Apple Motion 4 - Manual (Page 184)

Media
This section in the General Preferences pane contains the “Automatically manage unused
media” checkbox. When the checkbox is selected, Motion removes unused media from
the Media tab whenever you delete that media from the Canvas, Layers tab, or Timeline
layers list. If you want to retain (in the Media tab) a copy of media that is no longer used
in your project, deselect this checkbox.
Keyframe Editor
This section in the General Preferences pane contains the “Lock Keyframes in Time”
checkbox. When the checkbox is selected, you can change the values of keyframes in the
Keyframe Editor, but you cannot move the keyframes forward or back in time. This helps
prevent changing your animation timing as you adjust values.
Appearance Pane
The Appearance pane of the Motion Preferences window contains settings that control
visual elements of the Motion interface, grouped into the following categories: HUD,
Thumbnail Preview, Timeline, and Status Bar.
HUD
The HUD (heads-up display) is a semi-transparent window that floats above the other
windows on your screen. Use the Window Opacity slider in the HUD section of the
Appearance pane to set the opacity (transparency) of the HUD.
Thumbnail Preview
The thumbnails that appear in the Layers tab of Motion can provide helpful information
about the items selected in that window. For items that are partially transparent (contain
an alpha channel), you can set the background that appears behind the image. There are
two background options: Checkerboard and Color. Choose either of these options from
the Background menu in Thumbnail Preview section of the Appearance pane.
Background: A pop-up menu with two options for thumbnail backgrounds.
• Checkerboard: This is the default setting. It displays a checkerboard pattern where
transparent pixels appear.
184 Chapter 5 Preferences