Question Material Blending between different GameObjects

I'm not exactly sure how to word this as I've only seen it a few times but I'm looking for a method to blend the material/shader result of overlapping GameObjects.

For example, I have a river mesh that meets with an ocean mesh.

I'd like to learn how to blend these two material/shaders. Not sure if it's another shader or post processing effect so any advice would be great!

 

There's not really any magical technique you can use to blend between two materials. The usual solution to something like this would be to have a small waterfall & effects to hide the transition. Otherwise you have to just have to treat them as "the same mesh" and not have them overlap. If they have different colors / textures, then you'd have to have the shader they're using have some feature to fade from one set to the other.