[OSM-dev] Tagging of multipolygons with holes within holes

[Peter Wendorff]

Hi Igor.
But if we're talking about topology, why (as I understand it) are you 
trying to force topological stuff in the multipolygon RELATION?
That solves, well... nearly nothing.
You have to do exactly the same work for any topological issues that are 
not described by a mp relation, e.g. because they aren't multipolygons, 
but distinct buildings, forests, water-surfaces or whatever.
There you have to do exactly what you don't want to do here and where 
you want to have further restriction for multipolygon relations.

I would suggest you to work on the progress towards area types to be 
part of the future api: discussion, decision and implementation.
I would like to see additional topology introduced: along, beneath, .... 
are interesting, but yet difficult to get topological relations for osm 
data users.

But: Keep in mind that editing should not become more difficult for 
mappers. If topology requires to assemble complex relations that's no 
option.

regards
Peter

Am 17.10.2012 12:58, schrieb Igor Brejc:
>
>
> On Wed, Oct 17, 2012 at 10:35 AM, Peter Wendorff 
> <wendorff at uni-paderborn.de <mailto:wendorff at uni-paderborn.de>> wrote:
>
>     And where's the problem?
>     The island is part of the area described by the multipolygon, as
>     every other outer way is, too.
>     It can be handled exactly the same as long as you don't want to do
>     special stuff according to topology, but then again topology is
>     missing for most osm model elements, yet (or: you have to
>     interpret it from the geometry yourself).
>
>
> Yes, the key word is topology. Moving beyond the Painter's algorithm 
> and simple map rendering. Having the ability to do generalization with 
> topology - polygon simplifications, merging of polygons of similar 
> landuse, detecting/removing common edges, displacement, amalgamation 
> etc. All in order to produce more useful export data or vector maps. 
> That's what I've been doing for the last couple of months.
>
> Igor

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/dev/attachments/20121017/cee9a3ea/attachment.html>