A complaint by poster "umop ap!sdn" over on Bad Astronomy gave me an idea for a feature request: a view mode available with sync orbit of a body, in which the camera is automatically oriented so that the view direction and view vertical are in a plane intersecting the local planetary vertical.
In this mode, Celestia would therefore act much more like one conventionally expects a planetarium program (such as, say, Stellarium) to act: the view is that of somebody standing upright on the planet, and it's impossible to get turned upside down or sideways by just looking around. Camera motions, by mouse or keyboard, would effectively move you around in altazimuth coordinates.
(The one possibly hard bit would be handling what happens at the zenith and the nadir; preferably there should be hard limits to vertical view motion there, to avoid sudden disorienting shifts in the view orientation. But this is optional.)
Though I'm pretty ignorant of Celestia's internals, it strikes me as probably not harder to implement than track mode, and probably easier than phase lock. The big question is what to call it; I like "upright mode", but the proper key binding is anyone's guess. It would be particularly nice in combination with an azimuthal direction compass.
Granted, there are a lot of view modes already, but this one should be particularly useful to people using Celestia to model the night sky seen from Earth. (One risk is that somebody would immediately start asking for an equatorial mode as well, unless you just tell them to stand at the North Pole...)
Upright mode (altazimuth mode? planetarium mode?)
Did you try my "Show Azimuth and Elevation" script, available here:
http://celestia.h-schmidt.net/?
Does this do what you want (after pressing Shift-F)?
Harald
http://celestia.h-schmidt.net/?
Does this do what you want (after pressing Shift-F)?
Harald
selden wrote:Guest,
You really need to read the FAQ that's at the top of the User's Forum. See Q/A #19.
I believe the current AltAzimuth mode just alters the effect of the arrow keys. It's useful for now, but I think a mode which "locks" the up direction of the observer in alignment with the local vertical might be a better approach long term. I've been wanting to experiment with this myself, but haven't got around to it. I don't believe it would be difficult to implement.
- Hank