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points by echoangle 4 days ago | 0 comments

How does this work? You need to somehow flatten the globe into a plane, right? Are you just using a regular map projection? It says that everything is real scale in the description and that can’t really be true at high latitudes, right?

[–] Pirut 3 days ago

I used Web Mercator to flatten the map, so its "1:1" scale, but obviously not perfect because it is on a flat plane.

[–] robot_jesus 3 days ago

Neat project! It's an understandable limitation you had to commit to, but I'm curious how you've found the distortion away from the equator with Mercator. Probably not really noticeable in any major way within the arctic/antarctic circles but obviously closer to poles it's going to get quite wonky.

[–] Pirut 3 days ago

Distortion isn't too bad until you get to the arctic, but by then its all white so you don't really have a reference point to judge against anyways

[–] adrian_b 3 days ago

When mapping a sphere, the main choice is whether you want to preserve angles or you want to preserve areas. There is also the third option of not preserving anything, but attempting to not have too great distortions in either angles or areas.

I consider the third option worse, because it is better to choose the right map for your application than a map that is not optimal for any application.

Mercator is an angle-preserving map, so it is appropriate for navigation, but not for giving you a global view of the Earth, for which an area-preserving map is more useful.

Because I do not know the purpose of your map, I cannot judge whether Mercator is a good choice or not, but Mercator and similar navigation maps are seldom useful today, when navigation should be planned by computers, not with ruler and compass on a physical map.

[–] chronial 3 days ago

I thought Mercator was shape-preserving but has a different scale depending on latitude?