[Talk-de] Mapnik Probleme. Emails mit Steve Chilton

[Martin Koppenhoefer]

Ich habe vor ein paar Tagen wegen Mapnik mit Steve Chilton gemailt,
und poste hier mal die Mails (bis jetzt hat er auf die 2. Mail noch
nicht geantwortet).

Kurz zusammengefasst ging es darum, dass etliche features nicht in
Mapnik auftauchen, hauptsächlich das Problem der fehlenden Plätze
(nicht als Fläche) aber auch viele andere features, die mittlerweile
alle approved sind. Ich fand seine Haltung ein bisschen merkwürdig,
dass er aus Befürchtung, dass alles zugemüllt wird ("cluttering"),
etliche features nicht rendern will, und wollte Euch mal um Eure
Meinung fragen. Vor allem finde ich es seltsam, dass zwar PUBS
gerendert werden, aber z.B. historische Sehenswürdigkeiten,
archäologische Sites, Brunnen, Monumente, Leuchttürme, Türme, Kino,
Theater, Universitäten, Arts-Centre, U-Bahneingänge und sehr viel mehr
NICHT.

Hier in Rom sind sehr sehr viele features historisch / archäologisch,
und ich sehe es als großes Manko an, wenn die nicht auf der
Haupt-Karte auftauchen, weil die Engländer (ich sage das jetzt halt
mal so provokant) sie nicht haben wollen. Im allgemeinen finde ich die
Mapnik-Karte nämlich ansprechender als die Osmarenderversion, vor
allem hinsichtlich der Straßennamenanzeige.

Zuletzt noch meine Meinung: ich finde, ALLE features, mindestens die
"approved" sind, sollten auf der Karte auftauchen. Kann ja für die
unwichtigeren auch nur im höchsten / zweithöchsten Zoomlevel (größter
Zoom) sein. Dafür mappen schließlich die meisten hier. Naja, jetzt
warte ich erstmal seine Antwort ab und bin froh, dass die fehlenden
Plätze allgemein als Bug akzeptiert sind.

Martin

hier der Mailverkehr:

ZWEITE MEINER MAILS:

Hi Steve,

thank you for your reply. I'm not sure if there has to be a big change
for squares, as they should render the same as landuse, but with the same colour
as the streettype they are. Outlines from squares represent the outer
border of the square unlike the streets, that are mapped with the
center of the street beeing represented with a line. What I try to
point out is, that there should NOT be drawn a street and the the
center filled, but instead it should be drawn a polygon in the colour
of the street (and this should be with a priority, that it is drawn
under possible streets (because sqares are often pedestrian but
crossed by streets, that otherwise would not be visible).

I agree, that POI that can be turned on individually would be a great
feature in the future, but I'm little bit sad, that you won't put many
of the features (which indeed are all features that passed voting and
therefore can be considered as approved by the community), that are in
the current mapfeature list. I again agree, that on smaller zoomlevels
only the most important features should be present, but on higher
levels (before all the 2 highest levels) there should in my opinion be
as many features as possible, as the map otherwise will be somehow
empty. These very high zoomlevels, intended to give a detailed view of
the area, are enriched by these features.

The following of the proposed features are definitely also hitting the
navigate-to-it-criteria, you mentioned:

very important for Rome:
historic:
-monument
-ruins
-archaeological_site

man_made:
-lighthouse
-tower

amenity:
-theatre
-cinema
-university
-arts-centre
- fountain
- restaurant (if pubs are in, they should as well, maybe you can also
use the cuisine-tag if available for additional naming, like: xyz,
Pizza; or Hang Zhou, Chinese)

railway:
-subway_entrance

Please don't forget that mapnik is kind of THE original OSM-Map, as it
is standard on the OSM Page and many people, that have a first look on
OSM look on this map. From the German Mailing List as well as the
Italian one, I know that the rendered maps, Mapnik-OSM on the first
place, are for many people the main reason to contribute and put /
correct data. Putting a lot of features on the high zoom-levels can
motivate people, and is also good publicity, as you can see, how many
entries there are already in the database.

That's why I still think, that the following features should be
rendered as well (some of them as telephones and drinking water maybe
just in the highest zoomlevel, as otherwise there would really be some
cluttering):

-pharmacy
-drinking_water (there is a icon here, which is according to this page
PD: http://wiki.openstreetmap.org/index.php/Talk:Proposed_features/Potable_Water:
http://www.blm.gov/nstc/mapstandards/downloads/inter.pdf number 37)
-telephone
-fuel

shop:
-bicycle
-book (is still a proposed feature, unlike all the others mentioned above)

the mentioned issue with shops, that they tend to change a lot, is
partly true, partly also not. There are many traditional, historic
shops, some of them existing for hundreds of years (this applies even
to some book shops). On the other hand: if they were rendered, people
could delete / modify them, when necessary, otherwise this data will
remain in the database, mostly unused and invisible, and therefore
much more likely will become outdated and false. I believe in the
wiki-quality of our map, that leads faster to corrections and updates
as any commercial solution.

I would be glad to hear from you again,

cheers,

Martin

2008/4/13, Steve Chilton <S.L.Chilton at mdx.ac.uk>:
- Zitierten Text ausblenden -
> Martin
>
>  Sorry for late response, I have been away on a mapping party this weekend.
>  I do indeed "care for" the mapnik rendering on the slippy map, though I am not the only one, but perhaps the most frequent.
>  I agree with you on the squares issue. I have tried to sort it, but it is a bit complicated.
>  Mapnik sees things as either lines or polygons. I think square is unique in that it is the only highway= tag that can be a polygon.
>  Someone needs to make changes to the osm2pgsql script to get the data from db to pgsql for use by the style sheet.
>  It is on someone's "todo" list and will hopefully be sorted soon. Then I will sort the rendering, once I cab pick up the polygons.
>  You are not correct in saying the things listed were once in the maps.
>  They may have been (or still are in fact) in the osmarender layer but have never been in the mapnik layer.
>  I personally have a bit a thing about putting loads of points of interest symbols on the map map, and have held back from rendering many of these because of that. I am hoping that a points of interest (switchable - ie on/off) will be done sometime.
>  I tend to use a rule of thumb - would you navigate by it. So yes to pub and church, no to types of shops (which also change frequently).
>  I will have a look at the bike-paths issue. Could you email me a URL of where this issue arises please?
>  I can't really comment on realtions as I only just getting to grips with their intricacies myself.
>
>  Cheers
>  STEVE
>
>
>

ERSTE MAIL:

>         Subject: Problems in Mapnik
>
>
>
>         Hi Steve,
>
>         I'm a big fan of the mapnik render engine, but suffering a bit because
>         of some deficits, still immanent. I was told in the German Mailing
>         List that you are the one caring for Mapnik, and as I couldn't put a
>         Mapnik-Ticket in the trac, I'm trying to contact you via Email.
>
>         The most serious issue IMHO is the missing squares. Mapnik unlike
>         Osmarender renders highways that are tagged with area=yes just with
>         outlines. As squares are very important for the grafical appearance /
>         for orientation, this should be very nice to have also in Mapnik.
>         This is also a problem for buildings, that share nodes with
>         surrounding areas and by now are cut by overlappings from
>         highway-outlines that should be areas instead.
>
>         I don't know, but I seem to remember, that most of the features listed
>         down here once have been in the Maps, anyway, at the moment they
>         aren't but would be really nice to have.
>
>         There are some features missing, that I would love to have in Mapnik,
>         the following amenities:
>         -pharmacy
>         -drinking_water (there is a icon here, which is according to this page
>         PD: http://wiki.openstreetmap.org/index.php/Talk:Proposed_features/Potable_Water:
>         http://www.blm.gov/nstc/mapstandards/downloads/inter.pdf number 37)
>         -telephone
>         -theatre
>         -cinema
>         -university
>         -fuel
>         -arts-centre
>         - fountain
>
>         and also historic:
>         -monument
>         -ruins
>         -archaeological_site
>
>         and man_made:
>         -lighthouse
>         -tower
>
>         railway:
>         -subway_entrance
>
>         shop:
>         -bicycle
>         -book (is still a proposed feature, unlike all the others mentioned above)
>
>         also I suggest to put bicycle-paths generally above streets in the
>         render, as they are dottet lines and allow to see the streets that lie
>         underneath in cases, where bicycle paths follow the street in a narrow
>         distance. For areas instead, this should not apply, as squares are
>         often represented as highway =pedestrian, area = yes, with highway=
>         <some car accessible street> running over it to show the actual
>         traffic possibilities.
>
>         Some days before I also experienced a problem with churches, who would
>         on highest zoom level display only the icon whilst one zoomlevel below
>         show also the name, but today, this wasn't there any more, so maybe
>         it's already corrected (but still some churches don't even show their
>         name on any zoom level).
>
>         of course it would also be great to have relations in a more advanced
>         way, but this will be more work to implement, I guess. (e.g. someone
>         put all river segments in Rome into one relation (41,8014855
>         12,3865226) with the result, that it doesn't appear on the map any
>         more).