> Ack, really? I was honestly under the impression that you were > handing out the coordinate frame too; I thought I had checked this in > code when writing YASim.
Perhaps this is related to the misunderstanding of our gear model and how we determined where we were? > Why c.g.? Since it moves, it forces the > model renderer to track the current value and do an extra translation. When we wrote the code for this initially, and for years afterwards, there *was* no model renderer. :-) In hindsight, I realize we may have erred in this. I'll add that initially we didn't model moving the CG around either, so it wasn't a big deal. I'll repeat points 3 and 4 I made earlier: 3) The turn coordinator instrument (to my knowledge) works in consideration of where it is located, typically right in front of the pilot. The accels sensed by this instrument include rotational effects at the pilots moment arm _from_the_current_CG_. 4) If FlightGear was ever to be hooked up to a motion base, the motion of the base might be linked to the second derivative of the body velocities _at_the_pilot_location_ relative to _the _current_CG_. Thus, again in this case and with point #3, above, the flight model still needs to know where the pilot is. I still recommend that the FDM be allowed to at least _recommend_ a pilot eyepoint, as some calculations inside the FDMs will use this value. It would be nice if this value could be useful to FlightGear. FlightGear could still be allowed to shift the viewpoint as it wished, but with the understanding of points 1 - 4, above. In any case, to the best of my recollection, this is how LaRCSim does it, how McFarland's paper describes it, etc. This is how to do it naturally. It may be that we should take it a step further and extrapolate the "reference point" from that, whatever that should be, and report the lat/lon/alt (henceforth known as LLA). Jon _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
