Those un-textured cubes are not assets present in ARK normally. I have literally never done material creation before, so I will just quickly throw something together. I glanced over at the tutorial here, I screen shot this thread (because I’m certain this thread isn’t a texture in ARK :rolleyes:), created a new material, imported the texture, made a new material, threw that texture in to the material as a texture sample, gave it a texcoord with a -1 UTiling (since it was inverted), created a vector for a normal map (I bet a dev will laugh at me because I am sure I am doing something horribly wrong), linked them up, applied the material to the mesh, copied in the UE4 mesh to the mod folder, renamed it and applied it to the floor, set the floor collision to ground, threw in the post process blueprint, tested it in the editor, saved everything, cooked, uploaded, and ran it. I hope you can appreciate the humor of this experiment but honestly hope it helps you to create your own materials.
Let me know if there is something that I’m not understanding in your request, but for the most part you can find how to do just about anything in the UE4 manual.
Edit I covered how to get a material asset in to the game, as for creating one specifically for a landscape from scratch follow this tutorial.