DD4hep Meeting March 20th, 2025

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

Apologies: A.Tolosa Delgado, T.Madlehner 

Link to minutes of previous meeting

Merged PRs

• PR1415: Improve coverity scans (Markus)
• PR1416: Improve help replies (See issue 1409, closed) (Markus)
• PR1417: Support multithreading in Geant4EDM4hepOutput plugin (Wouter)
• PR1420: Allow to selectively disable DD4HEP sub-packages (Markus)

  $> cmake -DDD4HEP_DISABLE_PACKAGES="DDRec DDEve DDDigi"  ../DD4hep

• PR1421: fix typo in CMakeLists.txt (Charles)
  --> Fix to above PR1420. I tested though...
• PR1422: Add LANGUAGES CXX to the project command not to depend on a C compiler (Juan Miguel)
• PR1414: Fix the result of innerMaterial() and outerMaterial() depending on if the other is called first (Juan Miguel)
  --> Important fix. Should improve tracking.
  --> Fixes ISSUE1413
• PR1425: Documentation fixes  (Juan Miguel)
  --> Let's thank Juan-Miguel!. Let's remind ourselves that documentation is really treated like a step-child.
• PR1426: Only build components that need ROOT::Eve if it's available (Charles)
  --> Continuation of story starting with PR1420 and PR1421 . Still there is ISSUE1424 and PR1428 (see below).
  --> ISSUE1418 was closed, but probably premature
• PR1427:  Remove C++ preprocessor checks for a standard before C++14

Pending Problems

• 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;
• ISSUE1296:  DetectorImp::endDocument() called twice for some geometries?
                        ==> Unsure if it is a problem wrongly configuring multiple xml inputs.
• 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.

• ISSUE1419:  Assigning multiple sensitive volumes to a single readout Id
• ISSUE1429:  Error with ROOT::Eve when building DD4hep

• 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:

• PR1428:  CMake: do not build DDEve if ROOT::Eve does not exist

Closed issues and fixed problems

• ISSUE1409:  Cannot get help with -h or --help?enhancement
• ISSUE1413:  The result of innerMaterial and outerMaterial depends on if the other function is called beforebug
• ISSUE1418:  Possible to build without Eve dependencyquestion

Round Table

Andre:       NTR
Markus:    NTR
Peter:        NTR

AOB

----

Next meeting:   April 10th, 2025