https://github.com/cspanring/avidgeo-meetup

Meetup material
https://github.com/cspanring/avidgeo-meetup

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Meetup material

• Host: GitHub
• URL: https://github.com/cspanring/avidgeo-meetup
• Owner: cspanring
• Created: 2012-06-15T15:03:29.000Z (over 12 years ago)
• Default Branch: master
• Last Pushed: 2012-06-15T15:05:57.000Z (over 12 years ago)
• Last Synced: 2023-03-11T09:43:04.091Z (almost 2 years ago)
• Language: JavaScript
• Size: 728 KB
• Stars: 3
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: readme.md

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README

        
# Avid Geo Meetup

[at MAPC, June 14th 2012, about MAPC's Basemap toolchain](http://www.meetup.com/avidgeo/events/65674052/)

Agenda, in a nutshell:

1. [MassGIS data](http://www.mass.gov/mgis/massgis.htm) - public domain data

2. [TileMill](http://mapbox.com/tilemill/) - cartography studio

3. [TileStache](http://tilestache.org/) - simple tile server

4. [Amazon S3](http://aws.amazon.com/s3/) - efficient storage

5. [Leaflet](http://leaflet.cloudmade.com/) - client map

## Our [Basemap](http://tiles.mapc.org/basemap.html)

**Why create and host our own basemap?**  

It's easy enough, doesn't require much resources and gives us most flexibility for our online maps.

Find the TileMill project (with branches for the Trailmap or Parkmap) in our [GitHub repository](https://github.com/MAPC/basemap).

[Instructions](https://gist.github.com/2923720) about how to include MAPC layers in your own mapping project.

## Data

Get it from [MassGIS data](http://www.mass.gov/mgis/massgis.htm) or OpenStreetMap (e.g. [Metro Extracts](http://metro.teczno.com/) and [Imposm](http://imposm.org/docs/imposm/latest/) is a good start)

Create a Postgres/PostGIS database, noticeable faster than Shapefiles, and load some data:

... import Shapefiles

    $ createdb -T template_postgis -O avidgeo avidgeo

    $ shp2pgsql -s 26986 -I myshape.shp public.myshape | psql -d avidgeo

...or load the prepared dump file

    $ createdb -T template0 -O avidgeo avidgeo

    $ pg_restore -d avidgeo -O avidgeo.dump

## Cartography

Know CSS and GIS? Use [TileMill](http://mapbox.com/tilemill/)!

For MassGIS data you'll need to add the Spatial Reference:

    +proj=lcc +lat_1=42.68333333333333 +lat_2=41.71666666666667 +lat_0=41 +lon_0=-71.5 +x_0=200000 +y_0=750000 +ellps=GRS80 +datum=NAD83 +units=m +no_defs

Export your map as Mapnik XML style file or readily rendered MBTiles.

## Tile Rendering

TileStache is a lightweight tile server, supporing a range of data providers - MBTiles, Vector (PostGIS, GeoJSON, Shapefiles), Mapnik, etc. - and caches - Memcache, Disk, Amazon S3.

Run the server for on-demand Tile rendering behind your web server:

    HTTP request <=> Web Server <=proxy=> WSGI server <=> TileStache

e.g. at MAPC we use a combination of [Nginx](http://nginx.org/) as web server, [Gunicorn](http://gunicorn.org/) as WSGI and [TileStache](http://tilestache.org/) as tile server.

Sample TileStache configuration for rendering to the disk cache and adding the avidgeo mapnik xml:

    {

      "cache": {

        "name": "Disk",

        "path": "/home/avidgeo/www",

        "umask": "0000",

        "dirs": "portable"

      },

      "layers": 

      {

        "avidgeo":

        {

            "provider": {"name": "mapnik", "mapfile": "avidgeo.xml"},

            "projection": "spherical mercator",

            "metatile":

              {

                "rows": 4,

                "columns": 4,

                "buffer": 128

              },

            "preview":

              {

                "lat": 42.3551,

                "lon": -71.0618,

                "zoom": 14,

                "ext": "png"

              }

        }

      }

    }

For production, pre-seed tiles to Amazon S3 and turn tile server off. S3 is great for serving static tiles and will save you some resources.

    $ tilestache-seed.py -x -c tilestache-s3.cfg -l basemap -b 40.59 -75.58 43.98 -69.98 9 10

**Extra points**: add [UTFGrid](http://mapbox.com/developers/utfgrid/) tiles for attribute data in your raster map.

## Client side map

Most JavaScript mapping libraries can consume tile server. Below is a simple example using Leaflet:

    var avidgeo = new L.TileLayer('http://render.mapc.org/avidgeo/{z}/{x}/{y}.png', {

        attribution: 'Tiles: MAPC, Data: MassGIS',

        maxZoom: 18

    });

    var map = new L.Map("map",{

        minZoom: 14,

        maxZoom: 18

    })

    .setView(new L.LatLng(42.3551, -71.0618), 14)

    .addLayer(avidgeo);

[Wax](http://mapbox.com/wax/) will allow you're client map to consume UTFGrid tiles.