Difference between openpmd and amrex plotfile field data

[AlexGlock]

Hi,

While preparing an example input file for another discussion, I encountered an interesting discrepancy between the openPMD and plotfile field data.

The example shows a perfectly centered STL cylinder, where the green crosshair marks the origin (0,0,0). When exporting the raw AMReX plotfile data, it looks as expected:

However, when I export the exact same data as openPMD field data, I get something that appears to be shifted by (dx/2, dy/2, dz/2):

Interestingly, the openPMD particle positions, when injecting particles from the volume surface, seem to be unaffected by this shift:

Does this mean that the AMReX plotfile (with raw field data enabled) shows the actual discretization as used by the field solver, while the openPMD format includes some averaging or interpolation of the field values in order to enable volume renderings?