Hello everyone,
Thanks for the suggestions. I've had an offer of hosting (many thanks!) but it's good to know what options are available. Roland - thanks for the info on Overpass. Am aware that GeoJSON isn't supposed to be epsg:3857 but I do it that way as it saves a reprojection stage. Thank,s Nick ________________________________ From: Roland Olbricht <roland.olbri...@gmx.de> Sent: 05 February 2019 16:59:48 To: Nick Whitelegg; d...@openstreetmap.org; talk-gb@openstreetmap.org Subject: Re: [Talk-GB] OSM augmented reality project - affordable hosting recommendations or Overpass? Hi, > As an alternative, I was wondering how acceptable it would be to use the > Overpass API to obtain the data? Downloaded data would be cached on the > device so for a given area, data would only need to be downloaded once. I'm fine with such a usage. The fine print is about other issues: - Overpass API does support GeoJSON indirectly, but GeoJSON does not support EPSG:3857, see https://tools.ietf.org/html/rfc7946#section-4 To get GeoJSON I suggest [out:json]; way(south,west,north,east)[highway]; convert link ::=::,::geom=geom(); out geom; where (south,west,north,east) is the bounding box. As an act of courtesy I suggest to set the "Accept-Encoding: deflate, gzip" header and use [out:json]; way(south,west,north,east)[highway]; if (count(ways) < 20000) { convert link ::=::,::geom=geom(); out geom; } else { make error what="Too many ways in this bounding box"; out; } This compresses the data and bails out if there are more than 20000 ways in the bounding box, corresponding to between 1 MB and 2 MB of data. Overpass would happily deliver about 1 GB per user and day, but the users may have data plans with rather 1 GB per month. Thanks, Roland
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