Adobe AFTER EFFECTS CS3 PROFESSIONAL User Manual page 573

Layer Properties attributes and methods
When you add masks, effects, paint, or text to a layer, After Effects adds new properties to the Timeline panel. There
are too many of these properties to list here, so use the pick whip to learn the syntax for referring to them in your
expressions.
Return type: Property [2 or 3].
anchorPoint
Returns the anchor point value of the layer in the layer's space.
Return type: Property [2 or 3].
position
Returns the position value of the layer, in world space if the layer has no parent or in the parent's layer space if there
is a parent.
Return type: Property [2 or 3].
scale
Returns the scale value of the layer, expressed as a percentage.
Return type: Property.
rotation
Returns the rotation value of the layer in degrees. For a 3D layer, it returns the z rotation value in degrees.
Return type: Property.
opacity
Returns the opacity value for the layer, expressed as a percentage.
Return type: Property [2].
audioLevels
Returns the value of the Audio Levels property of the layer, in decibels. This is a 2D value; the first value represents
the left audio channel, and the second value represents the right. The value is not the amplitude of the source
material's audio track; instead, it is the value of the Audio Levels property, which may be affected by keyframes.
Return type: Property.
timeRemap
Returns the value of the Time Remap property, in seconds, if Time Remap is enabled.
Return type: MarkerKey.
marker.key(index)
Argument type: index is a Number.
Returns the MarkerKey object of the layer-time marker with the specified index.
Return type: MarkerKey.
marker.key(name)
Argument type: name is a String.
Returns the MarkerKey object of the layer-time marker with the specified name. The name value is the name of the
marker, as typed in the comment field in the marker dialog box, for example,
marker on the layer has the same name, this method returns the marker that occurs first in time (in layer time). The
value for a marker key is a String, not a Number.
This expression on a property ramps the property's value from 0 to 100 between two markers identified by name:
m1 = marker.key("Start").time;
m2 = marker.key("End").time;
linear(time, m1, m2, 0, 100);
Return type: MarkerKey.
marker.nearestKey(t)
Argument type: t is a Number.
. If more than one
marker.key("ch1")
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