Adobe After Effects CS4 - Manual (Page 564)

558 USING AFTER EFFECTS CS4
Effects and animation presets
Last updated 12/21/2009
Water controls
Water Surface Specifies the layer to use as the surface of the water. Caustics uses the luminance of this layer as a height
map for generating a 3D water surface. Light pixels are high, and dark pixels are low. You can use a layer created by
using the Wave World or Radio Waves effect; precompose the layer before using it with Caustics.
Wave Height Adjusts the relative height of the waves. Higher values make the waves steeper and the surface
displacement more dramatic. Lower values smooth the Caustics surface.
Smoothing Specifies the roundness of the waves by blurring the water surface layer. High values eliminate detail. Low
values show imperfections in the water surface layer.
Water Depth Specifies depth. A small disturbance in shallow water moderately distorts the view of the bottom, but the
same disturbance in deep water distorts the view greatly.
Refractive Index Affects the way the light bends as it passes through the liquid. A value of 1 does not distort the
bottom. The default value of 1.2 accurately simulates water. To add distortion, increase the value.
Surface Color Specifies the color of the water.
Surface Opacity Controls how much of the bottom layer is visible through the water. If you want a milky effect,
increase the Surface Opacity and Light Intensity values; a value of 0 results in a clear liquid.
Set Surface Opacity to 1.0 to perfectly reflect a sky later. With a suitable texture map, you can use this technique to
create the effect of liquid mercury.
Caustics Strength Displays the caustics, the concentrations of light on the bottom surface, caused by the lensing effect
of the water waves. This control changes the way everything looks: The dark spots of the waves get much darker, and
the light spots get much lighter. If you don’t set a value for this control, the effect distorts the bottom layer when the
waves pass over it, but it doesn’t render the lighting effect.
Sky controls
Sky Specifies the layer above the water. Scaling makes the sky layer larger or smaller. If the edges of the sky layer show,
scale the layer up. Scaling down is useful for tiling a layer to make a complex pattern.
Repeat Mode Specifies how a scaled-down sky layer is tiled. Once uses only one tile, basically turning tiling off. Tiles
uses the traditional tiling method of abutting the right edge of one layer tile to the left edge of another layer tile. This
option works well if the layer contains a repeating pattern, like a logo, that needs to read a certain way. Reflected abuts
each edge of a layer tile to a mirrored copy of the tile. This option can eliminate a hard edge where the two tiles meet.
If Layer Size Differs Specifies how to handle the layer when it is smaller than the composition. Intensity specifies the
opacity of the sky layer. Convergence specifies how close the sky and the bottom or water layer appear, controlling the
extent to which the waves distort the sky.
Foam effect
This effect generates bubbles that flow, cling, and pop. Use the controls for the effect to adjust attributes for the bubbles
such as stickiness, viscosity, life span, and bubble strength. You can control exactly how the foam particles interact with
each other and with their environment, and specify a separate layer to act as a map, controlling precisely where the
foam flows. For example, you can have particles flow around a logo or fill a logo with bubbles.
This effect works with 8-bpc color.