[OSM-talk] area_with_holes as alternative to multipolygon relation

[Robert Vollmert]

On Mar 12, 2008, at 11:47, Dirk-Lüder Kreie wrote:
> Robert Vollmert schrieb:
>>
>> Certainly the "multipolygons" which are just a polygon with several
>> ways making up the border are broken and should be fixed. I hope to
>> get a handle on these.
>
> What do we do with ways that get excessively long if we combine the
> polygon border? (some really big forests and lakes come to mind)

I don't know -- create a new relation type specifically for this? As  
far as I can tell, the fact that putting multiple border ways in a  
multipolygon relation may have worked is due to the implementation of  
multipolygons in the renderers. But this isn't what the relation is  
meant to do.

There could be a general purpose relation for collecting several ways  
that meet at the ends into one virtual longer way. Say type=long_way,  
with roles part_1,...,part_n (relation members aren't ordered). And  
if this forest has a hole, put the long_way relation in a  
multipolygon relation.

Cheers
Robert