Geometry Work Plan for 2022

Version 1.0

NOTE: Any dates assigned to items are to be considered just indicative.
- Items marked with refer to new developments.
- Items marked with will involve new man-power or contribution from external sources interested in the project.
- Items marked with will require coordination with more than one Working Group.
- Items marked with (*) may or may not be achieved.

  1. Navigation & optimisation:
    • Validation of interface with navigator based on VecGeom - (1)

      Improve robustness of current interface/adapter to VecGeom navigator: identify cause(s) of differences between native Geant4 navigation and VecGeom.
      Extend test cases & Performance testing for mid and high complexity setups.

    • Alternative BVH navigator and optimisation structure - (1)/(2)

      Offer alternative navigation system through acceleration structure, based on Bounded Volume Hierarchy (BVH) technique, either natively in Geant4 or through the VecGeom library.

    • Separate safety computation and its state from navigator - (2)

      Loose coupling of G4Navigator in the computation of the safety distances from geometrical boundaries, factorising out the implementation now included in G4Navigator class, to get rid of potential side effects.

    • Revision of the transportation processes; specialised transportation processes for neutral and charged particles - (2)

      Factorise implementation of G4Transportation (and G4CoupledTransportation) for considering having at least two specialised transportation processes, one for neutral and one for charged particles (perhaps also one specific for optical photons), in order to optimise and speed-up transport by reducing redundant calls and code branches.

    • Prototype navigation indexing class - (2)/(*)

      An integer index identifying all touchables, or those up to a given level.
      Transportation process that uses this to replace touchable handles.

  2. Field transport:
    • New QSS integration methods (Quantized State Simulation) - (1)

      Alternative integration method which creates adapted polynomials and evaluates the limit of their validity.

    • Review accuracy of boundary crossing in field - (1)/(2)

      Study boundary crossing accuracy when field integration is enabled, reviewing behavior when using current default parameters in typical geometry setups.

  3. Solids modelling:
    • Prototype study on surface bounded volumes in VecGeom - (2)

      Design and implement demonstrator targeting a geometry setup of relatively simple complexity based on a data model for bounded surface description of solids and compare performance/efficiency on accelerators vs. existing implementation in VecGeom.

  • Routine activities
    • Review of user documentation

(1) First semester
(2) Second semester

Created: 28 January 2022
Modified: 31 January 2022