Hi Steve

Thanks for that information.  Gradually getting the hang of them on the simple 
examples but when I struck Lake Gordon wonder what on earth the "incomplete [id 
31755640]" meant.  It looks like an error message but as you commented earlier 
the lake is rendering as it should.  Do notice that in JOSM the lake does not 
render correctly once I split a way and then refine it probably due to the size 
of the lake exceeding the downloadable segment. 

Due to the size of the Lake I am splitting sections out and tracing them in 
with more nodes and then reconnecting them.     The delay in tile render can 
make this a bit challenging to check but looks like based on your notes that I 
am doing the right thing.

And finally mastering getting maps on my Garmin with contours and rendered like 
mapnik.  Thanks to a fellow list member I now can update the Australia pbf file 
and also extract contours for any part of the globe that has them.  Typviewer 
means I can create or "steal" icons.  Gradually figuring out the style sheet 
plus a few Garmin idiosyncrasies that mean things like resolution levels do not 
work past a certain pre-set Garmin point.  

Next step will be implementing sac_scale for walking tracks and revisiting the 
unpaved road issue.  Plus seeing if I can liberate the higher 1 second contour 
line scans that were down as part of the SRTM contours for Australia.

Cheers Brett


Date: Thu, 1 Aug 2013 22:45:05 -0400
From: stev...@email.com
Subject: Re: [talk-au] Gordon Lake - Multipolygon relations - I just do not     
understand
To: brussell...@live.com.au; talk-au@openstreetmap.org

Brett,

Don't overthink the multipolygon.

It is just a collection of nodes and ways, which is then (almost) tagged as if 
it is a way.

Lake Gordon looks ok at the moment, so you might have worked it out...

For lakes in JOSM,
1) Draw the outer edge of the lake as one way or a series of connnected ways.
2) Draw the edge of the islands as one way per island or a series of connected 
ways per island.
3) Select all the ways you have drawn for the lake and go to the 'Tools' menu 
and select 'Create Multi-polygon CTRL+ALT+A'. This will get JOSM to create a 
multipolygon relation, this is where you have all the lake related tags, not 
tags specific to the islands, the natural=island goes directly on the island 
way.
4) To add tags to the multipolygon, select one of the ways then under the 
normal properties side bar you should see a 'Member Of' area, double click on 
the multipolygon shown.
5) The tags for a multipolygon relation (lake) are:
   - type=multipolygon
   - natural=water
   - name=Lake Gordon
   - source=...
  etc.
6) For each way/node in a multipolygon you need to define its role.  JOSM will 
attempt to do this automatically for you if you had all the ways selected when 
creating the multipolygon.  If not:
   - All ways that form the outer edge of the lake have the role of 'outer'
   - All ways that form the islands in the lake have the role of 'inner'

Note that when you are in the relation editor window, do not add or delete 
nodes in the map window behind, as it sometimes confuses it (will it sometimes 
asks you some questions which confuses me...).  So always click OK (or cancel) 
on that window prior to changing nodes in the main window.

Hope that helps, let me know if you need more details.  I suggest you read the 
multipolygon and relation wiki pages.

Stephen.
  ----- Original Message -----From: Brett RussellSent: 07/30/13 10:45 PMTo: OSM 
Australia mailing listSubject: [talk-au] Gordon Lake - Multipolygon relations - 
I just do not understand Hi

Must admit that multipolygon relationships have me confused.  Lake Gordon is a 
good example.  Thought, great I will refine the shoreline by selecting two 
points and breaking them and then deleting the section and rebuilding it with 
both ends joined.  But I notice weird lines across the lake and incomplete 
inner and out mentioned in the relationship.  Tried deleting them incomplete 
ones but all I get is confused. 

Rather than just fix my stuff up can some one walk me through fixing it as I 
loathed to touch them.  Generally it is only the 2000 point limit and islands 
that forces me to use them.  I am using JOSM.

Cheers                                            
_______________________________________________
Talk-au mailing list
Talk-au@openstreetmap.org
http://lists.openstreetmap.org/listinfo/talk-au

Reply via email to