CELESTIA(1)						      General Commands Manual						       CELESTIA(1)

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)