[josm-dev] Wireframe saves the day for a complex multipolygon

[Matthias Julius]

Frederik Ramm <frederik at remote.org> writes:

> Hi,
>
> Marko Mäkelä wrote:
>>> Btw. outer polygons are not used correctly in the lake, when there is
>>> small lake inside of island on the big lake, the small lake shouldn't
>>> be part of the big lake multipolygon.
>> 
>> I followed the example on the wiki page
>> http://wiki.openstreetmap.org/wiki/Relation:multipolygon
>> which does suggest that lakes within islands can be defined as role=outer:
>
> I wrote that Wiki page and I still think it makes sense. This method 
> (where there may be additional outers inside inners) also conforms to 
> the OGC "simple features" geometry rules, i.e. "everybody does it".

This might be correct use of the Multipolygon relation, but is the lake
on the island really part of the outer lake?

If it is a separate lake with its own name I would say it should be a
separate object for OSM.

Matthias