Trying to understand terrain construction in BF

Battlefield is a great inspiration for me when it comes to WM terrains. The end results are amazing. What makes me more curious, though, is the gameplay flow designed on the terrain. Take this map, for example:

[ul][li]Have they used layout generators to force certains areas to be “flatter”?[/li]
[li]How can i generate those “walkable” somewhat flat areas, that are not very noisy?[/li]
[li]That terrain seems like a simple Advanced perlin + Erosion combination, or is there anything else on it?[/li][/ul]

Here’s the workflow in BF3.

http://blogs.battlefield.com/2012/08/inside-dice-alborz/

Thanks. Apparently, they use a workflow similar to Splash Damage’s. Did you ever try to model the terrain in MudBox first and then bringing it into WM? How did you set the dimensions?

Yes you can start with a flat plane in mudbox. It’s dimensions don’t matter at all. You just have to have a good sense of scale when sculpting it otherwise you might find a mountain or something being smaller or larger than you want in game and it ruins the gameplay and I think that’s the reason they do the sculpt in engine and then export out to world machine. But that said, the game engine itself has to have a comfortable terrain sculpt tool otherwise it’s a nightmare (and it is).