DD4hep Developers Meeting

Thursday 3 Jul 2025, 15:30 → 16:00 Europe/Zurich

zoom

Andre Sailer (CERN), Markus Frank (CERN)

Please Join DD4hep developer's meeting via Zoom

DD4hep Meeting June 19th, 2025

Present:    Andre, Peter, Thomas

Apologies: Markus

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Link to minutes of previous meeting

Merged PRs

• PR1465 : Improve Linux Workflows
• PR1464: Add concurrency to the workflows (abort of new commits pushed)
• PR1463 : Fixes around memory leaks 

• PR1462: Mention edm4hep output in ddsim --help

Closed PRs, closed issues and fixed problems

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• ISSUE1459 Beginner question about new detector (plugin)

Pending Problems

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• 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.
• PR1240:        Add multithreading support to ddsim
• PR1304:        SurfaceManager: lazily construct surface maps on demand (Leonhard Reichenbach)
• 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.
  
  New issues:
• ISSUE1458: XML file vs TGeoStored geometry in GenFit

Round Table

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Andre:      NTR
Peter:       Issue that fastsim is called when particle is created in relevant region (e.g., muon undergoing bremstrahlung), also not reproducible with fixed random seed.
                 But also a problem if particle enters the volume from "the side". How to figure this out? Check with the Geant4 people?
                 TriggerSurface used at the moment might be tweaked to do the desired thing.

Thomas: Same issue as Peter

AOB

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Next meeting:   July 3, 2025

15:30 → 15:50 Around the table