Hello, I have added a WMS server as a data store to my GeoServer, mainly because I was planning to use the integrated GWC to cache the tiles from the cascaded WMS. I was expecting GeoServer to display exactly the same tiles I get when I request them directly from the remote WMS, but the tiles I receive from GeoServer are distorted (meaning: ugly!).
( This question <http://osgeo-org.1560.n6.nabble.com/cascading-WMS-rendering-problem-td3793876.html> seems to address a similar problem, but I'm not sure if it's really the same problem because the links there aren't working anymore! Also, it doesn't seem to be a file format issue in my case.) These are requests to the original WMS server (first one jpeg, second one png): http://ows.terrestris.de/osm-basemap/service?LAYERS=OSM-WMS-Deutschland&SRS=EPSG%3A31467&FORMAT=image%2Fjpeg&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&BBOX=3474387.6290625,5526143.6123375,3474554.910375,5526310.89365&WIDTH=256&HEIGHT=256 <http://ows.terrestris.de/osm-basemap/service?LAYERS=OSM-WMS-Deutschland&SRS=EPSG%3A31467&FORMAT=image%2Fjpeg&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&BBOX=3474387.6290625,5526143.6123375,3474554.910375,5526310.89365&WIDTH=256&HEIGHT=256> http://ows.terrestris.de/osm-basemap/service?LAYERS=OSM-WMS-Deutschland&SRS=EPSG%3A31467&FORMAT=image%2Fpng&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&BBOX=3474387.6290625,5526143.6123375,3474554.910375,5526310.89365&WIDTH=256&HEIGHT=256 <http://ows.terrestris.de/osm-basemap/service?LAYERS=OSM-WMS-Deutschland&SRS=EPSG%3A31467&FORMAT=image%2Fpng&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&BBOX=3474387.6290625,5526143.6123375,3474554.910375,5526310.89365&WIDTH=256&HEIGHT=256> Now, my GeoServer isn't publicly available, so I cannot link directly to the tiles I receive, but this is what they look like for MY_GEOSERVER_URL?REQUESTS_FROM_ABOVE : http://i47.tinypic.com/2v8pdzt.jpg <http://i47.tinypic.com/2v8pdzt.jpg> http://i47.tinypic.com/67jf9t.png <http://i47.tinypic.com/67jf9t.png> (Streets look "fat", labels are bigger, some labels are missing completely...) I checked my GeoServer's logs to find a clue about what was causing the rendering difference, and I found out that GeoServer is actually issuing this request for the above tile: http://ows.terrestris.de/osm-basemap/service?SERVICE=WMS&LAYERS=OSM-WMS-Deutschland&FORMAT=image%2Fpng&TRANSPARENT=FALSE&HEIGHT=266&BGCOLOR=0xFFFFFF&REQUEST=GetMap&BBOX=3474381.4213575437,5526136.751189917,3474561.771522583,5526317.101354956&WIDTH=266&STYLES=&SRS=EPSG:31467&VERSION=1.1.1 <http://ows.terrestris.de/osm-basemap/service?SERVICE=WMS&LAYERS=OSM-WMS-Deutschland&FORMAT=image%2Fpng&TRANSPARENT=FALSE&HEIGHT=266&BGCOLOR=0xFFFFFF&REQUEST=GetMap&BBOX=3474381.4213575437,5526136.751189917,3474561.771522583,5526317.101354956&WIDTH=266&STYLES=&SRS=EPSG:31467&VERSION=1.1.1> So apparently it is not just handing my request through to the original WMS, but instead it requests a larger tile (266x266 instead of the original 256x256), and receives an "ugly" tile from the original WMS! (Then it resizes the tile to the correct size and compresses it a little more, but that's not what causes the ugliness.) Then I tried to be clever by requesting a 246x246 tile from my GeoServer, leading GeoServer to request the following 256x256 tile from the original WMS: http://ows.terrestris.de/osm-basemap/service?SERVICE=WMS&LAYERS=OSM-WMS-Deutschland&FORMAT=image%2Fpng&TRANSPARENT=FALSE&HEIGHT=256&BGCOLOR=0xFFFFFF&REQUEST=GetMap&BBOX=3474487.279063145,5526130.216763615,3474661.094801882,5526304.032502458&WIDTH=256&STYLES=&SRS=EPSG:31467&VERSION=1.1.1 <http://ows.terrestris.de/osm-basemap/service?SERVICE=WMS&LAYERS=OSM-WMS-Deutschland&FORMAT=image%2Fpng&TRANSPARENT=FALSE&HEIGHT=256&BGCOLOR=0xFFFFFF&REQUEST=GetMap&BBOX=3474487.279063145,5526130.216763615,3474661.094801882,5526304.032502458&WIDTH=256&STYLES=&SRS=EPSG:31467&VERSION=1.1.1> Which is, again, an ugly tile. (Maybe because the bbox is different from the one used above, because it's created by enlarging a 246x246 box? This kind of issue makes me think of GWC, but it's a total guess.) Does anyone have any idea how (or if!) I can get the desired "nice" tiles from this WMS when using it as a data store in GeoServer? Is there any way for me to "tell" GeoServer to just hand the request it receives for the cascaded layer through to the original WMS, instead of asking for a slightly larger tile (as that results in distorted/ugly tiles)? Thanks a lot in advance! -- View this message in context: http://osgeo-org.1560.n6.nabble.com/Rendering-problem-distortion-with-cascaded-WMS-tp5007406.html Sent from the GeoServer - User mailing list archive at Nabble.com. ------------------------------------------------------------------------------ Don't let slow site performance ruin your business. Deploy New Relic APM Deploy New Relic app performance management and know exactly what is happening inside your Ruby, Python, PHP, Java, and .NET app Try New Relic at no cost today and get our sweet Data Nerd shirt too! http://p.sf.net/sfu/newrelic-dev2dev _______________________________________________ Geoserver-users mailing list Geoserver-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geoserver-users
