Aviation is a free flight simulator meant to be somewhere in-between accurate but complicated simulators and simple toy simulators that don't provide any level of realism. Currently Aviation allows you to fly around in an area of around 600 square kilometers centered around the Columbia river.

Aviation (or rather Techne, the platform Aviation runs on) implements a continuous level-of-detail terrain triangulation engine capable of handling very large datasets, a configurable atmosphere model and a non-linear flight model. The default geographic dataset spans about 600 square kilometers and the currently defined flight model is that of a light aerobatic aircraft, to be used for Airrace. Adding more datasets or flight models is easy enough. Aviation doesn't do much by itself, you can only fly around. It is meant to be used as a base for other applications or games. One such example is Airrace, described in the next section but much more is possible.

Aviation is written on top of Techne. Have a look at Techne's homepage for more information and while you're at it, check out Billiards as well.

Airrace is a proof-of-concept Application written on top of Aviation implementing an air race game where the player has to pilot a light-weight aircraft through a track consisting of pylons or air gates. Although its written as a test of Aviation and in order to promote its development, it's still a full-fledged game. Currently there are 7 training courses and 5 race-tracks but adding more is a piece of cake.

The game features a flight model calculated through JSBSim's aeromatic to represent a light-weight aerobatic aircraft. This means that if we disregard a couple of points of no interest to our application like Mach-induced drag which only becomes significant at higher speeds or ground effect which becomes prominent when close to the ground etc. the flight-model is pretty realistic and accurate although not modelled after any particular plane but as a generic light, agile aircraft. In fact a couple of tests showed that the characteristics seems to agree with todays prominent race aircraft. At high speeds wings stall at about 12 G and above and the roll rate is about 400+ degrees per second. The top speed is a little higher. Maybe the engine needs a few hp of output less. All this makes the plane harder to handle and get the hang of but it also makes the whole game a lot more challenging.

Apart from that there's a graphical interface allowing you to select tracks save replays and export them for sharing with your friends and to keep track of your times and race results. The only thing missing is perhaps a central point for keeping times where pilots all over the world can compete.

Here's some of the obligatory eye-candy. The shots are more or less taken at random trying to capture some of the features like the configurable atmosphere model and toon-style cel shading.

Sunrise at low altitude A turbid atmosphere Clear skies and blue mountains A cel-shaded sunset

These are some shots from Airrace featuring the currently available tracks.

This is trickier than it looks Through the starting gate Into the chicane This doesn't look good

Here are a couple of recordings from Airrace. Sadly technical difficulties currently forbid proper audio extraction and synchronization from Techne.

Both Aviation and Airrace are Techne derivatives so in order to run them you'll need a working installation of Techne 0.2. Depending on the distribution you're using there might be packages available or you may need to compile the sources yourself. Head over to Techne's homepage to see the hardware and software requirements.

The latest releases of the sources and required datasets can be found by following the links in the following tables. In addition to these you'll also need to install Techne version 0.2 which you can find here. The provided Debian packages can be installed on a Ubuntu system as well as long as the proper Techne package is also installed.

The latest version of Aviation is 0.2 released on the 6th of December 2010.

Filename Size Description aviation-0.2.tar.gz A few Kilobytes Source tarball aviation-data-0.2.tar.gz 4.1M Data tarball columbia-0.1.tar.bz2 77M Data tarball amd64 Debian/Ubuntu packages aviation_0.2-1_amd64.deb A few Kilobytes Debian unstable/sid package aviation-data_0.2-1_amd64.deb 3.2M Debian unstable/sid package aviation-columbia_0.1-1_amd64.deb 86M Debian unstable/sid package i386 Debian/Ubuntu packages aviation_0.2-1_i386.deb A few Kilobytes Debian unstable/sid package aviation-data_0.2-1_i386.deb 3.2M Debian unstable/sid package aviation-columbia_0.1-1_i386.deb 86M Debian unstable/sid package

The latest version of Airrace is 0.1 released on the 6th of December 2010.

Filename Size Description airrace-0.1.tar.gz A few Kilobytes Source tarball airrace-data-0.1.tar.gz A few Kilobytes Data tarball amd64 Debian/Ubuntu packages airrace_0.1-1_amd64.deb A few Kilobytes Debian unstable/sid package airrace-data_0.1-1_amd64.deb A few Kilobytes Debian unstable/sid package i386 Debian/Ubuntu packages airrace_0.1-1_i386.deb A few Kilobytes Debian unstable/sid package airrace-data_0.1-1_i386.deb A few Kilobytes Debian unstable/sid package

Older versions can be found here.

Using Aviation is easy enough. You only need the mouse and as it is currently configured the left mouse button controls the elevators and ailerons, the middle one the rudders and the wheel allows you to adjust the throttle. Airrace has detailed instructions built into its interface describing the controls, the object of the game and giving a bit of theoretical and practical insight into what it takes to pilot a plane as well. Comments on their effectiveness is of course welcome.

It would probably help to have some sort of description of how Aviation can be configured and programmed too. I'll try to prepare something when the design settles a bit and spare time becomes available. Until then you can contact me by email if you need any help.

Discussion on the various matters concerning the development and usage of both Aviation and Airrace can be carried out in the Aviation-devel and Aviation-users mailing lists respectively. Please use these instead of my personal e-mail address for matters that might potentially be of interest to other users as well. Also remember to use the support tracker if you're having trouble getting Aviation to compile and run properly.

Since Aviation and Airrace have only been running on my machine up to now it probably contains heaps of bugs just waiting to reveal themselves in other configurations. If you're having trouble compiling, installing or running it please submit a bug report using the support tracker at the project's home page which can be found by following this link. Also please search or browse the tracker first to make sure your bug hasn't already been submitted by another user.

Dimitris Papavasiliou dpapavas at gmail.com

Both the sources and dataset of Aviation and its derivatives are released under the terms of the GNU General Public License. Use of the Columbia elevation and imagery data set is free to all.