Only afterwards I noticed that the function computing the tree distribution stopped working correctly after some variables (namely the local terrain curvature) changed in magnitude as they are computed slightly differently. So the trees now grow on much steeper slopes than they should. I won't deal with it now, it has to be reworked into a generic vegetation placement module anyway, when climate info becomes available.
Just now I have to optimize tile manager and generator because it not very efficiently handles GPU memory.
