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How realistic is [[FlightGear]] [[aircraft]] and environment? How can I get the most realism out of the FlightGear environment?
How realistic is [[FlightGear]]'s [[aircraft]] and environment? What is needed to get more realism and immersion from the FlightGear environment?


== Aircraft ==
== Aircraft ==


Todo: instruments
[[File:DR400_Dauphin_Rembrandt_02.jpg|800px|center|The [[DR400|DR400 Dauphin]].]]


== Flight ==
The underlying instrumentation models are very accurate, with many physical effects accounted for.


Todo: qualities of flight models
* The panel-mounted magnetic compass takes time to slew to your heading.
* The artificial horizon can tumble.
* The windshield or panel-mounted compass will rotate in all three axes.


== Environment ==
== Flight dynamics ==


=== Extensive and Accurate World Scenery Data Base ===
Since FlightGear uses many [[FDM|flight dynamics models]] under the hood, including [[YASim]] and [[JSBSim]], the realism of an aircraft depends on its FDM. Both of these support winds and turbulence; YASim generally has more realistic ground interactions with different surfaces, while JSBSim FDMs are generally truer to the real-life aircraft. It's important to note that both of these can produce similar results if the FDM is worked on enough.
* 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.


Real world tower registration data was used to locate towers in the United States. The data was sourced from the United States Federal Communications Commission tower registration database.
== Scenery==


Thousands of objects have been added through the [http://fgfsdb.stockill.org/ FlightGear Scenery Database].
<gallery mode="packed">
File:Southwest04.jpg|
File:Kansas_Scenery_Two.jpg|
</gallery>


* 2700+ obstructions added for France (not sure of the source for this obstruction data)
* Over 20,000 real world airports included in the full [[scenery]] set. The recent world scenery version 2 brought many major improvements, including more detailed heightmaps and man-made features such as roads, rivers, and train tracks.
* Correct runway markings, runway lighting, and approach lighting.
* Detailed taxiways available for many airports.
* Sloping runways.
* Airport beacon lights with rotating beacons.
* Accurate worldwide terrain based on the most recently released SRTM terrain data. 3 arc second resolution (about 90m spacing) for North and South America, Europe, Asia, Africa, and Australia.
* Roads, rivers, and train tracks.
* Realistic night lighting with lit urban areas and headlights on roads.


Todo: what are the sources for scenery database? The FAA obstructions data may have been used to populate the scenery database, but I am not sure.
Real world tower registration data was used to locate towers in the United States. The data was sourced from the United States Federal Communications Commission tower registration database.
 
Over one million objects have been added to the [http://scenemodels.flightgear.org/ FlightGear Scenery Database].


== Weather ==
== Weather ==


Todo: weather
[[File:Local_weather_1.00_06.jpg|center|[[Advanced weather]].|800px]]
 
FlightGear can periodically download weather ([[METAR]]) data. This information is used to influence the environment. This can be most easily enabled with <tt>--enable-real-weather-fetch</tt>
 
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 wind 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.
 
* The METAR weather fetch, parsing and rendering process causes momentary reductions in the simulator's frame rates.
 
* The METAR wind updates are applied without any smoothing, which can cause an aircraft yaw response, sometimes described as a "rudder kick".
 
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-clouds3d
--enable-specular-highlight (enabled by default)
--enable-real-weather-fetch
--shading-smooth (default)
--enable-skyblend (default)
--enable-textures (default)
 
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.''
 
{|
| [[File:Clouds1_2006-06-23.jpg]]
''Default Clouds''
| [[File:Clouds2_2006-06-23.jpg]]
''Volumetric (3D) Clouds''
|}
 
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.
With [[Advanced weather]], cloud patterns and winds will change throughout the day. With [[atmospheric light scattering]] enabled, fog and clouds are more realistic, and lighting changes throughout the day and during overcast periods. Advanced weather can be driven with live [[METAR]] data or manually configured for specific weather scenarios.


Real Weather (METAR)
== Rendering ==


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.
[[Atmospheric light scattering]], or ALS, features a realistic skydome and properly lit terrain, in addition to detailed terrain texturing and trees swaying in the wind. With advanced weather enabled as well, cloud shadows and volumetric fog are also fully supported.


Time
[[Rembrandt]] is FlightGear's shadow and lighting engine; with Rembrandt enabled, realistic shadows and lighting are possible. Note that not all aircraft support Rembrandt yet. In addition, it's not possible to use Rembrandt in conjunction with ALS.


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


Yoke and Rudder Pedals
<gallery mode="packed">
File:Southwest09.jpg|
File:Water-sky01.jpg|
File:Rayleigh_blue.jpg|
File:Tree02.jpg|
</gallery>


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.


FlightGear's night sky features accurate placement and lighting of stars, planets, and the moon.


=== Accurate and Detailed Sky Model ===
Atmospheric light scattering features accurate lighting of the sky and terrain; in addition, oceans and rivers are realistically shaded with ripples and sun reflections. Rayleigh scattering of distant terrain is supported, tinting the ground blue or red depending on the sun angle. With random trees, tree shadows are available; experimental aircraft ground shadows are also available.
[[File:Moon.jpg|thumb|270px|The full texture moon]]
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.

Revision as of 22:32, 11 March 2015

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How realistic is FlightGear's aircraft and environment? What is needed to get more realism and immersion from the FlightGear environment?

Aircraft

The DR400 Dauphin.

The underlying instrumentation models are very accurate, with many physical effects accounted for.

  • The panel-mounted magnetic compass takes time to slew to your heading.
  • The artificial horizon can tumble.
  • The windshield or panel-mounted compass will rotate in all three axes.

Flight dynamics

Since FlightGear uses many flight dynamics models under the hood, including YASim and JSBSim, the realism of an aircraft depends on its FDM. Both of these support winds and turbulence; YASim generally has more realistic ground interactions with different surfaces, while JSBSim FDMs are generally truer to the real-life aircraft. It's important to note that both of these can produce similar results if the FDM is worked on enough.

Scenery

  • Over 20,000 real world airports included in the full scenery set. The recent world scenery version 2 brought many major improvements, including more detailed heightmaps and man-made features such as roads, rivers, and train tracks.
  • Correct runway markings, runway lighting, and approach lighting.
  • Detailed taxiways available for many airports.
  • Sloping runways.
  • Airport beacon lights with rotating beacons.
  • Accurate worldwide terrain based on the most recently released SRTM terrain data. 3 arc second resolution (about 90m spacing) for North and South America, Europe, Asia, Africa, and Australia.
  • Roads, rivers, and train tracks.
  • Realistic night lighting with lit urban areas and headlights on roads.

Real world tower registration data was used to locate towers in the United States. The data was sourced from the United States Federal Communications Commission tower registration database.

Over one million objects have been added to the FlightGear Scenery Database.

Weather

Advanced weather.

With Advanced weather, cloud patterns and winds will change throughout the day. With atmospheric light scattering enabled, fog and clouds are more realistic, and lighting changes throughout the day and during overcast periods. Advanced weather can be driven with live METAR data or manually configured for specific weather scenarios.

Rendering

Atmospheric light scattering, or ALS, features a realistic skydome and properly lit terrain, in addition to detailed terrain texturing and trees swaying in the wind. With advanced weather enabled as well, cloud shadows and volumetric fog are also fully supported.

Rembrandt is FlightGear's shadow and lighting engine; with Rembrandt enabled, realistic shadows and lighting are possible. Note that not all aircraft support Rembrandt yet. In addition, it's not possible to use Rembrandt in conjunction with ALS.

Sky


FlightGear's night sky features accurate placement and lighting of stars, planets, and the moon.

Atmospheric light scattering features accurate lighting of the sky and terrain; in addition, oceans and rivers are realistically shaded with ripples and sun reflections. Rayleigh scattering of distant terrain is supported, tinting the ground blue or red depending on the sun angle. With random trees, tree shadows are available; experimental aircraft ground shadows are also available.