Well I learned most of it in university (I've studied Computer Science, Mathematics, and Geography) and by reading Wikipedia, Wolfram, and other websites. The math on most of the Wikipedia pages for instance really isn't that hard. Undergrad level at worst (My own math knowledge is pretty much all undergrad level) and plenty of it is high school level.Originally Posted by Alex
So yes, I do want to do those fun things and would very much like to do it correct *since it is too late for the map of my novel...*.May I ask for suggestions on where to start for someone who has little to no knowledge of it? Perhaps books to buy/rent *that doesn't read as if its assuming you are a professor or something lol*, or easier sites I can check out? I have tried wikipedia, but seldom do I understand it...
So, if you want to approach it via math, you might want to try working on your geometry (Particularly Spherical and Analytic Geometry) and trigonometry, say at Khan Academy.
Otherwise, it's a matter of trying to remember a bunch of odd things that don't seem all that related. It's possible to deal with without a mathematical understanding, but it's harder to have a clear idea of what's going on. Since I didn't learn that way, I can't give a lot of advice.
I'll try to walk you through a few basic projections and what their good and bad points are.
The most basic form of projection is probably what's called "Gnomonic Azimuthal" It's the basis of the Dymaxion projection I mentioned above, but it's rarely used directly. Basically, you can think of it this way: you take your flat map, touch it to the globe at one point, stick a light at the centre of the globe, and "project" the features on the surface of the globe onto the map, then trace. Obviously it has the problem that you can't fit the entire globe on the map. You can't even fit an entire hemisphere on a map as the light going through the globe 90° from the central point is perpendicular to the map and will never reach it. Also, the further from the point of contact you get, the more distorted the map gets.
Another simple one is called "Equidistant Cylindrical". It can be varied a bit, but the simplest form is called "Platee Carre" and works like this, you take the longitude, and that's left and right on the map, and you take the latitude, and that's north-south on the map. The map is essentially wrapped around the equator in a cylinder, and then the light used to project it is 'curved' to make north-south distances work to a fixed scale (All other distances are distorted). You can vary it by making the cylinder smaller so it cuts through the Earth, and you can tilt it so it doesn't wrap around the Earth's axis but these are much less common. This projection gives the higher latitudes an ugly "stretched out" look. If you use it, you have to draw that distortion into the map, otherwise when you convert to another projection, or put it on a sphere, you will see the opposite distortion (The poles will look "pinched").
Besides wrapping the map in a cylinder, or laying it flat at a point, you can also wrap it around in a cone. This is good for smallish continents or similar sized extents in middle latitudes. Canada and Europe are often mapped with conic projections. If you see "Conic", "Cylindrical", or "Azimuthal", they mean "Wrapped in a cylinder", "Wrapped in a cone", and "Laid flat" respectively. The also have standard shapes, Cylindrical maps are Rectangles, Conic maps are Fan shaped, and Azimuthal maps are Circular, though you can crop a part of the map to any shape you want.
Probably the simplest projection that's fairly widely used for serious maps, is Stereographic Azimuthal, which is often used for maps of the poles. It's much like the Gnomonic Azimuthal above, except that the light is on the far side of the globe from the map (The "antipode") rather than the centre. This can fit a hemisphere onto a finite map, but not a full globe. It also has a very useful property called "conformality". A conformal map preserves angles. If two roads meet at 45° on the surface of the earth, then the roads on a conformal map will also meet at 45°. In a more vague sense you can think of conformality as preserving "shape". It does this by distorting area. The further you get from the centre, the bigger things are drawn. (Gnomonic does this too, but it does it too much and so isn't conformal)
There is also a conformal cylindrical projection, and it is called Mercator, after a cartographer who developed it. When wrapped around the axis (What's called the "Normal Aspect") it also preserves compass directions and is the ONLY projection which does so. This is why it was used for early marine charts when the only navigational instrument available was a magnetic compass. It's also used by zoomable web maps like Google Maps where it's useful to be able to zoom in and get something that's mostly the right shape. It makes things bigger as you get further from the equator though, and the poles are infinitely far away. If you've seen the traditional rectangular wall map of the world that shows Greenland as being as big as Africa, that's Mercator.
There's also a Conformal Conic ("Lambert's Conformal Conic" or "LCC") which I won't go into. There are equal area and equidistant projections for all three shapes, with Equal Area squashing shapes more to keep areas equal, and equidistant sort of sitting in between.
There are also projections that are neither Cylindrical, Conic, nor Azimuthal. These often have elliptical or oblong shapes but they can vary a lot and most are purely for mapping full globes while trying to balance distortion of area, distance, and shape. Most modern full world maps use one of these, with Winkel Tripel and Robinson being popular.
If you don't mind a labour intensive solution that gives imprecise results, you could try drawing your world map in a suitable projection, with a graticule (A grid of latitude and longitude lines) and then set up a blank map covering the area of a region you want a map of with a graticule for a suitable projection (say a conic for a mid latitude continent) and then use the two grids to transfer the shapes on the map across. All you need are suitable graticule templates. I've drawin up templates for Normal Mercator and Equatorial Stereographic Azimuthal here http://www.cartographersguild.com/sh...ector-Template and I'm working on a program to draw Equidistant Conic graticules for any particular latitude range for larger scale maps of continents. For very large scale maps, it gets a lot simpler as you can mostly pretend it's flat.
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