[OSM-talk] Mulltipolygons and Mapnik

[Cartinus]

On Saturday 31 May 2008 19:07:31 Dermot McNally wrote:
> Multipolygons with untagged inner elements (per wiki): Don't render on
> Mapnik Multipolygons with inner elements tagged as the outer ones: Do
> render on Mapnik
>
> At this point, we _could_ define the current behaviour as a standard,
> update the wiki and change whatever data isn't compliant.
>
> *or* we can see if the Mapnik brains are willing/able to support
> multipolygons according to the current wiki instructions.

Here in Utrecht I have drawn a building with a "courtyard". The inner polygon 
does not have any tags.
* The hole shows OK in T at H/Osmarender
http://tile.openstreetmap.nl/?zoom=17&lat=52.08396&lon=5.10485&layers=000000BF
* The hole does not show in the osm2pgsql/Mapnik generated tiles from 
openstreetmap.org.
http://tile.openstreetmap.nl/?zoom=17&lat=52.08396&lon=5.10485&layers=00000B0F
* The hole shows OK in the osm2pgsql/Mapnik generated tiles from 
openstreetmap.nl.
http://tile.openstreetmap.nl/?zoom=17&lat=52.08396&lon=5.10485&layers=B000000F

I think openstreetmap.nl uses a newer version of osm2pgsql than the main site. 
If that is true than it is just a question of time till multipolygons defined 
as per wiki description will show OK on the main site too.

A multipolygon with the same tags on inner and outer shows OK at all three:
http://tile.openstreetmap.nl/?zoom=15&lat=52.05845&lon=5.16772&layers=000000BF
http://tile.openstreetmap.nl/?zoom=15&lat=52.05845&lon=5.16772&layers=00000B0F
http://tile.openstreetmap.nl/?zoom=15&lat=52.05845&lon=5.16772&layers=B000000F


-- 
m.v.g.,
Cartinus