[Tagging] natural=bay as nodes are evil

Christoph Hormann chris_hormann at gmx.de
Mon Oct 27 15:24:39 UTC 2014

On Monday 27 October 2014, moltonel 3x Combo wrote:
> >
> > This extremely simple approach will probably result in reasonable
> > polygons for label placement in more than half the cases.  You can
> > easily improve the algorithm of course to properly deal with
> > various special cases, in particular the case of small islands
> > within a bay deserves consideration.
> That's a very fragile algorythm.

Have you tried it?

On the contrary - due to its simplicity it is a very robust algorithm, 
it will hardly ever generate something completely wrong and fail 
gracefully in difficult cases.  And as said it is strait away to extend 
this approach to specifically take care of cases where it does not work 
so well.

> [...] And until you get something working
> reasonably well upstreamed in all data consumers, we mappers should
> bite the bullet and map bays as areas 

No, that is not how OSM works.  The mappers can choose a method to map 
they deem appropriate - which in this case quite clearly is nodes (less 
than 0.5 percent ways and relations according to taginfo).  If you want 
to get the mappers to change their mapping you need to convince them 
that it is better to do so and just making it easier for those 
rendering maps is not a convincing argument, even in cases where unlike 
here there is no additional work involved.  Of course by not rendering 
bays mapped as nodes in the standard style you could 'encourage' 
mappers to change their approach.  This however would be mapping for 
the renderer which is generally frowned upon.

I can't help but notice that in the whole discussion here no argument 
has been put formward indicating a practical advantage of bays mapped 
as polygons other than the ease of rendering labels.

> (in other words, not treat them
> any different than any other area-like obbjects in osm).

You mean like place=town, place=city etc?


Christoph Hormann

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