[Talk-GB] Windermere and Rydal Water - missing

[Dave F.]

On 24/03/2013 13:13, Roger Calvert wrote:
> The problem seemed to be that the boundary of Rydal Water had been 
> split into 3 parts which, although they were assigned to the Rydal 
> Water relation, had no tags of their own. Potlatch was not identifying 
> the area as water.
>
> I have joined them up, and given them the natural=water tag. Potlatch 
> now recognises Rydal Water as a lake. I chose this approach after 
> reviewing how Grasmere was tagged. I assume something similar happened 
> to Windermere, but have not time to investigate now.
>
> If anyone is not happy with what I have done, let me know - there are 
> always subtleties of these things to be learnt.

Please read the link on multipolygons:
http://wiki.openstreetmap.org/wiki/Multipolygon

By making your edits you now incorrectly made Rydal Water a part of the 
River Rothay multi-polygon.

The natural=water tag is included in the multi-polygon. Adding it to the 
way is an unnecessary & confusing duplication. To avoid this confusion I 
often put a note tag explaining where the data is stored.

Remember that just because you think the potlach editor is displaying 
data incorrectly it doesn't actually mean the the data is wrong. In this 
example the lake doesn't have to be shaded blue to be correct. It's how 
the renderers handle it that matters.

ASAIK, there's nothing specifically wrong to to have ways split like 
this. In fact it was encouraged for long, many noded ways which were 
causing certain problems (I forget the details).

Dave F.





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