Elastic Keyframes and Fixed Keyframes
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| Elastic keyframe |
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| Fixed keyframe |
With standard keyframes, all keyframes are elastic. When you trim an effect, the Avid editing application scales the keyframes to fit the new duration. For example, suppose you want to have a PIP effect appear, be visible for 16 frames, and then pop off the screen. If the original clip is 2áseconds long and you trim out the clip to 3 seconds, each event takes proportionally longer. After the trim, the PIP effect remains visible for 24áframes.
Start of clip | 02:00 | 01:00 |
PIP effect on | 02:18 | 01:27 |
PIP effect off | 3:04 | 2:21 |
End of clip | 3:29 | 3:29 |
With fixed keyframes, when you trim out a clip, the Avid editing application extends the first or last keyframe value by duplicating parameters in the trimmed-out area. When you trim out a clip, the keyframes remain fixed at their original timecodes. Fixed keyframes allow you to "pin" a parameter change to a particular timecode. Using the previous example, if before the trim the PIP appears for 16 frames at 02:18, after the trim the PIP appears for 16 frames at 02:18.
Start of clip | 02:00 | 01:00 |
PIP effect on | 02:18 | 02:18 |
PIP effect off | 3:04 | 3:04 |
End of clip | 3:29 | 3:29 |
Effect parameters default to elastic keyframes. You select elastic keyframes or fixed keyframes from the shortcut menu for a parameter.
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You can select elastic keyframes or fixed keyframes for each parameter of
an effect. That is, some parameters can have elastic keyframes and other
parameters can have fixed keyframes.
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All keyframes for a parameter are either elastic or fixed. You cannot mix
elastic keyframes and fixed keyframes within a single parameter.
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| Elastic keyframe |
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| Fixed keyframe |
To select elastic keyframes or fixed keyframes for a parameter:
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Right-click (Windows) or Ctrl+Shift+click (Macintosh) the keyframe
graph or keyframe track for the parameter with which you are working,
and select Fixed or Elastic.
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The keyframes for the parameter change to the selected keyframe type
and the keyframe indicators for the parameter display the selected
keyframe type.
All subsequent keyframes you add to this parameter appear as the
selected keyframe type.
To select elastic keyframes or fixed keyframes for a parameter group:
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Right-click (Windows) or Ctrl+Shift+click (Macintosh) the parameter
group title track, and select Fixed or Elastic.
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The keyframes for all parameters in the parameter group change to the
selected keyframe type. The keyframe indicators display the selected
keyframe type.
All subsequent keyframes you add to this parameter group appear as
the selected keyframe type.
