headerbug
    ---> See MR #1478 .
    ---> Fix confirmed by LHCb.

Pending Problems

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• ISSUE1297:  Possible to dump all available readout elements?
                        ==> Possibly a copy of unsolved ISSUE580 from Valentin about enumerating all sensitive cells.
• 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.
• PR1240:        Add multithreading support to ddsim
• PR1314:        Cylinder segment surface (Armin Ilg)
• ISSUE1373:  Add GeneratorInfo to EDM4hepReader (Andre)
• ISSUE1443:  Make user particle handler extensible
                         ---> Maybe we should take advantage and re-collect requirements.
• ISSUE1458: XML file vs TGeoStored geometry in GenFit
• ISSUE1487: The test t_DDDigi_sim_test_weighted_deposit_overlay can fail (Juan)
    ---> Unstable test 
• ISSUE1489:  using SkinSurfacequestion
  
  New:
• ISSUE1492:  Readout segmentation for multiple cylinders with offset axesquestion
                        ----> Unclear code in CylindricalGridPhiZ.cpp line 80
                        ----> Try special case where axis is identical to beam axis.
• ISSUE1501: Bug/Feature: Condense duplicated particle contributions in calorimeterquestion
• ISSUE1502: genStatus, reason and statusquestion
  
  Pending:
• PR1497:  Increase tolerance of a test to avoid failures (Juan)
• PR1498:  Modernize code related to Surfaces and the SurfaceManager (Juan)
• PR1499:  Add the pass-through of generator event information for EDM4hep (Thomas)
• PR1500:  Add a [[maybe_unused]] to prevent a warning in ConditionExampleObjects.cpp (Juan)

Round Table

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Andre:     NTR
Juan:      Investigating problems with assemblies.
Markus:  NTR
Peter:      Investigation into particle flow related to back-scattering (See issue 471 from Frank)

AOB

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Next meeting:   October 2nd, 2025

15:30 → 15:50 Around the table