11 December 2021

Actual Test: World, Climate and Globe Mapping Tools

tl;dr: testing online tools for generating world maps then simulating the climate.

I stumbled across a piece of paper, scribbled with notes that make up a hard-core world-building workflow I got from a guy at an Adventurers League in the before-times. I pass on the steps and hope this might bring joy to those among us who like super-crunchy world-building.

First step is to generate a random height map. For this we use the Planet Map Generator. There are a few sliders you can play with here but what you need for the next step is to generate a greyscale height map in Mercator projection. Adding a coastline contour will allow you to track the 'normal' coastline as you fiddle with water levels later.

Next you generate a map with "Make map" then right-click, save-as to get your grey-scale height map.

Next you want to push this into the Climate Simulator on Space Calcs by uploading the height map using Browse...

Assuming all has gone well, the climate will simulate automatically - if nothing is happening you have a misfire, something is wrong with the uploaded map. I had a few go splat because I did not have Mercator projection or I had some texturing or contouring turned on but after trial and error, the settings shown above are what worked for me.

To me the most interesting view is biomes - here is the standard. You can twiddle the biomes by adjusting Water level, Equatorial rotation speed and Solar irradiance. Water level adjustment is direct up/down along your height map. Equatorial rotation speed is fairly insensitive and adjusts the shape of the biomes inland. Solar irradiance is extremely sensitive - a small adjustment and you have an ice or desert planet so tweak gently.

Here we see the heightmap with water level reduced.

Then elevated.

Immediate use of these for me is 'where have the long-lasting civilizations persisted', 'where do you find drowned ruins','where was nice when the seas were low/high, is now desert'.

Finally you can upload your biomes images to Map to Globe and get 3D representation for some nice local maps of a campaign space.

I am still trying to figure out how to get all this to work with Azgaars to auto-generate the fantasy cultures over this physical world but for inspirational maps and 'what ifs' this is a neat workflow and I hope some of you can find use for it.


  1. This is very cool. Thanks for sharing, going to play around with it!

    I check your blog all the time but never comment, btw. I think it's fantastic. Keep up the good work!

    1. Thanks! Hope you get good use out of the tools, do keep visiting, there are more posts in the pipeline!

  2. Since you were asking, and I was attempting to use this, I figured out a method to get this to work with Azgaar's!

    What I did was export a copy of my map in Olsson Coloring from the generator. On Azgaar's, go Tools > Heightmap > Erase and then upload image. Select the exported image and then select the icon that looks like stacked pages on the right, which will automatically detect the elevation. I also recommend upping the number of points for a more detailed map, since this doesn't need to be manual at all!

    1. Thanks for figuring this out! Going to have to do a full end-to-end test of all these bits now.