Closed donovanhide closed 13 years ago
Hi Donovan,
You can find a discussion with links relevant to your question here: http://gis.stackexchange.com/questions/3712/create-vector-geojson-tiles-for-polymaps
The code for GeoJSON tile generation is all public in the TileStache project (http://tilestache.org/), look for the PostGeoJSON provider (http://tilestache.org/doc/TileStache.Goodies.Providers.PostGeoJSON.html)
In the particular case of the Polymaps examples, we decided to host the generated GeoJSON tiles on Appspot because it offers support for the cross-origin resource sharing needed to read the JSON tiles from any web page. It's not necessary to choose AppSpot if you're doing everything under a single domain.
Hi Mike,
thanks for the reply. I read that stackexchange post, but got a bit confused - I'm new to GIS and all the various file formats associated with it.
I have a number of shapefiles from:
http://www.ordnancesurvey.co.uk/oswebsite/products/boundaryline/techinfo.html
I can make them into GeoJSON files using:
ogr2ogr -f "GeoJSON" output.json input.shp
but obviously this results in highly detailed, untiled polygons. Tilestache looks like it requires a working PostGIS db to do the conversion from .shp to multiple .json files. I would like to use AppEngine too for the project and would be happy to serve static files as polymaps.org does.
I suppose my question is, how would you get from a shapefile to a directory full of GeoJSON files in the shortest amount of steps!
Thanks for your time!!!
Donovan.
Hi Donovan,
You're right that PostGeoJSON requires a working PostGIS database. I think it would be worthwhile to support the use of Shapefiles and other file-based data sources like you describe - it's something I can add to TileStache, but it might take me a few days to do. Are you in a hurry? Contact me via Github mail, maybe I can help if you're not willing to wait.
Hi, a few of the example maps make use of tiled GeoJSON to allow for progressively more detailed vectors. This can be seen here:
http://polymaps.org/ex/statehood.html
Is there any chance you could release some of the code or detail the methodology by which you created these individual GeoJSON files? Would be very grateful!
Cheers, Donovan.