Maik Justus > Subject: Re: [Flightgear-devel] External Cargo, was: Re: > screenshots (and "snapshots") > > > Hi Vivian, > Vivian Meazza schrieb am 06.01.2008 01:01: > > Maik Justus wrote: > > > > > > > >> Hi Vivian, > >> Vivian Meazza schrieb am 21.12.2007 00:11: > >> > >>> 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 > >>> > >>> > >> Thank you for the enhancement of AIBallistic. The external > load works > >> here, but not perfectly. I need to limit the force to approx > >> 1000 lbf > >> (which is not enough to simulate it properly). If I do not > limit the > >> force, the load (the 3d-model) disappears, but it is still in the > >> property tree and reacts on forces (maybe not correct, not > >> sure, but it > >> is still there). Any idea, what could cause this? > >> > >> > > > > Hmm - the mass of the load in load_demo is only 170 lbs - applying > > 1000lbf could well send it into orbit! Note your mass is in > slugs, and > > you need a realistic Cd and eda. I _think_ the math is correct, but > > I'll look at it again > > > > Vivian > > > > > Sorry, I limited the force to 1000N (about 200lbs). > 200lbs are enough to lift the load. Lifting works. Therefore the math > itself is correct. But something strange happens, if I do not > limit the > force. (and sometimes forces greater than 200lbs are needed.... ) > >
That sounds better, phew. There is a small "dead zone" when the load is on the ground, so you need a bit more force than you might expect to get it off the ground (this is to prevent oscillation, but is not totally unrealistic) I can reduce or eliminate this. Beyond that I would need a better explanation of what you are doing, and of the problem to speculate on a bug or a fix. Vivian ------------------------------------------------------------------------- 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
