Well, it's been another few days, and I haven't been able to put my Theia world map away.
I wanted new rivers, generated from the precipitation levels - but that turned out to be a lot harder than anticipated. I've tried to get QGIS to work, but r.terragen from GRASS only gave me error messages and SAGA's hydrology modules gave me a few results, but not the ones I wanted. I ended up using WILBUR again, even though I know it doesn't really work well on equirectangular maps. To get a better result than before, I started up After Effects, and generated various layers of fractal noise, which I merged into my height map. I also tried to make some continental lift by cutting the world into the largest tectonic plates and applying various gradients to try and simulate the tilt of, say, continental North America. Setting these layers to SCREEN and adjusting FILL made me able to make a rather nice and detailed height map that made my previously flat and boring continental shelves a new life.
In the end, after coloring it, my height map looked like this:
NEW HEIGHT MAP:
Theia-Equirectangular-WIP-climatetut-heightmap-2.jpg
I put the greyscale height map into Wilbur, and started generating rivers. I made them simple white lines on a black surface, in two different amounts, and put them back into Photoshop. If I couldn't get the GIS software to generate precipitation-based rivers for me, at least I could do it manually! But first, I needed to know the climates from which they'd flow.
I used the new height to re-create temperature maps and adjusted the precipitation maps as well, and ran the 6-step climate GIMP-script again, giving me this map:
KÖPPEN CLIMATES:
Theia-Equirectangular-WIP-climatetut-climates.jpg
From this, I painstakingly masked out every separate climate, learning a lot about each from Wikipedia in the process. :)
Armed with climate masks, and referring to my precipitation maps, I could start tracing rivers. Sure, they are some enormous continent-crossing river systems, but this time, they feel a lot less random. I selected the "short" rivers and expanded the selection with 1 pixel, giving me a base for the larger, main rivers - and kept the "long" rivers at their 1 pixel width. Using the pencil tool and a mask, I could follow the major rivers until they branched off too much, and delete the rivers appearing in dry areas.
With this done, I could start painting my biomes. I grouped similar climate zones together, and ended up having jungle, savanna, warm desert, cold desert, mediterranean, temperate forest, warm steppe, cold steppe, tundra and permafrost biomes. I based them on the riverless terrain texture from WILBUR, and simply recolored and tweaked before filling in my climate masks. It took quite a bit of re-painting to avoid the hard climate zone breaks, but I think I managed to get a rather pretty end result:
THEIA - Main World Map:
Theia-Equirectangular-Biome-nosnow.jpg
In the end, I made a couple of seasonal variations, to show the shifting sea-ice and the reach of snowy winters.
THEIA in January:
Theia-Equirectangular-Biome-Jan.jpg
THEIA in July:
Theia-Equirectangular-Biome-Jul.jpg
So, what has all of this work shown me? That I wasn't very far off with my previous climate guesses, and that I can keep writing as intended. :D
My next project might be to re-paint my main continent map according to the new climates, and see if I have to adjust my population calculations, or if it's all good.
Again, I want to say a big thank you to Azélor and Charerg - without your help, scripts and considerable body of work leading up to this, I would have never managed to make this a reality. You guys rock! :D
-Niels