adding antarctic icesheet rendering based on preprocessed shapefiles #1540
Conversation
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@gravitystorm thoughts, as this is a big change, involving new pre-processed data? |
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Could we get this out some time soon? If you have a look at previous discussions you can see this is my third attempt at getting this to render in the style and technically this is about as easy as it gets. If getting support for this into operations takes some time i understand but it would be good to have a decision. |
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I'm happy to have these used, and taken from openstreetmapdata.com, but we need to have some source available to generate them in case that site is unavailable. I realise there's some "magic sauce" with the coastlines wrt comparing them against each other every day, but I'm not concerned about that. We can generate alternative shapefiles from available code if required. Is there existing code available (not necessarily that run by openstreetmapdata.com, but that would be nice) to generate these ice sheets? If so, where does it live? |
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See http://blog.imagico.de/easier-rendering-of-the-antarctic-land-ice/ for a description of how it is done and https://github.com/imagico/icesheet_proc for the code. |
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Tom already provided the link - i just pushed the version running on openstreetmapdata.com - the only magic sauce running there in addition is zipping the results and maintaining feature count statistics from osmium_noice (if anyone wants to know - since processing began in March noice feature count decreased from 57278 to 57272 features, explicitly mapped glaciers increased from 634 to 793). And of course we directly use the SQLite db produced by osmcoastline as input and not the shapefiles. |
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@gravitystorm Does that answer your question, or is there anything more we need? |
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@math1985 I'm happy |
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For all involved people this is probably clear, but on the osmf tile servers there is more adaption needed on their side: |
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@imagico Thanks a lot! @pnorman @gravitystorm @matkoniecz Please don't forget to run |
| @@ -11,6 +11,8 @@ mkdir -p data/simplified-land-polygons-complete-3857 | |||
| mkdir -p data/ne_110m_admin_0_boundary_lines_land | |||
| mkdir -p data/ne_10m_populated_places | |||
| mkdir -p data/land-polygons-split-3857 | |||
| mkdir -p antarctica-icesheet-polygons-3857 | |||
| mkdir -p antarctica-icesheet-outlines-3857 | |||
get-shapefiles.sh is not run on the rendering servers at all, nor is it particularly well-suited for production use, with a lack of consideration of failure handling. |
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In any case there should be something on production that downloads the shapefiles... |
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Already done in openstreetmap/chef@cecd219 ;-) |
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Thanks @tomhughes! |
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Is it intentional that borders are no longer rendered (unlike preview images)?
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@math1985 - yes, paths were off but apparently this did not matter. In general get-shapefiles.sh is very testing-unfriendly - you can only test it all together newly downloading all files. This would be good to improve. @matkoniecz outlines are drawn at ice-water edges and ice-land edges but not at ice-ice edges since those are already drawn by the explicitly mapped glaciers. So if you don't have any glacier data in your database you get missing outlines at the edges, in particular towards the ice shelves. Thanks everyone to finally get this out, after in total nearly 2.5 years - the land ice polygon in Antarctica was removed on March 16 2013. |
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@imagico Yes, I checked it without data loaded for this location. |
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It would be great if the Antarctica shape files could be mentioned under 'Manual download' in INSTALL.md too. Thanks. |
Since the preprocessed Antarctic icesheet data is now regularly available on openstreetmapdata.com (where also the coastlines come from) this PR adds rendering of the Antarctic ice based on that data. Style-wise this should be an exact equivalent to normal glacier rendering.
See also #960 for more background information.
Rendering examples:
Resolves #960