Wikipedia:Reference desk/Archives/Miscellaneous/2021 September 14

Welcome to the Wikipedia Miscellaneous Reference Desk Archives
The page you are currently viewing is a transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

September 14

Term for "hidden" areas on a map?

I'm pretty sure that there's a cartography term of art for areas on a map that can't be seen because the map was drawn in perspective and the area is behind a hill or large feature or something.

I can't find it by googling, though. Every search I can think of results in click-baity articles about how everything you know about maps is wrong. Any help would be appreciated. Thanks. ApLundell (talk) 03:55, 14 September 2021 (UTC)

Presumably the type of map you have in mind is a panoramic map. The fact that some features are hidden from view by something in front is not tied to the map being drawn in perspective. You can also observe the issue in, for example, this map of lower Manhattan, which uses a dimetric projection – a limiting case of perspective when the point of view is infinitely far away. It is a property of all graphical projections that depict a 3D reality on a 2D sheet. In satellite-view maps, the view of building interiors is blocked by the roofs of the buildings. In 3D rendering in general (not applied specifically for cartographic purposes), most texts use the term hidden ("hidden surfaces", "some surfaces are hidden behind others"). A technical term is occlusion. It is used in this article: Mario Spengler and Stefan Räber (2013). Panoramic Maps – Evaluating the Usability and Effectiveness (PDF). Proceedings Mountain Cartography Workshop in Taurewa 2012. New Zealand Cartographic Society. pp. 49–56. So hidden features would then be "occluded features".  --Lambiam 06:26, 14 September 2021 (UTC)

Hah, call that a map of Manhattan? Here's one with the rest of the world included. Or in case that link is a copyright violation, see here. --184.144.99.72 (talk) 17:44, 14 September 2021 (UTC)

Thanks for adding that IP. That has to be one of the most famous New Yorker covers ever. The fact that the mag only cost 75 cents back then is amazing. Thanks again. MarnetteD|Talk 19:02, 14 September 2021 (UTC)

The "map of lower Manhattan" linked by Lambiam, is odd in several respects. To take an area I'm familiar with as an example, it shows the Chelsea Hotel on the north side of 23rd St., whereas it's actually on the south side of the street, and it shows the Empire Diner (misspelled "Dinner") on the north side of 23rd St. west of 10th Ave., whereas it's actually a block south of 23rd St. on the east side of 10th Ave. Deor (talk) 17:08, 15 September 2021 (UTC)

See also:  Here be dragons. —2603:6081:1C00:1187:A934:2EEB:D930:A61D (talk) 21:27, 14 September 2021 (UTC)