Hi Ditto, yes you can use the Construct > Curve > Silhouette command in MoI to calculate that parting curve.

Select your object, then run Construct > Curve > Silhou :


In the command options set "View: Top", the silhouette curve generated from the Top view is the parting line. You can then use Edit > Trim to cut the object with that curve to separate it into pieces.



- Michael