ADOBE AFTER EFFECTS 7.0
User Guide
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You can also substitute any image or movie for bubbles. For example, you can create swarms of ants, flocks of birds,
or crowds of people.
Note:
On a frame-by-frame basis, Foam renders quickly, but the slightest adjustment in the initial settings is likely to
result in very different output a few seconds into the simulation. When making adjustments to Physics controls, the
farther into the simulation you are, the longer the adjustments take to render, because each adjustment results in the
simulation being recalculated all the way back to the beginning. Not every frame takes this long to calculate; once Foam
adjusts to the change, rendering speeds up again.
View controls for the Foam effect
Draft
Displays the bubbles without fully rendering them. This is a fast way to preview the behavior of the bubbles.
Draft mode is the only way to preview the universe edges, the Flow Map alignment, and the Producer location, orien-
tation, and size. Bubbles are represented by blue ellipses. The Producer Point is represented by a red ellipse. The
bubble universe is represented by a red rectangle.
Draft + Flow Map
Displays the Draft view wireframe superimposed over a grayscale representation of the flow map,
if selected.
Rendered
Displays the final output of the animation.
Producer controls for the Foam effect
The Producer controls specify the location where the bubbles originate, as well as the speed at which they are
generated:
Producer Point
The center of the area from which the bubbles can be produced.
Producer X Size, Producer Y Size
Adjust the width and height of the area from which the bubbles can be produced.
Producer Orientation
Adjusts the rotation (orientation) of the area from which the bubbles can be produced.
Producer Orientation has no noticeable effect when Producer X Size and Producer Y Size are identical.
Zoom Producer Point
Specifies whether the producer point and all of its associated keyframes remain relative to the
universe (selected) or to the screen (deselected) when you zoom in or out on it. For example, if you set a position for
Producer Point in the upper left corner of the layer and then zoom out on that layer, the producer point stays in the
upper left corner of the screen if you don’t select Zoom Producer Point. If you select Zoom Producer Point, the point
moves with the universe as it is zoomed out, and the point ends up closer to the center of the screen.
Production Rate
Determines the rate at which bubbles are generated. This control does not affect the number of
bubbles per frame. Rather, the rate is the average number of bubbles generated every 30th of a second. Higher
numbers yield more bubbles.
If a large number of bubbles appear in the same point at the same time, some may pop. If you want a lot of foam,
increase the values for Producer X Size and Producer Y Size so that the bubbles don’t immediately pop each other.
Bubbles controls for the Foam effect
Size
Specifies the average size for adult bubbles. Size Variance, Bubble Growth Speed, and Random Seed also affect
the size of a bubble in any particular frame.
Size Variance
Specifies the range of possible bubble sizes. This control uses the Size value as the average and creates
smaller-than-average and larger-than average-bubbles by using the range you specify here. For example, a default
bubble Size of 0.5 and default Size Variance of 0.5 generate bubble sizes ranging from 0 to 1 (0.5 –.5 = 0 and 0.5 + 0.5
= 1).
