Hi , Vivian Meazza schrieb am 21.12.2007 00:11: > I wrote: > > >> Sent: 19 December 2007 09:17 >> To: 'FlightGear developers discussions' >> Subject: RE: [Flightgear-devel] External Cargo, was: Re: >> screenshots (and "snapshots") >> >> >> >> >> >>> -----Original Message----- >>> From: [EMAIL PROTECTED] >>> [mailto:[EMAIL PROTECTED] On >>> Behalf Of Maik Justus >>> Sent: 18 December 2007 23:12 >>> To: FlightGear developers discussions >>> Subject: Re: [Flightgear-devel] External Cargo, was: Re: >>> screenshots (and "snapshots") >>> >>> >>> Hi Viviam, >>> Vivian Meazza schrieb am 18.12.2007 23:41: >>> >>>> I've just a few moments ago added a few lines of code to >>>> >>> AIBallistic >>> >>>> which apply an external force (using the same math as >>>> >>> above). The rest >>> >>>> works as before. I just need few properties to set the >>>> >>> magnitude and >>> >>>> vector of the external force and it will be done, at least for >>>> testing. >>>> >>> Thank you, very good. Is it possible to pass the forces in the earth >>> fixed coordinates axes base? (in Newton or pof)? >>> >> I'm planning, and have tested the passing of the force in >> terms of magnitude (pound force), azimuth (degrees, north = >> 0) and elevation (degrees, horizontal = 0, up = 90). I hope >> this is what you need, and can work with. >> >> >>>> It's trivial >>>> really, but I'm assuming that the external force applies no >>>> >>> rotational >>> >>>> force to the object. >>>> >>> I think this could be easily faked. e.g. new_roll = old_roll + >>> cos(old_roll) * force_in_y_direction * a_magic_constant * dt >>> but i f I read the code correctly, yaw and hdg are pointing >>> at the speed >>> direction (slightly filtered)? Therefore we need something >>> like _elevation = atan2(force_in_z_direction,force_in_x_direction) >>> and then your filter to add some inertia? >>> >> Right now there are 2 options - 1, the ballistic object >> aligns with the velocity vector (damped), or 2, it remains >> static. These options both work with the new code. I think >> option 1 will do for an under slung load? >> >> >>>> I haven't a great deal of time available in the run up to >>>> >>> Christmas so >>> >>>> no promises on completion. >>>> >>>> >>> Same here. I will have very limited access to my computer (family >>> visiting tour). Fortunately my computer is a notebook, but I >>> am not sure >>> if there is any space in the car for my joystick. >>> >> We have a horde of family visitors over the coming days - all >> competing for my time and the computer. We'll see how much >> can be done (not a lot I expect). >> >> Similar here (but with the difference, that we are part of the horde of family visitors ;-) )
> > Christmas has arrived slightly early! I've got something which: > > A. runs > > B. looks OK with limited testing > > The ballistic object aligns with the direction of flight in pitch and > heading with an external force applied. It would be possible to align it > with the direction of the external force, but I think that would need roll > as well. I'm not sure which one would look best. > > The external force is defined in terms of: > > Magnitude (lbf) > Azimuth (deg, North = O) > Elevation (deg, up = 90) > > In a user-defined property. Of course, some external program needs to set > the external force data. > > This all now needs testing in a more realistic environment. I'm not totally > convinced that the ballistic object won't disappear into space/to the centre > of the earth, or oscillate like a deranged spring. > > Vivian > > I will try to combine this with YASims winch feature (but I think I will not find time earlier than end of the month). Maik ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel