What Tools to use to generate a fantasy world map with some preset parameters?

Question

I have a world I would like to use for a fiction I am using, and the free tools I got from google (first page) mostly don't do it well. The world is a Disc. The landmass is about 475 million square kilometers. With 60% ocean, and 40% land. Of the land, 40% is either desert or the arctic, 20% mountainous, flatlands are about 25% and the rest is plateaus, valleys, rivers, etc. Now, the tool does not have to be that specific, but it would be fine if I could at least model a Discworld with the ratio of ocean, land, mountains right. It's fine if it is paid but free is preferred.

Answer 1

Azgaar's Fantasy Map Generator is probably the best (free) map generation tool available.

It's not perfect and it can take quite a bit of playing around with to get the results you want but it is miles ahead of most of the other generators around.

That being said it makes typical spherical worlds. It should be possible to use it to make a discworld but you'd have to take the output and modify it to suit your needs, whether through using some kind of projection or just cutting a circle out of the generated map and calling it your world.

Answer 2

Take a look at the Sid Meier's Civilization game series, now on number 6.

It generates game maps randomly with configurable parameters that may or may not allow matching your choices.

It's round, but projected into a rectangle, so should be easily adaptable to a ring.

It's usually output into a new game under a lot of fog of war, but look into the modding scene, there may be a fast way to see the whole of it.