Ae-2222 Region Based Terrain Control

[fluffyfreak]

Brilliant idea that needs some attention, could lead to other possibilities.

pioneerspacesim#1476

[fluffyfreak]

The original PR/issue and my copy of the branch with the work done on it by Ae.

So, mostly I wouldn't go changing the terrain generation itself but add flattening as a process of the GetTerrainHeight or something like that. With a, hopefully quick, lookup at to whether or not terrain smoothing should be applied.

Alternatively it's worth thinking about doing it as another layer in the terrain generation process where artist made/driven tools can modify the terrain to add customised craters, valleys, rifts, etc.