I know you don’t want to change the mesh, but if you have to…there’s Manthax’s fork of this… Link
But there is a fully explored method of how to do what you want with shaders… User prisoner849 here made one with a fish bowl and a cloud, there was another with a wood grain cube being cut with an invisible sphere.
I cannot find the links to them right now.
Possibly people that see this will know what I’m talking about.
Edit: or was it User gkjohnson with something like this… Link