Water System - Interaction "Ripple" effect

Hey guys!

I’m making a project which involves a swamp. I thought it would be cool to add water interaction from the objects.

I found this tutorial on Youtube:

The problem is that the render texture always render the sprites. I made them disappear and appear whenever the object moves but I’m still not quite happy with the results.

Is there a way to render only the objects moving?

I mean, instead of using sprites, render the actual object only when it moves?

I tried using motion vectors but I don’t really know how to do it and it didn’t work as expected. I though of drawing the collision points into the render texture but I also don’t know how to do it properly.

Can someone help me?

(btw, this would be cool if Unity implemented in their Water System)