24.1 TRACK AIM modes
By selecting a Location mode on the Location panel, you can define how you move through space relative to an object (such as a planet, moon, comet or spacecraft). If you set time running using the Control time panel, your direction of view will, by default, remain fixed relative to the selected co-ordinate system (planetographic, orbital or heliocentric - see More about Location modes). For example, if you have selected Space: track body location mode, as time changes, the object remains in the center of your screen.

Often, however, you may wish to lock your view in some other way. Use the pop-up menu in the TRACK AIM panel to choose one of three modes for controlling the direction of view while running time (time tracking):
  • Relative to the co-ordinate system - changing location type automatically changes this mode:
         Choosing location type: Observe from surface or Space: track surface, sets TRACK AIM mode to Relative to horizon
         Choosing location type: Space: track body, sets TRACK AIM mode to Relative to the body's orbit
         Choosing location type: Heliocentric, sets TRACK AIM mode to Relative to sun
  • Relative to sky - simulates the view of an observer looking at a fixed point in the sky
  • Lock aim - simulates the view of an observer whose view is locked on an object whilst orbiting relative to the object selected in the location panel (this control is linked to the lock aim button in the Aim panel).

    To get a clearer picture of what each of these modes means, use the Motion preview sub-panel - see 24.3.

    • 24.2 Lock/unlock the base plane
    By default, the roll angle is fixed. By clicking the Lock base plane button in the TRACK AIM panel it is possible allow the roll angle to change with each time (or other) step.
     24.3 Using the Motion preview sub-panel
    If you're new to RedShift, and not yet familiar with the different co-ordinate systems, take a look at the explanatory animations in the Motion preview sub-panel.
    Click the Motion preview sub-panel button to open the sub-panel and play the animations. You can also show this sub-panel by choosing Motion preview from the Control menu, or pressing F11 on the keyboard. With the Motion preview sub-panel open, click each of the options in the TRACK AIM and Location type pop-up menus to view an animation which demonstrates the different TRACK AIM and Location modes.

    For example, if you choose Observe from surface location mode (using the pop-up menu in the Location panel), the TRACK AIM mode automatically switches to Relative to horizon mode. The animation in the Motion preview sub-panel shows the camera (the observer) located in a fixed position on the surface of the planet, with the observer's direction of view always pointing in the same direction relative to the surface of the planet. Change TRACK AIM mode to Lock aim. Now you can see the difference. The observer remains in a fixed position on the surface, but now the observer's direction of view changes to keep it locked on an object in the sky.

    Each illustration shows an example of what happens when time runs forward. Heliocentric location mode is a special case; here the illustration shows what happens when position is changed, as well as time running forward.