You need to study up.
1000 x 1000 = 1,000,000 quods which = 2,000,000 tris. And Probably wasted tris at that.
Landscape is poor because it is pure and unmitigated ■■■■.
It was designed nearly 20 years ago for the second sdk and it has hardly had any worthwile improvement since then.
In fact, It had a lot of whatever the opposite of improvement would be - lets go with “sheer stupdity”. Which instead of producing a worthwile system made the whole thing heavier to render than it should be. By around 60 to 80%.
What you should do is produce an analytical mesh - where there are verts only where verts are required.
On top of that, usually you section the mesh(es) for occlusion following best practice standards.
So in the end you have like 2k tris on screen and a handful of drawcalls instead of 1 drawcall of 2m tris.
There’s some decent (of all things one would never think of mentioning EA after decent, but here goes) EA talks on geo-rendering. And there are some perhaps better ones from Edios (hitman).
Anyway, only removing visibility can definitely be achieved with just a material.
Lets see… if i find a link in the first search ill share it…
You are in luck
