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reacting to Audio with Falloff
I have these squares that i have jumping up to a beat, but I want them to have falloff instead of just shooting right back down when the audio level is at zero.
How do i do this?
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“hand me my patching trowel, boy!”
peep my over-the-interweb band, redabbott.
“we electro-rock over long distances…”
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6 Replies
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Play around with this, it might get you started. It assumes that you converted your audio to keyframes. It should cause your layer to jump vertically from wherever you position it. “amp” adjusts the jump amplitude and “falloff” adjusts the falloff speed. It will bog down if your comp gets too long.
aud = thisComp.layer(“Audio Amplitude”).effect(“Both Channels”)(“Slider”);
falloff = 1;
amp = 5;val = 0;
t = 0;
while (t <= time){ val = Math.max(aud.valueAtTime(t), val - falloff); t += thisComp.frameDuration; } value - [0, val*amp] Dan -
Whoa, thanks Dan! You rock and roll.
I’m trying to break down and understand what you did here (because i wouldn’t be learning by just copying, would I?) and I understand, for the most part, what’s going on, but I’m unsure of what “thisComp.frameDuration” is representing. ???
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“hand me my patching trowel, boy!”
peep my over-the-interweb band, redabbott.
“we electro-rock over long distances…”
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It’s just the duration of one frame, in seconds. At each frame, the expression starts at time zero and looks at the audio value for each previous frame. This is necessary because expressions can’t retain data from one frame to the next so in a situation like this where you need to know what happened in the past, your expression has to essentially recreate the past.
Dan
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Ok, now I have sort of the opposite or inverse question.
What if I want the layer, when it’s born, to jump to the audio value (say in scale) but then not retreat down. Maybe the jump is 2 frames and then it just lives at that height.
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I’m not sure exactly what you’re after here, but this might be close:
aud = thisComp.layer(“Audio Amplitude”).effect(“Both Channels”)(“Slider”);
amp = 1;val = 0;
t = 0;
while (t <= time){ val = Math.max(aud.valueAtTime(t), val); t += thisComp.frameDuration; } value + [1, 1]*val*amp It will scale up at the largest amplitude and hold that value (unless a larger one comes along). Dan -
that’s perfect. thanks again!
———————————-
“hand me my patching trowel, boy!”
peep my over-the-interweb band, redabbott.
“we electro-rock over long distances…”
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