1) The AIStorm sets the properties:
/environment/turbulence/magnitude-norm
/environment/turbulence/rate-hz
The actual turbulence effects are handled by the FDM.
If the effects are deemed unrealistic, then that will
have to be fixed in the FDM(s).
2) The zone of turbulence is cylindrical, and is centered
at the AIStorm's lat/lon. The diameter is set with
<diameter-ft>, the top with <height-msl>, the bottom is
assumed to be at <altitude> minus 1000 feet.
3) Note that the zone of turbulence may not match well with
the visual model of the storm. In this case I had to
x-offset the storm model by 4700 meters to match the zone
of turbulence. (i.e. the storm model is 4700m off center).
4) While I was in there I also increased the speed of the
lightning flashes to look more realistic.
The value of rho (air density) varies with height. (Including the upper
stratosphere, ust in case someone wants to model ICBMs.) The standard
atmosphere is used (based on a sea-level temperature of 15 deg C.).
Erik Hofman:
I moved this code over the AIBase::update() so all AIModels can make
use of rho, temperature, pressure, etc.
I added some things to the AI stuff to improve the AIThermal processing.
Before, all the thermals were processed in order, and the last one overwrote
the prior one. Now, only the data from the nearest thermal is kept. This
way a tile can be populated with many thermals, and (as long as they have the
same diameter) the one nearest the airplane correctly takes effect. This
will make us ready for the next step, "auto-thermaling", where FlightGear's
tile manager can cover a tile with thermals, and set the thermal strength
based on land-use type.
I moved the enumerated object_type to the base class. When an AI object is
created it now sets the _otype variable in the base class. This lets the AI
manager find out what kind of AI object it is dealing with, using the base
pointer. I also added a function isa() to the base class, so the manager can
process objects differently based on their type.
The AI manager now sends AIThermal processing to a different function, where
only the data from the nearest thermal is kept. After the manager processes
all the AI objects, then the results from the nearest thermal are applied to
wind-from-down.
