Erik Hofman writes: > But then again, how about the aero refference point? This is > single the location in the aircraft that can be used to describe > the aircrafts flightpath because all other locations will rotate > around it in flight. This point has to be known by 3D modellers > already because the aircraft will rotate around that point (which > basically makes it the origin for the model).
As others have mentioned, though, that point moves around during flight depending on how the plane is loaded, how much fuel you've burned, whether you're subsonic or supersonic, whether the flaps are extended, whether you've just dropped skydivers or a bomb, etc. etc. In a Cessna 150, the change is going to be very small; in a supersonic bomber, the change might be very, very large (I'm just guessing, though). That's why we need to establish a fixed reference point for each aero model (it doesn't matter where, though I prefer the published FAA weight and balance datum) and then report the offset from the C.G. to that reference point every frame. The A/C 3D code simply has to apply that offset so that the centre of rotation (and the plane) is always in the right spot. All the best, David -- David Megginson, [EMAIL PROTECTED], http://www.megginson.com/ _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
