Using 'Blink', but eliminating middle values

[N***@adobeforums.com]

I earlier need help with random blinking using wiggle. Now I need uniform blinks.
I'm trying to make a layer blink at regular intervals. I've been using:

blinkSpeed =2;
lowOpacity =0;
highOpacity = 100;
opNormal = (Math.cos(blinkSpeed * time * Math.PI *2)+1)/2;
linear(opNormal,0,1,lowOpacity,highOpacity);

BUT... this expression goes through the middle values 1-99% so low blinkSpeed values fade on and off. Is there a way to have it blink regularly at 0 and 100% opacity (or between two values x & y), but nothing inbetween?

[d***@adobeforums.com]

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[D***@adobeforums.com]

Lots of ways to do it. Here's one:

blinkSpeed =2;
lowOpacity =0;
highOpacity = 100;
if(Math.sin(blinkSpeed * time * Math.PI *2) < 0) lowOpacity else highOpacity;

Dan

[D***@adobeforums.com]

Here's another favorite :-)

period = .25;
if (Math.floor(time/period)%2) 0 else 100

Dan

[N***@adobeforums.com]

Wow... thanks guys! Really interesting ways to go about it.

Didgi -- where do I put the loopOut expression? Is it with Time Remap?

Dan, in your last expression, how is period defined? It seems to be 1/2 second. (which doesn't make it as easily understood as the others)

[D***@adobeforums.com]

Yeah, it just means it's on for .25 sec, off for .25 sec, etc.

For Didgi's solution, you'd put the loopOut expression in the value of the CheckBox.

Dan