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<p class="MsoNormal"><span style="color:#1F497D">Hi there!<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I tested some more and it seems that this is not only a problem for WMS layers, but for Raster layers as well. Here is an example GeoTiff:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><a href="https://github.com/mapserver/mapserver/files/1047153/test.zip">https://github.com/mapserver/mapserver/files/1047153/test.zip</a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I can warp this to HEALPix using GDAL on the command line:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">gdalwarp -t_srs '+proj=healpix +a=1 +b=1 +wktext' -te -0.5 0.6 0.5 1 test.tiff healpix.tiff<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">The result looks as supposed (see example in the original issue:
<a href="https://github.com/mapserver/mapserver/issues/5437">https://github.com/mapserver/mapserver/issues/5437</a></span><span style="color:black">)</span><span style="color:#1F497D">.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">However, if I let mapserver do the reprojection, the result is distorted (e.g. Libya is missing on the map). This is my layer (except for some metadata):<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">LAYER<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> name "test"<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> status ON<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> type RASTER<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> data "test.tiff"<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> PROJECTION<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> AUTO<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"> END<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">END<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">This is in my epsg file:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><900916> +proj=healpix +a=1 +b=1 <><o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">This is the relevant part of the WMS request:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">...&LAYERS=test&WIDTH=600&HEIGHT=300&SRS=EPSG:900916&BBOX=-0.5,0.6,0.5,1<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">The example test.tiff I linked above covers exactly the area I am requesting to be reprojected to HEALPix. As soon as this input tiff is larger, the reprojection works as supposed. I guess that this is the reason
why I observed the issue with CONNECTIONTYPE WMS first: Here the input data is usually exactly as large as required by the reprojection!<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Where do I have to go bug hunting? Is it a configuration issue? Is it a reprojection issue specific to HEALPix?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Thank you for your support!<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Simon<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b><span lang="DE" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">Von:</span></b><span lang="DE" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> mapserver-users [mailto:mapserver-users-bounces@lists.osgeo.org]
<b>Im Auftrag von </b>Simon.Schneegans@dlr.de<br>
<b>Gesendet:</b> Dienstag, 30. Mai 2017 13:17<br>
<b>An:</b> mapserver-users@lists.osgeo.org<br>
<b>Betreff:</b> [mapserver-users] Reprojection error for CONNECTIONTYPE WMS<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hi there!<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am happily using mapserver to reproject raster data to the
<a href="http://proj4.org/projections/healpix.html">HEALPix projection from proj.4</a>. This works pretty well for local raster sources, however I get severe reprojection problems when using an external WMS as source for my layer.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I reported this issue on Github (<a href="https://github.com/mapserver/mapserver/issues/5437">https://github.com/mapserver/mapserver/issues/5437</a>) but was told to ask here for assistance. Instead of copy-pasting the text from the Github
issue to this mail, I kindly ask you to refer to this Github issue for further information; there I also included several images illustrating the problem.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am looking forward to get any feedback or input that helps me solving this issue!<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you very much!<o:p></o:p></p>
<p class="MsoNormal">Simon<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="DE" style="color:dimgray">——————————————————————————</span><b><span lang="DE" style="font-family:"Arial","sans-serif";color:dimgray;mso-fareast-language:AR-SA"><o:p></o:p></span></b></p>
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<p class="MsoNormal" style="line-height:16.0pt"><span style="font-size:8.5pt;font-family:"Arial","sans-serif";color:dimgray;mso-fareast-language:AR-SA">Simulation and Software Technology | Software for Space Systems and Interactive Visualization | Lilienthalplatz
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><b><span style="font-family:"Arial","sans-serif";color:dimgray;mso-fareast-language:AR-SA">Simon Schneegans</span></b><span style="color:dimgray;mso-fareast-language:AR-SA">, M. Sc.</span><span style="font-size:8.5pt;color:dimgray"><o:p></o:p></span></p>
<p class="MsoNormal" style="line-height:16.0pt"><span lang="EN-GB" style="font-size:8.5pt;color:dimgray">Telephone +49 531 295-2333 | Telefax +49 531 295-12100 |</span><span lang="EN-GB" style="font-size:8.5pt">
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