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Given an area with extremely few nodes (e.g. open ocean), it would make sense to display certain nodes (e.g. the only buoy on a 10-km radius) at more zoom levels than it would normally would.

Is there a way to indicate this in the node definition, or otherwise force this sort of display, maybe with a URL parameter? I'm not limited to an OpenStreetMaps solution. If this requires CloudMade or OpenLayers or some OpenSeaMap hack, that'd be fine too.

Example: NOAA buoy 46012. Zoom level 11 shows nothing, even though there would be plenty of space to show the buoy. It takes zoom level 14 to show the buoy, and by then, it's out of any useful context, surrounded by plain sea tiles.

asked 29 Aug '12, 04:10

dandv's gravatar image

accept rate: 0%

The map you get on is composed of individual static images. You can right click on the map and choose "View image" or similar in your browser and you will see one individual image. There is no way to dynamically change the rendering of these images. So the answer to your question is: no.

The only way to achieve this would be to render your own map from the raw OSM data and choose to make buoys more prominent in your stylesheet. How to set up a tile rendering server is covered on the site but it is not a simple thing for a worldwide map. You can also render your own map using applications like Maperitive although that will only do a limited area.

Or you could talk to the operators of OpenSeaMap and convince them to adjust their style instead if you think buoys should be more prominent.

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answered 29 Aug '12, 05:26

ToeBee's gravatar image

accept rate: 27%

Re. prominence of buoys - that's a particular case, and the easiest. But in principle, if a node is surrounded by nothing for a certain distance, it should be displayed at lower zoom levels, as long as it doesn't touch other nodes. This may not be trivial to implement, but it would elegantly solve the problem of buoys, or, say, features in deserts. The only drawback is that the nodes might suggest a larger map feature than in reality, but we do that routinely with POIs as well.

(29 Aug '12, 08:19) dandv

Mapnik (the software that renders the tiles) does have an algorithm for de-cluttering crowded areas. This is why not every POI in the middle of a big city gets rendered. But that's just removing things that conflict. I don't think it has the ability to "re-clutter" things from a higher zoom and I'm not sure you can assign any kind of priority. This would be one way of doing it though... render buoys at a lower zoom but make them low priority so they get de-cluttered quicker than other things. But I think you'll have to take that up with the mapnik devs.

(29 Aug '12, 08:40) ToeBee

If you want to see a point from the data on the map, you can use this online tool, and ask for your wanted tag to get all objects with this tag. I have had the same frustration than you a lot of times, so I've found this way to display data that aren't (and maybe will never be) on standards map renders.

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answered 29 Aug '12, 07:05

NicolasDumoulin's gravatar image

accept rate: 13%

In your particular example it might be worth raising it with the OpenSeaMap devs** - perhaps you may be able to persuade them that a single buoy in the open ocean is worth rendering at a higher zoom level.

If that's not an option, then as ToeBee suggests rendering your own maps is probably the way to go. Various questions have been asked on this before here - try reading the answers to a search like this or this.

** There are some mailing lists mentioned on this wiki page.

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answered 29 Aug '12, 09:54

SomeoneElse's gravatar image

SomeoneElse ♦
accept rate: 16%

The openseamap-develop mailing list is hosted on Sourceforge - gah! Can't search.

(15 Jul '13, 10:51) dandv
(15 Jul '13, 11:34) dandv

Probably not satisfactory, but you can, for example, do this.

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answered 29 Aug '12, 12:05

sdoerr's gravatar image

accept rate: 8%

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question asked: 29 Aug '12, 04:10

question was seen: 20,095 times

last updated: 15 Jul '13, 11:34

NOTICE: is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum