Tip:
Highlight text to annotate it
X
Hello everyone and welcome to Genius DV After Effects tutorial. Today we are going to take
a brief look at expressions. I am going to introduce you to the wiggle expression. I
have created this simple 3-D composition and added a light. I wanted to add fluctuation
to the light intensity so it would appear the light was flickering. To add an expression
just simple alt or option click on the stopwatch in front of the parameters name, this will
enable expressions for the associated property. Now navigate to the expression line and type
wiggle then open bracket and lets start with a value of 25 then add a comma and lets try
75 for our amount and then add a close bracket. Click away to close the expression line. You
must type this exact or the expression will not work. The 25 represents how many times
per second and the 75 represents how much the intensity of the light will fluctuate.
Lets try 5 and 100. As you can see, it is a very slow animation with great variation.
Now lets try 100 for the frequency and 40 for the amount. As you can see this adds very
small fluctuation but at a high rate. This wiggle expression can be added to any parameter
that is keyframable. Here lets apply a wiggle to scale of 30 and 30 and lets just see what
we get. As you can see it fluctuates the scale. Looks interesting, but now lets try something
with the position property. Again the amount you will need to flavor to taste. Once again
I’ll trim the comp area and alt click the stopwatch. I’m going to try wiggle
3 and 100. The position now moves randomly. This candle is a great example of how you
can use the wiggle expression in After Effects. To learn more tips and tricks like these log
onto Genius DV .com and sign up for an After Effects training course and I’ll see
you on the next tutorial, I guess I should blow out this candle.