Lars,<br><br>Can you give us an example, or extract of, a location where the rendering problems are? Having trouble with some of the terminology too - multipolygons are multipart polygons, each polygon of which is a single part but can be a donut with multiple holes?<br>
<br>Steve<br><br><br><br><br><div class="gmail_quote">2009/10/22 Lars Westerlind <span dir="ltr"><<a href="mailto:lars.westerlind@enera.se">lars.westerlind@enera.se</a>></span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br>
Hello Steve,<br>
Thanks for your attention.<br>
I fully agree that there is nothing yet indicating a bug in mapserver. The shapefiles I've inspected just lack the inner polygons, which certainly are available when editing open street data at their site; Mapserver can't guess, can it?<br>
<br>
But if I got it right you answered a question I've got but not expressed. You say Mapserver would handle a multipolygon shapefile correctly, that is, there would be no need to make special entries in the mapfile for the islands; they would just be drawn as holes in the lakes automatically? I was thinking I had to draw lakes first, and then islands in lakes.<br>
<br>
If so I'm even more curious why nobody have put the pieces together. Maybe it's about competition? I guess I'll have to leave the issue until when/if I'll get time to do learn how to do my own data extracts, or other sources will be available.<br>
<br>
/Lars<br>
<br>
<br>
-----Ursprungligt meddelande-----<br>
Från: Steve Lime [mailto:<a href="mailto:Steve.Lime@dnr.state.mn.us">Steve.Lime@dnr.state.mn.us</a>]<br>
Skickat: 21 October 2009 17:11<br>
Till: Lars Westerlind; <a href="mailto:mapserver-users@lists.osgeo.org">mapserver-users@lists.osgeo.org</a><br>
Ämne: Re: SV: [mapserver-users] Shapefiles with islands<br>
<div><div></div><div class="h5"><br>
I'm not using the OpenStreetMap data but am rendering and querying lots<br>
of complex lake<br>
polygons with multiple outer rings (basins) and inner rings (islands).<br>
You need not do anything<br>
special. Sounds like a data production problem more so than a MapServer<br>
bug. Here's a sample:<br>
<br>
<br>
<a href="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" target="_blank">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</a><br>
<br>
All the lakes are multi-polygons...<br>
<br>
For example, if islands are represented as individual features and not<br>
inner rings of lake<br>
polygons then you might be running into draw order issues. MapServer<br>
renders the features<br>
in the order they show up in the shapefile. I suppose it's possible<br>
then that islands might<br>
be getting drawn before the lake (which has no holes). If that's the<br>
case (try drawing<br>
outlines only and no fill) then you'd need to sort the data based on<br>
some sort of land<br>
vs. water attribute so that lakes are drawn first then the islands on<br>
top.<br>
<br>
>>> On 10/21/2009 at 12:33 AM, in message<br>
<2349CC72A0B01C4FAA4FFAE6C735E1DDE293AD@enerasrv01.Enera.local>, "Lars<br>
Westerlind" <<a href="mailto:lars.westerlind@enera.se">lars.westerlind@enera.se</a>> wrote:<br>
> So,<br>
> How is the lack of response to be interpreted? Nobody render islands<br>
in<br>
> lakes? Everybody make their own data extracts? Or there are other<br>
(for me)<br>
> hidden sources of information?<br>
><br>
> /Lars<br>
><br>
><br>
> -----Ursprungligt meddelande-----<br>
> Från: <a href="mailto:mapserver-users-bounces@lists.osgeo.org">mapserver-users-bounces@lists.osgeo.org</a><br>
> [mailto:<a href="mailto:mapserver-users-bounces@lists.osgeo.org">mapserver-users-bounces@lists.osgeo.org</a>] För Lars Westerlind<br>
> Skickat: 19 October 2009 11:43<br>
> Till: <a href="mailto:mapserver-users@lists.osgeo.org">mapserver-users@lists.osgeo.org</a><br>
> Ämne: [mapserver-users] Shapefiles with islands<br>
><br>
> Hi,<br>
> I wonder if anyone renders islands in lakes? I use OpenStreetMap<br>
Data,<br>
> where lakes are tagged as multipolygons, with islands as inner<br>
polygons.<br>
> The source I use, mainly the "Mapserver recommended" cloudmade make<br>
> simple extracts where those inner polygons are simply skipped,<br>
AFAIU.<br>
> Looks rather funny for islands that are large enough to keep some<br>
> roads...<br>
><br>
> So, what is recommended? Should I make my own OpenStreetMap extracts<br>
for<br>
> this purpose? Or does anyone have any other good sources?<br>
><br>
> BTW,<br>
> Do I understand correctly that multipolygon files must be converted<br>
in<br>
> order to be possible to handle by mapserver? I mean, inner polygons<br>
> should have at least an extra column in the DBfile, telling it's<br>
level,<br>
> or such?<br>
><br>
> Regards,<br>
> Lars<br>
><br>
><br>
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</div></div></blockquote></div><br>