I'm not using the OpenStreetMap data but am rendering and querying lots of complex lake polygons with multiple outer rings (basins) and inner rings (islands). You need not do anything special. Sounds like a data production problem more so than a MapServer bug. Here's a sample:
http://maps.dnr.state.mn.us/cgi-bin/mapserv56?mode=map&map=/usr/local/mapserver/apps/mr/landview/landview.map&mapext=523963.26347152865+5289818.927668251+570217.999745758+5313957.83079347&mapsize=1006+525&layers=lakes+roads+bdry_munipy3&layer=bdry_statepy2&map.imagetype=aggpng24 All the lakes are multi-polygons... For example, if islands are represented as individual features and not inner rings of lake polygons then you might be running into draw order issues. MapServer renders the features in the order they show up in the shapefile. I suppose it's possible then that islands might be getting drawn before the lake (which has no holes). If that's the case (try drawing outlines only and no fill) then you'd need to sort the data based on some sort of land vs. water attribute so that lakes are drawn first then the islands on top. >>> On 10/21/2009 at 12:33 AM, in message <2349cc72a0b01c4faa4ffae6c735e1dde29...@enerasrv01.enera.local>, "Lars Westerlind" <lars.westerl...@enera.se> wrote: > So, > How is the lack of response to be interpreted? Nobody render islands in > lakes? Everybody make their own data extracts? Or there are other (for me) > hidden sources of information? > > /Lars > > > -----Ursprungligt meddelande----- > Från: mapserver-users-boun...@lists.osgeo.org > [mailto:mapserver-users-boun...@lists.osgeo.org] För Lars Westerlind > Skickat: 19 October 2009 11:43 > Till: mapserver-users@lists.osgeo.org > Ämne: [mapserver-users] Shapefiles with islands > > Hi, > I wonder if anyone renders islands in lakes? I use OpenStreetMap Data, > where lakes are tagged as multipolygons, with islands as inner polygons. > The source I use, mainly the "Mapserver recommended" cloudmade make > simple extracts where those inner polygons are simply skipped, AFAIU. > Looks rather funny for islands that are large enough to keep some > roads... > > So, what is recommended? Should I make my own OpenStreetMap extracts for > this purpose? Or does anyone have any other good sources? > > BTW, > Do I understand correctly that multipolygon files must be converted in > order to be possible to handle by mapserver? I mean, inner polygons > should have at least an extra column in the DBfile, telling it's level, > or such? > > Regards, > Lars > > > _______________________________________________ > 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
