The first project on this site will be detailing the surface of the planet Sadwillow.
Here is what I started with, a map created in Torben Mogensen’s marvelous planet map generating program imaginatively named, planet.
As you can see, this is a planet very close to being in a Pangaea state. A temporary situation, I’m sure, and it’s likely to break up before that continent in the northeast can join up. This sort of thing could be really interesting!
In order to use this, at least for my first draft, I needed to get the elevations as a grayscale image. The best I could work out was to run planet with my own grayscale.rgb color file. The result was this 8-bit bumpmap.
This clearly had limitations. Lots of really bad terracing and the like. That and I had to kind of guesstimate the proper sealevel. So I imported this into Wilbur, kind of my all-purpose tool for this kind of activity.
In Wilbur, I messed with the sea level till I found one that matched my original map pretty well. I used the offset filter to set that sea level to zero.
After that, it was time to try using some erosion and noise to weaken the terracing due to the inadequate heightfield(8-bit? Pfeh!). I lowered the sea level in the texture settings to allow the pitfill algorithm to open up spurious pits. Then I ran erosion, both incise flow and precipiton, added noise, especially to the higher elevations and after some more erosion and a last pitfill, I ran a river-finding texture. The result is shown here.
Now, I think this is fairly attractive, don’t get me wrong. But I’ve decided to discard the original height data for a variety of reasons. First, the distribution of mountains isn’t terribly realistic. Basically, the high areas are more or less centered in the continents. This is pretty much the way it is with all noise algorithms. Secondly, if you look at the slopes on those mountains, assuming that the heights are reasonably realistic, you are looking at an eight-kilometer-high Great Plains. Like Iowa without air. Third, and perhaps most important, where’s the challenge in letting the computer churn out some noise and calling it terrain?
Noise has it’s place, and I am a bit of an aficionado of good noise. Noise is good for obscuring the fingerprints and tool marks from editing. Also, it can be good for creating interesting initial shapes for land masses and mountain ranges and such. Since I’ve grown used to the shape of these land masses, that’s what I will do here.
Actually building terrain is where the fun is. It also gives us a chance to use our little gray cells to make the terrain realistic and believable. So that is what we will be doing. I hope you will join me in this effort.
This and later posts on the building of Sadwillow will be blocked together under the category, “Sadwillow Project.”
Thank you for your attention.