Hi Jonathan,
Thanks for the clear images; those help illustrate the issue quite
nicely!
As some good news, I can explain the issue, hopefully provide a
work-around (and a diagnosis step).
With 'large' polygons, there is a corner case where it becomes
challenging to know whether or not the desired polygon crosses the
anti-meridian or not. For your second case, the query re-writer
uses Spatial4J and assumes that the connections between the upper
left and right corners goes the other way around the planet. That's
why the result set seems to flip.
Incidentally, for BBOX queries, there's no such confusion and hence
those work just fine.
The solution is to add additional way points so that successive
coordinates have a difference in longitude less than 180 degrees.
As a debugging step, check out the GeoMesa query explainer:
http://www.geomesa.org/documentation/user/datastores/explaining.html
http://www.geomesa.org/documentation/user/geoserver.html#geoserver-explain-query
I think the filter re-writing would have already happened. That'd
give some insight into whether or not GeoMesa has flipped the query
around.
Cheers,
Jim
On 12/19/2017 05:09 PM, Jonathan Meyer wrote:
I am using Geomesa with a Cassandarda data
store. I have come across a potential issue that I’m not sure
how to deal with and am hoping someone may be able to shed
some light. I have a front end web app using leaflet to
display point data queried from Geoserver. So I am using the
Geomesa Cassandra plugin to geoserver. I have an edge case
where if a user enters a very large (80% of the world) polygon
search area, the search results will return all the points
outside the polygon and not inside the polygon. Using a BBox
instead of a polygon in the same approximate area will return
all the points within the bbox as expected. Drawing a polygon
that is say 60% of the world will also return expected
results. There seems to be some point where polygon searches
don’t return what is expected. The only thing that changes
in these searches is the shape or size of the geometry.
Any help or suggestions greatly
appreciated.
See the below images as examples:
Jonathan Meyer
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