Strange Missing Textures On Landscapes

Hey Andrew, thanks for the response!

I looked around a bit to see if I could find the answer for this myself, but found nothing, so I’m curious as to what sort of values the extensions take? Would you put in the size of the terrain itself, or something else?

As far as the material is concerned, I’m not, at least right now, doing any sort of displacement, at least as far as I know (I am rather new to all this…) Below is an image of the setup, the bottom wires, in case you’re wondering, lead to an unused tessellation bit.

A quick break down would be that I have a set of four textures for albedo, normals, roughness, specular, and AO, feeding into a layer blend set to alpha blend on each layer, which is then hooked up to the main node.
Each layer has been populated with a raw image output from World Machine (as well as the heightmap itself.)

You mention landscape bounds, could it be that the textures themselves are not lining up correctly? Or would that present itself in other ways?
I’m wondering because I’m not so sure my raw image bounds match the landscape’s…

Again, I’m really new to this, so in essence I have no idea what I’m doing.