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#1 2012-01-07 20:41:48

PeterFacey
Member
Registered: 2012-01-07
Posts: 4

JOSM: can't see coniferous property of mulitpolygon

Some forests are rendered (by mapnik) as coniferous whilst others are just plain light-green coloured.
I expected to be able to see in JOSM a tag of wood=coniferous to account for this, but I cannot find one, for example, on the selected multipolygon below. Are there some other properties on this multipolygon or its members that I'm failing to find?
josm_conifer.PNG

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#2 2012-01-08 08:14:19

Tordanik
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From: Germany
Registered: 2008-06-17
Posts: 2,533
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Re: JOSM: can't see coniferous property of mulitpolygon

In your screenshot you have selected the outer way of the multipolygon. JOSM therefore shows you the properties of the outer way.

If you want to see the properties attached to the multipolygon relation, you need to select the relation first. You can double-click on the multipolygon entry in the "Member Of" list to open the relation editor, or right click on that entry and choose the "select relation" context menu item.


OSM in 3D: OSM2World

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#3 2012-01-08 15:25:19

Vclaw
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From: Alba
Registered: 2009-02-25
Posts: 522
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Re: JOSM: can't see coniferous property of mulitpolygon

PeterFacey wrote:

Some forests are rendered (by mapnik) as coniferous whilst others are just plain light-green coloured.

I think this difference in Mapnik rendering just depends on whether it is tagged as natural=wood (shown as light green) or landuse=forest (darker green, with pine tree symbols).
There is some debate as to when to use either of these tags. Some people say only use natural=wood if it is entirely unmanaged, otherwise use landuse=forest. Though there's no clear distinction between them. These tags do not say anything about what type of trees are there, best to specify that with wood=coniferous / wood=deciduous / wood=mixed etc. I don't think the wood=* tag affects the Mapnik rendering.

In your screenshot, the way is tagged as landuse=forest and natural=wood. This is unusual, and I'm not sure what its actually supposed to mean. And I'm not sure how Mapnik will render it. Plus as Tordanik says, there may be extra tags on the multipolygon which affects this. Can you give a Permalink to the location on the map?

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#4 2012-01-08 16:49:22

PeterFacey
Member
Registered: 2012-01-07
Posts: 4

Re: JOSM: can't see coniferous property of mulitpolygon

Thanks for replies. I had a look at the multipolygon tags, which still don't mention wood=coniferous. The data seems to have come from OS vectormap district.

The permalink is http://www.openstreetmap.org/?lat=50.85 … 6&layers=M

I've been revising the course of the stream here, which was put back to the meandering course it had before 1850 (when it was made into a straight drain) by a stream restoration project in 2009.

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#5 2012-01-09 09:19:59

ajoessen
Member
Registered: 2009-09-16
Posts: 2,074

Re: JOSM: can't see coniferous property of mulitpolygon

Vclaw wrote:

In your screenshot, the way is tagged as landuse=forest and natural=wood. This is unusual, and I'm not sure what its actually supposed to mean. And I'm not sure how Mapnik will render it. Plus as Tordanik says, there may be extra tags on the multipolygon which affects this. Can you give a Permalink to the location on the map?

The problem is that landuse=forest (with the tree symbol) and natural=wood (brighter type of green without symbol) are not expected to be on the same object. So Mapnik will render it in the rule which comes last in inc/landcover.xml.inc, in this case natural=wood. Coniferous is not rendered at all in Mapnik.

The multipolygon relation only has landuse=forest, and this overrides the tags of the individual outer members.
So you see the parts of the multipolygon in different color than the other forest-wood-landuses.

HTH,
ajoessen

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#6 2012-01-09 12:34:45

PeterFacey
Member
Registered: 2012-01-07
Posts: 4

Re: JOSM: can't see coniferous property of mulitpolygon

Thanks. I'll correct that. (I may have caused it by mistake; I've only been using osm for a few days).

The tree symbol shown by mapnik is what the OS uses for a coniferous forest, so that rendering is a little confusing to UK users. But presumably in due course mapnik might be developed to take note of wood=*

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