airmule1 / labs-geojson2mvt

Cuts a file pyramid of static vector tiles from a geojson file.

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geojson2mvt

Cuts a file pyramid of static vector tiles (.mvt) from a geojson file

Why

We are using mapboxGL in The Capital Planning Platform, and needed an alternative to downloading large static data files for local rendering on the map. We didn't want to put them into a service that would require $ and maintenance, so static vector tiles seemed like a useful alternative for data that will not change very often.

How to Use

Install npm install geojson2mvt

geojson2mvt takes a config object with the GeoJSONs to encode and other options, and builds the pyramid in the specified output directory

var fs = require('fs');
var geojson2mvt = require('geojson2mvt');

var options = {
  layers: {
    layer0: JSON.parse(fs.readFileSync('bus_routes.geojson', "utf8")),
    layer1: JSON.parse(fs.readFileSync('stops.geojson', "utf8"))
  },
  rootDir: 'tiles',
  bbox : [40.426042,-74.599228,40.884448,-73.409958], //[south,west,north,east]
  zoom : {
    min : 8,
    max : 18,
  }
};
// build the static tile pyramid
geojson2mvt(options);

Check out /example for a test project that you can try locally

Options

layers - Object<string,Object> (required) - GeoJSONs to create a vector tileset from. Keys are the layer names that will be used to access data from the respective GeoJSON when displaying data from the MVT.

rootDir - string (required) - the filepath of the directory that will be the root of the file pyramid. It will be created if it doesn't exist.

bbox - array (required) - array of lat/lon bounds like [s,w,n,e]

zoom - object (required) - object with min and max properties for the desired zoom levels in the tile pyramid

Backwards compatibility

Instead of providing a single config object, you can provide two arguments: a geoJson and config object without a layers property, but instead with a layerName property for the name for the imported geoJson in the MVT.

About

Cuts a file pyramid of static vector tiles from a geojson file.

License:MIT License


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