NAME
celestia - A real-time visual space simulation
SYNOPSIS
celestia [options]
DESCRIPTION
This manual page documents briefly celestia, a 3D space simulator.
Celestia is a real-time visual simulation of space in our local region
of the universe. Choose a point within about 1000 light years of Earth,
and Celestia will show you an approximation of how it would appear to
your eyes were you actually there. Some of what Celestia shows is
necessarily hypothetical--the farther away from Earth you get, the less
real data there is and the more guesswork is involved. Thus Celestia
supplements observational data with good guesses based on models of
stellar and planetary processes.
Celestia is unique in its ability to allow you to navigate at an
immense range of scales. Orbit a couple kilometers above the surface
of a tiny, irregular asteroid, then head off toward Jupiter, watching
it grow from a bright point of light into a looming sphere filling your
field of vision. Leave our solar system entirely and observe the sun
as it fades from a brilliant disk to a bright star, disappearing almost
entirely as you head off toward the Upsilon Andromeda system to orbit
around its innermost giant planet.
OVERVIEW
Celestia will start up in a window, display a welcome message and some
information about your target (top left corner), your speed, and the
current time (Universal Time, so it'll probably be a few hours off from
your computer's clock.) In Celestia, you'll generally have an object
selected; currently, it's Eros, but it could also be a star, planet,
spacecraft, or galaxy. The simplest way to select an object is to
click on it. Try clicking on a star to select it. Right drag the
mouse to orbit arround the selected target. Left dragging the mouse
changes your orientation too, but the camera rotates about its center
instead of rotating around the target. Rolling the mouse wheel will
change your distance to the space station--you can move light years
away, then roll the wheel in the opposite direction to get back to your
starting location. If your mouse lacks a wheel, you can use the Home
and End keys instead.
Press G and you'll zoom through space toward the selected star. If you
press G again, you'll approach the star even closer. Press H to select
our Sun, and then G to go back to our solar system. You'll find
yourself half a light year away from the Sun, which looks merely like a
bright star at this range. Press G three more times to get within
about 30 AU of the Sun and you will be to see a few planets become
visible near the Sun.
USAGE
Mouse functions:
Left drag orient camera
Right drag orbit the selected object
Mouse wheel,
Middle drag adjust distance to selection
left click select target, double click to center
Keyboard commands:
Navigation
H Select the sun (Home)
C Center on selected object
G Goto selected object
F Follow selected object
Y Orbit the selected object at a rate synced to its rotation
ESC Cancel motion
Free movement
HOME Move closer to object
END Move farther from object
F1 Stop
F2 Set velocity to 1 km/s
F3 Set velocity to 1,000 km/s
F4 Set velocity to 1,000,000 km/s
F5 Set velocity to 1 AU/s
F6 Set velocity to 1 ly/s
A Increase velocity by 10x
Z Decrease velocity by 10x
Q Reverse direction
X Set movement direction toward center of screen
Time
Space stop time
L Time 10x faster
K Time 10x slower
J Reverse time
Options
U Toggle galaxy rendering
N Toggle planet and moon labels
O Toggle planet orbits
V Toggle HUD Text
I Toggle planet atmospheres (cloud textures)
W Toggle wireframe mode
/ Toggle constellation diagrams
= Toggle constellation labels
; Toggle earth-based equatorial coordinate sphere
B Toggle star labels
P Toggle per-pixel lighting (if supported)
[ Decrease limiting magnitude (fewer stars visible)
] Increase limiting magnitude (more stars visible)
{ Decrease ambient illumination
} Increase ambient illumination
, Narrow field of view
. Widen field of view
Other
D Run demo
` Show frames rendered per second
It's possible to choose a star or planet by name: press Enter and type
in the name, and pressing Enter again. You can use common names, or
Bayer designations and HD catalog numbers for stars. Bayer and
Flamsteed designations need to be entered like "Upsilon And" and "51
Peg". The constellation must be given as a three letter abbreviation
and the full Greek letter name spelled out. HD catalog numbers must be
entered with a space between HD and the number.
OPTIONS
The glut based version accepts the usual X Window System specific
options, namely:
-display DISPLAY
Specify the X server to connect to. If not specified, the value
of the DISPLAY environment variable is used.
-geometry WxH+X+Y
Determines where window's should be created on the screen. The
parameter following -geometry should be formatted as a standard
X geometry specification. The effect of using this option is
to change the GLUT initial size and initial position the same
as if glutInitWindowSize or glutInitWindowPosition were called
directly.
-iconic Requests all top-level windows be created in an iconic state.
-indirect
Force the use of indirect OpenGL rendering contexts.
-direct Force the use of direct OpenGL rendering contexts (not all GLX
implementations support direct rendering contexts). A fatal
error is generated if direct rendering is not supported by the
OpenGL implementation.
If neither -indirect or -direct are used to force a particular
behavior, GLUT will attempt to use direct rendering if possible
and otherwise fallback to indirect rendering.
-gldebug
After processing callbacks and/or events, check if there are
any OpenGL errors by calling glGetError. If an error is
reported, print out a warning by looking up the error code with
gluErrorString. Using this option is helpful in detecting
OpenGL run-time errors.
-sync Enable synchronous X protocol transactions. This option makes
it easier to track down potential X protocol errors.
AUTHOR
Celestia has been written by Chris Laurel <claurel@www.shatters.net>
and it's available under the terms and conditions of the GNU General
Public LIcense from http://celestia.sf.net/
May 23, 2001 CELESTIA(1)