OpenStreetMap, an open source compeditor to Google Maps does a similar 'split the word into tiles'. This is how they do it:<p><a href="http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames" rel="nofollow">http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames</a>
<i>If you've ever done any computer programming, you know that the top left of the screen is considered the origin</i><p>If you've ever done any OpenGL programming, you know that the bottom left of the screen is considered the origin
The reasons he states is why Miller (EPSG 54003) is a better projection. Not really a significant increase in complexity either.<p><a href="http://mathworld.wolfram.com/MillerCylindricalProjection.html" rel="nofollow">http://mathworld.wolfram.com/MillerCylindricalProjection.htm...</a>
Nice article, I, too, hadn't noticed the change in scale just by panning around.<p>The Google LatLong blog (<a href="http://google-latlong.blogspot.com/" rel="nofollow">http://google-latlong.blogspot.com/</a>) is packed with information related to Google Maps, and the maps API Google Group also is.<p>There's lots of talk about the Mercator projection on the list, tradeoffs, pros, cons, etc. So there really was no need to read the obfuscated code. Also, I'm not sure if "ease of implementation" was really what had them choose this projection, so it wouldn't hurt to dig around a little bit more before saying stuff like that, I think.<p>Still, pretty good stuff for people that want to know a bit more about how Google Maps work.
Projects such as OpenStreetMap make me wonder: isn't there a community-driven, open-source project that allows to do all this <i>offline</i>? In general, could anyone point me to offline alternatives, where you simply download all the data? In some situations using a static snapshot could prove good enough.
I guess the Cartographers for Social Equality aren’t too happy with Google Maps :)<p><a href="http://www.youtube.com/watch?v=n8zBC2dvERM" rel="nofollow">http://www.youtube.com/watch?v=n8zBC2dvERM</a>
What I like about this is that its a special case of BSP tree projected onto the sphere. If you think of the tiles as projected half-spaces...<p>In other words if you look through the details of projection and coordinate systems the spacial partitioning scheme used is the familiar BSP tree.<p>I'm going to remember this the next time someone tries to tell me they can't handle large open areas effectively... "what, you mean like THE WHOLE PLANET!!111 lolz"<p>:D
I had not noticed that the scale bar on Google Maps constantly changes as you scroll around (not just zoom in and out) due to the Mercator projection. Interesting article.
The Mercator projection is useful to navigators on high seas, but nowadays, that's just irrelevant. De-zoom and look at the size of Groenland or Antarctica to see :)