On Saturday 14 February 2004 13:52, Vivian Meazza wrote: > Lee Elliott > > > Sent: 14 February 2004 13:35 > > To: FlightGear developers discussions > > Subject: Re: [Flightgear-devel] Aerodynamic centre and 3D models > > > > On Saturday 14 February 2004 13:07, Vivian Meazza wrote: > > > Lee Elliott wrote > > > > > > > On Friday 13 February 2004 06:16, Jon Berndt wrote: > > > > > > True, but... This is a chunk of calculations running > > > > > > > > every frame. > > > > > > > > > > In the olden days, the cost would be too high. > > > > > > > > > > These days, it's not even a spec on a flea on the butt of > > > > > > > > an elephant > > > > > > > > > in terms of the overall FDM calculations - which in turn > > > > > > > > are not much > > > > > > > > > of a spec on a flea in the overall FlightGear calculations. > > > > > > > > > > > Our Aerodynamic modelers always seemed to know where > > > > the empty > > > > > > > > weight CG was every frame without additional calculations. > > > > > > > > > > That's not the issue, though. We FDM guys know absolutely where > > > > > everything is at all times within the FDMs. > > > > > > > > Yep:) Everything's right where we put it:) > > > > > > > > LeeE > > > > > > I'm about halfway through generating a 3d cockpit for the Seahawk > > > model - are you going to move the origin of the model? I'd like a > > > heads up, it will probably affect how I go about the rest > > > > of the work. > > > > > Regards > > > > > > Vivian > > > > That's great news. > > > > The only change that's likely to the Sea Hawk model will be > > to shift the > > origin to the nose;) > > > > This won't actually be too much of a problem and will only > > require simple > > offsets to the numbers in the anim and fdm files: > > > > Say I need to move the model 3 metres back and 0.1 metre up, > > then all we need > > to do is add 3 metres to all the 'x' measurements, and 0.1 to > > all the 'z' > > measurements in the fdm and anim files to line everything up again. > > > > (Heh!... or it might be _subtract_ 3 metres... maths was > > never my strong > > point) > > Then readjust all the animations to make them work correctly - fun eh? > > I'll try to make the cockpit reasonably independent of the origin - I've > done it for instruments and I'll try and extend it to other stuff. > > Vivian
The only readjustments that would be needed are the simple x & z offsets - all the axis would remain unchanged so, for example, the aileron axis numbers wouldn't need to be changed, just their location, in line with the simple x/z offsets. LeeE _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
