#149 Particle Wind - Error

[Anonymous]

Originally created by: vivian.m...@lineone.net

What steps will reproduce the problem?
1. start with --aircraft=buccaneer
2. select particles ON in the render menu
3. Taxi to the vicinity of a windsock

What is the expected output? What do you see instead?

It is expected that the particles generated by the engine will move in the direction indicated by the windsock. They actually move at an angle into the true wind. Increase the wind speed using the environment menu if the error is not readily seen

Th attached pic demonstates the error between the wind calculated and applied to submdels with that used by particles.

Please use labels and text to provide additional information.
 

[Anonymous]

Originally posted by: vivian.m...@lineone.net

One of these 2 statements is in error:

particle.hxx

    /**
     *  Set and get the wind vector for particles in the
     * atmosphere. This vector is in the Z-up Y-north frame, and the
     * magnitude is the velocity in meters per second.
     */
    static void setWindVector(const osg::Vec3& wind) { _wind = wind; }

environment_mgr.cxx

  osg::Vec3 windVec(-_environment->get_wind_from_north_fps(),
                    -_environment->get_wind_from_east_fps(),
                    _environment->get_wind_from_down_fps());
  simgear::Particles::setWindVector(windVec * SG_FEET_TO_METER);

I am yet unable to estblish which is correct.

[Anonymous]

Originally posted by: zakalawe@mac.com

Vivian, can this issue be resolved following Curt's changes?

[Anonymous]

Originally posted by: vivian.m...@lineone.net

James, This problem is fixed by Curts patch. It is however a work-around. The problem is also fixed by changing the sign:

  osg::Vec3 windVec(_environment->get_wind_from_north_fps(),
                    -_environment->get_wind_from_east_fps(),
                    0);

It would be better, I think, to resolve the underlying issue so we can use the built- in function rather than using purpose built trig functions.

[Anonymous]

Originally posted by: cumuluni... (code.google.com)@gmail.com

I assume this issue is fixed?

Labels: Priority-Low
Status: Stalled

[Anonymous]

Originally posted by: vivian.m...@lineone.net

You assume wrong - it was fixed, but it now appears to be unfixed again. Perhaps OSG changed their minds about winds from/to?

[Anonymous]

Originally posted by: cumuluni... (code.google.com)@gmail.com

Just verified:
fgfs --aircraft=buccaneer --airport=ksfo --runway=28r --wind=190@40
and I can see the particles blowing to the north (right wing).
Looks completely right for me.

I consider this fixed.

Labels: Milestone-2.4.0
Status: Fixed