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<div class="moz-cite-prefix">On 2013-10-23 21:37, Bruce Crevensten
wrote :<br>
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cite="mid:CA+7ktctqnaCfJLG5k20D3cBE9mbPqe0eO7ihpVFVnvgXiPT8UQ@mail.gmail.com"
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<div>I'm trying to use MapProxy to present OpenStreetMap layers
in a nonstandard projection, EPSG:3338 (Alaska Albers). The
end goal is to use this as a base layer in an app that adds
other layers showing historical sea ice extent around Alaska,
which is why this (or a similar polar projection) is needed.<br>
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<div>Instead of a clean map, I'm seeing extreme distortion
around the antimeridian/date line. Screenshot of distortion
around antimeridian/date line is here:</div>
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<div><a moz-do-not-send="true"
href="https://github.com/ua-snap/mp-config/blob/master/distortion-example.png">https://github.com/ua-snap/mp-config/blob/master/distortion-example.png</a></div>
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OSM is unable to handle lines (what it calls "ways") that cross the
antimeridian. If you try to draw a very small one, it will loop the
other side all around the globe. For that reason, the unlucky people
who happened to have their island across were not able to draw their
coastline and some inside roads in one piece and had in fact to
split their island in two glued pieces.<br>
At first sight, this doesn't look like the reason for such
distortion, but it's a "feature" to keep in mind.<br>
I have seen various programs produce various rendering behaviors
when crossing that line and an idea would be to try displaying a
single side map that stops very near the line to see is the crossing
is the problem.<br>
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Cheers,<br>
<br>
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<td>André.</td>
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