Adobe After Effects CS3 User Manual
Page 584
AFTER EFFECTS CS3
User Guide
579
the last keyframe. For example,
loopOut("cycle", 1)
loops the segment bounded by the last keyframe and
second-to-last keyframe. The default value of 0 means that all keyframes will loop. See the entry for
loopIn
for more
information.
David Van Brink provides a blog post and sample project that show how to use the Echo effect, the Particle
Playground effect, and the loopOut expression to animate a swarm of stylized swimming bacteria:
loopInDuration(type="cycle", duration=0)
Return type: Number or Array.
Loops a segment of time that is measured from the first keyframe on the layer forward toward the layer’s Out point.
The loop plays from the layer’s In point. The segment to loop is determined by the specified duration. The duration
value sets the number of composition seconds in a segment to loop; the specified range is measured from the first
keyframe. For example,
loopInDuration("cycle", 1)
loops the first second of the entire animation. The default
of 0 means that the segment to loop begins at the layer Out point. See the entry for
loopIn
for more information.
loopOutDuration(type="cycle", duration=0)
Return type: Number or Array.
Loops a segment of time that is measured from the last keyframe on the layer back toward the layer’s In point. The
loop plays until the layer’s Out point. The segment to loop is determined by the specified duration. The duration
value sets the number of composition seconds in a segment to loop; the specified range is measured backward from
the last keyframe. For example,
loopOutDuration("cycle", 1)
loops the last second of the entire animation. The
default of 0 means that the segment to loop begins at the layer In point. See the entry for
loopIn
for more infor-
mation.
key(index)
Return type: Key or MarkerKey.
Argument type: index is a Number.
Returns the Key or MarkerKey object by number. For example,
key(1)
returns the first keyframe.
key(markerName)
Return type: MarkerKey.
Argument type: markerName is a String.
Returns the MarkerKey object with this name. Use only on marker properties.
nearestKey(t)
Return type: Key or MarkerKey.
Returns the Key or MarkerKey object nearest to a designated time.
numKeys
Return type: Number.
Returns the number of keyframes on a property. Returns the number of markers on a marker property.
propertyGroup(countUp = 1)
Return type: Group.
Returns a group of properties relative to the property on which the expression is written. For example, if you add the
propertyGroup(1)
expression to a Brush stroke’s Rotation property, the expression targets the Transform property
group, which contains the Rotation property. If you add
propertyGroup(2)
instead, the expression targets the
Brush property group. This lets you establish name-independent relationships in the property hierarchy. This is
especially useful when duplicating properties that contain expressions.
propertyIndex
Return type: Number.
Returns the index of a property relative to other properties in its property group, including property groups within
masks, effects, text animators, selectors, shapes, trackers, and track points.