Dynamically filling bottles

Not really anything brag worthy, but thought I might share this and wanted to also see if anyone knew how to make this better without adding anything else inside the mesh itself. This could probably use a little polish in it’s current state but it’s a fun little trick nonetheless. It doesn’t look bad from the side, except when viewed from the top that hollowness nature from the two-sided material. I figured there’s probably no other trick or illusion to make it look like a solid center unless setting it to emissive.

See gif here: