swimming_pool outlines too noisy

[daganzdaanda]

It's not a big problem, but have a look at
http://www.openstreetmap.org/#map=18/-20.27700/-40.29099
and then zoom out. The outlines of the many small pools create a lot of visual clutter. Even at z14 there are tiny dark blue lines:
http://www.openstreetmap.org/#map=14/-20.2731/-40.2982

I would say that the outlines should only render at close up zooms, 18 and 19 maybe. And the outlines could be less prominent.

[matthijsmelissen]

Thanks for reporting! I think an alternative would be to only render them on low zoom levels if they are over a certain size.

[Grillmannen]

Shouldn't these also be tagged access=private? It seems strange to map private space.

[matkoniecz]

Why not? This kind of data is useful and interesting.

Anyway, I think that it was mapped from aerial images and somebody preferred to avoid any, also reasonable guessing.

[daganzdaanda]

access=private would be right, I guess, but anybody human would assume that these aren't public just by the location and size. The ethics of mapping private stuff is a bit of a dilemma. I guess as long as you can see it on bing aerial images, it's no secret anyhow. Still, osm data can be used much easier for automated tasks than an aerial image.

But I guess this is not the problem of openstreetmap-carto and really doesn't belong here.

[matthijsmelissen]

In my opinion, the tagging is correct and the rendering wrong, so I will leave this open.

[matthijsmelissen]

See also https://trac.openstreetmap.org/ticket/3709

[CloCkWeRX]

I'd be keen to keep the current rendering for public pools, and maybe fainter rendering for private stuff.

Mockup:

Imagine the bigger pool = public/default.

Private pool: no border, color: C5DDDD

[matthijsmelissen]

It is not clear what the solution for this is. I can think of the following:

• Drop outlines altogether (however, this makes it harder to recognize swimming pools).
• Drop outlines for small swimming pools (however, this is ugly if there are different sized swimming pools in one area).
• Drop outlines based on zoom level (but it is not clear what zoom level this should be, as the example above is a problem at z17 and lower, but public swimming pools are still quite big at z17).

[matthijsmelissen]

Any suggestions?

[matkoniecz]

Testing following renderings would be nice:

Drop outlines for access=private swimming pools? (new idea)
Drop outlines for small swimming pools (by @math1985 )
Drop outlines based on zoom level (by @math1985 )

[kocio-pl]

I would take 2 (drop outlines for small swimming pools) with at least z19 showing everything. Probably similar filters we have for some other small objects could be used here.

[kocio-pl]

I don't feel this problem is too common nor serious. If there are no similar places (or their amount is small), I'm inclined to close this issue.

[matthijsmelissen]

It is a serious issue to me.

https://www.openstreetmap.org/search?query=andorra#map=14/43.7283/7.3771

[andrewharvey]

https://www.openstreetmap.org/#map=15/-33.8783/151.0839

[pnorman]

I'm not too worried about the Strathfield example, because the mapping there is so atypical, with swimming pools and very little else.

@matthijsmelissen shows a good example of the problem on z14, and I think part of the problem is we reduce the visual weight of the building outline going from z15 to z14, but not of swimming pools.

z14

z15

Higher zooms might need some adjustment, but z14 is particularly bad.

[jragusa]

1/ Vésenaz near Geneva, following suggestion of @CloCkWeRX
https://www.openstreetmap.org/#map=16/46.2311/6.1972

z=16
Before

After

z=18
Before

After

[Tomasz-W]

@jragusa Can you try with:

polygon-fill: @water-color;
line-color: saturate(darken(@water-color, 30%), 20%);

for all swimming pools? I think that adding different shades of water is a bad idea and it might be misunderstood (eg. confused with ice rink #3330)

[jragusa]

2/ following suggestion of @Tomasz-W
z16

z18

3/ slight modification:

polygon-fill: @water-color;
line-color: saturate(darken(@water-color, 10%), 20%);

z16

z18

[Tomasz-W]

I like effect of 3/, We can also try middle one: line-color: saturate(darken(@water-color, 20%), 20%);

[jragusa]

4/
z16

z18

[Tomasz-W]

I think 4/ gives the best effect - outline is visible, but it's not too dark.

[jragusa]

The initial purpose of the issue is to reduce the noise of swimming-pool at low zoom. So I suggest following the comment of @kocio-pl to remove the outline from z14 and then add from z17 with proposition 4.

z16

z17

[Tomasz-W]

@jragusa It would be nice to see some before/ after test renderings with locations from previous posts:
https://www.openstreetmap.org/#map=17/-20.27660/-40.28934
https://www.openstreetmap.org/#map=15/-33.8776/151.0818
https://www.openstreetmap.org/#map=16/43.7054/7.3070

[jragusa]

Ok I will try tomorrow

[jeisenbe]

Great ideas, guys. It's looking good. Are many of these backyard pool tagged with access=private? I would think this should be used on backyard pools. Would it make sense to render public pools sooner than private pools, or render the border on pools with public access? I would think that a swimming pool at a public park, even if it has a fee, is much more interesting than a pool that is only accessible to one house.

…

On Tue, Oct 9, 2018 at 5:24 AM Jérémy Ragusa ***@***.***> wrote: Ok I will try tomorrow — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#585 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AoxshArCldUv_dj55HCHAJxz9ftCfgE4ks5ui7RlgaJpZM4B_fTt> .

[jragusa]

@jeisenbe the code to render differently private swimming-pool is already available in my branch. I don't know what do @kocio-pl and @Tomasz-W think about it but it would easy to tweak this.

https://www.openstreetmap.org/#map=17/-20.27660/-40.28934
z16

z17

z18

https://www.openstreetmap.org/#map=15/-33.8776/151.0818
z16

z17

z18

https://www.openstreetmap.org/#map=16/43.7054/7.3070
z16

z17

z18

[jragusa]

1/ What do you think about z17 as threshold or do you prefer I move it to z18 or z19 ?

2/ As most of the swimming pool displayed in the pictures are private, I would propose to use this for former and to use a different strategy for public ones. What do you think ?

[kocio-pl]

I don't have a strong opinion how to solve this problem and I'm not involved in it. I think you should probably talk with @matthijsmelissen about it, because for him it's important (#585 (comment)).

[Tomasz-W]

I don't see both of 'no-outline' and 'different fill' versions as good, intuitive way to show that is a private pool. No-outline may be interpretated as some pool construction thing, and different fill may be considered as totaly different feature. At the other hand a swimming pool is always private or not in real world, but this information may be provided or not, so it migth be confusing if someone will take untagged private swimming pool as a public one. I would render all swimming pools the same.

[jragusa]

To summarise, I just have to remove the private condition or is there anything else ?

[Tomasz-W]

@jragusa There was also suggestion of not using outlines up to some zoom level (#585 (comment)), I don't remember if you included it or not.

[jragusa]

Yes that's already included in my branch and in the screenshots above