Eye-Blink Expression

[Dan Ebberts]

Try this one. Set the range of times between blinks with the first two parameters.

minSeg = 2.0;
maxSeg = 5.0;
blinkDur = .5

seedRandom(index,true)
segStartTime = -random(minSeg,maxSeg);
segEndTime = segStartTime;
i = 1;

while (time >= segEndTime){
i += 1;
seedRandom(i,true);
segStartTime = segEndTime;
segEndTime = segEndTime + random(minSeg,maxSeg);
}

if (time > segStartTime + blinkDur) 100 else 0

Dan

[Scott Brignac]

Thanks so much Dan. Those parameters are great. The only issue now is that the blink is reversed. The expression is on the blink (eyes closed) layer and instead of blinking, the layer is on and his eyes open like a blink.

What am I missing? The blink duration is .2, so shouldn’t that work?

[Dan Ebberts]

Ah, OK – try reversing it:

minSeg = 2.0;
maxSeg = 5.0;
blinkDur = .5

seedRandom(index,true)
segStartTime = -random(minSeg,maxSeg);
segEndTime = segStartTime;
i = 1;

while (time >= segEndTime){
i += 1;
seedRandom(i,true);
segStartTime = segEndTime;
segEndTime = segEndTime + random(minSeg,maxSeg);
}

if (time > segStartTime + blinkDur) 0 else 100

Dan

[Scott Brignac]

Great! Got it. Thanks Dan!

[Navarro Parker]

Hi Dan! I ran across this today and thought it was really fun.

Instead of the blink being either 100% or 0% opacity, how would you ramp the opacity so it quickly fades on/off?

[Dan Ebberts]

Something like this, probably:


minSeg = 2.0;
maxSeg = 5.0;
blinkDur = .25

seedRandom(index,true)
segStartTime = -random(minSeg,maxSeg);
segEndTime = segStartTime;
i = 1;

while (time >= segEndTime){
i += 1;
seedRandom(i,true);
segStartTime = segEndTime;
segEndTime = segEndTime + random(minSeg,maxSeg);
}

if (time < segStartTime + blinkDur/2)
easeOut(time,segStartTime,segStartTime+blinkDur/2,0,100)
else
easeIn(time,segStartTime+blinkDur/2,segStartTime+blinkDur,100,0)


Dan

[Navarro Parker]

Fantastic!

And I would mess with “segStartTime+blinkDur/2” to change the speed of the fade in/out, right?

[Dan Ebberts]

blinkDur sets the duration of the entire blink. If you wanted to adjust the fade time separately, it would be something like this:


minSeg = 2.0;
maxSeg = 5.0;
blinkDur = .25;
fadeTime = .1;

seedRandom(index,true)
segStartTime = -random(minSeg,maxSeg);
segEndTime = segStartTime;
i = 1;

while (time >= segEndTime){
i += 1;
seedRandom(i,true);
segStartTime = segEndTime;
segEndTime = segEndTime + random(minSeg,maxSeg);
}

if (time < segStartTime + blinkDur/2)
easeOut(time,segStartTime,segStartTime+fadeTime,0,100)
else
easeIn(time,segStartTime+blinkDur-fadeTime,segStartTime+blinkDur,100,0)


Dan

[Navarro Parker]

You knock me out, Dan! Thanks! 🙂

[Navarro Parker]

Ran into a stumper. If I apply the same expression to multiple layers, they all blink in unison. (which is weird, because the seedRandom(index,true) shouldn’t do that)