Geometry Work Plan for 2008

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:
    • Usage of safety on exiting surfaces in navigator
      by May 31st, 2008

      Fix behavior of G4Navigator for the treatment of the safety which currently ignores exiting surfaces.

    • Interoperability of multiple navigators/geometries
      by October 15th, 2008

      Identify critical test cases for use of parallel geometries and combined use-cases (scoring+fast_parameterisation, biasing+scoring, etc..).
      Review current design and implementation to address remaining open issues.

    • Usage of direction in replica navigation
      by October 15th, 2008

      Review and extend implementation of G4ReplicaNavigation to take into account of position and direction when locating on egdes or along surfaces.

  2. Robustness checking & performance tuning:
    • Field performance evaluation and tuning/benchmark
      by May 31st, 2008
      • Complete study on electromagnetic-field tuning of parameters and algorithms used for stepping and integration.*\
      • Study potential use of derivatives, average values, access to field value (GetFieldValue()), composite steppers, new available algorithms (Brent method). Study the possibility of utilising a user minimum step.*
    • Review response precision of solids on points close to surface and normals. Verify accuracy of 2nd order equations
      by May 31st, 2008

      Reiterate the tests on surface for random points close to (and far from) the solids’ surface, to quantify the precision of the response according to the geometrical tolerance. Verify the conditions under which the surface normal must be computed and the accuracy of the algorithms implemented.

  3. General code review and improvements:
    • Organise a code review for selected CSG shapes
      by June 30th, 2008

      Identify places where code is duplicated and could be simplified; study ways of caching calculation of constants and reuse them efficiently; identify hot-spots performance critical.
      Give priority first to most common used shapes.

    • Revision of use of angular/radial tolerances in CSG solids
      by June 30th, 2008

      Review implementation of sphere, tubs, cons and torus for usage of angular and radial tolerances; identify cases which may lead to imprecise response in the current code.

    • Extension of G4Region to local magnetic fields
      by July 31st, 2008

      Allow for associating magnetic fields to detector regions and propagate the attributes to volumes which are part of the region.

    • Review of magnetic field classes
      by September 30th, 2008

      Identify and improve areas where the implementation is performance critical.
      Improve existing implementation to allow easier and more intuitive API to users for tuning performance and field response.

  4. Detector description persistency:
    • GDML writer and support for parameterised volumes
      by May 31st, 2008

      Implement ability to dump on GDML files geometries loaded in memory.
      Extend existing GDML plugin to support missing features, like parameterised volumes, optical properties, external attributes, etc… Verify that all existing features available in GDML 2.X series are supported and generated GDML files are readable.
      Integrate stand-alone tool for conversion of CAD geometries to tessellated solids.

    • ASCII detector geometry description persistency
      by July 31st, 2008

      Allow for importing detector descriptions defined in ASCII format.

  • Routine activities
    • Extend testing suite for solids (CSG/specific/Boolean/BREPS)
    • Review of user documentation and publication of a preprint paper on a refereed journal

(1) First semester
(2) Second semester

Created: 31 January 2008
Modified: 31 January 2008