Adobe 12040118 - After Effects Standard Tutorial page 476

Time Offset Type Specifies how you want to use the frames of a multiframe layer. For example, if you are using a layer of a bird flapping its
wings and you choose Relative for Time Offset Type with a Time Offset of 0, the flapping wings for all the instances of the bird are synchronized.
While this may be realistic for a marching band, it is not realistic for a flock of birds. To make each bird start flapping its wings from a different
frame in the layer, use Relative Random.
Relative Starts playing the layer at a frame based on the Time Offset you specify, relative to the current time of the effect layer; then
advances in step with the current time of the Particle Playground layer. If you specify a Time Offset of 0, all particles show the frame that
corresponds to the current time of the effect layer. If you choose a Time Offset of 0.1 (and your composition is set to 30 fps), each new
particle displays the frame that is 0.1 seconds after the previous particle's frame. Regardless of the Time Offset you specify, the first
particle always displays the frame of the source layer that corresponds to the current time of the effect layer.
Absolute Displays a frame from the layer based on the Time Offset you specify, regardless of the current time. Choose Absolute when
you want a particle to show the same frame of a multiframe source layer for its entire lifespan, instead of cycling through different frames
as the effect layer advances in time. For example, if you choose Absolute and specify a Time Offset of 0, every particle shows the first
frame of the source layer for its entire lifespan. If you want to show a frame other than the first frame, move the layer earlier in time until
the frame you want to show corresponds to the In point of the Particle Playground layer. If you specify a Time Offset of 0.1, for example,
each new particle displays a frame that is 0.1 second after the frame of the previous particle (or every third frame of a 30-fps animation).
Relative Random Starts playing the layer from a frame chosen at random, within the range between the current time of the effect layer
and the Random Time Max you specify. For example, if you choose Relative Random and specify a Random Time Max of 1, each particle
starts playing from a layer frame chosen at random from between the current time and 1 second after the current time. If, for another
example, you specify a negative Random Time Max value of - 1, the Random Time Max is before the current time, so that the range within
which new particles start playing advances as the current time advances. However, the range is always between the current time and one
second earlier than the current time.
Absolute Random Takes a frame at random from the layer, by using a time in the range from 0 to the Random Time Max you specify.
Choose Absolute Random when you want each particle to represent a different single frame of a multiframe layer. For example, if you
choose Absolute Random and specify a Random Time Max of 1, each particle shows a layer frame from a random time between 0
seconds and 1 second into the duration of the layer.
Time Offset Specifies the frame from which to start playing sequential frames from the layer.
Affects Specifies which particles the Layer Map controls affect.
Replace default Cannon particles with text
You can use text characters as particles. For example, you can type a message that the Cannon shoots across the frame. You can also change
the attributes of any three sets of characters. For example, you can make some of the characters larger or brighter than others.
1. In the Effect Controls panel, click Options.
2. Click Edit Cannon Text.
3. Type text in the box, and then set the following options:
For Font/Style, choose the font and style for Cannon characters.
For Order, click to specify the sequence in which characters exit the Cannon. The sequence is relative to the character order typed in the
box. For example, if the Cannon Direction is set to 90° (making it point to the right), English text must exit the Cannon last letter first to
be in readable order. Therefore, select Right to Left.
For Loop Text, select to continuously generate the characters you typed. Deselect to generate only one instance of the characters.
4. Click OK to close the Edit Cannon Text dialog box, and then click OK to close the Particle Playground dialog box.
5. Click the right-facing triangle next to Cannon so that it points downward.
6. Click the Font Size value, type a value of 10 or greater, and press Enter (Windows) or Return (Mac OS).
If you want to stop replacing default particles with text, delete all text from the box in the Edit Cannon Text dialog box.
Replace default Grid particles with text
1. In the Effect Controls panel, click Options, and then click Edit Grid Text.
2. Set the following options:
For Font/Style, choose the font and style for Grid characters.
For Alignment, click Left, Center, or Right to position text in the box at the Position specified in the Grid control, or click Use Grid to
position each letter in the text on consecutive grid intersections.
For Loop Text, select to repeat the characters you typed until all the grid intersections contain one character. Grid intersections are
specified by the Particle Across and Particle Down controls. Deselect to generate only one instance of the text. (This option is available
only if you select Use Grid alignment.)
3. Type text in the box. If Use Grid alignment is selected and you want to skip a grid intersection, type a space. To force the next character
down to the next grid row, press Enter (Windows) or Return (Mac OS).
4. Click OK to close Edit Grid Text, and then click OK to close the Particle Playground dialog box.
5. Click the right-facing triangle next to Grid so that it points downward.