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i am generating vector tiles from mapnik-vector-tiles which is bundled by avecado. i am in need of ocean polygon for the world. Please refer http://gis.stackexchange.com/questions/120708/where-can-i-get-osm-water-polygon-for-lower-zoom-level https://github.com/mapbox/mapnik-vector-tile/issues/70 and |
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Hi. If you are still interested in "ocean polygon" here is one option that can maybe help you. From your text I assume that you are interested in the Global Ocean area (everything blue, outside the continents) or maybe in the Planet-sea (as the inverse of the Planet-land areas created from the coastline dataset). The Planet-sea in 11 scale levels you may download (shp format) from here |
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Thanks for your @stephan and @sanser. i tried OpenStreetMap Data, its size is 377MB it fits for zoom level above 8 or 9. But what about the scenario for zoom level from 0 to 8. simply if i use openstreetmap Data in zoom level 0 it will take more size in creating vector tiles. so i go with Natural Earth data. Test Case for Using Natural Earth data. 1) Initially i used shape file directly. it didnt show any error at the same time it didnt show proper result so i checked the pbf file. In geometry same values repeating again and again please see https://github.com/mapbox/mapnik-vector-tile/issues/70. so it fails. 2) i convert the shape file to postgis and import the geometry from postgis again i got same output. 3) Later i checked the geometry projection. In new natural_earth table i found geometry is normal latitude and longitude but in planet_osm_node table it is transformed lat long. so i prefer to change the lat long. this is my new query select ST_AsText(ST_Transform(geom, 900913)) from ne_110m_ocean it works fine except poles. yes, st_transform show error in poles is ERROR: transform: couldn't project point (-180 90 0): tolerance condition error (-20) Error here is due to poles. srid 900913 did not accept 90. so in geometry instead of 90 change to 89.9999999. then transform the srid to 900913 select ST_AsText(ST_Transform(geom, 900913)) from ne_110m_ocean it works fine and correct vector tiles also generated. |