ah okay. so you dont edit the actual dataset/heightmap for the craters, you just put a displacement "patch" on the top of it and leave the datasource untouched? how does that work with the collision mesh? is the collision mesh updated extra or how did you do that... ?
is it possible to edit the terrain, with a "paint tool" at runtime like in sim city. klick safe, and the next day, your holes and new mountains are still there? or can you just apply "patches"??? must be tricky with a giant dataset like bluemarble. how did you manage to update these TONS of data in seconds??