Hey!
My goal is to create modular cliff meshes to use as both near and far details for an exterior level - to achieve this, I’m hand painting an RGB mask, and then apply albedo, normal, roughness etc. where these textures should apply. My ability to hand-paint these meshes isn’t great, though - I really lack the ability and time to hand-paint natural masks for erosion, for example. So I’m seeking a procedural/function driven method to create these masks. Similar to what World Machine does with erosion and/or angle based mapping, but for a complete 3D mesh. The tools I have available for this is 3D Coat, 3Ds Max, and Mudbox.
Sorry if this is coming out like gibberish - for some reason I can’t word good when I’m describing my goal. Also I haven’t asked this for a while because every time I try to describe myself, I end up sounding like a dolt. I swear I’m not new to this! 
Also - the reason I’m using masks is so I can use parameters to define the scale of the textures, either matching the terrain texel detail or scaling much higher for the meshes the player won’t ever reach - I’m also using the same textures as the terrain to keep texture calls down (else, I’d just hand paint every mesh - which is also something I’m trying to avoid, for time reasons).