Learning to Fly
Learning to Fly
Goals: To learn basic functions and review navigation.
Before starting, turn on: stars, mwVis
You will be using: no additional groups
Your Initial Location
When you launch the Milky Way Atlas, the preset position has you looking toward the constellation Orion, with the stars Sirius and Procyon in the foreground. The size of their labels is proportional to their distance from you, so you can gauge the distance of objects based on their label size. But from where are you viewing these stars?
When you start the Milky Way Atlas, you are on a unique point. In Partiview it is called the Point of Interest. The Point of Interest is the point about which rotations and orbiting take place. In the Milky Way Atlas, it is set to the Sun's location at (x, y, z) = (0, 0, 0). (You are actually positioned a negligible distance from the Point of Interest for reasons we'll discuss later in this section.)
Panning Around the Sky
With the left mouse button pressed, move the mouse inside the Graphics Window to pan around the sky. You will notice the stars, a few star labels, and the band of the Milky Way (mwVis). The stars resemble those in the sky in luminosity and color. We place a texture, or image, on each, giving depth to the star field. If you don't care for these textures, you can click the Polygon Toggle Button to turn off the star's polygons (the textures are drawn on polygons). Remember, for this change to take effect, stars must be the active group. (A group becomes active when you right-click on its Group Button or select it from the Group Menu.) Of course, once you turn the textures off, the stars will all look similar to one another, so we prefer to have the polygons on.
Moving Off the Point of Interest
Let's exercise our navigational skills. Partiview starts in the Orbit Flight Mode. You can confirm this by looking at the active Flight Mode printed below the Flight Mode Menu, which should read [o]rbit.
You've seen what the left button does from this position; it moves your head without moving your position in space. If you try holding the right button (Option-mouse for Mac), you won't see too much happen. Because Orbit Mode is a logarithmic flight mode, you will have zero speed when sitting on the Point of Interest. Because you're not exactly on the Point of Interest, you are likely to begin moving backward or forward after some time.
Now, using the Flight Mode Menu, switch the flight mode to Fly. With the right button, fly backward away from the Sun. Fly is a linear flight mode, so it remains the same speed no matter where you are in the Atlas. Using the left button in Fly Mode, pan around a bit, keeping the Sun in view. Here you're moving your head but not your position.
Using the Keyboard to Switch Flight Modes
Now switch back to Orbit Flight Mode. With the left button, you will now orbit the Point of Interest, in this case the Sun. The bracketed first letter in each flight mode may be used in the Graphics Window to switch flight modes.
To test this, activate the Rotate Flight Mode by pressing ‘r’ (not ‘R’) in the Graphics Window. You should see [r]ot appear below the Flight Mode Menu. You'll quickly notice that the left button is the same as Orbit Flight Mode, orbiting the Point of Interest. The right button twists the view about the Point of Interest, in a plane parallel to your screen.
Translate Flight Mode
Finally, switch to Translate Flight Mode and, with the left button pressed, move the mouse. Here you move your position but always keep your eyes forward. The data always move parallel to your screen in the direction of mouse motion. The right button moves you forward or backward.
Now switch to Orbit Mode and press the Home Button to bring you back to the Earth's view. You're ready to continue to the next tutorial.
© 2002-2005 American Museum of Natural History
Last Modified: 2007-12-19 by Brian Abbott