[OSM-talk] Tagging, map-features and rendering

[Andy Robinson]

You make a lot of valid points here Steve and hopefully you and others can
find the time to bring theses bits of information together on the wiki. We
have moved on a long way from the original editing platform of the Online
Applet adding nodes and segments. That was just a few short months ago. Now
we are all interested in seeing the fruits of our editing labours and that
has to be good.

You raised a question about JOSM and the gpx tracks. If you load in a gpx
track raw with the "Draw lines between raw trackpoints" box checked from the
"Preferences/Display Settings" window (this can be turned on and off at
will) then you will see your tracks better if they are sparse. I find that
for most transport modes setting the gps to record at 1 sec intervals shows
up very nicely in JOSM without the need to draw lines between the
trackpoints, although I tend to recolour the points for different files (or
data from OSM) so that I can se what track relates to what.

Cheers,

Andy

Andy Robinson
Andy_J_Robinson at blueyonder.co.uk 
>-----Original Message-----
>From: talk-bounces at openstreetmap.org [mailto:talk-
>bounces at openstreetmap.org] On Behalf Of Steve Chilton
>Sent: 31 May 2006 11:14
>To: talk at openstreetmap.org
>Subject: [OSM-talk] Tagging, map-features and rendering
>
>Recent posts from Jo and Andy just highlight the inherent problems with
>a cooperative venture such as OSM. By its open nature participants are
>encouraged to explore whatever route forward takes their fancy (and
>suits their skills/inclination).
>
>I started off thinking that creation of suitable data was a simple task
>of getting out and doing it. How wrong can you be.
>Having explored the existing data, and in particular investigating which
>method of editing and outputting to use (initially for proofing
>purposes), I have come to a better understanding of the problems the
>project is setting itself.
>
>I naively started using the import GPS traces through OSM interface
>route, but soon got frustrated by the wait for file to be validated and
>appear for editing (pure impatience to get on with the task, having done
>some surveying I wanted to get on with the next phase). Then I moved to
>uploading via the excellent JOSM interface. My first surveys were
>circular bike rides that didn't cross over, re-trace, or doing anything
>else complicated. So, using the JOSM option to NOT open as raw data
>seemed the way forward - as it joined up the data to segments
>automatically. Incidentally, when you do import as raw data I find the
>data points very small in the editor. Have I missed something or can you
>re-size these to suit (as you can with nodes in the applet)? Then I did
>a small test survey of local roads near home, producing more complicated
>data points. Subsequent investigation shows that the autojoin now
>produces multiple paths, spurs, segments not in order that they were
>mapped in (important for rendering textpaths with Etienne's excellent
>Osmarender), etc. So, back to entering raw data and compiling the line
>segments in the editor (tagging as I go).
>
>I started tagging using class=xxxx as that was what the applet's
>drop-down menus seemed to be leading me towards. However, when I
>discovered the Map Features page in the wiki and saw the first output
>from Nick's development renderer and Osmarender I realised this might
>need a re-think. Having scanned the osm-map-features and osmarender
>files I have now fixed on a subset of features that are recognised by
>this system of outputting. Seeing the ouput in SVG format gives you
>clues about tagging and compilation inconsistencies. I have gone back to
>the local data that I have collected and re-ordered segments [usually by
>deleting and replacing the segments as the applet's re-order segments
>tool is not intuitive to use (to me)].
>
>Enough of these ramblings and let's get positive. I today obtained my
>Garmin bike handlebar holder and am raring to get out some
>evenings/weekends and map more of the local area (Enfield in North
>London). Howvere, can I suggest that some information is put on wiki
>pages that highlights "tagging" matters? Once any responses to this note
>have been assessed I am happy to have a bash at writing that page. And
>also that an "Outputs" page be compiled - preferably with major input
>from the various renderer developers - explaining what they pickup on
>(ways, segments, class, highway, etc), what needs to be considered when
>compiling data, and what external routes onwards there are (eg SVG to
>PNG, SVG to Inkscape). I don't feel particularly competent to do that
>task. There is already an Osmarender page, but it could use summary of
>what the tool picks up on so folks are aware (forewarned is forearmed).
>Incidentally, reading Jo's mail I would vote for option 3 to auto change
>class= tags to highway= tags (sorry maybe that should read ADD rather
>than replace), and suggest that the idea of "core attributes" be
>propagated strongly amongst contributors to make data as usable as
>possible. Anyone who objects to this needs to shout out as to why they
>have reason to keep their class data (Nick's renderer?).
>
>Whilst discussions are rightly going on about Foundation, copyright,
>data sources, appropriate development paths, etc it is important that
>the foundation (the data itself) is solid. By that I mean accurately
>compiled, relevantly tagged and accessible data.
>
>[Osmarender hint: if you use the highway=residential tag the 40%
>startOffset placement for the road name will invariably throw the name
>off or truncate it because these roads are often very short. Editing the
>file (in 2 places) to a more suitable number like 20% helps a lot]
>
>Cheers
>STEVE
>
>Steve Chilton, Learning Support Fellow
>Learning and Technical Support Unit Manager
>School of Health and Social Sciences
>Middlesex University
>phone/fax: 020 8411 5355
>email: steve8 at mdx.ac.uk
>
>Big Shave for Wateraid - after PICTURE at:
>http://www.mdx.ac.uk/www/gem/bigshave.htm
>
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