Steve Hosgood wrote: > The position of any astronomical object relative to a viewer standing on > the planet's surface is usually given as "altitude" and "azimuth" - with > the true horizon and true "North" used as the references. > [...] > Additional entertainment will be provided by the fact that and code for > FG needs to work with a WGS84 spheroid, meaning that the distance to the > earth's centre will vary with lat and long
I humbly submit that this is yet another area where an Euler (angle) representation is a bug, not a feature. We have a sane cartesian coordinate system for the earth. All that's needed is to define one for the solar system* and then do reasonably trivial conversion. The moon should be even easier, presuming that the moon's orbit passes through the equatorial plane (it does, doesn't it?). * It can be 2D, in fact -- on the plane of the Earth's orbit and with one of the axes aligned with the orbit's major axis. _______________________________________________ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
