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# Random Motion only when opacity >= 20

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 Random Motion only when opacity >= 20 on Jan 6, 2017 at 4:02:33 pm

Hi there,

I have a light, which intensity is linked to audio track (via soundkeys)
I need the light to random change position (only x and Y) everytime the intensity is >=30.

I am trying with no success ☹

PLEASE HELP...

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 Re: Random Motion only when opacity >= 20on Jan 6, 2017 at 4:05:54 pm

I need something like dan ebberts expression :

holdTime = .5; //time to hold each position (seconds)
minVal = [0.1*thisComp.width, 0.1*thisComp.height];
maxVal = [0.9*thisComp.width, 0.9*thisComp.height];

seed = Math.floor(time/holdTime);
seedRandom(seed,true);
random(minVal,maxVal)

but instead of evry .5 sec, evrytime light intensity is >= 20

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 Re: Random Motion only when opacity >= 20on Jan 6, 2017 at 7:23:48 pm

It's not at all clear (to me at least) what you're asking for. Does the layer move to a new random position every time the opacity goes from below 20 to above 20, or is it something else?

Dan

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 Re: Random Motion only when opacity >= 20on Jan 7, 2017 at 1:43:10 am

Yes, exactly.
I need the light layer to move to a new random position(only X and Y) everytime the light intensity is <=20. It must hold that position until the light intensity goes under 20 again..
i hope is clean now.. Thanks 😁😁
Mauro

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 Re: Random Motion only when opacity >= 20on Jan 7, 2017 at 6:03:13 am

Something like this maybe:

``` P = lightOption.intensity; threshold = 20; trig = false; for (f = timeToFrames(time); f >= 0; f--){ tCur = framesToTime(f); v = P.valueAtTime(tCur); if (trig && (v > threshold)) break; if (v <= threshold) trig = true; } t = trig ? framesToTime(f+1) : 0; seedRandom(t,true); minVal = [0.1*thisComp.width, 0.1*thisComp.height]; maxVal = [0.9*thisComp.width, 0.9*thisComp.height]; xy = random(minVal,maxVal); [xy[0],xy[1],value[2]]<b></b> ```

Dan

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