Cesium¶ ↑

WebGL Virtual Globe and Map Engine

<img src=“https://badge.fury.io/rb/cesium.png” alt=“Gem Version” />

Requirements¶ ↑

In Gemfile file add line:

gem "cesium"

Run the bundle command to install it.

This gem relies on ‘requirejs-rails’ gem.

Make sure you follow the instruction from:

https://github.com/jwhitley/requirejs-rails

and you understand the concept of RequireJS:

http://requirejs.org

Now you are ready to use this gem :-)

Examples¶ ↑

Example 1:¶ ↑

For the convenience there is prepared route that will show you the globe. All you need to do is to modify your route.rb and add:

get 'cesium', to: 'cesium#index'

Now you can see the WebGL globe by visiting:

http://localhost:3000/cesium

Example 2:¶ ↑

Usage of this gem inside your own Rails application.

1. I presume you have a canvas tag in your view with id “globe”:

   <div class="fullSize">
     <canvas id="globe" class="fullSize"></canvas>
   </div>

2. You should have some CSS to define canvas size.

Here is an example that shows how to display the globe and cover 100% width & height of the wrapper

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden;
}

.fullSize {
    width: 100%;
    height: 100%;
}

1. In the javascript module that is related to the view

Here I use application.js (coffee):

require [
  'jquery'
  'Cesium'
], ($, Cesium) ->

  $ ->

    canvas = $('#globe')[0]  # change this to match your needs!!!

    @scene = new Cesium.Scene canvas

    primitives = @scene.getPrimitives()

    bing = new Cesium.BingMapsImageryProvider(
      url: 'http://dev.virtualearth.net'
      mapStyle: Cesium.BingMapsStyle.AERIAL
      proxy: if Cesium.FeatureDetection.supportsCrossOriginImagery() then undefined else new Cesium.DefaultProxy('/proxy/')
    )

    terrainProvider = new Cesium.CesiumTerrainProvider(
      url: 'http://cesium.agi.com/smallterrain'
    )

    ellipsoid = Cesium.Ellipsoid.WGS84
    centralBody = new Cesium.CentralBody(ellipsoid)
    centralBody.getImageryLayers().addImageryProvider(bing)
    centralBody.terrainProvider = terrainProvider
    primitives.setCentralBody(centralBody)

    new Cesium.SceneTransitioner(@scene, ellipsoid)

    ##################################################################
    #   INSERT CODE HERE to create graphics primitives in the scene.
    ##################################################################

    animate = =>
      # INSERT CODE HERE to update primitives based on changes to animation time, camera parameters, etc.

    tick = =>
      @scene.initializeFrame()
      animate()
      @scene.render()
      Cesium.requestAnimationFrame(tick)

    tick()

    canvas.oncontextmenu = =>
      false

    onResize = =>
      width = canvas.clientWidth
      height = canvas.clientHeight
      return if canvas.width == width and canvas.height == height
      canvas.width = width
      canvas.height = height
      @scene.getCamera().frustum.aspectRatio = width / height

    $(window).on('resize', onResize)
    onResize()

Contribution¶ ↑

To write new feature or fix a bug:¶ ↑

We follow git-flow branching model which means:

• “master” branch should be more less stable

• “develop” branch is the place to integrate features & bug fixes

More about git-flow: github.com/nvie/gitflow

1. Fork it

2. Clone it

3. *Check out “develop” branch*

4. Create locally feature/fix branch

5. Write code & test it

6. Merge it back into local “develop” branch *as one commit*

7. Test it!

8. Send “pull request” against “develop” branch on github

To report an issue/bug:¶ ↑

1. Please check that the issue you are about to report is not already reported

2. Report it on GitHub Issues:

   https://github.com/bogwro/cesium/issues
   

Maintainers¶ ↑

• Bogumil Wrona (github.com/bogwro)

How to upgrade to latest version of the Cesium¶ ↑

Clone specific version of the Cesium (-b VERSION_NUM):

git clone [email protected]:AnalyticalGraphicsInc/cesium.git -b 1.3 cd cesium ./Tools/apache-ant-/bin/ant clean ./Tools/apache-ant-/bin/ant combine ./Tools/apache-ant-/bin/ant buildApps ./Tools/apache-ant-/bin/ant runServer

After executing all of the build steps:

1. copy all files from Source folder

2. copy all files from Build/CesiumUnminified/Workers but not: „cesiumWorkerBootstrapper.js” and overwrite existing ones

• cesiumWorkerBootstrapper.js should be copied from Source folder

1. check which worker files are NEW and add them to the lib/ENGINE_NAME/engine.rb

License¶ ↑

• Rails’ Engine & all code which is part of this gem AND not part of the Cesium WebGL Globe:

  MIT License.

• All of the code that is part of Cesium WebGL:

  Apache License, Version 2.0

Please check the Cesium website for details:

http://cesium.agi.com
https://raw.github.com/AnalyticalGraphicsInc/cesium/master/LICENSE.md