FlightGear Newsletter May 2016
|This newsletter is a draft.
Please feel free to add content that you think will be of interest to the FlightGear community.
Terrasync started out as a standalone rsync-based utility. However, there doesn't appear to be any good/robust multi-platform librsync available for our use. We wanted to embed terrasync right into the core code so we could better coordinate downloading tiles and then loading them immediately into the sim (versus sometimes running into no tiles or partial tiles if an external tool was running rsync.)
as some of you have probably noticed, some coding is currently happening in the terrasync corner, mostly by James and some small parts by Torsten. The main intention is to get rid of the SVN protocol to distribute scenery but use easier to implement protocols. The idea is to use plain HTTP as the access method for files required by terrasync. This should make it much easier for hosts to set up a mirror, probably enables us to use a CDN for load balancing and also makes the client code slim. We already have three mirrors of the complete scenery online, one at sourceforge and two at privately owned servers. The sourceforge mirror receives daily updates from the main scenery export from http://scenery.flightgear.org/ and all other mirrors pull their data from the sourceforge server. We decided to drop the previous method of telling the client about it's nearest mirror by querying a web service ( http://scenery.flightgear.org/svn-server) in favour of using a more stable service provider of the internet: the domain name service (DNS) system. The fgfs client will query a fancy resource record (RR) type of NAPTR (network authority pointer, https://en.wikipedia.org/wiki/NAPTR_record) for the dns name terrasync.flightgear.org and analye the entries to find the best terrasync mirror. Those entries are already configured and can be examined here: https://toolbox.googleapps.com/apps/dig/#ANY/terrasync.flightgear.org This technique should enable us to provide different sets of scenery, eventually even for only parts of the world in a much easier fashion that it would have been the case with SVN. It also spares many gigabytes on the scenery mirror as they don't have to keep all the 50,000+ revisions we already carry around. I'll start adding the required code over the next couple of days to have it running hopefully for the 2016.2 release. I'll post a message to this list when I flip the final switch and enable the new terrasync. In the mean time, you might see some build failures on Jenkins or other hickups of the system. I promise to fix those as quick as possible. BTW: If you use terrafs, you already receive your data from the new http mirrors, although not use the DNS service resolver.
the http download method will function very much as before where only the changed files (if any) are downloaded. The svn method requires 2x the actual space because of the way svn works under the hood. Git typically requires that you download every version ever created to get the latest copy (there are work arounds if you just want the most recent version.) So the end result for the average user that just wants to download and use the scenery is that the http method will be lighter weight overall. It also simplifies the code inside FlightGear quite a bit and should make the synchroniation more robust. And as mentioned before, it should simplify the task of setting up a scenery mirror for those that wish to do that. As before, power users will have multiple options for updating scenery or mixing and matching from different sources if they choose. 
The technique of the http repository is much simpler than that of the svn repository and it will be pretty simple to create a local mirror or to download chunks of data. With a bit of to-be-developed scripting (python e.g.) there is no need to download existing data again. I don't know how terramaster works but I am sure it is easy to adapt to the new http access method. 
The goal is to completely remove SVN and only use the HTTP repository. I'd like to reach that goal better sooner than later as we currently have two single-points of failure for the SVN-service. The first is the http://scenery.flightgear.org/svn-service web service (runs on a private web server) and the second is the one-and-only svn-server available for public access, also hosted on a private server. If either on of those fails, the SVN-terrasync is dead. I have learned the hard way that not having a fallback is a bad idea.
- Curtis Olson (May 3rd, 2016). Re: [Flightgear-devel] The future of terrasync.
- Torsten Dreyer (May 2nd, 2016). [Flightgear-devel] The future of terrasync.
- Curtis Olson (May 4th, 2016). Re: [Flightgear-devel] The future of terrasync.
- Torsten Dreyer (May 4th, 2016). Re: [Flightgear-devel] The future of terrasync.
- Torsten Dreyer (May 4th, 2016). Re: [Flightgear-devel] The future of terrasync.
New support for expressions was added in the volume and pitch sections of audio configuration files .
It works as follows:
- If an expression is found in <pitch/> or <volume/> it gets processed and the rest is ignored.
- If an expression was defined in a volume or pitch definition of a sound-section then all other volume or pitch sections containing a property are ignored.
- Sections with <internal/> are always processed so timed sounds are still available.
This way you can add volume and/or pitch sections with an expression before all other sections and keep backward and forward compatibility. But you could, for example, make the expression section more complex for newer versions of FlightGear.
An example would be:
<engine> <name>engine</name> <mode>looped</mode> <path>Aircraft/paraglider/Sounds/wasp.wav</path> <property>engines/engine/running</property> <volume version="2.0"> <expression> <product> <min> <max> <product> <property>engines/engine/mp-osi</property> <value>0.23</value> </product> <value>1.0</value> </max> <value>0.3</value> </min> <min> <max> <log> <property>orientation/alpha-deg</property> </log> <value>1.2</value> </max> <value>1.0</value> </min> </product> </expression> </volume> <pitch version="2.0"> <expression> <min> <max> <sum> <value>0.4</value> <product> <property>engines/engine/rpm</property> <value>0.0001</value> </product> </sum> <value>1.2</value> </max> <value>0.4</value> </min> </expression> </pitch> <volume> <property>engines/engine/mp-osi</property> <factor>0.23</factor> <min>0.3</min> <max>1.0</max> </volume> <volume> <property>orientation/alpha-deg</property> <type>log</type> <min>1.0</min> <max>1.2</max> </volume> <pitch> <property>engines/engine/rpm</property> <factor>0.0001</factor> <min>0.4</min> <max>1.2</max> <offset>0.4</offset> </pitch> </engine>
In the hangar
The c172p team has just created a new branch called "release/2016.2" with the latest developments from the last months: https://github.com/Juanvvc/c172p-detailed/tree/release/2016.2 These include:
- Decreased rudder authority
- Added propwash effect for 180 HP version
- Improvements to the irradiance effect
- Better oil dialog
- Flap lever is now dragable and scrollable
- Added normal map to wheels and other objects
- Improvements to the heading indicator
- Correct rudder pedal animation
- Updated tutorial to Barcelona
- Changed "Autostart" menu item to actually start the engine as well
- Split instrument light knob into a knob that two knobs: one that controls the instruments, and one that controls the radio's 
ICARO Laminar 13 MRX
The aim of this project is to provide a very realistic hang glider which shows all the specific properties of a real hang glider. In particular the unique flight dynamic behavior (compared to common aircraft) is focused on.
David's paraglider model has had a major FDM and 3d update. The FDM is of true ram-air type, a small engine has been added and the parachute itself is now animated. Warining: a bug prevents the Paraglider from loading properly at the current default airport Barcelona. Any other airport does not seem to cause a problem.
|The FlightGear Wiki still needs help for translating it into various languages. If you are interested in making the FlightGear Wiki multilingual, you can start by looking at Help:Translate.|
|Le wiki de FlightGear a toujours besoin d'aide pour être traduit en différentes langues. Si vous êtes intéressé par le rendre multilingue, commencez par lire Help:Traduire.|
|Das FlightGear Wiki braucht noch Hilfe für sie in verschiedene Sprachen zu übersetzen. Wenn Sie bei der Herstellung der FlightGear Wiki mehrsprachiger interessiert sind, können Sie, indem Sie auf Help:Übersetzen beginnen.|
|De FlightGear Wiki kan nog steed hulp gebruiken bij het vertalen van artikelen. Als je interesse hebt om de wiki meertalig te maken, raden we je aan om een kijkje te nemen bij Help:Vertalen.|
|La wiki de FlightGear todavía necesita ayuda para traducirla a varios lenguajes. Si estás interesado en hacer la FlightGear wiki multilingüe, entonces comienza en Help:Traducir.|
|La wiki de FlightGear encara necessita ajuda per traduir-la a diverses llengües. Si esteu interessat en fer la wiki de FlightGear multilingüe, llavors comenceu a Help:Traduir.|
|A wiki de FlightGear ainda necessita de ajuda para traduzi-la em vários idiomas. Se estás interessado em tornar a wiki de FlightGear multi-lingual, por favor começa em Help:Traduzir.|
If you want some graphic elements for your FlightGear-related site (such as a hangar or YouTube channel), please feel free to visit FlightGear logos for a repository of logos. And if you have some art skills, please don't hesitate to contribute with your own design creations.
The FlightGear project always needs screenshots, which show features that were added since the last release. These should be of good quality, especially in content and technical image properties. It is therefore recommended to use the best viable filter settings (anti-aliasing, texture sharpening, etc.). More info at Howto:Make nice screenshots.
Screenshot of the Month
Entries for this month's best screenshot can be submitted to this forum topic. Be sure to see the first post for participation rules. For purposes of convenience and organization, after all the entries have been submitted, a new forum topic will be started containing all shots in an easy-to-view layout. The voting will then take place there. Once the voting has finished, the best screenshot will be presented on this page.
- Erik Hofman (May 31st, 2016). [Flightgear-devel] New XML Sound feature .
- Gilberto Agostinho (May 17th, 2016). [Flightgear-devel] c172p ready for the Barcelona release .