Per Wikipedia <https://en.wikipedia.org/wiki/Terrain_cartography>:
*Shaded relief*, or hill-shading, simulates the cast shadow <https://en.wikipedia.org/wiki/Shading> thrown upon a raised relief map, or more abstractly upon the planetary surface represented. The shadows normally follow the English convention of top-left lighting <https://en.wikipedia.org/wiki/Top-left_lighting> in which the light source is placed near the upper-left corner of the map. If the map is oriented <https://en.wikipedia.org/wiki/Map#Orientation_of_maps> with north at the top, the result is that the light appears to come from the north-west. Many people have pointed out that this is unrealistic for maps of the northern hemisphere, because the sun does not shine from that direction, and they have proposed using southern lighting. However, the normal convention is followed to avoid multistable perception <https://en.wikipedia.org/wiki/Multistable_perception>illusions (i.e. crater/hill confusion).[2] <https://en.wikipedia.org/wiki/Terrain_cartography#cite_note-2> On Thursday, November 17, 2016 at 7:53:17 AM UTC-8, Anders Hedelund wrote: > > Can anyone explain why the relief layers are made with hill shades as if > the sun is shining from the north? > > All slopes are dark grey on the south side. See this example with hill > shades + contour lines to give the elevation.. > . > Weird! > -- You received this message because you are subscribed to the Google Groups "Osmand" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
