zip package: https://gitlab.com/h2mm/minetest/-/arch ... inbrot.zip
GitLab branch: https://gitlab.com/h2mm/minetest/tree/terrainbrot.
After that you can see the "terrainbrot" as one option.
Warning! The settings are currently subject of change. If you download a new version of terrainbrot, reset the settings to default.
This mapgen is based on the "fractal" mapgen. It iterates a rational function and uses perlin noise to generate stuff endlessly. Its variety is very huge. It can generate anything from flat lands to insane mountains. It also generates rivers. Some areas are full of rivers, other areas contain no rivers at all. Some rivers are straight, other rivers are curly.
It is not supposed to be a realistic terrain. I focused that on being simple and using a lot of variety. However, there are many places those look very realistic. I think, it might be also a good fantasy world.
Some screenshots: https://imgur.com/a/HSv5oCN
A short explanation of how it works:
Spoiler
This makes quite good terrain but it's still more or less limited to the unit disc because the farther points always diverge. The complex number z is generated by two perlin noises. They have the same parameters, only the seed is different. And that's not all. The coeficients of the rational functions are also generated by perlin noises. In the default settings, the rank of these rational functions is 10. The rank of the polynoms on the top is 10, the rank of the polynoms on the bottom is 8. The upper polynoms have 11 coeficients, the lower polynoms have 9 coeficients. Each coeficient has both real and imaginary part. There are totally 80 parameters and one perlin noise for each. Again, the noise parameters are the same, just the seed is different.
Rivers are generated by escape-angle. If the point hits the correct angle in its last iteration and is in the correct distance, it is a river point. There are some minor tweaks to prevent the rivers from flowing out of its banks but it still happens sometimes.
License LGPLv2.1+
Changelog:
Spoiler
2018-07-16 Improved speed
2018-07-19 Added Cavebrot
2018-09-03 Fixed spawnpoint bug