[OSM-dev] Looking for guidance on interpreting multipolygon relations
mdeen at xs4all.nl
Sat Nov 3 09:49:16 GMT 2007
Frederik Ramm wrote:
>> As a side note, can someone explain what a multipolygon is good for and
>> in what circumstances you would want to use it?
> It is used for areas with holes in them.
That is a bit terse. With an explanation like that I still don't know
what it is good for (and judging from what I see on the map I'm not the
only one). But Bart mailed me a good example which I think should be
added to the wiki page about mulipolygon.
1) it should not be applied to ways, only to areas?
2) it should not be used to single areas that are contiguous?
ex 1): I've seen multiploygons tying the left and right way of a
motorway together, I assume that's false.
ex 2): I've seen multipolygons applied to a natural=water where a lot of
ways were double and they were connected with a multipolygon (making the
T&H renderer do silly things)
Additionaly, the discusstion Bart started needs to go on the wiki page,
because those are exacly my questions now I know what it is good for.
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