Thanks for the tip. Best I can tell it's not a tool to create terrains but rather to add details to terrain by merging the contact area, for example adding displacement waves to a ball on a water surface or blending a river to the underlying terrain.... I'll have to explore it a bit more though.

I may want to also add more Ram to my 8GB PC to hold more trees in memory. And I should try creating my own trees as 3-4 polygon billboards, at least for some of the distant trees. 

 

I seem to recall in the days of C5 or C6 there was a plugin from an external tool that was also sort of standalone and it made amazing rocky canyon scapes.Maybe it was just a standalone terrain tool and it was able to export an elevation map, I don't recall exactly.

 

I've completed clip #3 by the way:

http://www.youtube.com/watch?v=BmZZwqySk6E

 

I'm adding more foliage now for clip #4, and snow covered trees. Carrara does have some nice capabilities. It's all a matter of learning and exploring.