Adobe 12040118 - After Effects Standard Tutorial page 486

out the grays, and higher values create a wider range from black to white (until clipping occurs).
Gamma Adjustment Controls the slope of the waves in relation to the Brightness. Results are visible only in Height Map view. Higher values
result in rounder peaks and narrower valleys, while lower values result in smoother valleys and pointier peaks.
Render Dry Areas As Specifies how the water surface is rendered when a dry area exists. Dry areas are created when a portion of the ground
layer rises above the surface of the water. You can manipulate the dry area by using the Steepness control.
This control is useful for compositing a Wave World effect into a scene. For example, you can use a precomposed Wave World scene with
transparency as a displacement map for the Caustics effect, and as a track matte for the effect layer.
Transparency Controls the clarity of the water by adjusting how opaque the alpha channel is in shallower areas. For example, you can easily see
to the bottom of a pool filled with fresh water, but you can see only an inch or two into a pool filled with coffee. This control is most useful when
compositing a Wave World effect into another scene. For example, you can use a Wave World composition as a source layer for Caustics, and
also as a track matte for the effect layer.
Simulation controls
The Simulation controls specify the resolution of the water surface and ground grids.
Grid Resolution Specifies the number of horizontal and vertical divisions that make up the wave surface and ground grids. Higher values greatly
increase the precision of the simulation but require more memory and increase rendering time.
Grid Res Downsamples Reduces the internal simulation resolution when the output resolution decreases, increasing the rendering speed.
However, the result may cause the output to look very different.
Wave Speed Specifies how fast waves travel away from their starting point.
Damping Specifies how quickly the energy of a wave is absorbed by the liquid it travels through. The higher the value, the quicker the wave
energy is absorbed, and the shorter the distance the wave travels.
Wave Speed, Damping Specify the apparent viscosity of the liquid, and the apparent size of the body of liquid. For example, waves in water move
faster and farther than waves in honey; waves in a sink move much faster and fade out much more quickly than waves in a lake.
Note: Wave World is optimized for small- to medium-sized bodies of water—anything from a teacup to a small lake. Large bodies of water, like an
ocean, include swells or wide, stable waves with no apparent slowdown. Even at the lowest settings, Wave World cannot generate swells because
the waves fade out relatively quickly.
Reflect Edges Specifies how waves bounce off the edges of the layer and back into the scene.
Pre-roll (seconds) Specifies when the waves start moving. By default, the effect starts with a still surface without waves or ripples. Use this
control to start the waves moving before the layer begins. The settings at the first frame of the effect are applied to the layer during the pre-roll.
Ground controls
The Ground controls specify the appearance of the ground layer.
Ground Specifies the layer that appears at the bottom of the water. If you use an animated layer for the ground, Wave World samples only the
first frame. Wave World determines the intersection of the water surface with the edge of the ground, computes the waves bouncing off the shore,
and properly adjusts the speed of the waves depending on the depth. The brightness of the layer determines the ground surface: White represents
higher elevation, and black represents lower elevation.
Steepness Adjusts the steepness of the ground by expanding and contracting the height of the displaced wireframe. The mesh is locked at the
black level, so it always grows up from the bottom. In other words, you cannot adjust the bottom of a canyon to be deeper; instead, you can adjust
the rim to be higher. To make the canyon deeper, combine a higher Steepness setting with a lower Height setting.
Height Controls the distance between the water surface and the deepest possible point of the ground. Use this control to make the body of water
deeper or shallower. When you change the depth of the water, the waves behave accordingly: They move faster in deep water and slower in
shallow water. (Adjusting the Height control when using the wireframe preview may appear to lower the ground level, but the wireframe camera
always moves with the water level.)
Wave Strength Controls how big the resulting waves are when the ground height or steepness is animated. A value of 0 results in no waves.
Note: You can create a pulsing wave effect by animating the steepness of the ground so that the ground pokes through the water, producing
waves. Then use the Wave Strength control to intensify the effect.
Producer 1 and Producer 2 controls
The Producer controls specify the point at which the waves begin.
Type Specifies the type of producer. Ring creates a wave as if a stone were dropped into a pond; waves radiate outward in circles (or ellipses,
depending on the size settings of the effect point). Line creates waves that emanate from the producer position in a line instead of an ellipse. This
setting is useful for creating waves that look as though they were generated from much farther away. The waves are produced perpendicular to
the edges of the line. The length of the line is based on the Height/Length setting.
Position Specifies the location of the center of the wave producer.
Height/Length Specifies the (vertical) height of a Ring producer and adjusts the length of a Line producer.
Width Specifies the (horizontal) width of the producer area.
Angle Specifies the angle of the wave producer area for the Line and Ring types. This control sets the orientation of the line and thus controls the
initial direction of the waves, which emanate from either side of the line, perpendicular to its length.
Amplitude Controls the height of the produced wave. Higher values create more dramatic waves but may result in clipping, which you can repair
by using the Brightness and Contrast controls.
Frequency Controls how many waves are produced per second. A value of 1 has the effect of waves surfacing once every second.