Actualy that's not my terrain engine...Mine's better.

That is the Refractor 2 Engine designed by Digital Illusions CE.
They use patching for thier system but I'm not sude if they use patch occoulsion. I'm sure they do but alot of the time it doesn't seem like that. I also have triple texture alpha patching with a detail texture. I want to add at least a dual alpha detail patching (for roads and such) and maybe even sub pixle map terrain patching (kinda like lightwave's sub patching, but for terrains). but that's still far ahead.