Worldbuilding with Excel

Recently I showed off a work in progress, the world of Veleastra. (All names should be considered placeholders at this point.) Some expressed interest in my use of an unconventional mapping tool, Microsoft Excel, to design the world’s landmasses at the global level. I did use Excel for a lot of the background math as well, although I “drew” the map by hand, essentially pixel by pixel, with unfilled cells representing land and with water cells colored in blue.

The last version of the world map that I shared, with the Super-Regions, Regions and Subregions indicated.

The last version of the world map that I shared, with the Super-Regions, Regions and Subregions indicated.

As the venerable Paul Czege pointed out, it would have been relatively easy to do this fractally, by putting a formula in each cell and using conditional formatting to determine the cell’s color based on that value. This method could also have provided other useful data, such as elevation values. But I did it by hand, for reasons of aesthetics and personal preference, and because I could make the world fit neatly into the mapping system I devised for it. So I’d better talk about that.

I started by plugging in numbers for the mass and diameter of the planet, then computing a density and surface gravity based on those values. I wanted a world somewhat larger than Earth but still basically Earthlike, so by setting these parameters up in a spreadsheet I could play with the numbers until I got results I liked. But to do so I also needed to look at the other extreme, at the smallest scale, of individual hexes.

I’m a fan of the six-mile hex, because it’s geometrically elegant and because I think it works well for travel and exploration-based adventuring and nation-building. However, I’m just as happy to say that hexes are about six miles across and call it a day, since I plan to present distances in in-setting units anyway. So I made the hexes 10km across — a unit you would never see in a finished product. Ten kilometers is equal to 6.2 miles, and that’s close enough for me. Then I could figure out how many hexes I needed to span the world’s calculated circumference.

Where hexes get tricky, though, is that the distance from one hexside to the opposite hexside (with hexes stacked vertically, as is traditional,) is different from the distance between opposing vertices. So some irregular setup is necessary to get approximately square groupings of hexes, which I needed for my mapping system. I settled on 10km because an array 12 hexes wide and 10 hexes tall, with the horizontal distance between hexes measured from the centers, comes out to 103.9km wide and 100 km tall. So more or less square. I call this 10×12 hex grouping a block, for lack of a better term. Not only is it an area that’s manageable but containing plenty of space for interesting adventure, but it will also fit nicely on a standard 8.5″ x 11″ page. A larger subregion is 4 blocks high by 6 blocks wide, and the still-larger region is 3×3 subregions. The super-region is six regions wide by four regions high — but the polar regions (about 80-90° north and south latitude) are excluded, and they center nicely on the equator.

None of this would be presented as such in a finished product, of course, save that one block is what you’d see on a one-page map. But it’s a convenience that I’m using to structure the map and to provide approximate locations to place cultures, nations and other setting elements. So a given “region” might be more or less the Llythran Isles, while another might be mostly the timeworn remnants of once-mighty Imperial Attalos.

So back to Excel. I set this all up as a grid of square cells with the subregions, regions and super-regions marked at the appropriate cell boundaries (there was no need to denote blocks, since one block was a single cell,) painted the whole thing blue, then decided which super-regions contained land and which did not. I removed the cell color on those that did, leaving them white. Then I did the same thing at the regional level, again for subregions, and then one final time for the blocks/cells. It took substantial fiddling and several shifts of the grid until I was happy with the result — the map that you see in this post.

Now, Excel is obviously not an ideal endpoint tool for fantasy mapping. So while I now have a digital image of the world map with a 432×192 resolution, it needs to be punted into something I can produce a finished map in. I’m using Campaign Cartographer 3. Setting up the same Super-Region/Region/Subregion/Block grid — this time including hexes — at the appropriate scale in CC3, I “printed” the Excel sheet to a .png file, then dropped it into CC3 as a background graphic scaled to fit that grid. More or less, which is close enough. I can trace over the rough Excel graphic at increasing levels of detail until I have something that works printing one block per page.

There are many places here where I did fairly rough calculations: Earth is not a perfect sphere, for example, whereas my math assumed that Veleastra is. I figure that’s close enough, and my figures supply verisimilltude without me going bananas trying to calculate the surface area of an oblate sphereoid. And because my maps leave out the extreme polar regions, I have some room to clean things up a bit (There is a north polar archiapelago, so I’ll need to do a map of that.)

The current version of the world map, with the grid hidden.

The current version of the world map, with the grid hidden.

For the curious, Veleastra is 8,879.67 miles in equatorial diameter, compared to Earth’s 7,296.33 miles. The former world is about 25% more massive: 7.388×10^24 compared to Earth’s 5.972×10^24 — but Veleastra is less dense (perhaps due to vacant pockets in its interior, unknown to the inhabitants of the surface) at 4.83g per cm^3 compared to Earth’s 5.49g/cm^3. Veleatra’s surface gravity is about 1% less than Earth’s (9.656m/s^2 versus 9.796m/s^2,) but her total surface area is about 26% greater. These numbers might seem organic — and they’re intended to appear so — but this is an illusion. They are in fact precisely calibrated to fit the mapping system but are obfuscated by the not-quite-square dimensions of the block and the inexact conversion between metric and Hillbilly units.

Now the work of massaging the rough map into a usable state has commenced. Thankfully I only intend to map one Super-Region, and then to zoom into a single region within it. So I don’t need to block out every single nook and cranny of the planet.


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