For world-builders who work upwards, from physical detail to people, there comes a phase in every project when you have to worry about climate: the long-term patterns in weather that will matter to the civilizations of your world. This article is a practical guide to getting yourself a decent, believable climate without enormous amounts of work. You can consider this a first-order approximation of climate; there are many ways to add more detail and realism, and I’ll point some of these out as we go. I often do world-building with the computer, but here I’ll mostly talk about drawing on a paper map, for simplicity.
This post is about a world-building tool I've been working on. The goal is to generate semi-realistic landscapes including rivers and other effects of erosion. The tool is a bit of code, written in R. At heart, it models a map in the form of a grid, where each cell has an altitude, forming a height map.