the spring bounce back movement, with only 1 kf and an expression?

[Kevin Camp]

i’ve played around with ease & wizz a bit and i think it has a setting that will give you what you are describing… it’s a neat little script with a ui panel, it has limitations, but it may work for you.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Dan Ebberts]

Something like this should give a little bounce at the last keyframe:

k = .05; // spring constant
d = 10; // damping constant
freq = 4; // oscillation frequency

if (numKeys > 0){
if (time > key(numKeys).time){
t0 = key(numKeys).time;
t = time – t0;
v = velocityAtTime(t0)*(k*Math.cos(freq * t * Math.PI * 2)/Math.exp(t*d));
valueAtTime(t0) + v;
}else{
value
}
}else{
value
}

Dan

[Bert Brown]

thanks for the responses. that last code doesnt seem to do anything. i have it applied to the position property of a solid with two keyframes, in a right to left 1 sec motion.

———————————-

peep my over-the-interweb band, red abbott.
“we electro-rock over long distances…”

[Dan Ebberts]

Try increasing the spring constant to .25 or so.

Dan

[Bert Brown]

nothing. is it working for you? maybe i’m doing something wrong. i’ve played with all the different levels at the top of the code.

———————————-

peep my over-the-interweb band, red abbott.
“we electro-rock over long distances…”

[Dan Ebberts]

What’s the velocity at your last keyframe?

Dan

[Kevin Camp]

it worked perfectly when i tried it…

i just key framed a position change from point a to b, then added the expression to position… when the layer hits the last keyframe it comes to a spring-like ‘soft bounce’ then to a full stop after a few oscillations.

i had never used ‘velocity’ before, i had actually wondered what the difference was between ‘velocity’ and ‘speed’ but never explored it… ‘velocity’ is multidimensional, which is very cool… thanks dan.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Nate Ledet]

I installed ease & wizz and really like it, but the Elastic effect does not work, and it’s one of my favorites. I e-mailed him about it and he said he is working on it, but I haven’t seen an update in months. Instead of springing back and forth to a stop, it arcs into a stop, which is not what it’s supposed to do.

Has anyone else noticed this?

~ Nate ~

[Reynaldo Der]

When I tried it, it works on regular keyframes, but not on keyframes with easy ease.

Thanks for the code Dan!

[Ross Newton]

Awesome! It worked for me first try. The only catch I found was that the last keyframe can’t be on Easy Ease. It had to be linear to work for me.

This same code also works in Flash too. It’s like the universal springiness equation.