"Blending" Materials across multiple actors?

Is it possible to ‘blend’ together materials across actors somehow? Maybe some other solution?

I mean the effect that i’m looking for is following (ignoring possible Z-fighting issues at the moment):

Imagine material that is just one color, with a hard edge of another color, however if another separate actor is placed next to it - the edge would vanish and create a nice blended effect between the two actors.

Very simplified representation:

if they aren’t moving then you would use a world aligned material.

some examples:

https://www.artstation.com/artwork/lJ3z5

Thanks I’ll look into it. I’m not sure it will fit my specific scenario but I’ll try and do the reasearch based on what you have provided but I think for purposes of original question it would fit.

Basically I have a Planet mesh formed out of hexes and pentagons which ultimately form a sphere and each one of the hexes/pents will have a material instance applied to them, I want all the instances of same type to ‘mesh’ together and have hard edges on the outer edge of each ‘patch’.

EDIT:
Issue of course being that I would somehow have to take surface normal into account when creating it, because ‘up’ for specific planetary meshes would be facing negative Z at some points and positive at others.