User`s guide

64 Starry Night User’s Guide
an OpenGL graphics card but do not wish
to run the OpenGL version of Starry
Night, uncheck this box.
Use sub-pixel accuracy when plotting
labels: Sub-pixel accuracy gives labels a
smooth feel as they move on the screen.
However, depending on your video card,
this can cause labels to flicker.
Draw stars using polygon smoothing:
Some video cards have trouble doing
what's called polygon smoothing and this
can cause "blocky stars". By default,
polygon smoothed stars are turned off on
the PC and turned on on the Mac. If you
are experiencing the "blocky star" effect
on the Mac you can try turning this feature
off. On the PC, if your card supports it,
turning this feature on can improve the
speed at which stars are drawn; if your
card doesn't support it, it can result in stars
being drawn slower or having a blocky
appearance.
Show specular reflection on planet
surfaces: Realistically models the Sun’s
glare on planet surfaces.
Use prespective correction when
showing planet surfaces: Corrects for
prespective when viewing planet surfaces.
Number Formats
You can change the number format for the
information displayed by the HUD by
choosing Preferences from the File menu
(Windows) or the Starry Night menu
(Macintosh) and choosing Number
Formats from the dropbox in the upper
left corner of the Preferences dialog box.
There are a number of different formats in
which declination, altitude, right
ascension, and azimuth can be displayed,
and you can choose appropriate formats
for each of these options using the
dropboxes.
•d: degrees
•m: minutes
•s: seconds
The number of occurrences of each letter
indicates the number of decimal places.
For example, “dd mm.mmm” indicates
that degrees will be displayed by up to two
digits, with minutes being displayed by up
to two digits rounded off to three decimal
places — 25° 30.123'.