search

mattrei / aframe-tangram-component

Use Mapzen's Tangram Maps within A-Frame
https://mattrei.github.com/aframe-tangram-component
MIT License
17 stars 1 forks source link

readme

aframe-tangram-component

A Mapzen Tangram component for A-Frame.

Supports A-Frame 0.8.0.

Example

API

tangram-map component

The geojson component has the material and geometry components as a dependency from the entity. It implements a raycaster logic that fires an event if a GeoJSON feature gets selected.

Schema
Property Description Default Value
apiKey Sets the global API key of the Tangram map. May be empty if the style needs no API. ""
style The style definition document for the ovleray style. Must point to a custom style or to a basemap style. ""
center Center of the map, in the form of [longitude, latitude] [0, 0]
zoom The zoom level of the map. 13
pxToWorldRatio The multiplication factor between meters in A-Frame and the pixels of the map. ie; when set to 100, will display 100 pixels per 1 meter in world space. (see a note on fidelity) 100
highDensityDisplay Flag if the devicePixelRatio property should be considered. Mobile devices may have a high ppd so the output texture size may be 3 times as high as on desktop which may lead to crash of the browser false
Events
Name Data Description
tangram-map-loaded None Fired when the map has finished loading.
tangram-map-moveend None Fired when the map parameters have been changed and the map has reloaded.
API
Name Data Description
project lon, lat Returns the pixel x and y coordinates of the given longitude and latitude.
unproject x, y Gives the longitude and latitude of the pixel coordinates.
getMap Returns the Leaflet instance to work programmatically with the map.

Styling

The Mapzen Tangram are styled within a (set) of YAML files or ZIP files. See the Tangram documentation for details. You can also directly load the prefabed styles provided by Mapzen

A note on fidelity

The higher pxToWorldRatio, the more map area will be displayed per world unit. That canvas has to be translated into a plane in world space. This is combined with the width and height in world space (from geometry.width and geometry.height on the entity) to set up the plane for rendering in 3D.

The map is rendered as a texture on a 3D plane. For best performance, texture sizes should be kept to powers of 2. Keeping this in mind, you should work to ensure width * pxToWorldRatio and height * pxToWorldRatio are powers of 2.

Dependencies

The Mapzen styling documents are in the YAML format, so you need a possiblity to require those files. If you are using Webpack install npm install yml-loader --save-dev and configure the webpack configuration file

If you are using browserify install the nmp install yamlify --save-dev and give pass the transform (-t) parameter to browserify.

Installation

Browser

Install and use by directly including the browser files:

<head>
  <title>My A-Frame Scene</title>
  <script src="https://aframe.io/releases/0.8.0/aframe.min.js"></script>
  <script src="https://unpkg.com/aframe-tangram-component/dist/aframe-tangram-component.min.js"></script>
</head>

<body>
  <a-scene>

      <a-tangram-map 
        position="0 0 -2"
        width="7"
        height="5"
        api-key="mapzen-tDHBHDp"
        map-style="#zip-style"
        center="16, 48"
        zoom="12"
        px-world-ratio="100"
        >
      </a-tangram-map>
  </a-scene>
</body>

npm

Install via npm:

npm install aframe-tangram-component

Then require and use.

require('aframe');
require('aframe-tangram-component');

Known issues

Notes