Then your map is distorted, Google maps uses EPSG:3587 (or epsg:900913 if
you are using old terms) and that is a web Mercator projection which has an
increasing E-W distortion as you move away from the equator. The other
possible issue is that depending on how you projected your point into a
local CRS and then projected the buffer back to WGS there is a chance to
introduce inaccuracies into the process. Unless you just guessed a degrees
to metres conversion factor that seemed about right for one of your points?
Anyway, on that map circular buffers should look stretched out like yours
do.
Ian
On 23 October 2017 at 16:26, Alexandre Barboza <ambarb...@hotmail.com>
wrote:
> Hi Ian
> Thanks for your answer!
> We are using EPSG 4326 projection, and display it on Google Maps API,
> always tiled. When we open it on QGIS the buffer size dos not is the same
> that we specified on X axis and Y axis. sample: when we do a buffer of 500
> meters (radius) the x axis result about 450 meters and Y axis have 500
> meters.
> On this url http://www.ide.emplasa.sp.gov.br/geoserver/emplasa/TESTE_
> BUFFER_GEOWGS84/wms? we did a buffer with distance of 500 meters using
> EPSG 4326 layer
>
>
>
>
> On our website the buffer url is
> http://www.ide.emplasa.sp.gov.br/geoserver/emplasa/
> LOCALIDADES_EMPLASA_SAUDE/wms?styles=SYS_SIMM_ESTILO_BUFFER_
> DINAMICO_THE_GEOM&env=polygonStrokecolor:003300;polygonFillcolor:FF0000;
> bufferSize:500&CQL_FILTER=NOME_MUNIC%20LIKE%20%27Diadema%27&service=WMS&
> version=1.1.1&request=GetMap&layers=emplasa:LOCALIDADES_
> EMPLASA_SAUDE&format=image/png&tiled=false&TRANSPARENT=
> true&srs=EPSG:900913&bbox=-5190379.968676608,-2727273.1692150906,-5187933.
> 9837714825,-2724827.184309963&width=256&height=256
>
> ------------------------------
> *De:* Ian Turton <ijtur...@gmail.com>
> *Enviado:* segunda-feira, 23 de outubro de 2017 12:49
> *Para:* Alexandre Barboza
> *Cc:* geoserver-users@lists.sourceforge.net
> *Assunto:* Re: [Geoserver-users] Buffer error
>
> TBH that looks like a projected (EPSG:3857) map to me, so I would expect
> some distortion. You probably don't want to use tiles for that layer
> either, or maybe experiment with gutters to see if that helps with the edge
> cases.
>
> Please show the actual request to the buffer process so we can test it and
> see if there is any distortion when there is no projection.
>
> Ian
>
>
>
>
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