Flow Map Controls For The Foam Effect; Random Seed Control For The Foam Effect; Particle Playground Effect (Pro Only) - Adobe AFTER EFFECTS 7.0 Manual

ADOBE AFTER EFFECTS 7.0
500
User Guide

Flow Map controls for the Foam effect

The Flow Map controls specify the map that the flow of the foam follows:
Specifies the layer used to control the direction and speed of the bubbles. Use a still image layer; if you
Flow Map
select a movie as the flow map layer, only the first frame is used. A flow map is a height map based on luminance:
White is high, and black is low. White is not infinitely high; if a bubble travels fast enough, it can travel past a white
obstacle. Make sure that the map is a little blurry; sharp edges can create unpredictable results. For example, to make
bubbles flow through a canyon, create a flow map with a white canyon rim, a black canyon, and blurry gray walls.
Use wind to blow the bubbles in the direction you want them to flow, and the walls of the canyon contain them. You
can also use a gentle gradient on the floor of the canyon to control the flow direction, but this is somewhat more
difficult to set up.
Note: If the bubbles don't follow the map, use the Simulation Quality control. Also, try blurring the flow map a little to
make sure that it does not have excessively abrupt edges.
Controls the difference between white and black as they are used to determine steepness. If the
Flow Map Steepness
bubbles are ricocheting randomly off the flow map, decrease this value.
Specifies whether the flow map is relative to the layer or to the universe. The flow map resizes itself to
Flow Map Fits
fit whichever you specify. This control is useful when you want to enlarge the universe but the flow map is designed
for a particular layer, or when you want the bubbles to start off-screen and be affected by the flow map as they arrive
on-screen.
Increases the accuracy, and therefore the realism, of the simulation. However, the higher the
Simulation Quality
value, the longer the composition takes to render. Normal generally produces good results and takes the least amount
of time to render. High returns better results but takes longer to render. Intense increases the rendering time but
produces more predictable bubble behavior. Use this option if the bubbles aren't following the flow map. It often
solves problems of erratic behavior that can occur with small bubbles, high bubble speeds, and steep slopes.

Random Seed control for the Foam effect

The Random Seed control affects all parameters that have any randomized elements in them. If the settings are the
same, any given random-based parameter looks exactly the same every time you apply it. That is, you get predeter-
mined randomness. Using a different Random Seed value makes things appear different while still using the same
settings. Changing the Random Seed value doesn't make things more or less random; it only makes them random in
a different way.

Particle Playground effect (Pro only)

The Particle Playground effect lets you animate a large number of similar objects independently, such as a swarm of
bees or a snow storm. Use the Cannon to create a stream of particles from a specific point on the layer, or use the
Grid to generate a plane of particles. The Layer Exploder and Particle Exploder can create new particles from existing
layers or particles. You can use any combination of particle generators on the same layer.
This effect works with 8-bpc color.
Particles shooting out of the spacecraft layer (left) and text characters used as particles shooting out of a ray gun (center) and Layer Exploder
used on spacecraft layer (right)