OpenEMS is FTDT electromagentic solver where simulation is defined in Matlab files, also it's possible run it using Octave.
To simplify geometry, meshing and simulation settings I developed this GUI plugin for FreeCAD.
Project github: https://github.com/LubomirJagos/FreeCAD-OpenEMS-Export
Nevermind... Found some documentation on how to use the macro at https://github.com/LubomirJagos/FreeCAD-OpenEMS-Export-Plugin-Documentation. Thanks