[OSM-talk] the coast and colour of the sea

Paul mylists at wilsononline.id.au
Thu Nov 1 20:43:23 GMT 2007


I'm not entirely sure I understand, but I take it from this thread that correcting this 
requires some sort of hack or re-programming to fix the colour and isn't something that is 
likely to be fixed automatically?

Paul



On 1/11/2007 7:45 AM, Jon Burgess wrote:
> On Wed, 2007-10-31 at 19:38 +0000, Andy Allan wrote:
>> On 10/31/07, Jon Burgess <jburgess777 at googlemail.com> wrote:
>>> On Wed, 2007-10-31 at 19:32 +0100, Martijn van Oosterhout wrote:
>>>> On 10/31/07, David Groom <reviews at pacific-rim.net> wrote:
>>>>> I belive Artem had some tools which took the OSM natural=coastline data and
>>>>> converted this to the files needed for the sea layer in Mapnik.  This is why
>>>>> if you look at an area around
>>>> I could really use such a tool right now, any ideas where I might find
>>>> it? Otherwise I'll probably start writing one...
>>>>
>>>> Have a nice day,
>>> We don't have such a tool.
>> So how did Artem do it originally for the english coast? I'd really
>> like to have a go at extending the shapefiles up the west coast of
>> Scotland, so that my old hometown looks better.
> 
> I'm not exactly certain. I believe Artem started by import either the
> PGS coastline data or OSM coastline ways for the UK. He then edited this
> with Jump (see below) and made sure that the coastline formed a closed
> way (many of the OSM and PGS lines have small gaps, especially around
> the coast of Scotland!). 
> 
> You probably want to start by importing the shapefile which is currently
> used for the coastline polygons:
> http://tile.openstreetmap.org/shoreline_a.tgz (3MB)
> 
> The complete set of shapefiles we use is much larger ~600MB
> http://artem.dev.openstreetmap.org/files/world_boundaries.tar.bz2
> 
> The majority of this is a single shapefile called shoreline_l which I
> believe is a PGS import for the whole world. This is the source of the
> thin blue line shown at high zooms. You can use this as a reference to
> add more coastline to the shoreline_a file.
> 
> The shapefile can be edited in a tool like Jump. I used the one from
> Vivid solutions http://www.vividsolutions.com/jump/ 
> I see there is a newer version here: http://openjump.org/ but I have not
> tried this.
> 
> I'd be happy to take an improved shapefile. There are a couple of things
> which discourage anyone from spending much time updating them manually:-
> 
> - If lots of people want to make update then it will be difficult to
> merge the changes together. 
> 
> - At some point we will probably replace the shapefiles with something
> auto-generated from the natural=coastline ways from the main DB. I think
> it would be better if we spent the effort on writing such an
> auto-conversion tool.
> 
> - There is also an outstanding question as to whether the shapefiles are
> in the correct projection. I know the projection string we use currently
> ("+proj=merc +datum=WGS84  +k=1.0 +units=m +over +no_defs") is wrong and
> at some point we probably need to regenerate the shapefiles in the
> correct projection (I've mentioned this on the dev list previously). The
> error cancels itself out over the complete rendering pipeline but makes
> it tricky to use the Postgres DB or shapefiles for anything accurate.
> The fix requires updates to practically the entire set of mapnik tools
> (osm2pgsql, these shapefiles, re-import the planet data, update the
> render_from_list.py and probably a couple more scripts I can't
> remember). 
> 
>   Jon
> 
> 
> 
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