Gradient Controls For The Shatter Effect - Adobe AFTER EFFECTS 7.0 Manual

ADOBE AFTER EFFECTS 7.0
516
User Guide
Defines the size of the blast sphere. The radius is the distance from the center of a circle (or sphere) to the
Radius
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 determine when the pieces shatter, animate the Radius control, not the Strength control. Pieces inside the force
sphere are pulled off-screen by gravity even if Strength is set to 0.
Specifies the speed at which the exploded pieces travel—how hard they are blown away from or sucked
Strength
back into the blast point. A positive value blows the pieces away from the blast point; a negative value sucks the pieces
into the blast point. The greater the positive value, the faster and farther they fly away from the center point. The
greater the negative value, the faster the pieces launch themselves toward the center of the force sphere. Once the
pieces are launched, however, they are no longer affected by the force sphere; the Physics settings take over. A
negative Strength value does not suck the pieces into a black hole; instead, the pieces fly through each other and back
out the other side of the sphere. Setting Strength very low causes the pieces to break up into shapes, creating cracks
in the layer, but it doesn't actually blow the pieces apart. If gravity is set to anything other than 0, the pieces are pulled
in the direction of gravity after they break up.
Note: A shatter piece is made up of vertices (points or dots that define the corners of the shape), edges (lines that connect
the dots), and planes (walls of the shape). Shatter determines when a shape has come in contact with a force sphere based
on when a vertex comes in contact with the sphere.

Gradient controls for the Shatter effect

Gradient controls specify the gradient layer used to control the timing of an explosion and the pieces that are affected
by the blast.
Specifies which pieces in the force sphere shatter according to the corresponding luminance of
Shatter Threshold
the specified gradient layer. If Shatter Threshold is set to 0%, no pieces in the force sphere shatter. If it is set to 1%,
only the pieces in the force sphere corresponding to white (or very-nearly-white) areas on the gradient layer shatter.
If it is set to 50%, all the pieces in the force sphere corresponding to white-to-50%-gray areas on the gradient layer
shatter. If it is set to 100%, all pieces in the force sphere shatter. Because there are 256 shades of gray (including black
and white), each percentage point represents approximately 2.5 shades of gray.
Animating Shatter Threshold influences the timing of the explosion. If you leave it set to 0%, the layer never
explodes. However, if you set a Shatter Threshold keyframe at 50%, the pieces of your layer in the force field that
correspond to areas of your gradient layer that range from white to 50% gray explode. If you then animate Shatter
Threshold up to 100%, the remaining pieces in the force sphere explode.
Specifies the layer to use to determine when specific areas of the target layer shatter. White areas
Gradient Layer
shatter first; black areas shatter last. Shatter determines which pixels correspond to which pieces by subdividing the
layer into pieces, each with a center point or balance point. If you superimpose the shatter map over the gradient
layer, the gradient layer pixels that are precisely under each balance point control the explosion.
Note: Some shapes have a balance point that falls outside the actual area of the shape—for example, the letters C and
U. When designing a gradient layer in such a situation, avoid using grayscale versions of letters. Instead, use larger
shapes that cover the balance point of each character.
Inverts the pixel values in the gradient. White becomes black, and black becomes white.
Invert Gradient