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Controlling Google Earth via the Liquid Galaxy protocol

November 27, 2015

Given that the Google Earth API is coming to an end we are looking at alternative solutions. Yesterday we had a look at Google Earth’s internal browser and what its capabilities are. Today we are looking at a way of controlling Google Earth from another application.

Liquid Galaxy is the name given to a Google Earth demonstration using multiple displays to give an immersive experience. To see it in action, see the photos and videos on of various installations here. Liquid Galaxy works by allowing Google Earth on one computer to communicate with instances of Google Earth on other computers and synchronize their views so as to give the impression that there is a single instance of Google Earth running across multiple screens. To achieve this, Google Earth has a special Liquid Galaxy protocol that can be used to instruct Google Earth to show a particular location from a particular angle. It is possible to use this protocol for uses other than Liquid Galaxy installations.

Paul van Dinther of PlanetInAction has kindly released a small program that demonstrates this functionality. It is a Windows only program called GExplorer and it replicates the functionality of a JavaScript by the same name he created that works with the Google Earth plugin.

See this YouTube video to get an idea of what it does:

To try it for yourself first download the program here (Windows only).

Next, you need to configure Google Earth to accept Liquid Galaxy protocol instructions. To do this you need to edit the drivers.ini file found in the Google Earth program folder. The file is typically found in the folder
C:\Program Files (x86)\Google\Google Earth\client (for Google Earth)
or
C:\Program Files (x86)\Google\Google Earth Pro\client (for Google Earth Pro)

We found Windows Notepad does not display the file properly so you will need a more advanced editor. We used SciTE which can be obtained from here. Edit the drivers.ini file and insert the following lines at the start of the SETTINGS section.

ViewSync/send = false ViewSync/receive = true ViewSync/port = 21567 ViewSync/yawOffset = 0 ViewSync/pitchOffset = 0.0 ViewSync/rollOffset = 0.0 ViewSync/horizFov = 60

It should look like this:

Windows will not let you save it directly to the Google Earth program folder so save it on your desktop and then copy it to the Google Earth program folder.

Start Google Earth and GExplorer and make sure the GExplorer window is on the same monitor as Google Earth.

Initially nothing will happen because GExplorer is broadcasting to the wrong IP address. Click on the “Get my broadcast IP” button to adjust the IP address or type it in if you have different network requirements (Such as an actual Liquid Galaxy setup with multiple computers). If all is well it should say “UDP Connected” in red.

Next click “Start”.

The Google Earth view should now leap to the start latitude and longitude location. You will also notice that the view moves around as you move your mouse. You can now control Google Earth with a combination of the WASD keys and the mouse. SHIFT and CTRL can also be used to control height. Amplify any control input by holding down the spacebar with any combination of the above keys.

The view animates smoothly based on control inputs. The responsiveness can be modified with the “Inertia” dropdown. Low numbers means more responsive.

“Tilt limit” specifies the maximum angle you can look up or down. Try changing it to 90.

As you turn left or right the camera automatically rolls like an aircraft. If you don’t want this behaviour you can turn it off by ticking the “No roll” checkbox.

You can also switch between “Earth”, “Moon” or “Mars” by changing a dropdown.

Paul also suggests the great idea of creating a mobile app with the same functionality which would allow you to control Google Earth from your mobile phone. If any of our readers creates such an app please let us know about it in the comments.

Tour maker with the Google Earth API

November 13, 2015

With the end of life of the Google Earth API approaching, Paul van Dinther of PlanetInAction.com has decided to release a tool he created for his own use that uses the Google Earth plugin for making Google Earth Tours. Paul van Dinther has created a number of games based on the Google Earth API that we have featured on this blog, possibly the most sophisticated of which is a ship simulator. When he realized the Google Earth API would eventually be shut down Paul decided to base the next version, Ships 2 Career, on Google Maps instead. It will lack the 3D that the Google Earth API provides but we believe it will still be a great game and popular with ship enthusiasts. You can follow the development on his Google+ page.

The tour maker can be found here. To use it you will need to open it in a browser that still supports the Google Earth plugin. We tested it in Firefox but we believe it should also work in Safari.

Paul has provided the following instructions for using it:

Navigate to the location where you want the tour to start. (Sorry, there is no find location).

Set up your first start view exactly as you would like it to appear. You can use all the Google Earth navigation methods to set up your view.

Click the “Add view” button to add the first view to your view list. By default the speed at that point is 10 meters per second (more about that later).

Set up your next view and click “Add view” again. You need to add the third point before the track is drawn. Make sure you keep the spacing between the points reasonably even, because otherwise the cubic spline (a smooth curve between points) becomes hard to control and starts to do funny loops.

Now you have a spline with 3 points. You can left click and drag any of the numbered view markers in the Google Earth plugin to adjust the path. The spline will flip to a low resolution spline while you are manipulating the points.

Each point is represented in the view list in the right sidebar. It shows the point index, an input box for speed in metres per second, an input box for the view altitude and a delete link. You can click on any entry in the list and the Google Earth plugin view will teleport to that view.

IMPORTANT: While on that view you can adjust your camera tilt and heading (but not roll). You do this by holding down CTRL and left-mouse-drag the view (standard Google Earth behaviour). The new camera orientation will be stored for that view point as long as the camera latitude and longitude coordinates did not change. Both heading and tilt are controlled via the spline.

The altitude is also controlled by the spline. You can change the altitude of a point by holding down the right mouse button and dragging the point. Alternatively you can change the altitude in the view list (second input box).

Timing: Each point will have a speed defined for it in meters per second. The speed varies smoothly as it is also controlled by the spline. However, it is possible to lock the duration of the tour to a precise time by entering the duration in the “Duration (sec)” input box. All the speeds are then scaled to match total duration. Clear the Duration field if you don’t want the speeds to be scaled. By default the duration is set to 60 seconds.

Once you hare happy with your track you can save it by clicking on “Save project” this causes a file with the project name to be generated and placed in your download folder. Use this file later if you want to work on this track. To load a project, refresh the page and click “Choose File” and select the file you just saved. Crude but there still is no decent local file implementation in browsers.

You can specify a Field of View (FOV) for the tour. The default Google Earth FOV is 60 degrees but you can adjust that. FOV is not animated and applies to the whole tour.

Once you have your tour and the path looks reasonable, the tour can be tested by clicking “Test kml”. The program will generate KML and show it in the text area under the view list. You can copy and paste the KML straight into Google Earth Desktop without turning it into a file. The test feature will also load the KML data into the plugin and the tour starts automatically. “Generate KML” does the same but doesn’t start a tour in the plugin.

The “Make project” button is not relevant for you. It produces data that I import into my own software that translates the tour for each of my 9 screens.

“Rebuild spline”, “update track” and “rebuild track” are debug functions. However, if you update the altitude of a point in the view list you will want to click “Rebuild track” to see the changes.

Paul also says:

This has to be the ugliest program ever written. But it does the job I need it to do. It’s not very user friendly but I produced amazing animations with it.”

Google Earth plugin gradually fading away

October 17, 2014

Due to the uncertain future of the Google Earth plugin, many prominent sites that used to use it have started to transition to other alternatives.

Here are three examples:

Ships 2 Career from PlanetInAction.com

Back in 2009 PlanetInAction.com released a fantastic free ship simulator using the Google Earth plugin. In 2011 it was upgraded to version 1.5.

However, the developer, Paul van Dinther, is now working on Ships 2 Career, which is entirely Google Maps based. Follow his progress on his Google+ page. We are sure that when it is released it will be an excellent game.

Ships 2 Career will be entirely Google Maps based.

GE Teach

GE Teach, a site developed by 9th-grade geography teacher Josh Williams, received a Geographic Excellence in Media Award in 2012. The site, until now, has been making excellent use of the Google Earth plugin to show side by side comparison views of various maps.

However, the site is now transitioning to a new version based on Google Maps. Despite the lack of 3D, it still looks good and has a number of notable features, including drawing tools, access to Google Maps Gallery, and Street View.

GE Teach Google Maps version

YoubeQ

YoubeQ is a cross between a social network and a driving/flying simulator. It allows you to drive or fly a large number of different vehicles/aircraft around the globe while socializing with other people you meet on the way. When we featured it in June 2014, it had 13 vehicles and 3 languages. Until recently it was based on the Google Earth plugin. It has now been completely redone in WebGL using Cesium. Read more about it here. It now uses Bing Maps for the 3D portion and Google Maps for navigation.

The new YoubeQ, using Cesium and Bing Maps.

Destiny – Google Street View in a game world

September 5, 2014

With our recent story on the possible demise of the Google Earth plugin – at least in the Chrome browser – it begs the question, what is currently possible with the Google Maps API?

Paul van Dinther of PlanetInAction.com, whose many great Google Earth Plugin creations we have featured over the years, is developing a new version of his ship simulator, Ships 2 Career, based on Google Maps. The previous version is based on the Google Earth plugin and is still available at PlanetInAction.com. You can get an idea of what the game will be like from this YouTube video.

Upcoming console game Destiny will be released in 3 days. Game developer Bungie, who also created Halo, has created a website showing the worlds of Destiny – Moon, Mars, and Venus.
Although the intro does give the illusion of a 3D experience reminiscent of Google Maps ‘Earth Mode’, the website is really much closer to Street View than the Google Earth plugin. The website says “created with Google Technologies”, and appears to be more sophisticated than simply using the Google Maps API.

The worlds of Destiny.

Street View on Venus! I think they used the ‘Trekker’ for this one.

Street View on the Moon, looks much more exciting than the Google Maps version.

45th anniversary of the Apollo 11 mission

July 18, 2014

This Sunday 45 years ago, July 20, 1969, Apollo 11 astronauts Neil Armstrong and Buzz Aldrin became the first humans to set foot on the moon.

One great way to experience the landing is by viewing this amazing Google Earth tour that Sean Askay put together a few years ago.

As you can see in the tour, the landing that Armstrong made was remarkable. With very little fuel, he had to carefully maneuver the ship into a gentle landing. Paul van Dinther created a game to simulate the landing that he calls the Apollo 11 Moon Lander. The game is very fun, and quite challenging – here is a review written by Frank when it was released. In the years since then, Paul has updated the game with some new graphics, Facebook integration and bug fixes. You can also watch this short video of the game in action:

You can check out the game for yourself at planetinaction.com/moonlander/.

Lastly, of course, is the excellent “Moon” feature in Google Earth, released in 2009. There is some remarkably sharp imagery in places on the moon, and even 3D models of the Apollo 11 Lunar Module.