animate wiggle - after effects expression changes?
by greg beninger
on
Apr 23, 2008 at 8:03:05 pm
Hi guys, thanks ahead of time for helping me out. I'm trying to vibrate a still image on top of a still background; roller-coaster shot. I want to wiggle the coaster slightly and then ramp the wiggle to a more violent and dramatic shake. How can I accomplish this? Do I need to add additional values to the wiggle expression wiggle(frequency,variation)?
Re: animate wiggle - after effects expression changes? by Franklin Artisanal on Apr 23, 2008 at 9:12:09 pm
Well, one way would be to set up a slider. Select the layer you're trying to wiggle. Then select Effects > Expression Controls > Slider Control.
This should add an effect to the layer called slider control. Twirl this open so you can see the variable "slider".
Then in the expression where your wiggle lives (I'm guessing you're applying it to the layer's position), make a variable on the first line of the expression.
Write "amount=" then pickwhip to the "slider" variable in the slider control you just set up. Then type a semi-colon.
On the second line of the expression you put your wiggle, except you use your new variable, "amount," as the second value in the wiggle. So the wiggle would look like this: "wiggle(10,amount);"
Now turn on the stopwatch for the "slider" variable inside the slider control effect and you can keyframe the amount of wiggle.
You could do the same thing for the frequency, but that would require two slider controls.
