<div dir="ltr">Thanks again for your suggestions, André. Our team is going to review our options and see what approaches we may use for an interim solution, as well as look forward towards more permanent possibilities.<div>
<br></div><div>We are indeed in an area of the world that is challenging with respect to map projections that show large areas. Ideally, we'd be able to freely choose among any of the projections that are intended for polar regions -- including polar projections that are rotated to show our area of interest in an orientation of our choosing (i.e. Alaska at the bottom of the map).</div>
<div><br></div><div>Given the general academic interest in climate change impacts in the Arctic, it might be interesting to see if there are resources that could be applied to addressing this issue across some of the more common tools used for presenting Arctic data on web maps. I will raise that issue with our organization, since our challenges with Arctic/antimeridian map displays are not a problem that are going to go away or solve itself.</div>
<div><br></div><div>Huge thanks,</div><div> - Bruce</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Sun, Oct 27, 2013 at 12:20 PM, André Pirard <span dir="ltr"><<a href="mailto:A.Pirard.Papou@gmail.com" target="_blank">A.Pirard.Papou@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>On 2013-10-27 00:46, Bruce Crevensten
wrote :<br>
</div><div class="im">
<blockquote type="cite">
<div dir="ltr">Andre, Oliver, thanks very much for the responses.
I'll explore alternatives for the project I'm working on.
<div><br>
</div>
<div>Andre, can you give me more detail regarding your idea of
building the picture in two parts? Would that be a MapProxy
configuration, i.e. create two layers with bounding boxes to
prevent the problematic overlap, then add both layers on the
OpenLayers client to yield the desired result? Or are you
thinking of a different approach?</div>
</div>
</blockquote>
<br></div>
I was thinking of not producing an image that crosses the meridian.
OSM tiles are undoubtedly free of that problem, but a larger image
is not, an issue that Oliver put in terms of bounding boxes.<br>
Hence my idea to test if limiting your present display to right near
the meridian is OK and then, indeed, go confidently forward to a
solution like what you describe.<br>
Note that the OSM map itself is not problem free. If you notice that
line splitting <a href="http://www.openstreetmap.org/#map=5/66.267/170.662" target="_blank">Чукотка</a>
and zoom down to its Map data layer, you get a <a href="http://www.openstreetmap.org/#map=19/66.42085/-180.00000&layers=D" target="_blank">never
ending data loading page</a>. JOSM takes a very long time loading
across the line and times out, telling there's no data. Probably an
API problem timed out differently by the client.<br>
I can tell you tackled the trickiest part of the globe: I was there
before ;-)<br>
The best advisors would be the unhappy islanders maybe, if you can
find them ;-)<br>
<br>
Cheers,<br>
<br>
<table>
<tbody>
<tr>
<td>André.</td>
</tr>
</tbody>
</table>
<br>
PS: Curious me extracted the OSM html for <a href="http://www.openstreetmap.org/#map=19/68.97579/-179.99997" target="_blank">rendering
this across the line</a>: as expected, single layer happily mixing
x=0-1 and x=524286-524287, see below.<br>
BTW, wouldn't you be luckier reprojecting EPSG:3338 to OSM's
instead? (Just like me talking English ;-))<div class="im"><br>
<br>
<blockquote type="cite">
<div class="gmail_extra">
<div class="gmail_quote">On Thu, Oct 24, 2013 at 9:22 AM, André
Pirard <span dir="ltr"><<a href="mailto:A.Pirard.Papou@gmail.com" target="_blank">A.Pirard.Papou@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<div>On 2013-10-24 14:01, Oliver Tonnhofer wrote :<br>
</div>
<div>
<blockquote type="cite">
<pre>On 23.10.2013, at 21:37, Bruce Crevensten wrote:
</pre>
<blockquote type="cite">
<pre>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.
Instead of a clean map, I'm seeing extreme distortion around the antimeridian/date line. Screenshot of distortion around antimeridian/date line is here:
</pre>
</blockquote>
<pre>Unfortunately there is no explicit support for handling the antimeridian in MapProxy (yet).
You will get unwanted results as soon as you cross the dateline (and that may happen internally when MapProxy transforms bounding boxes between 3857 and 3338).
</pre>
</blockquote>
</div>
Out of curiosity, I'd like to know the result of the test
I suggested and hence the possibility of the same kludge
as for the unlucky islanders: build the picture in two
parts on each side of that line.<br>
<br>
Cheers,<br>
<br>
<table>
<tbody>
<tr>
<td>André.</td>
</tr>
</tbody>
</table>
<br>
</div>
</blockquote>
</div>
</div>
</blockquote>
<br>
</div><a href="http://www.openstreetmap.org/#map=19/68.97579/-179.99997" target="_blank">http://www.openstreetmap.org/#map=19/68.97579/-179.99997</a><br>
<br>
<div style="" class="leaflet-map-pane"><br>
<div class="leaflet-tile-pane"><br>
<div class="leaflet-layer"><br>
<div class="leaflet-tile-container
leaflet-zoom-animated"><img src=<br>
<a href="http://b.tile.openstreetmap.org/19/524287/121593.png" target="_blank">"http://b.tile.openstreetmap.org/19/524287/121593.png"</a>
style=<br>
"height: 256px; width: 256px;" class=<br>
"leaflet-tile leaflet-tile-loaded" /><img src=<br>
<a href="http://a.tile.openstreetmap.org/19/0/121593.png" target="_blank">"http://a.tile.openstreetmap.org/19/0/121593.png"</a> style=<br>
"height: 256px; width: 256px;" class=<br>
"leaflet-tile leaflet-tile-loaded" /><img src=<br>
<a href="http://a.tile.openstreetmap.org/19/524287/121592.png" target="_blank">"http://a.tile.openstreetmap.org/19/524287/121592.png"</a>
style=<br>
"height: 256px; width: 256px;" class=<br>
"leaflet-tile leaflet-tile-loaded" /><img src=<br>
<a href="http://c.tile.openstreetmap.org/19/0/121592.png" target="_blank">"http://c.tile.openstreetmap.org/19/0/121592.png"</a> style=<br>
"height: 256px; width: 256px;" class=<br>
"leaflet-tile leaflet-tile-loaded" /><img src=<br>
<a href="http://c.tile.openstreetmap.org/19/524287/121594.png" target="_blank">"http://c.tile.openstreetmap.org/19/524287/121594.png"</a>
style=<br>
"height: 256px; width: 256px;" class=<br>
"leaflet-tile leaflet-tile-loaded" /><img src=<br>
<a href="http://b.tile.openstreetmap.org/19/0/121594.png" target="_blank">"http://b.tile.openstreetmap.org/19/0/121594.png"</a> style=<br>
"height: 256px; width: 256px;" class=<br>
"leaflet-tile leaflet-tile-loaded" /><img src=<br>
<a href="http://a.tile.openstreetmap.org/19/524286/121593.png" target="_blank">"http://a.tile.openstreetmap.org/19/524286/121593.png"</a>
style=<br>
"height: 256px; width: 256px;" class=<br>
"leaflet-tile leaflet-tile-loaded" /><img src=<br>
<a href="http://b.tile.openstreetmap.org/19/1/121593.png" target="_blank">"http://b.tile.openstreetmap.org/19/1/121593.png"</a> style=<br>
"height: 256px; width: 256px;" class=<br>
"leaflet-tile leaflet-tile-loaded" /><img src=<br>
<a href="http://c.tile.openstreetmap.org/19/524286/121592.png" target="_blank">"http://c.tile.openstreetmap.org/19/524286/121592.png"</a>
style=<br>
"height: 256px; width: 256px;" class=<br>
"leaflet-tile leaflet-tile-loaded" /><img src=<br>
<a href="http://a.tile.openstreetmap.org/19/1/121592.png" target="_blank">"http://a.tile.openstreetmap.org/19/1/121592.png"</a> style=<br>
"height: 256px; width: 256px;" class=<br>
"leaflet-tile leaflet-tile-loaded" /><img src=<br>
<a href="http://b.tile.openstreetmap.org/19/524286/121594.png" target="_blank">"http://b.tile.openstreetmap.org/19/524286/121594.png"</a>
style=<br>
"height: 256px; width: 256px;" class=<br>
"leaflet-tile leaflet-tile-loaded" /><img src=<br>
<a href="http://c.tile.openstreetmap.org/19/1/121594.png" target="_blank">"http://c.tile.openstreetmap.org/19/1/121594.png"</a> style=<br>
"height: 256px; width: 256px;" class="leaflet-tile
leaflet-tile-loaded" /></div><br>
</div><br>
</div><br>
</div><br>
<br>
</div>
<br>_______________________________________________<br>
MapProxy mailing list<br>
<a href="mailto:MapProxy@lists.osgeo.org">MapProxy@lists.osgeo.org</a><br>
<a href="http://lists.osgeo.org/mailman/listinfo/mapproxy" target="_blank">http://lists.osgeo.org/mailman/listinfo/mapproxy</a><br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div dir="ltr"><div><b>Bruce Crevensten</b></div>
<div><b><br></b></div><div><b>Senior Software Engineer<br></b></div><div><div>(SNAP) Scenarios Network for Alaska & Arctic Planning<br></div></div><div><div><a href="http://www.snap.uaf.edu/" target="_blank">www.snap.uaf.edu</a><br>
</div><div><br></div><div><b>Engineering Coordinator</b></div><div>(ACUASI) Alaska Center for Unmanned Aerial Systems Integration</div>
</div></div>
</div>