Adobe After Effects CS4 - Manual (Page 582)

576 USING AFTER EFFECTS CS4
Effects and animation presets
Last updated 12/21/2009
Render control
The Render control renders the whole scene (the default), the unshattered layer, or the shattered pieces independently.
For example, if you want to apply the Glow effect only to shattered pieces and not to the portions of the layer that
remain intact, create the explosion and duplicate the layer. Next, for the back layer, choose Layer from the Render
menu, and for the front layer, choose Pieces. Then apply the Glow effect to the front layer.
Shape controls
Shape controls specify the shape and appearance of the shattered pieces.
Pattern Specifies the preset pattern to use for the exploded pieces.
Custom Shatter Map Specifies the layer you want to use as the shape of the exploded pieces.
White Tiles Fixed Prevents pure white tiles in a custom shatter map from being exploded. You can use this control to
force certain parts of a layer to remain intact.
Use this control when your shatter map uses images or letters such as O: Set the portion you don’t want to blow out,
such as the centers of the O and the background, to pure white and set the rest to another pure color.
Repetitions Specifies the scale of the tile pattern. This control works only in conjunction with the preset shatter maps,
which all seamlessly tile. Increasing this value increases the number of pieces on the screen by scaling down the size of
the shatter map. Consequently, the layer breaks into more and smaller pieces. Animating this control is not
recommended, as it can cause sudden jumps in the number and size of shatter pieces.
Direction Rotates the orientation of a preset shatter map, relative to the layer. As with Repetitions, animating this
control results in sudden jumps in the animation and is not recommended.
Origin Precisely positions a preset shatter map on the layer. This option is useful if you want to line up portions of an
image with specific shattered pieces. Animating this control results in sudden jumps in the animation and is not
recommended.
Extrusion Depth Adds a third dimension to the exploded pieces. The higher the value, the thicker the pieces. In
Rendered view, this effect isn’t visible until you start the shatter or rotate the camera. As you set this control higher,
the pieces may pass through each other. While this is generally not a problem in full-speed animations, it may become
visible when the pieces grow thick and move slower.
Force 1 and Force 2 controls
Force 1 and Force 2 controls define the blast areas by using two different Forces.
Position Specifies the current center point of the blast in (x,y) space.
Depth Specifies the current center point in z space, or how far in front of or behind the layer the blast point is. Adjust
Depth to determine how much of the blast radius is applied to the layer. The blast radius defines a sphere, and the layer
is basically a plane; therefore, only a circular slice of the sphere intersects the plane. The farther away the layer is from
the center of the blast, the smaller the circular slice. When pieces explode, they fly away from the force center. Depth
determines which way the pieces fly: Positive values cause the pieces to explode forward, toward the camera (assuming
the default camera settings of 0, 0, 0); negative values cause pieces to blow backward, away from the camera. To see the
result of the Depth setting, use the Wireframe + Force Sphere view.
Radius Defines the size of the blast sphere. The radius is the distance from the center of a circle (or sphere) to the edge.
By adjusting this value, you can fine-tune exactly which pieces explode. Changing this value can vary the speed and
completeness of the explosion. Animating it from small to large generates an expanding, shockwave explosion.
Note: To begin the shattering at a time other than layer time zero, animate the Radius property, not the Strength property.
Pieces inside the force sphere defined by the Radius property are pulled outside the frame by gravity even if Strength is set
to 0. Use Hold keyframes on the Radius property with the value 0 until the time when you want the shattering to start.