Adobe After Effects CS4 - Manual (Page 506)

500 USING AFTER EFFECTS CS4
Effects and animation presets
Last updated 12/21/2009
Direction Specifies the initial direction of a wave if Velocity is greater than 0. By default, particles are emitted from the
producer point in an expanding radial pattern.
Velocity Specifies the speed at which the wave moves in the specified direction.
Spin Controls the continued rotation of a shape after it is born.
Lifespan (sec) Specifies the time, in seconds (including the fade-in and fade-out times), that the wave exists.
To prevent waves from abruptly disappearing when their lifetime ends, use the Fade Out Time control.
Reflection Specifies whether the waves bounce off the edges of the layer and back into the scene. This option is
effective for generating displacement maps for use as water ripples.
Stroke controls
Stroke controls specify the appearance of the stroke of a wave.
Profile Controls the appearance of the stroke that defines the shape. The outline of the shape is animated in the wave
that emanates from the effect point. The quality of the stroke is defined as a 3D wave type.
Color Specifies the color of the stroke.
Opacity Specifies the maximum possible opacity of the stroke. The actual opacity of the stroke takes into account this
setting in conjunction with the Fade-in Time and Fade-out Time controls.
Fade-in Time Specifies the amount of time it takes the wave to fade into view. Fade-in Time is measured in seconds
and begins with 0 opacity at birth. For example, if the Lifespan is 3 seconds and Fade-in Time is 1 second, the stroke
is completely transparent at birth and fades smoothly to full opacity at 1 second.
Fade-out Time Specifies the amount of time it takes the wave to fade out of view. Fade-out Time is measured backward
in time from the end of the Lifespan. If the Lifespan is 3 seconds and Fade-out Time is 1 second, the wave begins to
fade out at 2 seconds. If the sum of Fade-in Time and Fade-out Time is greater than the Lifespan value, the intersection
point of the two fades is calculated so that the wave doesn’t reach full transparency. If either Fade-in Time or Fade-out
Time is longer than the Lifespan, that amount is truncated to equal the Lifespan.
Start Width Specifies the width of the shape at its birth. End Width specifies the width of the shape at the end of its
lifespan.
Ramp effect
The Ramp effect creates a color gradient. You can create linear or radial ramps, and vary the position and colors of the
ramp over time. Use the Start Of Ramp and End Of Ramp properties to specify the start and end positions. Use the
Ramp Scatter control to disperse the ramp colors and eliminate banding.
This effect works with 8-bpc, 16-bpc, and 32-bpc color.
Note: Ramps often don’t broadcast well; severe banding occurs because the broadcast chrominance signal doesn’t contain
sufficient resolution to reproduce the ramp smoothly. The Ramp Scatter control dithers the ramp colors, eliminating the
banding apparent to the human eye.
Scribble effect
The Scribble effect creates the appearance of hand-drawn artwork by filling or stroking a closed mask.