Thanks for your answers Roger & Pietro. I've followed your advice by trying these 4 test-cases :
1) Map proj set to : "init=epsg:3785" (web spherical Mercator, manually added into espg file) Layer proj set to : "init=epsg:4326" (latlon wgs84, proj system of my shapefiles) => got a blank map 2) Map projection set to : "init=epsg:4326" Layer projection set to : "init=epsg:4326" => got a map 3) Map projection set to : "init=epsg:3785" Layer projection set to : "init=epsg:3785" => got the same map as 2) 4) Map projection set to : "init=epsg:4326" Layer projection set to : "init=epsg:3785" => got a blank map I've also tried with another well-known existing epsg proj-system (instead of the manually-added 3785 code), but got the same results. I've made other attempts by replacing "init=3785" by full description proj-string like "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs no_defs" or "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m [EMAIL PROTECTED] no_defs" But it didn't change anything... It seems that : - a map is drawn only if the map's and layer's proj-systems are the same. - the output projection is always overridden by the shapefile system, no re-projection is done anyway. Let me know if you have any further leads to solve this issue. Thanks for your help Clément -----Message d'origine----- De : [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] De la part de Pietro Giannini Envoyé : vendredi 24 octobre 2008 21:40 À : [email protected] Objet : Re: [mapserver-users] projection = geographer's pain I can confirm that projection is often a pain! However, the problem may be in the projection of the layer. The PROJECTION section in a layer declare the projection of the data source of this layer, while the PROJECTION on the map level is the projection wich you want to show the whole map. So you can overlay more data sources in different projection in a single map. Try to set the layer PROJECTION as "init=epsg:4326". Let us know... ciao ........................... pg -- Pietro Giannini Bytewise srl - Area GIS 41°50'38.58"N 12°29'13.39"E On Ven, Ottobre 24, 2008 16:55, Monier Clement wrote: > Hi, > > > > I'm running MS4W v2.2.8 (including MapServer 5.2) on windows. > > My datasource is shapefiles with WGS84 projection (epsg:4326). > > I would like MapServer to render these data into a "Web (spherical) > Mercator" projected map (epsg:3785) in order to perfectly overlay the > GoogleMaps tile images (for the moment, my maps are slightly shifted > north.) > > > > I've added this string at the end of the file "epsg" in /ms4w/proj/nad : > > <3785> +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 > +y_0=0 +k=1.0 +towgs84=0,0,0,0,0,0,0 +units=m [EMAIL PROTECTED] +no_defs <> > > > > But I don't know how to modify my request and mapfile in order to get the > correct map. > > I've tried many combinations so far but with no success until now. > > > > Do I have to change the projection system of my shapefiles ? > > Is MapServer able to change projection between input and output ? > > > > Request : "&SRS=epsg:3785" > > > > MapFile : > > > > [Map section] > > METADATA > > "wms_srs" "EPSG:4326 EPSG:3785" # is this correct ? > > END > > > > PROJECTION > > "init=epsg:3785" # is this correct ? > > END > > > > [Layer section] > > METADATA > > "wms_srs" "EPSG:3785" # is this correct ? > > END > > PROJECTION > > "init=epsg:3785" # is this correct ? > > END > > > > With these settings, the pictures I got from MapServer are still shifted. > > > > Thanks for your help > > > > Clement > > > > _______________________________________________ > mapserver-users mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/mapserver-users > _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users
