tm2: A JavaScript repository from duboway

TM2 (development)

Experimental version of TileMill powered by vector tiles. There are currently no supported releases of this software.

What are vector tiles?

Vector tiles are the vector data equivalent of image tiles for web mapping. They apply the strengths of tiling -- developed for caching, scaling and serving map imagery rapidly -- to vector data. Consider an image tile at the zxy coordinate 14/4823/6160. This image is a PNG that depicts the corner of lower Manhattan with roads, building footprints, and parks:

http://a.tiles.mapbox.com/v3/examples.map-zr0njcqy/14/4823/6160.png

A vector tile at 14/4823/6160 would contain all the corresponding geometries and metadata -- like road names, area types, building heights -- in a compact, parsable format. Vector tiles are a highly performant format that provide greater flexibility in terms of styling, output format, and interactivity.

               +----------+   +----------+
               |          |   |          |
               |  vector  |   | cartocss |
               |   tile   +-+-+  styles  |
               |          | | |          |
               +----------+ | +----------+
                            v
                     +-------------+
                     |             |
                     |  renderer   |
                     |             |
                     +------+------+
                            |
     +---------------+------+------+---------------+
     |               |             |               |
+----v-----+   +-----v----+   +----v-----+   +-----v----+
|          |   |          |   |          |   |          |
| geojson  |   | png tile |   | utf tile |   |  ??????  |
|          |   |          |   |          |   |          |
+----------+   +----------+   +----------+   +----------+

Vector tiles are designed to use the same tiling and coordinate scheme used by image tiles and take full advantage of HTTP. CDN caching, high scalability and efficient distribution make vector tiles a much more attractive solution than running, say, a enormous cluster of database and application servers that respond to queries on demand.

Here are some rough details of our implementation at time of writing:

Vector tiles are Protocol Buffers, a compact binary format for transferring messages.
Vector tiles store a serialized version of the internal data that Mapnik uses when rendering maps.
Vector tiles are organized into layers (e.g. roads, water, areas), which contain individual features each with a geometry and variable number of attributes per layer(e.g. name, type, etc.).

TM2 architecture

TM2 ships with an example vector tile source: Mapbox Streets. When you create your first project you will have full access to style curated data from OpenStreetMap without setting up PostGIS, downloading and importing a large planet database file, or any of the other steps usually taken to work with OpenStreetMap data. If you have been working on styles for streets in London and want to check how well your styles apply to data in Paris, TM2 will download the vector tiles on-the-fly as you pan over to France. TM2 caches downloaded vector tiles to an MBTiles database on disk so that you can take your work offline in a limited fashion.

Unlike TileMill, TM2 makes a hard split between two types of packages:

Styles contain stylesheets, basic thin metadata (name, description, attribution, etc.), and a reference to a datasource.
Sources describe a source for vector tiles, for example a URL endpoint from which to download tiles. We also have an API for generating vector tiles on the fly from traditional Mapnik datasources (shapefiles, postgis, etc) -- see tilelive-bridge for more info.

Building TM2

Dependencies are:

Node.js v0.10.x (should also work with v0.8.x)
Protobuf compiler and libprotobuf-lite
Mapnik

Note: Mapnik is now bundled inside node-mapnik for common platforms (64 bit Linux and OS X). This means that you do not need to install Mapnik externally. However if node-mapnik fails to install from a binary then you are likely running a platform for which no node-mapnik binaries are available. In this case you will need to build node-mapnik from source.

Build status of modules:

mapnik -
node-mapnik -
carto -
tilelive.js -
tilelive-vector -
tilelive-bridge -

Mac OS X

Binary

Binary builds are available for OS X at http://tilemill.s3.amazonaws.com/index.html?path=dev/. Download, unpack, and double-click start.command to start TM2.

TM2 builds currently aren't Developer ID-signed, so you may see a warning dialog about an unidentified developer. In that case, right-click the start.command file and select Open. You will receive another warning dialog, then click the Open button to continue.

Follow the instructions below to install from source if you are interested in developing on TM2.

Source install

First install Node.js. You can do this with Homebrew, via the easy installer at http://nodejs.org/download, or via tools like nvm.

Then build:

git clone https://github.com/mapbox/tm2.git
cd tm2
npm install
node index.js

Ubuntu Linux

First install the latest Node.js v0.10.x version:

sudo apt-get install python-software-properties
echo 'Yes' | sudo apt-add-repository ppa:chris-lea/node.js
sudo apt-get update -y
sudo apt-get install -y nodejs build-essential