Thank you, people.
90% of effects is thinking creatively.
Remember: it's not magic, it's just analyzing your situation. A water surface, viewed from the side, is essentially a mirror (because of an optical effect called "fresnel").
So what you need is a liquid mirror surface. Therefore the canvas object, for reflection, and a few effects for making the canvas look like a liquid.
I don't know how Naves is doing it, but I'd do the following:
- paste all objects, one by one, on a canvas sized like a long rectangle
- set canvas height to canvas height * (-1) which mirrors the image vertically
and add a few layer effects.
Let me know if this helps.