Opened 11 years ago

Closed 11 years ago

Last modified 11 years ago

#969 closed defect (invalid)

[mapnik] leisure=common area inside landuse=residential related by a multipolygon: misrendering?

Reported by: achadwick Owned by: Tom Hughes
Priority: minor Milestone:
Component: mapnik Version:
Keywords: mapnik multipolygon Cc:

Description

I recently tagged a new landuse=residential (20175534) completely encircling an existing leisure=common (24777545) and set up a new multipolygon relation (16272) between the two objects, setting them as outer and inner respectively. See the map URL below for a quick overview. If you're looking at histories, ignore the revision at 2008-06-11T10:34:26+01:00, that's just me being a muppet with Potlatch.

The current multipolygon recommendation in the wiki says:

They can also be tagged as appropriate for the content of the respective holes. http://wiki.openstreetmap.org/index.php/Relations/Multipolygon

And that's what I've done. Osmarender copes with this reasonably, but the Mapnik layer renders the outer ring in "leisure=common" green, with a blank hole in the middle:

http://www.openstreetmap.org/?lat=51.70607&lon=-1.31916&zoom=16&layers=B00FT

I expected to see an outer ring of "residential grey" and an inner circle of "common green" because that is what the data said at the time.

I will update the wiki to reflect Mapnik's behaviour here, linking to this ticket.

(Note that I'm likely to change this example to be represented as a common inside a separate inner+outer multipolygon fairly soon - because it strikes me as cleaner data rather than because it might render better! A test case can be built from the histories of the 3 objects I mentioned using their state at or before 2008-06-08T20:50:04+01:00).

Attachments (3)

dry-sandford-mapnik.png (86.7 KB) - added by achadwick 11 years ago.
Possible Mapnik misrender?
dry-sandford-osma.png (70.9 KB) - added by achadwick 11 years ago.
How I expected it to look, via Osmarender
innerouter.osm (9.9 KB) - added by achadwick 11 years ago.
Minimal test case. Yep, the outer is clockwise and the inner anticlockwise.

Download all attachments as: .zip

Change History (6)

Changed 11 years ago by achadwick

Attachment: dry-sandford-mapnik.png added

Possible Mapnik misrender?

Changed 11 years ago by achadwick

Attachment: dry-sandford-osma.png added

How I expected it to look, via Osmarender

Changed 11 years ago by achadwick

Attachment: innerouter.osm added

Minimal test case. Yep, the outer is clockwise and the inner anticlockwise.

comment:1 Changed 11 years ago by achadwick

Priority: majorminor

To clarify, I'm uncertain whether this is a Mapnik bug. Certainly the behaviour is not what I expected, and is incosistent with the current wording of the Wiki page and with Osmarender.

If it's your opinion that this is a mistagging on my part, I'll amend the wiki with a don't-do-that-then and link here.

Setting as minor.

comment:2 Changed 11 years ago by Tom Hughes

Resolution: invalid
Status: newclosed

See http://lists.openstreetmap.org/pipermail/talk/2008-May/026872.html for Jon's comments on this.

As you seem to realise, it is logically incorrect to tag in this was as it is the residential area that has the hold, and the park is a separate entity that happens to sit inside that hole.

comment:3 Changed 11 years ago by achadwick

Wiki page updated. Thanks for the feedback.

Note: See TracTickets for help on using tickets.