|Page (1) of 3 - 05/07/03||email article||print page|
Wiggle it, just a little bitBasic expression just can?t be used enough
Wiggle allows you add randomness to a property of a layer. For example you can cause a jittery chaotic motion to a layer by applying the wiggle expression to the Position property of a layer. To create the wiggle expression Command+Click on the layer property stopwatch and enter the formula wiggle(freq, amp ,octave). The elements of the expression represent how the wiggle will be calculated.
For this discussion, open After Effects, create a New Composition, and create a 200 pixel by 200 pixel solid. With the solid layer selected in the Timeline, press the P key to display the Position property for the layer. Command+Click (Alt+Click in Windows) the Stopwatch Icon, and in the expression window add the expression wiggle(15, 50, 1).
Frequency defines how many wiggles happen each second. In this case 15 wiggles are happening every second, or every other frame.
Amp is calculated in units of the property for which it is applied. In our example, since we are applying the expression to the position property, 50 says that the layer can move 50 pixels in any direction.
The final value, Octave is the level of detail the wiggle should have. It should be noted that you dont have to use this third value in your expression. If you do not include it, After Effects will use the default value of 1 will be applied. So the expression could actually be written wiggle(15,50).
The other thing that is nice about wiggling a layer property is that you can also apply motion blur to the layer.
|wiggle(15,50) creates a fairly chaotic effect.|
Experiment with the wiggle command applied to other properties like Rotation or Scale.
|Rotation wiggle... IT'S ALIVE!|
|A scale wiggle will scale the X and Y axis independently.|
Related Keywords:wiggle, adobe after effects, schleicher, path text, zaxwerks
Source:Digital Media Online. All Rights Reserved