Looks real nice. And of course, 4 miles could mean anything - it's the resolution that matters.
I've been thinking about something that could be added to some of these custom terrain systems... you could have a heightmap or whatever that determines the height of each point - PLUS a displacement map, that stores an X and Z displacement for each point - that way you could have overhangs and caves and such. In fact, since you can get a heightmap that only uses the R value of a heightmap, the G and B could be the X and Z displacement.
Not sure how that would mess with LOD though.
I've been thinking about something that could be added to some of these custom terrain systems... you could have a heightmap or whatever that determines the height of each point - PLUS a displacement map, that stores an X and Z displacement for each point - that way you could have overhangs and caves and such. In fact, since you can get a heightmap that only uses the R value of a heightmap, the G and B could be the X and Z displacement.
Not sure how that would mess with LOD though.