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Sine wave on effect parameter?

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 Sine wave on effect parameter? on Jan 30, 2013 at 3:37:02 am

Hi there,

On a tight deadline and looking to put an expression on an effect parameter (specifically the turbulent displacement's evolution).

I'm looking to have numbers bounce back and forth from 360 to -360 over a couple seconds, indefinitely. I've been playing around with Math.sine() but can't seem to figure it out.

Any help is much appreciated! Thank you!

 Re: Sine wave on effect parameter?on Jan 30, 2013 at 4:09:17 am

Btw, I ended up just using some keyframes and a loop expression but would still like to know if this is possible. Thx!

 Re: Sine wave on effect parameter?on Jan 30, 2013 at 10:19:35 am

Patrick

You can use a Random Expression with a Slider Control attach to it.

See the example :

5339_usingrandomwithslider.zip

Vishesh Arora
3D and Motion Graphics Artist
Films Rajendra

Blog:
http://digieffects.wordpress.com

2011 3D Demo Reel:

 Re: Sine wave on effect parameter?on Jan 30, 2013 at 11:09:45 am

Hi,

The best resource for AE expressions is probably Dan Ebberts site:
http://www.motionscript.com/

You find lots of useful info there. Or there's a similar thread here on the Cow that looks useful:

Matthew Keane

Freelancer based in Paris, France
- Motion Graphics, Video Editing & Effects, Watchout Programming & Live Operation.

 Re: Sine wave on effect parameter?on Jan 30, 2013 at 3:32:17 pm

``` amplitude = 360; period = 2; refTime = inPoint; amplitude * Math.sin(2*Math.PI*(time-refTime)/period); ```

amplitude is the amplitude of oscillations, period is the duration of a cycle (in seconds), refTime is the time (in seconds) at which you want the oscillation to have 0 amplitude. Change these numbers according to your needs.

Don't enter a period of 0, this will generate an error.
Note : the best suited forum for this kind of questions is the After Effects expressions forum...