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12 <h1 align="center">FlightGear FAQ</h1>
17 <p>Welcome to the FlightGear FAQ. Here you will find the answers to
18 some questions that are frequently asked on our mailing lists. If
19 you have a question that is not answered here, feel free to ask
20 us on our mailing lists. Enjoy</p>
24 <a name="toc">Table of Contents</a>
27 <a href="#1">The FAQ</a>
29 <div class="indent">1.1 -
30 <a href="#1.1">Where can I get the latest version of this FAQ?</a>
32 <div class="indent">1.2 -
33 <a href="#1.2">Who do I contact if I have comments about this FAQ?</a>
35 <div class="indent">1.3 -
36 <a href="#1.3">How old is this document?</a>
38 <div class="indent">1.4 -
39 <a href="#1.4">What other important documentation should I read?</a>
43 <a href="#2">Distribution</a>
45 <div class="indent">2.1 -
46 <a href="#2.1">Where can I get FlightGear?</a>
48 <div class="indent">2.2 -
49 <a href="#2.2">What is the password for the FTP server?</a>
51 <div class="indent">2.3 -
52 <a href="#2.3">Why won't the FTP server let me in with the right login info?</a>
54 <div class="indent">2.4 -
55 <a href="#2.4">Where can I find the latest development source code?</a>
57 <div class="indent">2.5 -
58 <a href="#2.5">What is SimGear, and why do I need it?</a>
60 <div class="indent">2.6 -
61 <a href="#2.6">Where can I fly and where do I get the scenery?</a>
63 <div class="indent">2.7 -
64 <a href="#2.7">Where can I get different 3D models for my plane?</a>
66 <div class="indent">2.8 -
67 <a href="#2.8">How current is the data in FlightGear compared to the real world?</a>
69 <div class="indent">2.9 -
70 <a href="#2.9">Where is the moving map?</a>
72 <div class="indent">2.10 -
73 <a href="#2.10">Why don't you charge money for this?</a>
77 <a href="#3">Compiling</a>
79 <div class="indent">3.1 -
80 <a href="#3.1">Why won't FlightGear compile?</a>
82 <div class="indent">3.2 -
83 <a href="#3.2">I'm using RedHat 7, and ...?</a>
87 <a href="#4">Configuring</a>
89 <div class="indent">4.1 -
90 <a href="#4.1">How do I install new scenery?</a>
92 <div class="indent">4.2 -
93 <a href="#4.2">How do I setup my joystick(s)?</a>
95 <div class="indent">4.3 -
96 <a href="#4.3">What format should my personal .fgfsrc file be in?</a>
100 <a href="#5">Running</a>
102 <div class="indent">5.1 -
103 <a href="#5.1">Why do I get an error loading libopenal.so.0?</a>
105 <div class="indent">5.2 -
106 <a href="#5.2">Why do I get "ssgInit called without a valid OpenGL context"?</a>
108 <div class="indent">5.3 -
109 <a href="#5.3">What happened to the panel, keyboard, etc?</a>
111 <div class="indent">5.4 -
112 <a href="#5.4">Why doesn't audio work properly under Irix?</a>
114 <div class="indent">5.5 -
115 <a href="#5.5">Why is FlightGear so slow?</a>
117 <div class="indent">5.6 -
118 <a href="#5.6">Why is my SGI machine so slow?</a>
120 <div class="indent">5.7 -
121 <a href="#5.7">How do I see the frame rate?</a>
123 <div class="indent">5.8 -
124 <a href="#5.8">Stuck upside down after "crash"?</a>
126 <div class="indent">5.9 -
127 <a href="#5.9">Why does FlightGear die on startup saying "time zone reading failed"?</a>
131 <a href="#6">Hacking</a>
133 <div class="indent">6.1 -
134 <a href="#6.1">What language is FlightGear written in?</a>
136 <div class="indent">6.2 -
137 <a href="#6.2">How do I design a flight dynamics model for a new aircraft?</a>
139 <div class="indent">6.3 -
140 <a href="#6.3">How do I import planes from Microsoft Flight Simulator?</a>
142 <div class="indent">6.4 -
143 <a href="#6.4">How do I import BGL scenery from Microsoft Flight Simulator?</a>
145 <div class="indent">6.5 -
146 <a href="#6.5">How do I design or modify a panel?</a>
148 <div class="indent">6.6 -
149 <a href="#6.6">How do I place objects, like buildings, into FlightGear?</a>
151 <div class="indent">6.7 -
152 <a href="#6.7">Where can I learn 3D programming and how do I get involved?</a>
154 <div class="indent">6.8 -
155 <a href="#6.8">How do I add an airport?</a>
157 <div class="indent">6.9 -
158 <a href="#6.9">How do I generate my own scenery?</a>
162 <a href="#7">Flying</a>
164 <div class="indent">7.1 -
165 <a href="#7.1">Where can I learn about instrument flying and navigation?</a>
167 <div class="indent">7.2 -
168 <a href="#7.2">What is the difference between Aileron and Rudder?</a>
170 <div class="indent">7.3 -
171 <a href="#7.3">Is there support for multi-player flying?</a>
173 <div class="indent">7.4 -
174 <a href="#7.4">Is there support for any military scenarios like dog fighting or bomb dropping?</a>
178 <a href="#8">FlightGear v0.7.6</a>
180 <div class="indent">8.1 -
181 <a href="#8.1">Why do I get an error in viewer.cxx about `exit' being undeclared?</a>
193 <u>Where can I get the latest version of this FAQ?</u>
198 <a href="http://flightgear.org/Docs/FlightGear-FAQ.html">http://flightgear.org/Docs/FlightGear-FAQ.html</a>
204 <u>Who do I contact if I have comments about this FAQ?</u>
208 <p>First contact the author. If you get no response, send your
209 comments to the FlightGear-Users mailing list.</p>
214 <u>How old is this document?</u>
218 <p>See the <i>About This Document</i> section at the end of the FAQ.</p>
223 <u>What other important documentation should I read?</u>
227 <p>Most FlightGear documentation is linked to from
228 <a href="http://flightgear.org/Docs/">http://flightgear.org/Docs/</a>.
229 Definitely check out the <i>FlightGear Installation and Getting
230 Started</i> document available from the aforementioned location.</p>
231 <p>Also see the <code>FlightGear/docs-mini/</code> directory in the
232 source distribution for various other helpful documents.</p>
243 <u>Where can I get FlightGear?</u>
247 <p>The official download page is
248 <a href="http://flightgear.org/Downloads/">http://flightgear.org/Downloads/</a>.
249 Source code is our primary form of distribution, but precompiled
250 binaries are available for Windows and SGI IRIX.</p>
251 <p>Alternatively, FlightGear is packaged for Linux by SuSE, Debian
252 (sid), and Mandrake (Cooker) and can be directly installed through
253 those distributions.</p>
258 <u>What is the password for the FTP server?</u>
262 <p>The FTP server uses standard anonymous login procedures. Login
263 with the username "anonymous" and use your email address as the
264 password. Most FTP clients and web browsers will do this
265 automatically for you.</p>
270 <u>Why won't the FTP server let me in with the right login info?</u>
274 <p>This generally means that the server is at it's capacity. You
275 should receive a message saying such, but your FTP client may be
276 hiding it from you. Your options are to keep trying until a slot
277 opens up or try connecting to one of our <i>FTP</i> mirrors listed at
278 <a href="http://flightgear.org/mirrors.html">http://flightgear.org/mirrors.html</a>.</p>
283 <u>Where can I find the latest development source code?</u>
287 <p>The latest development code is available for everyone through our
289 <a href="http://flightgear.org/cvsResources/">http://flightgear.org/cvsResources/</a> for details.
291 <p>Otherwise, you can get relatively up-to-date snapshots of the
293 <a href="ftp://flightgear.sourceforge.net/pub/flightgear/Devel/Snapshots/">ftp://flightgear.sourceforge.net/pub/flightgear/Devel/Snapshots/</a>.
299 <u>What is SimGear, and why do I need it?</u>
303 <p>SimGear is a library of supporting code. SimGear is only needed
304 if you plan on compiling FlightGear -- it is not needed to run
305 precompiled binaries. For more information see
306 <a href="http://www.simgear.org/">http://www.simgear.org/</a>.</p>
311 <u>Where can I fly and where do I get the scenery?</u>
315 <p>While the base package only comes with scenery for the San Francisco
316 Bay area, you can currently fly just about anywhere in the world.
317 See the <i>"Additional Scenery"</i> section of
318 <a href="http://flightgear.org/Downloads/">http://flightgear.org/Downloads/</a>
319 for more information or go directly to our graphical downloader at
320 <a href="http://flightgear.org/Downloads/world-scenery.html">http://flightgear.org/Downloads/world-scenery.html</a>.
322 <p>Also visit our <i>"Places to Fly"</i> section of the website
323 (<a href="http://flightgear.org/Places/">http://flightgear.org/Places/</a>)
324 for some help navigating to some awesome locations.</p>
329 <u>Where can I get different 3D models for my plane?</u>
333 <p>While we are working toward building our own 3D models, we have
334 been given permission by several people to convert their models (which
335 where originally intended for use with <i>Microsoft Flight
336 Simulator</i>) to use with FlightGear. See Wolfram's Hangar
337 (<a href="http://home.t-online.de/home/Wolfram.Kuss/">http://home.t-online.de/home/Wolfram.Kuss/</a>)
338 for a list of what we currently have available as well as
339 information on how to convert models yourself.</p>
344 <u>How current is the data in FlightGear compared to the real world?</u>
348 <p>We use the same navaid and airport dataset that <i>X-Plane</i> uses. The
349 current dataset can be found in the <code>$FGROOT/Navaids/</code> and
350 <code>$FGROOT/Airports/</code> directories. If you have updates or
351 corrections to the dataset, see
352 <a href="http://flightgear.org/Docs/AirNav/AptNavFAQ.FlightGear.html">http://flightgear.org/Docs/AirNav/AptNavFAQ.FlightGear.html</a>
353 for instructions on contacting the database maintainer.</p>
358 <u>Where is the moving map?</u>
362 <p>A popular moving map display is avaliable under a separate
363 project called <i>Atlas</i>. See
364 <a href="http://atlas.sf.net/">http://atlas.sf.net/</a>.</p>
368 <a name="2.10">2.10 -
369 <u>Why don't you charge money for this?</u>
373 <p>We could do that, since the initial download is about 25
374 megabytes. Especially for people who have to pay per-minute charges
375 for internet access, buying a CD is a convenient and possibly
376 cheaper option. Although we offer that service (see the website), we
377 encourage other groups to redistribute it for their users, especially
378 within an operating system distribution which makes installation even
379 faster and easier for new users.</p>
390 <u>Why won't FlightGear compile?</u>
394 <p>Well, that depends. First make sure you are using the appropriate
395 versions of FlightGear, SimGear, plib, zlib. If any of
396 the packages are out of sync with the others, compilation may fail.</p>
397 <p>The FlightGear <i>Downloads</i> page
398 (<a href="http://flightgear.org/Downloads/">http://flightgear.org/Downloads/</a>)
399 should tell you what versions you need if you are trying to compile
400 the latest stable release. If you are using a development snapshot,
401 make sure all three packages are up-to-date.</p>
402 <p>Also ensure that you have some implementation of OpenGL with glut
403 support with the appropriate header files. Linux users with nVidia
404 cards should make sure you have the latest drivers from nVidia. Other
405 Linux users make sure you have Mesa3D
406 (<a href="http://mesa3d.org/">http://mesa3d.org/</a>)
407 and your X server installed correctly. Windows users see
408 <a href="http://www.x-plane.com/SYSREQ/v5ibm.html">http://www.x-plane.com/SYSREQ/v5ibm.html</a>,
410 <a href="http://www.x-plane.com/SYSREQ/v5mac.html">http://www.x-plane.com/SYSREQ/v5mac.html</a>.
412 <p>If your problems persist, subscribe to our FlightGear-Users mailing
413 list and let us know what problem you're having. See
414 <a href="http://flightgear.org/mail.html">http://flightgear.org/mail.html</a> for help with this.
420 <u>I'm using RedHat 7, and ...?</u>
424 <p>Update your gcc packages. See
425 <a href="http://redhat.com/errata/">http://redhat.com/errata/</a>
427 <a href="http://www.gnu.org/software/gcc/gcc-2.96.html">http://www.gnu.org/software/gcc/gcc-2.96.html</a>
428 for an explanation why.</p>
439 <u>How do I install new scenery?</u>
443 <p>The scenery archive files (ie. w100n30.tar.gz) should be untarred
444 into the <code>Scenery/Terrain</code> directory in your
445 <code>$FG_ROOT</code>.</p>
450 <u>How do I setup my joystick(s)?</u>
454 <p>FlightGear should come with a helpful program called <i>`fgjs`</i>
455 that can help configure your joystick. Run <i>`fgjs`</i> and then
456 copy the dot file it created into your home directory or add its
457 contents to your existing rc file.</p>
458 <p>Also, see the README.Joystick file located in the
459 <code>FlightGear/docs-mini/</code> directory of the source
460 distribution. This document is mirrored at
461 <a href="http://rockfish.net/fg/README.Joystick">http://rockfish.net/fg/README.Joystick</a>.
467 <u>What format should my personal .fgfsrc file be in?</u>
471 <p>Your <code>.fgfsrc</code> file should simply be a list of
472 command-line options with one option per line. The file is <b>not</b>
474 <p>If you would rather use an XML configuration file, you can add
475 something like the following in your <code>.fgfsrc</code>
478 <code>--config=/path/to/my/config.xml</code>
480 <p>Almost every option corresponds to a property, so you can choose
481 to use whichever method best suits your needs.</p>
492 <u>Why do I get an error loading libopenal.so.0?</u>
496 <p>With the default installation, libopenal.so.0 is installed into
497 <code>/usr/local/lib</code>. You need to ensure that that path is
498 listed in <code>/etc/ld.so.conf</code>, then run <i>`ldconfig`</i>as
504 <u>Why do I get "ssgInit called without a valid OpenGL context"?</u>
508 <p>In short, your GL libraries are broken. So far only Red Hat 7.x
509 users have experienced this (see
510 <a href="http://www.redhat.com/bugzilla/show_bug.cgi?id=18867">http://www.redhat.com/bugzilla/show_bug.cgi?id=18867</a>).
511 The only solutions are possibly complicated ones: you can either
512 change distributions (most of us prefer Debian) or upgrade/downgrade
516 <u>Why do some other GL applications work though?</u>
518 Steve Baker (Mr. PLIB) has explained this on the plib-users list
519 (<a href="http://www.geocrawler.com/lists/3/SourceForge/1867/0/6470648/">http://www.geocrawler.com/lists/3/SourceForge/1867/0/6470648/</a>).
525 <u>What happened to the panel, keyboard, etc?</u>
529 <p>The problem is almost certainly that your base package is out of
530 sync with FlightGear. Many configurable parts of FlightGear are
531 defined in XML files contained in the base package.</p>
536 <u>Why doesn't audio work properly under Irix?</u>
540 <p>FlightGear (as of June 2001) uses the Portable Libraries (PLIB)
541 for playing audio. The audio queue implementation of PLIB is far from
542 optimal (in fact it's just wrong). This seems to work on other
543 platforms quite well, but Irix expects things to be programmed
545 <p>There has been discussion about using OpenAL
546 (<a href="http://www.openal.org/">http://www.openal.org/</a>)
547 for the next release of both PLIB and FlightGear. Tests show that
548 the OpenAL audio implementation does the job right, meaning that
549 these audio problems should be gone by then. In the mean time it is
550 best to disable audio on Irix completely (by adding --disable-sound
551 either on the command line or to your <code>$HOME/.fgfsrc</code>
557 <u>Why is FlightGear so slow?</u>
561 <p>FlightGear supports hardware acceleration, but it seems not to be
562 activated. Make sure you have OpenGL libraries installed and
563 configured properly and make sure you have the latest drivers for your
566 <b>Linux users</b>: If you are an nVidia user, follow their
567 directions on getting your card working. For most other users, make
568 sure Mesa is installed property and ensure that you have the
569 appropriate kernel device drivers for your card. Most people (and
570 distributions) use modules for their video card device drivers; run
571 <i>`lsmod`</i> as root to see what modules are loaded. You should also
572 make sure that you are loading the appropriate modules in your
573 XF86Config and that your video device section is correct. Now try
574 running an OpenGL application (other than FlightGear) to see how it
575 performs. You can try the <i>gears</i> demo from Mesa or something
576 like <i>Quake3</i>.</p>
581 <u>Why is my SGI machine so slow?</u>
585 <p>First of all, one of the most common mistakes on SGI hardware is to
586 forget to specify --fog-fastest. On most SGI machines the EXP2 shading
587 model isn't hardware supported resulting in frame rates below 1 frame
588 per second (fps).</p>
589 <p>FlightGear makes extensive use of the OpenGL z-buffer feature,which
590 on most older SGI hardware is only supported in software. This means
591 that the CPU has to do all the z-buffer calculations in addition to the
592 other tasks FlightGear involves (flight dynamics, scenery tracking,
593 pushing commands into the graphics queue, etc). The following features
594 are software rendered on low-end SGI machines (like Indy and
597 <li>stencil and accumulation buffer</li>
598 <li>depth queuing and depth buffering</li>
599 <li>fogging, lighting, clipping and transforms</li>
602 <p>This means that running FlightGear with the following options may not
603 even get the desired result:</p>
605 <code>./runfgfs --fog-disable --shading-flat --disable-skyblend \</code>
607 <code>--disable-textures --disable-clouds --disable-sound \</code>
609 <code>--disable-panel --enable-hud --disable-anti-alias-hud</code>
611 <p>I could even imagine that adding --enable-wireframe doesn't work on
612 these machines (I would be happy to be proven wrong though).</p>
613 <p>On a machine like O2 the following options give an acceptable
615 <code>./runfgfs --fog-fastest --disable-sound</code>
616 <p>Since I don't have access to other SGI hardware I can't tell which
617 options would be appropriate for your situation.</p>
622 <u>How do I see the frame rate?</u>
626 <p>There are two ways. One way is to hide the panel without the HUD
627 showing. To hide the panel, use <i>Shift+P</i>; To make the HUD
628 disappear, use <i>H</i>. The second way is to use the alternative
629 HUD by <i>Shift+I</i> (Use <i>I</i> to switch back).</p>
634 <u>Stuck upside down after "crash"?</u>
638 <p>In his infinite wisdom the FlightGear Grand Master decided that
639 planes were to valuable to allow them to be destroyed by novice pilots
640 who seemed to crash a lot. The fact that nobody has bothered to model
641 crashes may have something to do with it too. :-)</p>
642 <p>The result of this as you have noticed is that with a little
643 practice an ingenuity you can trim the ship to fly inverted along the
645 <p>The quick answer is to hit Ctrl+U (with the default key bindings)
646 to warp the plane up 1000ft.</p>
647 <p>For the stubborn people out there: The trick to learn is to roll
648 back to normal (non inverted) do this by nursing the elevator to get
649 to about 500 feet or so and use the ailerons to snap roll 180*.
650 This is all good avionics except for the plane not destroying
651 itself. Remember the controls work in reverse when you are inverted
652 and keep that airspeed up!!!</p>
657 <u>Why does FlightGear die on startup saying "time zone reading failed"?</u>
661 <p>This is probably caused by a line-ending problem in the timezone
662 files. Win32 users can resolve the problem by downloading a DOS to
663 UNIX conversion utility available at
664 <a href="http://www.nottingham.ac.uk/~eazdluf/d2u.zip">http://www.nottingham.ac.uk/~eazdluf/d2u.zip</a>.
665 Run as `<i>d2u *.tab</i>` from within the timezone directory to fix
666 your timezone files.</p>
677 <u>What language is FlightGear written in?</u>
681 <p>Mostly C++ with some supporting C code that's primary contained
687 <u>How do I design a flight dynamics model for a new aircraft?</u>
691 <p>To define an aircraft for FlightGear's primary FDM (JSBSIM),
692 see <a href="http://jsbsim.sf.net/">http://jsbsim.sf.net/</a>.</p>
693 <p>If you want a simpler FDM to work with, try your hand at YASim,
694 an alternative FDM. For an guide on creating a YASim aircraft,
695 look in the FlightGear base package for
696 <code>Aircraft-yasim/README.yasim</code>.</p>
701 <u>How do I import planes from Microsoft Flight Simulator?</u>
705 <p>You can import the 3D model and textures, but the flight dynamics
706 (the .AIR file) must be completely redone for FlightGear. See
707 <a href="http://home.t-online.de/home/Wolfram.Kuss/">http://home.t-online.de/home/Wolfram.Kuss/</a>
708 for help importing .MDL files and textures.</p>
709 <p>If you wish to import a model made with gmax, you will need to
710 convert it to .MDL format using <i>Microsoft's MakeMDL SDK</i> which
712 <a href="http://zone.msn.com/flightsim/FS02DevDeskSDK08.asp">http://zone.msn.com/flightsim/FS02DevDeskSDK08.asp</a>.
718 <u>How do I import BGL scenery from Microsoft Flight Simulator?</u>
723 <a href="http://chiangt.virtualave.net/BGL/bgl_index.html">http://chiangt.virtualave.net/BGL/bgl_index.html</a>.
729 <u>How do I design or modify a panel?</u>
733 <p>See the README.xmlpanel file located in the
734 <code>FlightGear/docs-mini/</code> directory of the source
735 distribution. This document is mirrored at
736 <a href="http://rockfish.net/fg/README.xmlpanel">http://rockfish.net/fg/README.xmlpanel</a>.
742 <u>How do I place objects, like buildings, into FlightGear?</u>
746 <p>First, ensure that you have v0.7.7 or later, the scenery files
747 where you plan to place the object, the actual model, and the
748 longitude and latitude where you plan to place the object.</p>
749 <p>Now get the altitude for your point. If you don't want to
750 calculate this yourself, start FlightGear at your location and take
751 note of the altitude. Here's an example command:</p>
753 <code>fgfs --lat=45.50 --lon=-75.73 2>&1 | tee fgfs.log</code>
755 <p>The altitude is probably in feet, so divide the starting altitude
757 <p>Search the output log file for the first occurrence of the string
758 "Loading tile" and take note of the filename. In the above example,
759 the output line looks like:</p>
761 <code>Loading tile /usr/local/Scenery/w080n40/w076n45/1712601</code>
763 <p>Copy a 3D model in a format that Plib understands to the same
764 directory as the tile file. Edit the text file in that directory
765 consisting of the tile name with the extension ".stg". The file will
766 already exist if there is an airport on the tile; otherwise, you can
767 create it from scratch. In our example, the filename is:</p>
769 <code>/usr/local/Scenery/w080n40/w076n45/1712601.stg</code>
771 <p>At the end of the file, add a new entry for your object,
772 consisting of the word "OBJECT_STATIC" followed by the model name,
773 the longitude in degrees, the latitude in degrees, the altitude in
774 meters, and the heading in degrees. In our example the line looks
777 <code>OBJECT_STATIC Towerax.ac -75.73 45.40 60 0</code>
779 <p>Save the changes to the .stg file, restart FlightGear, and
781 <p>NOTE: The above information was taken from the following mailing
783 <a href="http://www.geocrawler.com/archives/3/11854/2001/6/0/5991409/">http://www.geocrawler.com/archives/3/11854/2001/6/0/5991409/</a>.
784 See that page if this one doesn't make sense.</p>
785 <p>An alternative approach using PPE is described at
786 <a href="http://mail.flightgear.org/pipermail/flightgear-devel/2001-December/002239.html">http://mail.flightgear.org/pipermail/flightgear-devel/2001-December/002239.html</a>
792 <u>Where can I learn 3D programming and how do I get involved?</u>
796 <p>Contributing to the 2D panel doesn't require any coding at all,
797 just a minimal knowledge of XML syntax (i.e. five minutes' worth)
798 and good skills with drawing and/or paint programs. Every instrument
799 on the current panel, with the partial exception of the magnetic
800 compass, is defined entirely in XML with no custom C++ code. If
801 you want to get started, take a look at John Check's excellent intro
802 (<a href="http://rockfish.net/fg/README.xmlpanel">http://rockfish.net/fg/README.xmlpanel</a>).
804 <p>Likewise, if you want to create a 3D cockpit for FlightGear, or to
805 create buildings, external aircraft models, etc., your help is
806 *desperately* needed. The only rule is to go easy on the triangles
807 -- a model with 50,000 triangles probably won't be usable in
808 FlightGear, and one with 5,000 triangles, only marginally. If you
809 can design a nice 3D cockpit interior for a Cessna 172 (for example)
810 in a 3D design program such as ac3D or ppe, we have coders who will
811 be happy to add the support code in the C++.</p>
812 <p>If, on the other hand, you really want to get your hands dirty
813 with C++ coding, you'll have to buy a good OpenGL book eventually.
814 However, FlightGear uses a high-level library, plib, that hides most
815 of the details of OpenGL. To get started with 3D C++ coding, you
816 can take a look at the plib documentation and learn only as much
817 OpenGL as you need, when you need it.</p>
822 <u>How do I add an airport?</u>
826 <p>You can add your airport to the
827 <code>$FGROOT/Airports/default.apt.gz</code> file, but to get the
828 airport to show up visually, you will have to rebuild the scenery
829 around the airport. The format of the default.apt file is
831 <a href="http://flightgear.org/Docs/AirNav/AptNavFAQ.FlightGear.html">http://flightgear.org/Docs/AirNav/AptNavFAQ.FlightGear.html</a>.</p>
836 <u>How do I generate my own scenery?</u>
840 <p>Yes, though it can be a difficult task. FlightGear's scenery
841 generation is handled by a sister project, TerraGear. For more
843 <a href="http://terragear.org/">http://terragear.org/</a>.</p>
854 <u>Where can I learn about instrument flying and navigation?</u>
859 <a href="http://www.navfltsm.addr.com/">http://www.navfltsm.addr.com/</a>
860 is a very good site for learning techniques for navigation. Also see
861 <a href="http://www.monmouth.com/~jsd/how/">http://www.monmouth.com/~jsd/how/</a>.
867 <u>What is the difference between Aileron and Rudder?</u>
871 <p>There is a bit of info on aileron vs. rudder here:
872 <a href="http://www.monmouth.com/~jsd/how/">http://www.monmouth.com/~jsd/how/</a>.
878 <u>Is there support for multi-player flying?</u>
882 <p>We have an initial stab at this that is incomplete and only seems
883 to work under Linux. We'd love to find someone to pick up the
884 slack here and develop this further. Specifically, plib now has
885 some low level networking support for mult-player games. It would
886 also be nice to develop support for the DIS protocol.</p>
891 <u>Is there support for any military scenarios like dog fighting or bomb dropping?</u>
895 <p>No, not at this time. Most of our developers are primarily
896 interested and focused on civilian aviation. We aren't explicitly
897 excluding these features -- we just haven't had anyone who seriously
898 wanted to develop these areas.</p>
905 FlightGear v0.7.6</a>
909 <u>Why do I get an error in viewer.cxx about `exit' being undeclared?</u>
913 <p>This error cropped up after the release of v0.7.6. To fix the
914 problem, add "<code>#include <stdlib.h></code>" to the top of viewer.cxx.</p>
921 <h2>About This Document</h2>
923 <b>FlightGear FAQ</b>
924 <br>$Revision$<br>$Date$<br>
927 This document generated from XML using
928 <a href="http://gingerall.com/charlie/ga/xml/p_sab.xml">Sablotron</a>.
932 <!-- vim: set ts=2 et nowrap: -->