<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
Hi Andreas,<br>
<br>
I think QGIS Server has to use the rendered geometries to identify
Feature.<br>
Is it possible to get the point layer to polygon rendred layer ?<br>
<br>
Regards,<br>
René-Luc<br>
<br>
<div class="moz-cite-prefix">Le 12/04/2019 à 15:43, Andreas Neumann
a écrit :<br>
</div>
<blockquote type="cite"
cite="mid:4a6ec21f5bbc102d213b2452a457d23a@carto.net">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<p>Hi,</p>
<p>I'd like to discuss an issue with GetFeatureInfo that we have
with point symbols.</p>
<p>(Point) symbols can have different sizes (sometimes rather
large), different anchor points and sometimes even with offset
away from the original feature geometry. Often, the rendering of
the point symbol differs substantially from the original point
geometry.</p>
<p>Now, our issue is that GetFeatureInfo often fails miserably in
such cases. People try to click on the visible symbol, which
doesn't correspond to the original geometry.</p>
<p>One such example WMS:</p>
<p><a class="moz-txt-link-freetext" href="https://services.geo.zg.ch/ows/Abfallsammelstellen">https://services.geo.zg.ch/ows/Abfallsammelstellen</a></p>
<p>The symbols are rather large, but the anchor point is at the
bottom of the symbol. Users now think that they can click
anywhere on the symbol, but in fact they can only click on the
original geometry at the very bottom of the symbol, taking into
account the FI_POINT_TOLERANCE parameter.</p>
<p>Things get even worse when one wants to identify points that
are displayed using the point displacement renderer. There,
GetFeatureInfo is only sensitive on the center point, and not at
all at the rendered points at a completely different position.</p>
<p>Now my question: could we improve QGIS server that
GetFeatureInfo responds to the bounding boxes of the rendered
geometries (as opposed to the raw geometries), taking into
account sizes, offsets, etc.</p>
<p>Would this be technically possible? </p>
<p>Would others also think that this is useful to have?</p>
<p>Or would this even contradict OGC standards?</p>
<p>Do other WMS servers implement such behaviors (Geoserver, UMN)?</p>
<p>Thanks for the discussion,</p>
<p>Andreas</p>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
QGIS-Developer mailing list
<a class="moz-txt-link-abbreviated" href="mailto:QGIS-Developer@lists.osgeo.org">QGIS-Developer@lists.osgeo.org</a>
List info: <a class="moz-txt-link-freetext" href="https://lists.osgeo.org/mailman/listinfo/qgis-developer">https://lists.osgeo.org/mailman/listinfo/qgis-developer</a>
Unsubscribe: <a class="moz-txt-link-freetext" href="https://lists.osgeo.org/mailman/listinfo/qgis-developer">https://lists.osgeo.org/mailman/listinfo/qgis-developer</a></pre>
</blockquote>
<br>
</body>
</html>