Skip to main content

Animated prism map in Google Earth

By using the time primitives in KML, you can create animated thematic maps showing how a variable change over time.

The prism maps above visualise the world population in four different years (1950, 1975, 2000 and 2050). This and this blog posts show how a prism map can be made with KML. Here, I've added country polygons for several years, each extruded and colourised according the the population value.

All polygons for one year are wrapped in a Folder with a TimeSpan element. Whenever time is specified in a KML file, a time slider appears in upper-right corner of Google Earth (I've not seen this functionality implemented in other geobrowsers). By dragging this slider, you'll see the human population explosion visualised:



You can download the KMZ file here and try yourself. The file is big (1 MB) because the complex country polygons have to be repeated for each year in the animation. It's not possible to change altitude values dynamically with KML. It'll be on my list of feature requests...

Population statistics from UNdata.

Comments

Unknown said…
Great work, looks fantastic. Can the time lapse animations be implemented in the Google Earth browser plugin as well?
25 September 2008 at 19:23
Bjørn Sandvik said…
Hi Nathan,
The Google Earth Plug-in is not yet supporting time data. It is the only KML feature that is not implemented.
26 September 2008 at 17:26
Post a Comment

Popular posts from this blog

Creating a WebGL Earth with three.js

This blog post will show you how to create a WebGL Earth with three.js , a great JavaScript library which helps you to go 3D in the browser. I was surprised how easy it seemed when reading a blog post  by Jerome Etienne . So I decided to give it a try using earth textures  from one of my favourite cartographers, Tom Patterson . WebGL is a JavaScript API for rendering interactive 3D graphics in modern web browsers without the use of plug-ins. Three.js is built on top of WebGL, and allows you to create complex 3D scenes with a few lines of JavaScript. If your browser supports WebGL you should see a rotating Earth below: [ Fullscreen ] To be able to display something with three.js, you need three things: a scene, a camera and a renderer. var width  = window.innerWidth,     height = window.innerHeight; var scene = new THREE.Scene(); var camera = new THREE.PerspectiveCamera(45, width / height, 0.01, 1000); camera.position.z = 1.5; var rende...
11 comments
Read more

Terrain building with three.js

In my last blog post , we converted a digital elevation model (DEM) to a WebGL-friendly format ( i.e. easy to transfer and parse by JavaScript in the browser). In this blog post, we'll use the elevation data to build a terrain mesh with three.js .  First we need to transfer the terrain data to the browser. The elevation values are stored in a binary file as 16-bit unsigned integers. This page explains how you can send and receive binary data using JavaScript typed arrays. I've created a TerrainLoader by adapting the  XHRLoader . You can also use this function: function loadTerrain(file, callback) {   var xhr = new XMLHttpRequest();   xhr.responseType = 'arraybuffer';   xhr.open('GET', file, true);   xhr.onload = function(evt) {         if (xhr.response) {       callback(new Uint16Array(xhr.response));     }   };     xhr.send(null); } Loading elevation data with the Terrai...
16 comments
Read more

Thematic Mapping Engine

It's time to introduce the Thematic Mapping Engine (TME). In my previous blog posts, I've shown various techniques of how geobrowsers can be used for thematic mapping. The goal has been to explore the possibilites and to make these techniques available to a wider audience. The Tematic Mapping Engine provides an easy-to-use web interface where you can create visually appealing maps on-the-fly. So far only prism maps are supported, but other thematic mapping techniques will be added in the upcoming weeks. The engine returns a KMZ file that you can open in Google Earth or download to your computer. My primary data source is UNdata . The above visualisation is generated by TME ( download KMZ ) and shows child mortaility in the world ( UNdata ). The Thematic Mapping Engine is also an example of what you can achieve with open source tools and datasets in the public domain: A world border dataset is loaded into a MySQL database . The same database contains tables with statistics ...
45 comments
Read more