Monier Clement wrote: Hi,
There is bigger than tiny difference in extents in epsg:4326 and in epsg:3785. The latter is using meters as an unit. I had a try with Finland polygon and here are the results: D:\TEMP>ogrinfo -summary Finland_WGS84.shp Finland_WGS84 Feature Count: 1 Extent: (19.648331, 59.804989) - (31.587299, 70.079422) D:\TEMP>ogr2ogr -f "ESRI Shapefile" -s_srs epsg:4326 -t_srs epsg:900913 Finland_ Spherical.shp Finland_WGS84.shp D:\TEMP>ogrinfo -summary Finland_Spherical.shp Finland_Spherical Feature Count: 1 Extent: (2187242.167179, 8356448.200347) - (3516282.078834, 11094615.004724) -Jukka- > Hi, > > I got the map extent from shpinfo. > Beside, I know that there should only be a tiny difference > between coordinates in latlon-wgs84 (data proj) and "web > spherical mercator" (map proj). > > You'll find the whole test-case files as attachement. > > Here's the command line to get the map : > C:\ms4w\tools\mapserv\shp2img -m > C:\ms4w\apps\gmap\htdocs\test.map -o test.png -l layer1 -i agga > > Thanks > > Clément > > > -----Message d'origine----- > De : Rahkonen Jukka [mailto:[EMAIL PROTECTED] > Envoyé : lundi 27 octobre 2008 12:46 > À : Monier Clement; mapserver-users@lists.osgeo.org Objet : > VS: [mapserver-users] projection = geographer's pain > > Hi, > > Have you double-checked that your map extent correspods with > the map projection? > Or if you could send your whole mapfile I am pretty sure that > you will get a final answer to your problem. > > -Jukka Rahkonen- > > > -----Alkuperäinen viesti----- > > Lähettäjä: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] Puolesta Monier > > Clement > > Lähetetty: 27. lokakuuta 2008 13:39 > > Vastaanottaja: 'Pietro Giannini'; mapserver-users@lists.osgeo.org > > Aihe: RE: [mapserver-users] projection = geographer's pain > > > > > > 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 > > : mapserver-users@lists.osgeo.org 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 > > > mapserver-users@lists.osgeo.org > > > http://lists.osgeo.org/mailman/listinfo/mapserver-users > > > > > > > > > _______________________________________________ > > mapserver-users mailing list > > mapserver-users@lists.osgeo.org > > http://lists.osgeo.org/mailman/listinfo/mapserver-users > > > > _______________________________________________ > > mapserver-users mailing list > > mapserver-users@lists.osgeo.org > > http://lists.osgeo.org/mailman/listinfo/mapserver-users > > > _______________________________________________ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users