ABAQUS DEM, Porosity of Granular Medium

Hello, I am trying to use ABAQUS DEM to model a steel bar penetrating a granular material. I was wondering if ABAQUS DEM has a built-in function or a specific way to measure the porosity of the granular material by the end of preparation and during the simulation? I would greatly appreciate if you could kindly show me how to do it. Thank you!