Difference between revisions of "Default head-up display"

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     size          (8)          float  Size of font
     size          (8)          float  Size of font
  /sim/hud/palette/color/        Settings of predefined colors, nearly
  /sim/hud/palette/color/        Settings of predefined colours, nearly
  /sim/hud/palette/color[n]/      the same options as in /sim/hud/color.
  /sim/hud/palette/color[n]/      the same options as in /sim/hud/color.
[[Category:FlightGear feature]]
[[Category:FlightGear feature]]

Revision as of 09:21, 3 May 2009

This article is a stub. You can help the wiki by expanding it.

This is a short description of FlightGears default Head-up display (HUD), it can be (de)activated with the [h]-key. To change the brightness, press [shift]+[h].

There are also two so called 'minimal' HUDs available which are accessible with [shift]+[i], to return to default HUD press [i].

Some of the HUDs options can be altered in the menu: View --> Adjust HUD Properties




Monitors the bearing of the control input on the ailerons axis.




Current speed relating to the ambient air in knot/knots (kt/kts) (1 kt = 1.852 km/h).



Current altitude relating to sea-level in feet (ft) (1 ft = 30.48 cm).


If autopilot is activ the direction of the next waypoint is displayed as well as the next two and the last waypoint of the Autopilot --> Route manager list.



Current altitude above ground in feet. Relating to the location of the aircrafts radio altimeter, therefore it's not zero if the aircraft is on the ground.



Monitors the bearing of the control input on the elevators axis.



Displays the g-force to the pilot in g - to avoid black-/redout.

The value riding on top of the Airspeed indicator.



Direction of the aircraft relating to the geographical North pole in degree (360 degree scale).




To change the coordinates-system, go to Autopilot --> Set Lat/Lon-format.


Like set with [Home]/[End].

It's the left marker of the Elevator indicator.

Pitch ladder

Displays the aircrafts pitch relating to the grounds level/horizontal in degree. It's used as an artificial horizon.

The big ladder like looking indicator at the HUDs centre.
Attitude indicator



Monitors the bearing of the control input on the rudders axis.




Monitors the thrust on airplanes or the collective of helicopters.


Turn Coordinator
HUD autopilot
HUD overview

Further Information

The basic setup of the above described default HUD is defined at


There is also a 'Runway projection' available which is, because of some issues, disabled by default.

Documentation can be found at


Since FlightGear 0.9.10 there is also a newer and more flexibly HUD-system available. An example can be found at

$FG_ROOT/Huds/NTPS.xml and documentation at

Also have a look at $FG_ROOT/Huds/README.


While the instruments and their behaviour are set in the Huds-directory, the basic settings and the look regarding to any HUD are set in $FG_ROOT/preferences.xml. Search the file for <hud> and you will find a list of properties. For a short description of those have a look at property tree. But I'll give some of them a closer look:


The prefered thing one would like to customize is, I guess, the HUDs colour.

Discover your own settings is quite easy: Access the property tree via the Menu File --> Browse Internal Properties ([/]-character) or via the Property server and your browser. Go to sim/hud/color, e.g. http://localhost:5500/sim/hud/color, edit a value and watch the result in FlightGears window instantly.

Once the decision is made head back to preferences.xml, copy the <color n="0">-tag and paste it on top of the colours within the <palette>-tag. Rename the existing tags in numeric order and finally put your discovered values in the new one. It should look like this, except your own values, of course:

   <current-color type="int">0</current-color>
    <color n="0">
     <transparent type="bool">true</transparent>
     <antialiased type="bool">false</antialiased>
     <brightness type="float">1</brightness>
     <alpha type="float">0.67</alpha>
     <red type="float">0.1</red>
     <green type="float">1.0</green>
     <blue type="float">0.3</blue>
    <color n="1"><!-- day -->
    <color n="2"><!-- night -->


    <name type="string">Helvetica.txf</name>
    <size type="float">8</size>

To change font just enter another name out of the ones in $FG_ROOT/Fonts (case sensitive!). For more information about those fonts and on .txf format peruse $FG_ROOT/Fonts/README.

Since the size is type 'float' values like '7.449' are allowed, too.


/!\ Just a draft and maybe not correct.

  <path>Huds/NTPS.xml</path>           <!-- new HUD -->

The first one is the default HUD mentioned above. It is for the old HUD only. The second is the first one of the 'minimal HUD's and it is for the new HUD only. The other 'minimal' one is called by the code (I guess), its path is Huds/Minimal/default.xml.

For each <path> are some more HUDs available, a complete list (except aircraft specific):

old HUD:


new HUD:


Property tree

More information about FlightGears property tree and on how to access it can be found at its page: Property Tree.

Paths starting with '$FG_ROOT/' apply to the file system, the others are intra-property tree.

  current-color   (0|1|2...)    int     One out of /sim/hud/palette
  enable3d        (false|true)  bool    hud n=0 3D off|on
  enable3d[1]     (false|true)  bool    hud n=1 3D off|on
  frame-stat-type (tris|???)            ???
  path            (Huds/...)            Path to hud n=0
  path[1]         (Huds/...)            Path to hud n=1
  visibility      (false|true)  bool    hud n=0 hidden|visible
  visibility[1]   (false|true)  bool    hud n=1 hidden|visible
/sim/hud/color/          Contains settings of current-color
    alpha         (0...1)       float   0=invisible, 1=nontransparent
    alpha-clamp   (???)                 ???
    antialiased   (false|true)  bool    Antialiasing off|on
    blue          (0...1)       float 
    brightness    (0...1)       float   0=dark/black
    green         (0...1)       float
    red           (0...1)       float
    transparent   (false|true)  bool    Transparency off|on
    name          (*.txf)       string  One out of $FG_ROOT/Fonts
    size          (8)           float   Size of font
/sim/hud/palette/color/         Settings of predefined colours, nearly
/sim/hud/palette/color[n]/      the same options as in /sim/hud/color.