I have an IGES model from a supplier for a piece of equipment that will be used on a tractor. The model imported as a set of surfaces so the model mass and center of gravity are currently incorrect. I know what the mass is and I have a rough idea of the center of gravity so I would like to assign these values to the imported model so that the CG and mass in my tractor model is correct. The problem is, I can't seem to figure out how to assign mass to a point. Anyone have any ideas?