Allow to change terrain height from the simulations. Would allow map authors to be more creative with their maps. Also other interesting things like ditches created on the go from entrenchments or catapult shots.
Known issues now: Dirtying is not done on all necessary vertexes. So the renderer doesn't update. And tests would fail obviously.
Will take care of these ASAP.
A related diff allowing to change textures is in the works. Which would allow for fun things like making dirt roads on trade routes.