Wildfire simulation

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A wildfire (woodland, grassland etc) simulation is available in FlightGear 2.0.0 and later.

It is based on a cellular automata model of how wildfires spread. It is possible to set up fires that are shared (replicated) among users over MP for joint fire fighting efforts.



Wildfire dialog.jpg

The wildfire simulation can be configured via the configuration dialog available from "Environment->Wildfire settings":

Enabled: Fire simulation on/off. Cycling Enabled resets the fire simulation.

Share over MP: When set fire events, i.e. ignition and fire fighting, are sent/received over the MP network.

Show 3d models: Enable/disable rendering of the wildfire 3d models.

Crash starts fire: If your aircraft crashes somewhere inflammable there will be a fire.

Report score: Copilot reports success/failure of firefighting actions.

Save on exit: Save the fire event log when FlightGear exits. (Experimental)

Load Wildfire log: Load and execute a saved fire event log. (Experimental, can be very expensive)

Note  The fire and smoke models are particle systems so to see them Particle Systems must be enabled in the View->Rendering Options dialog.
Warning  There is a hidden option called restore on startup that can be enabled via the property browser (or by a mischievous aircraft) and that will be saved when exiting FlightGear. On the next start of FlightGear the previous state of the Wildfire system will be loaded which can be very expensive indeed if the system is set to run the Wildfire module from the time stamps in the saved log to the current time (the same hold for Load Wildfire log, but there it should be clear to the user what happens). If this option gets enabled you can disable it by starting FlightGear with the command line option --prop:/environment/wildfire/restore-on-startup=0 and exit normally.

Fire fighting

The Consolidated Aircraft PBY Catalina air tanker / water bomber can be used to drop water on wildfires.

Developer information

See Docs/README.wildfire.

Known problems

  • Huge fires are expensive and cause significant fps drop.
  • It appears the wildfire models are not removed properly from the scene graph. The frame rate impact (or part of) remains when 3d models are disabled and even after the Wildfire module has been reset.
  • Wind is not considered.
  • Crash starts fire does not consider the type of aircraft and the circumstances of the impact/crash, only the inflammability of the terrain.
  • Prior to FG 2.4.0, to save the wildfire state you need to add the line "WRITE ALLOW $FG_HOMEWildfire/fire_log.xml" to $fgroot/Nasal/IOrules. In FG 2.4.0 this is no longer needed.
  • Sharing the wildfire state over the multiplayer network doesn't work in FlightGear 2.0.0. This is fixed in later versions.

External links