Adobe After Effects - Manual (Page 368)

To the top
To the top
selectorValue * textIndex/textTotal
10. Replace the default expression text with the following expression:
r_val=selectorValue[0];
if(r_val < 50)r_val=0;
if(r_val > 50)r_val=100;
r_val
11. Set the opacity to 0%, and preview the composition.
Example: Animate text position with expressions
This example uses the textIndex and textTotal attributes with the wiggle expression to animate a line of text.
1. Create a new composition.
2. Create a new text layer.
3. Expand the text layer in the Timeline panel to view the text properties. Add a Position animator group from the Animate menu.
4. Delete the default Range selector, Range Selector 1.
5. Add an Expression selector by selecting the Add menu, then choosing Selector > Expression. Expand the Expression selector to reveal its
options.
6. Expand the Amount property to reveal the expression. The following expression appears by default:
selectorValue * textIndex/textTotal
7. Replace the default expression with the following expression:
seedRandom(textIndex);
amount=linear(time, 0, 5, 200*textIndex/textTotal, 0);
wiggle(1, amount);
The linear method is used in this example to ramp down the maximum wiggle amount over time.
8. Set the vertical position value. The greater the value, the more the characters wiggle.
9. Preview your composition.
Example: Animate text as a timecode display
With no layers selected in the Timeline panel, double-click the Current Time Format animation preset in the Effects & Presets panel. (You
can locate the animation preset by typing its name in the Contains field in the Effects & Presets panel.)
A new text layer is created, with an expression on the Source Text property that makes the text show the current time in the time display
format set for the project.
364