[WIP] Aetherworld Map: Water flows up mountains too, right? Help with Rivers.

[Hai-Etlik]

Fair enough, but if I'm going to put my time and energy into a project like this I would prefer that it make some sort of logical sense. Hence my desire to get the rivers at least somewhat correct, and now to fix the graticules. So with that said please continue to throw your "arcane" comments in my direction.

Well, you might find the thread I'm working on to provide an introduction to GIS helpful. It covers a lot of ground quickly (and is still a massive wall of text despite that) but it will hopefully give you enough of an idea how to use some real world geography software that you can get something out of it. http://www.cartographersguild.com/sh...g-GIS&p=176512

[Lalaithion]

While Hai-Etlic is completely and totally right, your map doesn't look like it has been distorted in the same way as a Mercator; Mercator enlarges things that are far from the equator. Your map looks more like an equirectangular, where X maps to Latitude and Y to Longitude. The graticule will be a grid of evenly spaced lines in both directions.

[wittyoctopus]

I wish I could claim to have put half as much thought into my graticules as either Hai-Etlic or Lalaithion have done for me today. To be honest when I started my map it was designed to be a basic Mercantor projection. However, looking at my own idea of how the continents have been "distorted" the design does more closely resemble the equirectangular projection where the chief distortion is felt in the horizontal plane.

You have both given me a fair amount to think about. One solution that I have been tossing around is to make it a Mercantor projection and narrow the focus of the map so that extreme north and south remain unseen, therefore hopefully limiting the amount of extreme distortion you would normally see on a Mercantor projection map.

I appreciate all the thoughts that have been thrown in my direction today. Please keep them coming.

[Hai-Etlik]

While Hai-Etlic is completely and totally right, your map doesn't look like it has been distorted in the same way as a Mercator; Mercator enlarges things that are far from the equator. Your map looks more like an equirectangular, where X maps to Latitude and Y to Longitude. The graticule will be a grid of evenly spaced lines in both directions.

There are some wide things in the north and south, but they don't have the squashed/stretched look that Euqidistant Cylindrical/Equirectangular would produce.

[wittyoctopus]

I think what I'm going to have to do is borrow Hai-Etlik's Mercantor projection file and superimpose it on my map and compare that to a Mercantor map of the earth to get a better idea of how the world I have in my head would look on paper with similar distortions. From there I should be better able to decide what I want to do.

Along the way I've noticed that the extreme east and west don't mate up properly either so that will need to be remedied as well, by either narrowing the focus of the entire map or by touching up those sections. Thanks again for all of the input.

[Hai-Etlik]

I think what I'm going to have to do is borrow Hai-Etlik's Mercantor projection file and superimpose it on my map and compare that to a Mercantor map of the earth to get a better idea of how the world I have in my head would look on paper with similar distortions. From there I should be better able to decide what I want to do.

Along the way I've noticed that the extreme east and west don't mate up properly either so that will need to be remedied as well, by either narrowing the focus of the entire map or by touching up those sections. Thanks again for all of the input.

Well the map as it stands doesn't go all the way to 180 on either stands anyway so they shouldn't match up.

One solution would be to just drop the graticule and compass rose entirely. If it's a kind of vague representational map without the claim to precision which those elements make, these issues become less of a problem.

[Gamerprinter]

One solution would be to just drop the graticule and compass rose entirely.

Eh, I would never recommend not using a compass rose on a map. In fact, I'd say no matter what kind of map you're creating, always include a compass rose. The graticules may be best left of the map, I agree, but never the leave off the compass rose. Since this is supposed to be a world map, I understand Hai-Etlik's desire to see it as a mercator projection, but even I never use projection maps (but then I never create world maps that fit on globes, either, where it might become an issue...) I only create regional maps or smaller areas, never worlds.

[wittyoctopus]

I grant you all that as an amateur I may have gotten a bit over zealous by attempting to create a whole world with my first map. But hey, go big or go home.

[Hai-Etlik]

Eh, I would never recommend not using a compass rose on a map. In fact, I'd say no matter what kind of map you're creating, always include a compass rose. The graticules may be best left of the map, I agree, but never the leave off the compass rose. Since this is supposed to be a world map, I understand Hai-Etlik's desire to see it as a mercator projection, but even I never use projection maps (but then I never create world maps that fit on globes, either, where it might become an issue...) I only create regional maps or smaller areas, never worlds.

There are very good reasons you might want to use a non-bearing-preserving map and putting a rose on such a map would be wrong in the same way as putting a scale bar on a map that is not to scale. It would be saying something about the map that is not true. For a map of Canada, chances are you want a conic projection, or for a map of one of the poles, an azimuthal one.

For sufficiently small extents, yes you are usually safe treating it as bearing preserving, though it has to be fairly small otherwise you have to choose between preserving bearing or distance. Of course it doesn't matter how small the extent is if you are at a pole.

[Gamerprinter]

There are very good reasons you might want to use a non-bearing-preserving map and putting a rose on such a map would be wrong in the same way as putting a scale bar on a map that is not to scale. It would be saying something about the map that is not true. For a map of Canada, chances are you want a conic projection, or for a map of one of the poles, an azimuthal one.

For sufficiently small extents, yes you are usually safe treating it as bearing preserving, though it has to be fairly small otherwise you have to choose between preserving bearing or distance. Of course it doesn't matter how small the extent is if you are at a pole.

There are certainly exceptions, but I think polar maps are rare. I have seen only a few. Most world maps are at equatorial rather than polar.