After effect expression translation

Hi all,

I regularly use expressions in after effects including some that I don't fully understand yet, like the fantastic Dan Ebbert's key frame overshoot.

Dan's website (I'm sure many of you will know) is motionscriptDOTcom replacing the DOT with a .

I understand what it all does, but I don't know which parts are AE specific.

In Fusion I am still learning to use expressions and although I'm getting there, I'm still a way off translating key frame overshoot. Can anyone shed any light?

Dan himself got straight back to me but he doesn't use Fusion, so couldn't really advise.

Here is his script:

freq = 3;
decay = 5;

n = 0;
if (numKeys > 0){
n = nearestKey(time).index;
if (key(n).time > time) n--;
}
if (n > 0){
t = time - key(n).time;
amp = velocityAtTime(key(n).time - .001);
w = freq*Math.PI*2;
value + amp*(Math.sin(t*w)/Math.exp(decay*t)/w);
}else
value

And I know some parts are AE specific, but I don't know what the equivalent would be in Fusion.

Any thoughts?

Cheers

Matt

In my opinion, you can't easily transfer this script to Fusion the way it works in AfterEffects. Its simple expressions are too "simple" for a script like that. It would have to be an expression modifier. However, Fusion lacks functions like nearestKey that are necessary to know how far from a key frame you are so I don't think it's even possible.

There are workarounds. Dunn Lewis has made a Fuse that allows you to animate with various bounce effects. It might be available on the http://www.steakunderwater.com forum (at least Dunn would hang out there to help you out )

The other workaround would be writing a tool script that doesn't modify your animation in real time but instead bakes your animation with key frame overshoot. However, that means you can't tweak your animation once you've baked it unless you keep a backup of your raw spline somewhere

Another solution might be a frame render script (last tab of a tool's control panel). It might be possible for this kind of script to determine how far away from a key frame you are...

Maybe somebody from BMD knows a solution?

Hi Stefan,

thanks for the response, it's good to know these limitations.

I will continue to hunt for a solution and if I find one I will share it.

If BMD do have any tips, it would be good to know?

cheers

Matt