Jon Berndt <[EMAIL PROTECTED]> said: > > David Megginson <[EMAIL PROTECTED]> said: > > > > > It's the location on the plane where the FDM reports the > > > lon/lat/alt. It's kind-of a nifty idea, actually. > > > > In relation to? It is always 0,0,0 in Yasim. > > > > Best, > > > > Jim > > > JSBSim could also define the tip of the nose as (0,0,0). It really doesn't > matter a whole lot. However, internally, the FDMs really don't care about > exact locations - only relative distances. I think we all agree on that. So, > instead of defining some arbitrary frame, _we_use_an_industry_standard_, > which is the structural frame that the manufacturer defines, when available. > It is always (in my experience) X positive aft, Y positive right, with the > origin being seemingly arbitrary. For us, that solution works great and is > very appropriate. When the frame is not known, we could just as easily > decide that the origin could be at the nose tip. In any case, given the > potential variances in structural coordinate frames - and especially > considering that there are many FDMs, the 3D model placement code needs to > be able to match up with the FDM. I think our VRP solution works well, and > is versatile given our situation. >
Yes it is. I'm probably being really dense, but I can't think of a reason why it would be important to know what the origin is in fdm coordinates. So long as position is reported to fgfs at the nose, we should be fine. Best, Jim _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
