Adobe 65008009 - After Effects CS4 Using Manual page 176

Last updated 12/21/2009
If you use Brainstorm on a single one-dimensional property (such as Opacity, but not Position), the Randomness value
that controls the amount of variation (mutation) is replaced by a Spread value. The variants that are presented in the
Brainstorm dialog box are then not random, but represent a range of values around the central value. The original
composition appears in the center tile of the dialog box, and you can only select one variant on which to base the next
Brainstorm operation.
Though you can't directly use Brainstorm on expressions, you can use Brainstorm on the properties of Expression
Control effects, to which expressions can refer.
Set a work area and region of interest for the duration and spatial area of the composition that you want to preview
1
during the Brainstorm session. (See
Select one or more properties or property groups in the Timeline panel, and click the Brainstorm button
2
top of the Timeline panel.
The variant compositions all play in the Brainstorm dialog box simultaneously. Controls for each variant are only
visible when the pointer is over it. Use the playback controls at the bottom of the Brainstorm dialog box to play, pause,
or rewind the previews.
In the Brainstorm dialog box, do any of the following:
3
• To get a better look at a variant, click its Maximize Tile
to the grid view of all variants.
• To show or hide the transparency grid, click the Toggle Transparency Grid
Brainstorm dialog box.
• To mark a variant for inclusion in the next Brainstorm operation, click the Include In Next Brainstorm
for that variant.
• To save a variant as a new composition in the current project, click the Save As New Composition
that variant.
• To increase the randomness or spread for the next generation, adjust the Randomness or Spread value at the bottom
of the Brainstorm dialog box. Make this number small for precision work; make it larger for experimentation and
exploration.
(Optional) To create another generation of variants from the variants marked for inclusion in the next Brainstorm
4
operation, click Brainstorm at the bottom of the Brainstorm dialog box and return to step 2. If you click Brainstorm
without marking any variants for inclusion, the Brainstorm operation is repeated using the same input as the
current generation.
If the Brainstorm operation uses Randomness, the variants marked for input into the next generation are included
unchanged into the next generation, and remain in their positions in the dialog box. If the Brainstorm operation uses
Spread, only one variant is carried into the next generation, and it appears in the center tile.
Repeat this cycle until you have found the variant that you want to save as the current composition.
You can move back or forward a generation by clicking the arrow buttons on either side of the Brainstorm button at
the bottom of the Brainstorm dialog box. If you move back a generation and then perform another Brainstorm
operation, the later generations are lost.
Note: Press Esc to close the Brainstorm dialog box.
Note: If you use the Save As New Composition feature and the current composition contains expressions that refer to
itself using the
comp("<name>")
not each saved composition. If your expression needs to rely on the settings in its own composition, use the
object instead.
"Work area" on page 201 and
format, then the saved compositions' expressions will refer to the original composition,
"Region of interest
button. Click the Restore Tile Size
button at the bottom of the
USING AFTER EFFECTS CS4
Layers and properties
(ROI)" on page 201.)
at the
button to return
button
button for
thisComp
170