[Tagging] natural=bay as nodes are evil
moltonel 3x Combo
moltonel at gmail.com
Wed Oct 29 17:12:01 UTC 2014
On 29/10/2014, Richard Z. <ricoz.osm at gmail.com> wrote:
> On Tue, Oct 28, 2014 at 05:21:06PM +0100, moltonel 3x Combo wrote:
>> On 28/10/2014, Richard Z. <ricoz.osm at gmail.com> wrote:
> well even if the issues were nonexistent, mapping the area of a bay seems
> to me like mapping an artificially introduced concept for which there is
> very little real world use or recognition otherwise.
Huh ? Forget about maps and osm for a moment. A bay is "a body of
water mostly surrounded by land". You're "in" a bay, not "at" a bay.
It has a size, it's not a point in space with a buoy marking the spot.
It's an area.
The fact that a lot of sources have simplified it down to a point is
an entirely different issue. But there's no reason that, with modern
tools and manpower, we can't make a better job than those historical
sources. And remember that when you see a rendered bay label, you
don't actually know wether the source (wether it's some vector data or
an idea in the sailor's brain) was an area or a point to begin with.
> Also bays with very
> flat or deep geometry will result in disproportionately small areas so
> mappers may feel compelled to do some ugly workarounds if the name of the
> bay isn't shown as expected.
Disproportionate compared to what ? And fairly flat coastlines are a
good example of cases that are tricky for algorythms, where the human
mapper can probably make a better decision.
> So I would say
> * if there is some other reason valid to map the bay as area, do it
- bays are areas in real life
- it makes geocoding trivial
- it makes knowing which bays to render preferably easy (bigger bays first)
- it enables representing nested bays
- it is deterministic, as opposed to relying on a heuristic algorythm
- relations are harder to work with than nodes
- the extent of bays is usually fuzzy; nodes make that fuzzyness obvious
- most of the existing data (osm and potential imports) are nodes
YMMV, those are reasons enough for me.
> * something better needs to be invented for hinting the renderer.
It's not just the renderer, I actually think that the geocoding
usacase is more important. And geocoding requires an area, wether it
is provided in readily-usable form as osm data, or by a
heuristics-based algorythm that infers it from a node.
More information about the Tagging