Chris Metzler said:
> Hi. It appears that in initialization, if an airport and heading are
> specified on the command line, a runway is immediately chosen based
> upon the heading, and latitude/longitude is set to that runway's
> threshhold. This is sensible if the user is starting *at* the airport;
> but if the user is starting somewhere else, and using the airport
> as a reference point via --offset-azimuth and --offset-distance,
> the result is that starting position can jump by a large amount
> simply by changing the starting heading. Changing the heading
> changes the runway fg_init thinks is relevant, and the offset is
> taken from the position that's been set to an irrelevant runway
> threshold location.
> I ran into this tonight while trying to contrive some aliases for
> quickly starting FlightGear with the ufo at a specific vantage
> point near a structure I'm modelling. I decided I wanted to be on
> the other side of the structure, so I added a couple of degrees to
> my --offset-azimuth value, and changed my heading by 90 degrees.
> Upon restart, I didn't see the structure. I spent quite a while
> trying to determine why it wasn't loading before I realized that
> it *was* loading, and that the reason I didn't see it was because
> I was a kilometer and a half away from where I thought.
> Not very important at all -- it probably takes a fairly contrived
> situation (like mine) to get bit by this -- but figured I'd
> mention it.
True, but it is actually it is a fairly contrived feature. And I could see a
user wanting to start on a downwind leg or something like that. I'd call it a
bug as well. At the very least we ought to be able to change the behavior
during air starts, but then how would we choose a location to "offset" from?
What happens if you specify a runway?
Flightgear-devel mailing list