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Activity Forums Adobe After Effects Expressions Using linear and smooth in the same expression

• # Using linear and smooth in the same expression

Posted by on November 18, 2016 at 5:03 pm

Hi!

So, this is what I’m trying to do.

First, I followed Video Copilot’s tutorial on syncing an animation to audio. That provided me with this expression:

linear(value,A,B,C,D)

Where:
A = lowest average value in your audio waveform graph
B = highest average value in your audio waveform graph
C = Value to use instead of A
D = Value to use instead of B

This worked. But the animation turns out quite harsh, so I wanted to smooth it out.
Then I found this:

smooth(2,5)

Where:

2 would be the number of seconds it’s looking at;
And 5 is the number of frames the smoothing extends to.

So I tried to do it this way:

linear(value,2,30,60,100);
smooth(0.5,19)

It doesn’t work properly, because I’m trying to make a graphic in the composition, change scale with the music. It’s set to 60,100 in the first expression because I want the minimum size to be 60 and the maximum, 100.
But when I add that smooth expression below it, the graphic shrinks, I can see in the scale parameter, that’s using little sizes like 1% instead of the 60-100 I want.
What am I missing?

replied 1 year, 5 months ago 3 Members · 2 Replies
• 2 Replies
• ### Dan Ebberts

November 18, 2016 at 5:08 pm

I’d say try it this way:

s = smooth(0.5,19);
linear(s,2,30,60,100);

Dan

• ### Kun Chen

September 18, 2022 at 2:04 pm

wow!!! thank you! it solved my problem!

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