OpenStreetMap
Towards Creating General Melchett's Map
Posted by SomeoneElse on 2 September 2016 in English. Last updated on 26 April 2018.I’ve written before about the changes needed to render more zoom levels than 18 with a “Switch2Osm-style” tile server.
However, sometimes zoom level 20 isn’t enough. Here:
is part of Nottingham at zoom level 20. At least one of the office names doesn’t appear (it corresponds to here in OSM). The problem is that the way that the “standard” renderd stores metatiles means that only a certain number of tiles can be stored for each zoom level (see this list post for the details). In order to store more I changed renderd slightly so that more zoom levels can be stored - see here and here for the details.
Rendering works fine at higher zoom levels (up to 28 in my example) so that all of those office names now appear. Here’s the same area at zoom level 21:
The principle could be extended to an eventual goal of 1:1 to keep Melchett and Darling happy (roughly zoom level 32 at this latitude) but that seems unnecessary even to me currently.
Edit: Elsewhere someone’s created a version that supports zooms > 30! See here and here.
Discussion
Comment from -karlos- on 3 September 2016 at 12:08
I would drop that pixsel rendering at all - and go with client side vector rendering: No zoom limit, not even hard levels, and just a summing up symbol for to much names and symbols if in lower zooms.
Comment from SomeoneElse on 6 September 2016 at 12:58
There are a couple of problems with client-side rendering - one obvious one is that you need to have something on the client capable of doing the rendering. I’ve certainly seen examples in the past where even a regular desktop PC wasn’t up to the job of processing the data thrown at it.
The other issue is that (excluding the proprietary options) things that might support a vector rendering don’t seem very mature - OsmAnd is about the nearest I’ve found, and I suspect that producing data for a large area would be a challenge (and updating not an option; you’d need to regenerate). tilemaker is another option, but with major caveats (memory use on generation, lack of an “update” option). osm2vectortiles now has lots of documentation to go with it but as I understand it is geared around one rendering only, which isn’t what I’m looking for.
For completeness there’s a list of MB vector tile clients here but (like similar lists in the OSM wiki) there are no clues about which are “finished” and which were “ideas thrown together in a lunchtime”.
Can you suggest anything obvious that I’m missing here?
Comment from philippec on 21 May 2017 at 07:33
I don’t know if I am on topic, but the famous Manneken Pis statue in Brussels is obscured by a chocolate shop.
http://www.openstreetmap.org/#map=19/50.84497/4.34997
Comment from philippec on 21 May 2017 at 07:34
I don’t know if I am on topic, but the famous Manneken Pis statue in Brussels is obscured by a chocolate shop.
http://www.openstreetmap.org/#map=19/50.84497/4.34997
Comment from philippec on 21 May 2017 at 09:44
I don’t know if I am on topic, but the famous Manneken Pis statue in Brussels is obscured by a chocolate shop.
http://www.openstreetmap.org/#map=19/50.84497/4.34997
Comment from SomeoneElse on 21 May 2017 at 12:10
@philippec Yes, that;s the problem that this is designed to solve. I do now render maps of Great Britain and Ireland using the method above, but unfortunately not Belgium :(