Random character opacity on and off

[Dan Ebberts]

Add an opacity animator and set the value to 0. Add an expression selector and delete the range selector. Add this expression to Amount:

freq = 1;
seedRandom(textIndex,true);
if (rotation.wiggle(freq,1) > 0) 100 else 0

Adjust freq to meet your needs.

Dan

[Matthew Boron]

That is excellent Dan!, Is there a way/modification to that expression so that only one character is displayed at a given time? You have been a great help!

[Dan Ebberts]

Something like this should work:


freq = 1;

txt = text.sourceText;
curMax = -999;
for (i = 0; i < txt.length; i++){
seedRandom(i,true);
w = rotation.wiggle(freq,1);
if (w > curMax){
curMax = w;
idx = i;
}
}
textIndex == idx ? 0 : 100


Dan

[Matthew Boron]

Perfect Dan! Thanks!

[Ze’ev Gilad]

Dan, maybe you can help me…

This is driving me nuts. I have a block of text, and need the words to randomly fade in & out over time.
I tried various range selectors; fading IN randomly was easy, but getting them to fade in AND out has proved difficult.

The closest thing I found was this bizarre tip from Adobe – adding an Expressions Selector with this code:

seedRandom(textIndex);
wiggle(.1, 350);

But this completely baffles me! Isn’t seedRandom just for reseeding the random generator?? Why does it need textIndex as input? If I change it to ANYTHING else, ALL the words are faded.

The problem is I want to change the random order of what I’m getting! But I can’t change the random seed.

Thanks!

[Dan Ebberts]

>Isn’t seedRandom just for reseeding the random generator??

Yes it is.

>Why does it need textIndex as input?

With an expression selector, the expression get executed for each character/word. textIndex is unique for each word, so the random behavior is different. If you use the same seed for each word = same results. You could use some multiple of textIndex to get different results.

Dan

[Ze’ev Gilad]

Well, that worked!
I used seedRandom(textIndex*2) and that gave me new results, thanks!

But I’m still totally confused how this Expression Selector works. You haven’t happened to write some excellent tutorial on the subject, have you?

thanks again

[Navarro Parker]

CS6 is telling me there is Class ‘global’ has no property or method named “textIndex”. So it breaks all these expressions.

What can I substitute in its place?

[Dan Ebberts]

textIndex is only allowed inside an Expression Selector. Apply the expression to the Amount property. It should work fine in CS6.

Dan

[Navarro Parker]

Good to know. Thanks for the tip.