I cannot claim credit for the idea, I think I read it somewhere or other.

For roads, you need to get pic 2 to have marginal influence on the terrain - say 99% terrain to 1% road or thereabouts. It also depends on how close to the terrain your camera is - yet another variable.. It'll probably take at least 3 reloads to get the mixture right.. (but at least you get the opportunity to free up all that memory that Vue's lost track of).

OTOH, you can create dry-stone-walls (or the Great Wall Of China) effects by using greater proportions...

The approach does need a fair amount of experimentation beforehand to see what the effects are, and quite a bit of patience to gt it right (there are so many things that need to be taken into account) - but it CAN  work...

If you do try this method, I, for one, would be very pleased if you posted the results you get (assuming you can w/o infringing copyright), whether said results are good or bad...

Like I said, I'm learning too..

Cheers,
Diolma