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 |
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/