Controlling speed along a motion path, Controlling speed along a, Motion path – Apple Final Cut Express HD User Manual

Page 740

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Part IX

Effects

To remove Bezier handles from a keyframe in a motion path, do one of
the following:

m

Control-click a keyframe in the Viewer, then choose Make Corner Point from the
shortcut menu.

m

Select the Pen Smooth tool (press the P key three times), then click a curved keyframe.

Controlling Speed Along a Motion Path

The speed at which a clip travels along a motion path is determined by two factors:

 The spatial, or physical, distance between two keyframes in the Canvas.

The farther a clip has to travel in a given duration, the faster its apparent movement. The
less distance a clip moves, given the same amount of time, the slower it appears to go.

 The duration, or distance in time, between two keyframes in the center overlay of a

clip’s Motion tab.

Two keyframes 1 second apart result in faster motion than two keyframes
4 seconds apart.

You can modify a clip’s velocity, changing the quality of its movement. With no velocity
adjustments, clips move at full speed and then come to a full stop. This can result in
abrupt, artificial-looking motion. Final Cut Express HD gives you the ability to change
the velocity of a clip’s motion over time, using velocity handles to modify the keyframes
of a clip’s motion path in the Canvas.

By adjusting a keyframe’s velocity in the Canvas, inertia can be added to a clip’s motion.
Instead of taking off at full speed from a complete stop, you can adjust the first keyframe
of a motion path so that the clip starts off slowly, and then speeds up over time. These
speed changes are indicated by velocity tic marks along that clip’s motion path.

Note: In the two examples below, the motion is at a single constant speed.

Tic marks farther apart
indicate slower motion.

Tic marks closer together
indicate faster motion.

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