[Kstars-devel] Some user feedback

[Jason Harris]

Hello,

On Monday 28 May 2007 14:40, Alexey Khudyakov wrote:
> > Adding more stars is trivial.  I think I even have the kstars-formatted
> > Hipparcos catalog down to 12th magnitude on disk.  The problem is adding
> > millions of stars without bogging down the program or having ridiculous
> > memory requirements.  The way to do it is to selectively load faint stars
> > only in the region immediately surrounding the current focus point, and
> > only at high zoom.  We had someone working on the infrastructure required
> > to do this, but we haven't seen the results.  Let me know if you want to
> > know more about it.
>
> Yes I do. And how are stars and other objects stored in memory?
>
See kstars/kstars/skycomponents/README for a good start...

To learn more about the infrastructure to allow for a much larger number of 
objects to be displayed, search our mailing list archive for "htm".
I introduced the concept in this message:
http://lists.kde.org/?l=kstars-devel&m=114840892829281&w=2

The short version is, we had someone who put a lot of effort into implementing 
HTM for KStars, but he had to stop working on it before it was finished.

> > > I can't set kstars to display globular
> > > clusters brighter than 10m
> > > and stars. When I searching for globlar clusters I don't need nor
> > > galaxies nor nebulae.
> > > And too faint objects only clutter window and slows down rendering.
> >
> > It's an interesting idea, but why don't you just create an observing list
> > of all theglobular clusters?  That automatically highlights GCs in the
> > map. We'd need a way to add this feature without cluttering the interface
> > for the>90% of the users who wouldn't care about it.
>
> Yes, I can, and this is really nice feature. But it has one disadvantage
> it's slow. Adding merely 129 planetary nebulae takes about 30 seconds. List
> clearing take same amount of time. What can be cause of such slowness?
>
Adding objects isn't too slow for me, but I do see a big delay when clearing 
the list.  I'll look into it.

> > > Third - deep-sky rendering. Deep-skyes are rendered as outlines. I
> > > think, they should be filled
> > > with some color. It's too easy to overlook them. And deepskyes smaller
> > > than certain size should
> > > be rendered as symbols. One pixel deep-sky is very hard to notice and
> > > doesn't make much
> > > sense.
> >
> > Good ideas; I would welcome patches for these changes.
>
> And this is connected closely to point above. Now there are a _lot_ of
> faint objects on sky map. They are nearly invisible. If they will be
> rendered as symbols map would be filled with faint galaxies. And we would
> need to set cut off magnitude. May be manually, may be via some
> auto-adjustment, may be via some combination.
>
To avoid overcrowding the map at low zoom, we should render objects with their 
true angular size, even if it means drawing the object as a point (in fact, 
maybe we can save time by not rendering very small objects at all when they 
will only appear as points anyway).  Only at high zoom should we switch to a 
minimum size.  What do you think?

> > I don't want to put coordinates in the popup menu; they are better placed
> > in the details window.  I'm also not excited about putting the magnitude
> > there; you can already display stellar mags directly on the sky map, if
> > that's what you are interested in.  I'd be more willing to put magnitudes
> > and angular sizes in the "object infobox" (the floating box showing name
> > and coordinates of the currently-focused object).
>
> Do you mean small label which appears near sky object when I hold mouse
> cursor on it. It's simply faster to right-click on star than wait for
> pop-up. This is matter of opinion.
>
No, I mean the three lines of text in the upper right corner of the window, 
displaying the name of the centered object ("Focused on: Andromeda galaxy"), 
and then its RA/Dec and Az/Alt coordinates.  We could add another line 
showing things like angular size and magnitude of the centered object.

> > "not sufficient for me" != "bad or non-existent"
>
> I've forgot to mark that with four letters: "IMHO"

Remeber the KDE wisdom: "you are not necessarily your users"

regards,
Jason

-- 
Jason Harris
jharris at 30doradus.org