My GIS project is progressing and it is time to start preparing for the presentation side of things. Greyhawk suffers from some of the same problems as our reals world, it is is planet. With that comes the impossible task of convert a spherical surface onto a flat one. Its a problem as old as cartography and numerous ways of solving this conundrum have been devised over centuries of map making. The term projection is used on the various forms of bending a planet onto a map.
Real world maps are used for things like find our way across an ocean using compass, sextant and a map. This makes certain projections preferable to keep navigational calculations consistent and simple (read: add as little to the workload as possible). For our needs as gamers understanding what the world looks like is the key feature. To help with that we need to look at what kind of map projections will do the job best.
Lets start with a look at the whole planet of Oerth. Here seen in an Equirectangular projection
This projection is the go to for creating planetary maps, it has a 2:1 aspect which makes it easy to set up in Photoshop or Illustrator to work on continental layouts. The main problem with this very simple projection is that its only accurate at the equator, and gets progressively worse the father away from the equator you get. Below is the same image in an orthographic projection, meaning it a map "as seen from space", in this case centered on Greyhawk.
Orthographic projections are accurate at the center and gets progressively worse the further away from it you go. It preserves shapes and their relations to each other well which gives a good understanding of how the geography are laid out. Ortho projections are lousy for navigation but great for understanding and visualization. Ortho maps have a major limitation and that is they can't really show the whole planet, only the side facing the center point. So for whole Oerth maps we need to look at other projections.
Most world map of Earth use a Mercator based projection which is makes a planet fit in a neat rectangle easy to print or place on a book page. Here is what Oerth look like using this type of projection.
The benefits with this type of projections are that they preserve angles locally, meaning directions like north are the same across the map. To make this possible the shape and area or the land is distorted, which you can live with when you need the map to plot your route, but gives you the wrong information about distances and local terrain relations.
To present a whole planet for gaming purposes an equal-area projection is, in my opinion, my better for this. Thankfully there are a lot of the to choose from. The shape and area of the land is much better preserved, but the latitude and longitude lines are distorted instead. My favorite among these projections are Mollweide, its large oval is beautiful and it keeps a lot of the spherical feel, shows the whole planet and gives a good understanding on the geographic layout of the world.
Eckert is another projection of this type that comes in many variants, Eckert III is in my opinion the best. Below is Oerth using Eckert III.
Natural Earth is a slightly more compact version of Eckert which might be better for certain applications.
A number of attempts to give up on the idea of preserving any property perfectly and make a compromise that simply make things "look right", which have given us the "compromise projections". Winkle Triple is one of them.
Wagner IV is another one.
They are, in my opinion, like the equal-area projections but a bit worse since they try to be a bit more "navigation friendly" which makes land a bit more distorted. This also makes them lass useful for understanding what the world looks like.
When we move in regionally and look at our corner of the world, the Flanaess and its surroundings projections change a bit. The projection of the Darlene map is unknown, or non-existent, so a bit of guesswork is needed to place the Flanaess. Luckily we have several references which gives un latitudes and in a few cases even longitudes which I've tried my best to preserve.
Below is the Flanaess seen using WGS 84 which is an Mercator based projection that is industry standard. This map is close to the Darlene map is the way we are used to see our Greyhawk. In reality the northern part is exaggerated and the land distorted.
Lets look at the Flanaess using an ortho projection centered on Greyhawk, which lies conveniently in the center. This map is great to understand how things are related to the City of Greyhawk, and the center part of free from distortion.
Lets move in a bit and look at the regions of the Flanaess referenced in Adventure Begins and the Living Greyhawk Gazetteer using the ortho projection. For regional maps like this, the ortho projection works well providing a minimal distortion in the kay area and keeps the land shape and layout right. Below is the Bitter North using an ortho projection centered on the western Wolf Nomads.
Northern Reaches centered on the eastern Cold Marches
Old Aerdy West centered on Rel Mord
Old Aerdy East centered on Rauxes
and a more zoomed out map centered on Rauxes.
Old Ferrond centered on western Furyondy.
The Sheldomar Valley
And finally the Thillonrian Peninsula
For regional and local maps ortho projection works really well, offering low distortion and high shape accuracy. Ortho maps works well by themselves. If you instead want to have the Flanaess printed on a number of small maps that can be laid side by side and match ortho doesn't work, and a Mercator projection like WGS84 works much better. The price you pay are increased distortion the farther north you go.
The projections used for real world maps are developed for viewing a 3D sphere onto a 2D surface. When you have a world and the purpose of maps are to show the geographic data you have gathered. For a fantasy world the situation is different, for starters the world doesn't exists in the sense that it can be surveyed using normal means. This means the data of the world needs to be created and then presented using cartographic standards.
Terrain tools (at least so far) works on a 2D plane which means having the 2D - 3D problem in reverse when creating terrain with the intention of making it fit a planet. Then converting it back into a 2D map again. Real world surveying is a challenging and expensive undertaking, but fantasy surveying comes with its own set och challenges as well. Information gathering from texts and fragmented maps, inadequate tools and having to work in reverse makes it both interesting and hard.
GIS is needed to develop maps that can be both printed and used digitally and work well for both uses. This means the need for both WGS84, ortho and a few other projections as well, I know I want that Oerth large poster map using the Mollweide projection!
