A. Sailer, C. Vuosalo, F. Gaede,  M. Frank, T. Madlener, V. Voelkl

1)    Pending problems
1.1) Pending problems reported by Sang Hyun Ko:
     - Cannot setup Birk's constant as material property.
     - No analogy to G4PVParametrized. Unclear if a solution is possible.
1.2) Add GFlash parameterisation to DDG4 (issue #802).
1.4) Simulation instability in CMS
1.5) Subtraction/ExtrudedPolygons: https://github.com/cms-sw/cmssw/issues/33656 (Carl to open an issue in DD4hep)
1.6) Positioning of sensitive volumes: issue #822

2)    Closed issues and fixed problems
2.1) Divided volumes (issue 833). Solved - volume divisions are not real volumes
        though they come in the dress of a TGeoVolume. They are however not supposed to be
        physically placed.
2.2) CMS problem with subtraction - cause not confirmed. Needs further investigation.
2.3) PowerPC segment violations in CMS. Floating point exceptions from arithmetic
       processor in CMS-sw code.

3) Round table
   Markus:     Question of collaboration from University of Tiflis/Georgia about
                     integration of CATIA with DD4hep. Including software supported
                     geometry simplifications to speed up simulation.
   Ianna:       Not connected
   Carl:      NTR   
   Andre:     NTR
   Marko:     Not connected
   Thomas:    NTR
   Valentin:  
        * Want to have self reproducible files, including configuration in the file itself. How to include the complete compact XML as a string?
           * Frank: for iLCSoft/ddsim store the ddsim steering file including compact file
   Frank: Had a meeting with LuxE experiment proposed for the X-FEL. Fixed target experiment, bit of magnetic field + tracker and calorimeter. Pointed them towards DD4hep to describe detector model.

4) AOB

DD4hep vCHEP proceeding status? Inquire via email.

Next meeting in 2 weeks: 10/06/2021