The offline user manual

NOTE: This manual is under construction. Some sections might be missing or incomplete. OU is in beta so there're a few unresolved issues and we're sure there'll be a lot of bugs waiting to show up. If you think you've found a bug double check BUGS file first before reporting it to us.


This is the users's manual for OpenUniverse (OU) , a fun, fast and free OpenGL space simulator. It currently focusses on the Solar System and lets you visit all of its planets, most major moons and a vast collection of smaller bodies in colorful, glorious and realtime 3D. If you've ever had a chance to visit Mercury or asteroid Geographos, here you'll find them looking exactly the same way, following exactly the same path as when you've left them.

So what exactly is OpenUniverse?

Strictly spoken it's a piece of software, simulating the Solar System's bodies in 3D on your Windows or Linux PC (will work in most *NIX's as well). In difference to quite a few other programs it does so in realtime. Meaning you can view all the planets, moons and spaceships move along their paths, trace them, follow them, orbit them and even control them (time and spaceship contol). And you won't have to fight your way through hordes of green, slimey and one-eyed aliens for that ;-)

If you ask what it is besides a piece of software, we'd like to ask you a few questions first:

Are you one of those people who always wondered how it would be to live in the year 2000? Do you think you have a human right to know how it's to be orbiting around Uranus? Do you support the search for terrestial intelligence? Are you dissapointed with the progress on interstellar space drives lately? Did you always wonder how it would be to find people just like you? Do you want to explore and expand the known space at home?

If you answered a few of these questions with yes, then this is exactly the right stuff for you. Try it, use it and visit it at You will find new stuff, new ideas and nice people all over the place. And you decide whether OpenUniverse is just very asthetic, purely fun, rather scientific or educational for you and your friends.

System requirements for Windows:

  • Windows 9X or NT (The Windows package contains all the stuff you need to run OpenUniverse)
  • A working hardware accelerated OpenGL driver

System requirements for Linux / *NIX:

  • Linux / *NIX
  • OpenGL library (Mesa 3.2 recommended,
  • GLUT Library (v3.7 or higher required, and included in MesaDemos package)
  • GLUI 2.0 if you want the GUI (currently in beta). See GUI section.

System recommendations:

  • This program really benefits of a 3D accelerator graphic card. It's the only way to ensure a decent framerate (speed). OU has been tested on the following 3D chipsets:

    • Voodoo 1/2/3 (under Windows 9X and Linux)
    • RIVA 128 (under Windows 9X)
    • RIVA TNT/TNT2 (under Windows 9X)
    • Permedia (under Windows 9X)
    • Savage 3D (under Windows 9X)
    • Nvidia GeForce 256 (under Windows 9X)

    If your card's chipset is not listed here that doesn't mean OU will not run on it. There's simply no chance to test all chipsets. Try it out for yourself and test a few different resolutions, colordephs and refreshrates. OU won't run on all of their combinations on your card. But it's likely it will run if you have an fully OpenGL driver for it. Note: An socalled Mini OpenGL driver as provided by some companies (e.g. 3dfx) will not do it. It's soley purpose is to run a few games like Quake and Unreal which use only a subset of the full OpenGL. If you have such a driver, go to your 3D chipset's manufacturer's (not the card manufacturer's) website and download the full OpenGL driver if available. (For 3dfx a socalled Beta OpenGL driver is available, you just have to accept an online license agreement).

    If you do not own a 3D card yet, then it's simply time to get one. Not only OU but the majority of todays multimedia applications and games simply won't run without. If you go out and buy one try to go for one with a full OpenGL driver in the box and go for a fast one (around 100...150 Euro / $, as of May 2000).

    If you didn't heard about yet I suggest you take a look at Basically it's a 3D programming API. If you ever saw a Windows NT screensaver (rotating time or text) you've seen a basic example of an 3D OpenGL application. That's why Windows 9x / NT comes with a socalled software OpenGL driver. It will run OU just fine but very, very slow (we call it slideshow mode :). You can compare OpenGL with DirectX, except it's supported on a vast variety of computer platforms.

Installation under Windows 9X / NT / 2000:

  • As simple as running openuniverse.exe (the package you just downloaded). It will ask you for a destination folder, just select it and click extract.
  • Create an shortcut for OU on your desktop or in your startmenu to run OU.EXE from the directory you created above. To do so, simply drag the OU.EXE with pressed right mouse button from the explorer to your desktop. Select 'shortcut' when asked. (If you use a Voodoo1, 2 card, please use ounogui.exe instead. This is just OU without it's grafical user interface. You will still be able to see the full potential of OU, but the complete control is done with keystrokes.)
  • Double click the OU shortcut / icon left to start OU. (please read 'Running OU for the first time' and eventually 'The main screen' before doing so.)

Installation under Linux:

  • Uncompress the distribution file (i.e. "tar -xzf openuniverse.tar.gz")
  • Run the configure script ("configure")
  • Run "make"
  • Install it ("make install")
  • Run openuniverse (usually /usr/local/bin/openuniverse)

NOTE: Before you try to compile OU just make sure you have installed Mesa 3.2 (or any other OpenGL compliant library + headers), glut 3.7 and (optionally) GLUI. Please, make also sure all those libs are working (run test and examples supplied with them) before you proceed to compile OU. Read the INSTALL file in the root directory of your Linux distribution for further assistance.

Running OU for the first time:

To run OU you may directly go ahead and simply double click on it's shortcut / icon you just created on your desktop (or run the binary under Linux). This will work right away on most systems.

Only if you really can't get it up and running, we now suggest to take a look under the 'Tuning OU or command line parameters made simple' to switch to a combination of resolution, colordeph and refresh rate your card and your OpenGL driver will support. You can of course pay a visit to that paragraph later all the time to improve these 3 important settings for your system.

The main screen:

When OpenUniverse starts up we suggest to simply lay back for a few seconds. Because you have just reached Earth!

OU's main screen with it's helpful information shows up now and the blue planet will slowly rotate in front of you, while you have a moment to enjoy it's beauty and fragility. If you pay a close look, you will see the sunlight reflect from the oceans and clouds drift along with the trade winds...

Hold your breath, because we haven't started yet at all! Because now OU will send you on your first interplanetary voyage... You might call it simply amazing, we call it:

OpenUniverse's demo mode:

Demo mode is activated when you start up OU for the first time. It can allways be switched on and off by simply hitting the 'd' key. You can also leave OU by hitting the 'ESC' key at any time.

While in demomode, OU will not follow any fixed path on it's way around the solar system. It will find it's way on its own and it will not follow a shortest line from A to Z. Since it will visit some places quite often and others rather seldom, it may actually take a while before you've seen only a part of it's beauty.

When you're then ready to take control of the ship, disable the demo mode with the 'd' key and prepare to take the rudder in your hands with...

OpenUniverse's command keys:

After you have ensured you've switched off the demo mode as described above, we'll now confront you with a list of the keys you can use to pass your commands to OU's built in navigational computer.

If you notice a grey bar on the right side of OU's window, then you're using the GUI version of OU. Please note that you for the key strokes to work the graphical, left part of the OU main window has to get the focus. To ensure this, simply leftclick on the left, the black part of the window :)

To the keys: Granted, this list will apear not too short at first glance, but you'll remember the important ones after a quite short time of usage. Please note however that uppercase and lowercase is important here.

Open Universe - general functions

Demo mode
Switches demo mode on / off.
Online (quick) help
Displays a short list (two pages) of key commands.
Onscreen info
Enables / disables the on screen display of additional info. (E.g.: active modes and physical variables as speed, time, time factor...)
Camera mode 1 - 'linked'
Camera direction follows the selected target body. (Note: If the target body is far away, you might no see it at all this way.)
Camera mode 2 - 'body to body'
Camera views target body A as seen from observer's body B.
Camera mode 3 - 'orbiter'
Camera orbits target, allways pointing towards target body.
Camera mode 4 - 'free'
Use your cursor keys, your mouse or your joystick to guide the camera.
Camera "follow mode"
Camera follows selected spaceship to enable it's contol / navigation. (Current target must be a spaceship.)


OpenUniverse - action keys

Arrow keys
Camera/Spaceship control
As in most 3D programs, the arrow or cursor keys control the direction you're facing.

(CTRL key hold down while hitting an arrow key will control the ships role movement.

Booth actions are only available in 'free camera mode' (1) or 'follow mode' (w).)

Page up / down
Increase / decrease speed
Accelerates the camera / spaceship along the z-axis (simply put: into the monitor). (Useful in free camera or spaceship camera mode.) 

(If you press CTRL simultaneously the spaceship / camera will match the current target's speed.)

+ / -
Increase / decrease time factor or compression
The more time compression is increased, the faster the objects around you will move. A negative timefator will move everything backwards! A timefactor = 0 is excellent for positioning for a screenshot while all other objects stand still.

(Simultaeneousy presses SHIFT key allows faster change of time factor.)

Home / End
Select previous / next target body 
You can change the object you'd like to view with this key when in camera mode 1-3. (Cycles trough all objects within OU.)
SHIFT Home / End
Select observer's body
Useful, when in camera mode 2 - 'body to body' or to select a reference body for navigation
Move camera near target object
Useful in camera mode 1 and 2
Go, get a snack. OU will wait for you. (At least for the next 5 billion years ;-)
Takes a screenshot of the complete current scene in JPG format and stores it in the scrshot folder in your OU directory. (You might want to disable OU's on screen info text 'i' first!)
Joystick control on /off


OpenUniverse - visual toggle keys

Trail on / off
Toggles current target orbit trail. (Applies to planets, asteroids and comets, only.)
Labels on/off
(Useful to locate and distinguish remote bodies.)
Stars labels on/off
(This aplies to Messier object's labels as well.)
Real time on / off
(OU time will become equal to your current local time.)
Display logo
(Logo will fade out in a few secs, again.)
Texture on / off
Detailed / uniform object surfaces.
Light on / off
Object shading on / off.
Flat / smoothed surfaces
Object smoothing on / off.
Atmosphere on / off
(Currently available for Earth, only.)
Top view map on / off
Displays an overwiew map of the solar system as viewed from above. (See below.) 
Stars on / off
Hides / unhides stars.
m / M
Increase /decrease stars' brightness
o / O
Increase / decrease FOV
Field of view. (Much like an optic camera's zoom.)
u / U
Wider / narrower range in top view map
Gravity on / off
(Affects spaceships only at this time.)
z / Z
Increase / decrease zoom factor (camera distance from target)
(Only available in camera modes 2 and 3.)

To make life a bit easier for you, we suggest you simply print out these short lists and place them near to your keyboard or monitor. As we mentioned above, after a very short period of time you won't need them anymore.

In case you need to know a single command, simply press 'h' anywhere in OU to display the quick help on the screen.

Spaceship control:

Once you're in follow mode with an spaceship you'll be able to control ship with the arrow keys (see previous section). You'll notice there're some "X"s on the screen in diffenrent colors:

X : Where the gravity pulls the ship to.

X : Where the ship's nose is pointing towards.

X : Where the ship is moves towards (this is not necessarily where its nose is pointing :-).

X : Where the ships is comes from.


GUI, the User Interface:

If your 3D card supports OpenGL in a window then you're lucky as you'll be able to run the GUI version of OU (ou.exe). If you're getting weird colors or it simply won't work don't panic, we've included the non-GUI version for those of you with older 3D cards (ounogui.exe or see INSTALL under Linux).

This is our first GUI version and while we know it's still incomplete we think is quite useful, especially for selecting bodies (no more painful bizarre keystrokes). The GUI is very simple, just a frame on the right side of the screen and a couple of pop-up windows (used mainly for runtime options). But it allready get's the job done quite perfect :-) Because we believe an image's worth a 1k words:

This is what the GUI looks like when you run OU for the first time. Depending on the active camera mode some controls may be disabled.

  • 'Source' and 'Target' allow a quick body selection (note that 'Source' also sets current reference body and thus both distance and speed will be relative to the source body you have selected at the time).
  • The 'Go There!' button is very useful in Free and Linked camera modes. It will move the camera to a position nearby the selected target body.
  • Guess what camera mode does?
  • FOV is the control for Field of View (much like an optical zoom)
  • ZOOM is used for camera distance adjust in B2B and Orbiter camera modes (also plays its role in Follow mode, see below)
  • Options pops up a window with several (hopefully self-explantory) runtime options. Click on Trails button to enable/disable orbit trails for all major bodies.

Just play around with the available options here. You will soon have a feeling for each and every of those tiny boxes and how they combine :)


As mentioned above in the Keystroke department: If the current body is a spaceship (recognize that one? =) you'll be able to check the 'Follow' box and enter the Follow mode. Now you're able to control the ship's movement:

Use Heading and Roll/Speed to control the ship (tip: if you hold ALT pressed you'll be able to adjust one parameter at a time). Use CTRL+PageUp/PageDown to make the ship match current source body speed (not very realistic but fun and useful :-).

Camera movement with the mouse:

Besides GUI navigation you can use the mouse to move the camera when in free camera mode. Just left click over the rendering window and drag the mouse while you keep the left button down.

Closing the OpenUniverse:

Just press the 'ESC' key when you'd like to leave OU at any time, in any situation.

We hope though, you have enjoyed you stay and will come back as you like. Please don't hesitate to tell your friends about OpenUniverse and You're welcome and thank you for joining us ;-)

Tunining OU or command line parameters made simple (WINDOWS ONLY):

Command line parameters are quite important if you want to squeeze the best possible picture, the highest possible speed out of your system and your graphics card. Remember, the better your configuration, the better OU will look.

We recommend however that you write down the settings you started with (eg. no settings, meaning default settings) as a save base before you tweak the following parameters:

ou.exe -fullscreen 640x480:32@70

Where the first parameter 640x480 is one possible resolution, the second one is one colordepth and the last one is one refresh rate. This command line will run OpenUniverse in an resolution of 640x480 pixels, a colordeph of 32 bit (truecolor) and at a refreshrate of 70Hz. Please note that the characters 'x' and ':' are important and can't be removed (you don't have to suppy refresh rate if you don't want as it'll use default refresh rate for the supplied resolution). Note as well that a lot of 3D cards are only capable of resolutions up to 800x600 and colordepths up to 16bit.

  • You can easily use the command line option when you right click the shortcut on your windows desktop we created in the last step. If you then select 'properties' an dialog box will pop up. Behind 'target' it will display the complete path actually it points to. In this case the field may look much like


    To use the comand line parameters, place the cursor behind the ...ou.exe and type your parameters. Keep in mind that the whole line often can't be displayed in that field, so it may only show a part of it. The whole line may then look much like:

    C:\programs\ou\ou.exe -fullscreen 640x480:32@70

    But your milage may vary ;-)

Performance tweaking:

We've tried to make OU run as fast as possible (there's still a lot of room for improvements and optimizations though) but as there're so many different system configurations you'll have to help OU to run as fast as possible with the nicest visual quality. So, edit the ou.conf file located in the program root directory (windows) or conf subdirectory (Linux, most likely /usr/local/share/openuniverse/conf). Look for the LOD tag (level of detail) and select the value best fitting your 3D card. You may also want to adjust the color depth (just below LOD), font tags and texture compression (if your card supports it, read GeForce family). Just play around with these three config parameters until you're happy with performance/quality.

It can be helpful to change the resolution for performance reasons as well, as quite a few old 3D cards are limited on that. See 'Tuning OU or command line parameters made simple' on how to achieve that.

Useful Tips :

  • When controlling a spaceships you can match current source body speed by pressing CTRL+PageUp.
  • If you're looking for something set time factor to 0, camera mode to free and use the mouse to move the camera (see mouse section above).
  • Hold SHIFT to accelerate spaceships way faster.
  • Hold SHIFT to allow a much faster increase/decrease of timefactor (both in GUI and keyboard commands).


OpenUniverse (OU) was formely known as Solar System Simulator (Ssystem). It was initially released on Nov 1997 with the intention to create a rotating Earth display on a main stream PC. Since these early roots a continuing development and expansion has taken place.Was version 1.0 only aware of the major bodies (planets), version 1.2 added a whole bunch of moons. Solar System v1.6 then added more ways of movement for the user's eye (camera) within Solar System's virtual universe and last but not least better textures for a lot of bodies.

This version, called OpenUniverse (OU) finally has been renamed to underline the concept behind the further development of the program: Open for the whole Universe, not just the solar system. Open to use, extend and change. Finally open for all users, programmers and for you. :)

Programming OU has allways been a process of merging new creative concepts with physics, art and code. An expansion of frontiers bringing together quite different people with their own ideas, backgrounds, questions and abilities.


This finally is the paragraph to philosophate a bit, don't you think? We are all interested in the future, all the time. Whether it's the job, friendship or the complicated and often confusing live in general - why should OpenUniverse make an exception?

Considered all that, to what it boils down to here is amazingly enough rather simple: We are continuing the development of OpenUniverse, so you'll see future versions pop up at as soon as they'll get available. The progress will of course depend on all those people willing to support and contribute to OpenUniverse in the future. So if you think you've got an bright new idea, if you've got new material (eg. good textures or 3D models) about planets, moons, spaceships and such or if you even program with OpenGL please don't hesitate a single second. Check our site or look under 'First contact' in this manual.

Since OpenUniverse's needs will certainly shift over time, we will continually post our new ideas and our kind requests for especially needed resourses on our OU discussion forum. Please read 'our' as in 'we and you' ;-)

To wet your mouth here's finally a little bit of info about our ideas for the next months: We'll of course try to complete the collection of larger bodies. Expect to see a lot more moons of Saturn and Uranus pop up, whether they are spheric or irregular. That means we have to come up with quite a few new textures based on the official NASA images. Since these images are often just b/w and or incomplete quite some ammount of work and 'guess how' will flow in this. The next issue will be the improvement of OU's usability. That will be the simplification of controls, user keys, camera modes and an even more improved GUI (Graphical User Interface). The last big bang will be the expansion of OpenUniverse to our galactic neighborship. The surrounding solar systems will be included, hopefully featuring their already proposed planets. How we'll reach these new frontiers? That is exacly one of the challenges ahead of us. And we love it! =)

First contact:

If you feel interested in OpenUniverse and like to make any sort of contribution, whether it is a hello, a suggestion, a mirror to download it, to spend a few nice and new textures, 3D objects or even to participate in it's further programming and documentation. You are welcome.

Just give Raul Alonso a short mail.


Raul Alonso: Programming, textures and 3d models tweaking.

Axel Groll: Documentation, artwork (splash screens, logo).


A big THANK YOU to all the people who helped since Raul started this little project (in late 1997), go to for an up to date list

Quote for the day:

There is such a thing as a free lunch. You can't buy it though :)