DD4hep conditions Part 2: Enable the use of conditions at initialize time
This follows the discussion in Gaussino/Gaussino#15 (comment 6085263):
This is needed to enable the use of alignment conditions, magnetic field, and any other conditions that have to be known when converting the geometry and passing it to Geant4. The idea is to have a wrapper, similar to
ConditionAccessor
that would directly access theget_slice
method to retrieve the condition. This has to be done late enough during the initialization step. We will try to prepare a very simple example usingExternalDetector
, so that it can be easily tested by @clemenci. A good example would be a cube with a uniform magnetic field as in the figure below.