I wish to model a fluid's location within a tank as the tank is rotated about a single axis. The goal of this is to see where the center of gravity ends up in different orientations. I have a solid modeled of the interior volume of the tank that I have been taking extruded cuts from to replicate various levels of fill, but the problem is I have to manually change the cut every time to create the correct volume. Is there a way to create a solid that maintains a constant volume, but will also follow the curvature of the tank walls?