Landscape Auto Material

I’m looking to use this just for simple landscapes while in port (submarine simulator) just so I dont have to waste time doing terrain texturing. Unfortunatly out of the box it KILLS performance with my ocean setup and a big port town scene. The player wont ever actually be travelling in the landscape so will never see it up close. Only from huge distances away.

What are some suggestions for optomizations in this situation?

Edit: Mostly I’m thinking like above a certain height (0z) use a basic rock/sand with no foilage setup and below 0z use a few foilage meshes as they are out of the box with a simple rock/sand landscape layer. EVen better would be the further from 0,0,0 the less foliage (that would be further from port in these levels)

How would I go about acheiving this with LAM? I’m a programmer dont od much material stuff.