MRADSIM use OpenCascade

MRADSIM Converter is a CAD converter that converts STEP format to GDML format.
It converts commonly used CAD formats in engineering to GDML format, which allows it to be used in Geant4 physics simulations. It is an auxiliary tool for design validation in simulations such as space radiation.

Soruce: https://dev.opencascade.org/project/mradsim