Inertia in 6DOF
 

Hello,
I'm working in a project using the 6DOF Fluent modulus. I have to use a UDF to introduce the mass, inertia and external loads.
My question is about inertia: How to express moment and products of inertia? ...respect to my global coordinates origin or respect to gravity center position??

Sorry, my English is not very good :)
I hope your answer. Thank very much.

Best regards