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Universal Random Expression

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Filip Stillerska
Universal Random Expression
on May 26, 2018 at 7:31:09 pm

Is there an expression that meets the following requirements?:
  • Doesn't require existing keyframes (automatic).
  • Allows me to adjust how many times per second it spits out a new random value (like the first number in the wiggle expression).
  • Allows me to specify the smallest and largest value allowed (for example, a lowest value of -80 and a largest value of 30).


At first, I thought I would be able to achieve this with a simple wiggle expression, however, it doesn't allow me to specify the smallest and largest value.


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Dan Ebberts
Re: Universal Random Expression
on May 26, 2018 at 8:33:43 pm

Something like this maybe:

f = 3; // 3 random values per second
minVal = -80;
maxVal = 30;
seed = Math.floor(time*f);
seedRandom(seed,true);
random(minVal,maxVal)


Dan



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Filip Stillerska
Re: Universal Random Expression
on May 27, 2018 at 10:28:36 am

Thank you, Dan, however, I need an expression that generates "smooth transitions" between the values, just like the wiggle expression. In other words, I need an expression that works just like the wiggle expression except I need to be able to specify the largest and smallest value allowed AND how many times per second a new value will be generated.
Is this possible?


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Kalleheikki Kannisto
Re: Universal Random Expression
on May 27, 2018 at 1:40:02 pm

The same with an eased transition, for one-dimensional properties:

frequency = 1;
min= 500;
max = 250;
time1 = Math.floor((time-inPoint)*frequency);
seedRandom(time1, true);
val1 = random(min, max);
time2 = Math.floor((time-inPoint)*frequency+1);
seedRandom(time2, true);
val2 = random(min, max);
ease(time, time1, time2, [val1],[val2])


Kalleheikki Kannisto
Senior Graphic Designer


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Filip Stillerska
Re: Universal Random Expression
on May 27, 2018 at 4:44:24 pm

Kalleheikki, your expression works great UNTIL I change the frequency because when I do, the smooth transitions no longer works:



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Filip Stillerska
Re: Universal Random Expression
on May 27, 2018 at 5:12:40 pm

I finally found a working expression written by Dan Ebberts in this thread: https://forums.creativecow.net/thread/227/20157

The expression:

minVal = -80;
maxVal = 30;
w = wiggle(5,1)-value;
value + linear(w,-1,1,minVal,maxVal)


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