Removing mesh intersection seams

First off:
There is a technique in that video showing multiple meshes intersecting together and due to the material that’s on it + vertex normals that are pointing up, there is hardly a visible seam where the meshes intersect. My question is: what’s going on in that material? I talked to Hourences (the guy in the video) about it, but he was traveling and had a terrible internet connection, so all he could tell me is that is was the material + upward vertex normals for the mesh. I want to say that it’s some sort of triplanar mapping, but I’m not sure.

My wild guess would be that that both materials have world space coordinates and both normal maps are in world space.

Already desscused, here you can find material breakdown for it

Sweet, thanks for the link.