Aaron slags-off release 1.5

Release 1.5 is fine for making random heightfields. It is, however, very difficult to 'design' the heightfield using the intermediate map - you can do it, but it takes a lot of patience. It took me about half an hour yesterday just to make a river go between two mountain ranges. It should be easier than that, and it will be soon…

The solution: Last night I re-wrote the start of the HF algorithm and changed the contents of intermediate map - now when you specify in the intermediate map that you want an altitude of, say, 300m - that's exactly what you get. I'll release the new exe when I've finished the 'painting' tools for the intermediate map.