Sorry for the double post.
Well I've just made a weird discovery.
I've always assumed that to produce deserts you needed moderate temperature, though they do appear uncommonly in freezing or scorching areas, that you needed high drainage, and little rain. Well that's what I've gotten from the wiki anyway.
But I've been running extensive tests in the world editor, and apparently temperature doesn't have a whole lot of influence. What does influence the appearance of deserts is the rain, and drainage levels. As suspected you are required to have low rain levels but unexpectedly you are also required to have low drainage levels. Which is odd considering that sand is a high drainage material. If you have a high drainage level you will produce many levels of sand, peat, loam, but everything else being the same the biome will be a badlands. If you have a low drainage level you will only have 1 level of sand, but the biome will be a desert. I haven't yet tested whether elevation matters much, I know you can't have high elevation because that become mountains, but I'm unsure whether low elevations produce deserts. Medium elevation areas are confirmed to produce deserts.
Using the below worldgen stats I've been able to reproduce desert worlds several times, with all the varieties of sand represented with no loam, clay, sandy clay, or sandy loam. Which was just unprecedented according my past attempted, badlands were a tossup between sand, loam, or clay.
Drainage- 0-10
Rain - 0-0
temp- 25-30
Also interesting it seems that surface water freezes somewhere between 25-35. Using a temp range of 25-30, or 35, can produce almost all the major biomes with the upside that you have your rivers freeze during winter and fall/spring.
Unfortunately I've yet to be able to produce a mountain range that extends from north to south, or west to east, despite having the appropriate elevation variance set to 0. That doesn't include ranges that border the borders of the map, ranges extending the entire map being on the border being fairly easy to produce. Also even with an elevation variance of 1600 I get only 1 maybe 2 mountain ranges that extend south or north (joining up to a massive range that covers either the south or north).
I'm thinking that to make many thin ranges I'm going to have to manually edit the elevation variance to a level of 2000 or higher. Why would I want to do that? The same reason I dislike oceans, generally the massive amount of space in the center of a range is useless for embarking - though that's a personal preference, I prefer non mountainous areas or areas where mountains meet another biome.
Another interesting fact, if the lowest elevation is set above 100 you will have very very few oceans/seas and little to no aquifers.
EDIT:
I've re-run the tests with 0-0 and 100-100 drainage. Again 0-0 had 100% sand on the top layer, while 100-100 only had occasional sand, with the majority being undesirable things like peat. Also with 0-0 there was only 1 layer of soil while 100-100 had 2-4 layers with the majority falling in clusters of 1-2 or 3-4.
I also ran some tests with 100 rainfall and suddenly the drainage didn't seem to make much difference. Suddenly all the results were much more similar to the 100 drainage runs with 0 rainfall. The one thing I was able to clearly see a difference in was the river sizes. With 0 rain rivers always stayed small no matter how many rivers joined together, with 100 rain the rivers relatively quickly developed into major rivers.
In all of this rivers only seemed to influence the appearance of aquifers, not the soil type. I'd often find peat halfway across the map from the closest river while there was sand right on the river and vice versa.
Also I can't seem to get small strings of mountains no matter what. I can set the mountain peaks to 0, 300, elevation range from 400-4000. The closest thing I can see is that he has the worldgen set to blob mountains into ranges in a bloby fashion. I'm not entirely sure what that means either, but not once in 20+ generations did I get seperate ranges, they all joined up at a pole. The best strategy I've run into to maximize mountain-other surface is to set everything to 1600x1600.
If you want to see what a 10x6000 elevation range looks like, download this. I would have loaded it to imageshack but I can't get it beneath 3mb with paint.
Does anyone know how to batch generate worlds using custom settings? The wiki has a command for batch making using generic setting (I think) but I have no idea how to change that to using my template no. 1 settings. I'm interested because I know some of this is possible, because for instance I've seen a hell world generated by Toady I believe that had mountains on the east and west borders with a desert in the center but I've never even got close to that.
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Topic: Worldgen cookbook (Read 165302 times)