Star labels

[Matt McIrvin]

As I said over on the Motherlode forum right before Shatters came up again, I've been idly speculating about the future of star labels. Right now, the stars that have displayed labels are statically coded in the main .cfg file, which is less flexible than it could be, and seems like a waste of all the nice name and catalog information that already exists in starnames.dat. But displaying every star name as a label would be a mess.

Ideally it should be possible to leverage some of the excellent work done already on the hierarchy of planetary location labels, and get stars with proper names to behave similarly, using, say, the first-listed name in starnames.dat as the label name. (We could, perhaps, keep the .cfg mechanism around as a name override.) Visual magnitude seems like an obvious analogue for the size/importance metric, for most purposes; in a sense this would be just like the current behavior except that the star's label and the star itself could have different display cutoffs.

(What really inspired this was that I installed one of the big deep-space add-ons, and it occurred to me that similar treatment would be extremely useful for galaxy/globular cluster display once you've got a lot of them, both to speed up display with labels turned on, and to unclutter the screen. But stars are more important for the time being.)

That done, a next step could be to display Bayer designations where available (just the Greek letter, positioned differently from the name label so that both could be displayed if they exist), and possibly Flamsteed numbers where there is no Bayer designation. I'm imagining this as a separate option from proper-name display, possibly keyed to the constellation figures and/or boundaries.

This would go a long way toward making Celestia more useful for casual backyard astronomers, and for me, at least, it would also make flying around the galaxy more interesting.

[Matt McIrvin]

Visual magnitude seems like an obvious analogue for the size/importance metric, for most purposes; in a sense this would be just like the current behavior except that the star's label and the star itself could have different display cutoffs.

...One possible exception is the case in which you zoom out and look back at the sun's neighborhood from afar; in that case it might be useful to use visual-magnitude-seen-from-Earth as the importance metric instead. But this is a secondary consideration.

[t00fri]

Matt,

I find your idea with adaptive star (and nebulous object) labels very interesting. Indeed, extending some concepts I have previously explored for location labels could easily do the job.

A simple way would be to couple adaptive labels with my "automag" feature. It was designed such as to keep the number of visible stars on the screen area ~constant while the degree of zoom, i.e. the field of view changes.

I will continue to think about other options from the background of my substantial experience with location labels. We already have the big 'starnames.dat' file in use with Celestia. So this issue shouldn't be a big deal...

I think this would be a very neat feature to incorporate.


Bye Fridger

[Matt McIrvin]

Adaptive label display might also work well with the big asteroid files, with a much fainter range of magnitude cutoffs.

[TERRIER]

This is a nice idea.
I've recently 'hashed out' some of the named regions of nebulae from the dsc files of a few of my DSO add-ons, to make their labels more legible when viewing from the Earth.

Adaptive label display might also work well with the big asteroid files, with a much fainter range of magnitude cutoffs.

Similarly, I am wondering if the same could be done for moons orbiting planets ?