Realism

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How realistic is FlightGear aircraft and environment? How can I get the most realism out of the FlightGear environment?

Aircraft

Todo: instruments

Flight

Todo: qualities of flight models

Environment

Extensive and Accurate World Scenery Data Base

  • Over 20,000 real world airports included in the full scenery set.
  • Correct runway markings and placement, correct runway and approach lighting.
  • Taxiways available for many larger airports (even including the green center line lights when appropriate.)
  • Sloping runways (runways change elevation like they usually do in real life.)
  • Directional airport lighting that smoothly changes intensity as your relative view direction changes.
  • World scenery fits on 3 DVD's. (I'm not sure that's a feature or a problem!) But it means we have pretty detailed coverage of the entire world.
  • Accurate terrain worldwide, based on the most recently released SRTM terrain data.) 3 arc second resolution (about 90m post spacing) for North and South America, Europe, Asia, Africa, and Australia.
  • Scenery includes all vmap0 lakes, rivers, roads, railroads, cities, towns, land cover, etc.
  • Nice scenery night lighting with ground lighting concentrated in urban areas (based on real maps) and headlights visible on major highways. This allows for realistic night VFR flying with the ability to spot towns and cities and follow roads.
  • Scenery tiles are paged (loaded/unloaded) in a separate thread to minimize the frame rate hit when you need to load new areas.

Weather

Todo: weather

FlightGear can periodically download weather (METAR) data. This information is used to influence the environment.

As of FG 0.9.10, for the current METAR station, FG models:

  • Visibility for the rendered visual environment is set equal to the current METAR visibility. If the current METAR reports 10 statute mile visibility, the rendered visibility is 10 statute miles.
  • If the METAR reports rain, FlightGear renders rain (precipitation).
  • If METAR reports a thunderstorm, lightning is rendered and thunder produced through the audio system.
  • FG appears to honor METAR dewpoint, "altimeter" or air pressure and reported sea level air pressure. It honors wing direction, speed and gust speed.

Notes

  • Precipitation is modeled, but the graphics require improvement. Sufficient only to indicate rain.
  • Lightning is present when a thunderstorm is near, the graphics are a fair representation, but also require improvement.

References

If you want to prove the relationship between FG and METAR, you can open the property browser. Monitor

/environment/metar/max-visibility-m == 9656m

and

/environment/visibility-m == 9656m

The values should be the same. When you press Z/z on the keyboard, you should see the second value change, showing this value controls the rendered visibility.

You can do the same for cloud layers. For example METAR code SCT 10 translates to coverage: scattered, elevation: 10039 and FG automatically sets thickness and transition for the layer.

Visuals

Settings for maximum visual experience and rendering quality.

FlightGear command options:

--enable-horizon-effect
--enable-clouds-3d
--enable-specular-highlight (enabled by default)
--enable-real-weather-fetch
--shading-smooth (default)
--enable-skyblend (default)
--enable-textures (default)
--enable-real-weather-fetch

Sky Blend

This rendering option enables "fog" and haze in the distance. "sky and terrain look realistic"

Smooth Shading

Smooths shading.

Textures

Terrain texturing.

Volumetric (3D) Clouds

This renders clouds with three-dimensional realism.

Geometry/Resolution

This is the resolution the FlightGear window is rendered in. The higher the resolution, the greater the detail.

640x480 blocky and lacking in detail
800x600
1024x768
...
1600 x 1200 very fine detail
and up

Use anti-aliasing if you video card supports and your system can handle the extra load.

Real Weather (METAR)

This downloads current real world weather data into FlightGear from the nearest weather station (METAR report). The data is used to influence the environment. The cloud cover specified in the METAR report will be rendered.

Time

Set the current time for your location. If it's dark in San Francisco, it will be dark in the sim.

Yoke and Rudder Pedals

Rudder pedals add to realistic operation and make it much easier to accurately use the rudder over a twist stick. The yoke is less necessary, but can add to realism.


Accurate and Detailed Sky Model

FlightGear implements extremely accurate time of day modeling with correctly placed sun, moon, stars, and planets for the specified time and date. FlightGear can track the current computer clock time in order to correctly place the sun, moon, stars, etc. in their current and proper place relative to the earth. If it's dawn in Sydney right now, it's dawn in the sim right now when you locate yourself in virtual Sydney. The sun, moon, stars, and planets all follow their correct courses through the sky. This modeling also correctly takes into account seasonal effects so you have 24 hour days north of the arctic circle in the summer, etc. We also illuminate the correctly placed moon with the correctly placed sun to get the correct phase of the moon for the current time/date, just like in real life.