A challenge arose some days ago as to define a script that could calculate the Centre of Gravity in a Revit model, and of course Dynamo was made for solving these kinds of challenges. Based on the "Algorithm" found here, we applied it to three dimensions in Dynamo. The script uses project base point as Datum and no particular effort has been made to make the units in the calculation usable for anything else. The python script has however been modified to extract density in SI units.
A version of the script can be found here