Matt
Thanks for your reply. I have a oval shaped cup with internal features which effect the volume. I want to add graduations on the exterior of the cup showing 10ml, 20ml etc.
I placed a construction plane about 1/2" up from the bottom of the cup. I created an intersecting curve with the plane and the interior surface of the cup. I created an extrusion from this curve down to the floor of the cup using the "Up to Body" command. I can easily use mass properties to calculate the volume. I can then move the plane up and down to get the exact volume and then place the graduation line accordingly.
I was hoping I could use the "Equation" command to drive the height of the plane by inputing the desired volume.