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Posts Tagged ‘Tour’

Tours and 3D animation

February 19th, 2009 9 comments

Looking around the various tech reviews of the new Google Earth 5, one new feature seems to have slipped under the radar – the KML tags describing the new touring function include a seriously powerful method for defining smooth motion 3d animation.

I’ve been messing around with this a little, and hacked together a few basic (not much KML code), slightly weird 😉 , but dramatic examples. These are tours – view them by loading them into GE and double clicking on play me! in the side panel.

Fly wingman with a 3d model plane (also see the vid above)

Polygon morph France into Spain!

Dot-to-dot tour of European cities

How do these work ?

With the new <gx:AnimatedUpdate>. A container for the <Update> element. Which allows you to temporarily modify KML, and specify a length of time for that action to take place over.

Switching features on and off during a tour is the obvious example. Not so apparent, because it’s not directly available through tour recording inside Google Earth, is that for many other changes GE will smoothly interpolate (tween) the difference.

The example Google provide gradually increases the size of a placemark. But this effect can be applied to any KML attribute taking a range of values – orientation, colour, scale and coordinates. Significantly, these transitions will work in parallel, sequentially, across multiple features and alongside scripted camera movements.

This is powerful stuff! A much more convenient and concise method of animation than time slider hacks, where every intermediate step needs coding in KML. Only real downside in all this – and I guess it could be a biggie depending on your needs – you can’t fly around at will during tour playback.

About the examples

  • The first uses a single <gx:AnimatedUpdate> to gradually change location of a 3d model over a 60 second duration. Code for this below the fold if anyone wants to check it out.
  • Second does the same to transform all 38 coordinates in a polygon.
  • Last example combines a series of linestring coordinate transformations with color and scale changes for placemark icons.

Read more…

Google Earth 5.0

February 3rd, 2009 No comments

Latest version of Google Earth, 5.0 is now out. This is a massive ugrade to Google Earth, which takes the application forwards in lots of new ways. For sheer scope and range of new features easily the biggest update yet.

Headline features are Historic satellite images, 3D Ocean terrain, Google Mars!, and powerful new touring capability

Download the new version from the official download site here: Google Earth 5.0

A few observations:

  • Historical Imagery – For me the single most impressive and unexpected addition is the ability to see historic aerial and satellite imagery. Including stuff going back to the 1940s! Previously Google Earth only allowed the display of one image of any place taken at one particular time. Most other new features were predicted in one way or anther – this came out of the blue. Really excited about this. Must be costing Google a packet to acquire all this data.
  • Ocean – Displays 3d underwater terrain (bathymetry), with a neat wave effect for the ocean surface. Less excited by the possiblities of this than other people seem to be, but admittedly does look cool.
  • Mars – A complete 3D terrain model. Very impressive. Pretty much every conceivable layer provided – different types of imagery, space probe landing sites etc. The Mars rover tracks look ripe for time animation!
  • Touring – Provides the ability to record and play back tours. Especially like the fact recorded tours are stored as kml files. Makes it possible to share them, automatically generate them through scripts – e.g. as a black box recording from a flight simulator, and in future (hopefully) play them in the browser plugin.

Some User interface changes:

  • Time slider has some new features – zoom buttons which change the playback length between a minute, hour, day, week, month, year. Further options to set start and end times
  • Overview map – new location bottom left of screen, some options to change the size and zoom ratio.
  • The Ruler displays a compass heading in addition to distance.
  • Placemarks bounce when the mouse hovers over them.

Couple of niggles – might be due to my PC, internet connection or maybe just the number of people trying to use the application.

  • The new version took a very, very long time to install.
  • Imagery is being pulled in very slowly at times

Development Stuff

The KML changes are listed in the KML Reference. And a post on the devlopers blog here.

Some very tight control of touring is possible through the new kml extensions. Ability to set the satellite imagery date and sun position time in a lookAt or camera view. Hopefully this new provision for UI control will eventually be extended to things like toggling off individual 3d buildings in the layers.

On a side note, none of these new dev features have been rolled out in the Google Earth plugin yet. But a couple of the changes in GE 5 were effectively already in the browser version – the Javascript/CSS support in balloons, and the clickability of polygons and lines.