2 ms·

I thought all maps were drawn using web Mercator and that things were simply not large enough to be really distorted. Does gmaps and company do projected render

• sebstefan 3y ago
  They do, if you zoom out they're a mercator that wraps around, but when they give you latitude and longitude instead of x and y, you're getting the real sphere stuff
• samstave 3y ago
  I used to know a lot more about rendering than I do today, but (forgive me if this sounds stupid) - I wonder if you could add to a gps coordinate area (say 1 sq. km. to also include that patche's NORMAL from the surface of the globe that you're projecting your map to, and have the 1km tile's image adjusted based on a orthographic view from that tile's NORMAL, so effectively - you're projecting each 1k square more directly from areal imagery? Or is this already considered in modern projection methods?
  • mikhailfranco 3y ago
    This is already mentioned in the other comments, as the latitudinal correction to longitudinal dimension [i.e. use cos(latitude) as a scale for EW distances]. I call this the tangent-plane projection (which hints at your picture), where distances can be simply calculated by 2D Pythagoras in the EW-scaled coordinates. I recently discovered it is more often known as Equirectangular Projection: https://en.wikipedia.org/wiki/Equirectangular_projection https://en.wikipedia.org/wiki/Equirectangular_projection More details at this excellent resource for GIS coordinate geometry: https://www.movable-type.co.uk/scripts/latlong.html https://www.movable-type.co.uk/scripts/latlong.html
• modeless 3y ago
  Google Maps on web uses perspective projection, unless WebGL is disabled in your browser. Zoom out and see!