Magnetic Field Adaptability for Different Geometries

[samf25]

The old version had a static variable for the magnetic field. This change makes it so that TrackPerf gets the magnetic field value from the geometry. Currently it is set up to assume uniform B field throughout the detector, but it would be simple to sample different regions of the detector based on the track. (since it gets the B field information for each track)

[samf25]

Depending on how you want it designed, I could also change it so that it doesn't calculate Bz on a per track level. That would make more sense for how the magnetic field is now (uniform). But later, I believe this will be a useful setup for a non-uniform B field.

[kkrizka]

Hi @samf25 , this is a good idea. Thanks!

However is there a reason why you require ACTS for this? It would be good to keep this package independent of whatever library does the tracking.

In this case, you are retrieving a single variable from dd4hep to scale another variable in the LCIO EDM. I don't see why the ACTS machinery is needed at all.

If you want to handle variable magnetic field, then we should use whatever framework dd4hep has for describing it since that's where it will be defined.

[samf25]

Oh yes, you are totally right! I was simply copying over a method from CKFTracking to do this and it needed it there, but doesn't here. I'll fix that now

[samf25]

Ok! ACTS removed and simplified it a bit.