[OSM-talk] Lakes and relations, what did I break?

[Robert Vollmert]

On Apr 17, 2008, at 01:26, Dermot McNally wrote:

> To anyone who can show me what I broke:
>
> http://geo.topf.org/comparison/index.html?mt0=mapnik&mt1=tah&x=971&y=657&z=11

[...]

> So I decided to fix them. Rather than follow my usual practice of
> representing islands in lakes as land at layer 1 I decided to use
> relations to model them as holes in the water. Something has gone
> wrong, though, as can be seen from the rendered output, but my data
> looks clean to me in the editor and I think I've followed the
> guidelines on polygons with holes. (Though the lakes do have quite a
> few nodes, so maybe I'm just putting too much load on the T at H
> clients).

Perhaps it's because the holes aren't oriented counter-clockwise? It's  
possible that osmarender still relies on orientation for rendering  
multipolygons.

Cheers
Robert