Adobe After Effects User Manual
Page 700
temporalWiggle(freq, amp, octaves=1, amp_mult=.5, t=time)
smooth(width=.2, samples=5, t=time)
loopIn(type="cycle", numKeyframes=0)
amp_mult is the amount that amp is multiplied by for each octave. This value controls how fast the harmonics drop off. The default is 0.5; make it
closer to 1 to have the harmonics added at the same amplitude as the base frequency, or closer to 0 to add in less detail.
t is the base start time. This value defaults to the current time. Use this parameter if you want the output to be a wiggle of the property value
sampled at a different time.
Example: position.wiggle(5, 20, 3, .5) produces about 5 wiggles per second with an average size of about 20 pixels. In addition to the
main wiggle, two more levels of detailed wiggles occur with a frequency of 10 and 20 wiggles per second, and sizes of 10 and 5 pixels,
respectively.
This example, on a two-dimensional property such as Scale, wiggles both dimensions by the same amount:
v = wiggle(5, 10); [v[0], v[0]]
This example, on a two-dimensional property, wiggles only along the y axis:
freq = 3; amp = 50; w = wiggle(freq,amp); [value[0],w[1]];
Paul Tuersley provides a script on the
automatically adds wiggle, smooth, and loop expressions to selected
properties.
Dan Ebberts provides an example expression and a detailed explanation on his
that shows how to use the time parameter of
the wiggle method to create a looping animation.
Kert Gartner provides a video tutorial on the
that shows how to add organic motion to images using the wiggle expression
method on Puppet pins.
Return type: Number or Array.
Argument type: freq, amp, octaves, amp_mult, and t are Numbers.
Samples the property at a wiggled time. The freq value is the frequency in wiggles per second, amp is the amplitude in units of the property to
which it is applied, octaves is the number of octaves of noise to add together, amp_mult is the amount that amp is multiplied by for each octave,
and t is the base start time. For this function to be meaningful, the property it samples must be animated, because the function alters only the time
of sampling, not the value. Example: scale.temporalWiggle(5, .2)
Return type: Number or Array.
Argument type: width, samples, and t are Numbers.
Smooths the property values over time, converting large, brief deviations in the value to smaller, more evenly distributed deviations. This
smoothing is accomplished by applying a box filter to the value of the property at the specified time. The width value is the range of time (in
seconds) over which the filter is averaged. The samples value is the number of discrete samples evenly spaced over time; use a larger value for
greater smoothness (but decreased performance). Generally, you’ll want samples to be an odd number so that the value at the current time is
included in the average. Example: position.smooth(.1, 5)
Return type: Number or Array.
Loops a segment of time that is measured from the first keyframe on the layer forward toward the Out point of the layer. The loop plays from the In
point of the layer. The numKeyframes value determines what segment is looped: The segment looped is the portion of the layer from the first
keyframe to the numKeyframes+1 keyframe. For example, loopIn("cycle", 3) loops the segment bounded by the first and fourth keyframes.
The default value of 0 means that all keyframes will loop.
You can use keyframe-looping methods to repeat a series of keyframes. You can use these methods on most properties. Exceptions include
properties that can’t be expressed by simple numeric values in the Timeline panel, such as the Source Text property, path shape properties, and
the Histogram property for the Levels effect. Keyframes or duration values that are too large are clipped to the maximum allowable value. Values
that are too small result in a constant loop.
loop type
result
cycle
(default) Repeats the specified segment.
pingpong
Repeats the specified segment, alternating between forward and
backward.
offset
Repeats the specified segment, but offsets each cycle by the
difference in the value of the property at the start and end of the
segment, multiplied by the number of times the segment has
looped.
continue
Does not repeat the specified segment, but continues to animate
a property based on the velocity at the first or last keyframe. For
example, if the last keyframe of a Scale property of a layer is
100%, the layer continues to scale from 100% to the Out point,
instead of looping directly back to the Out point. This type does
not accept a keyframes or duration argument.
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