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Audio Expression start time delayed
So I found this expression by Dan that makes audio drive only the y position of a layer, which is exactly what I want but how do I control when this expression begins? It starts at a later time than I want it to & I want it to start sooner. Below is the expression.
multiplier = -5;
audio = thisComp.layer("Audio Amplitude").effect("Both Channels")("Slider");
value + [0,audio*multiplier] -
11 Replies
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There’s nothing about timing in that expression. The only reason it would start later is if the layer is moved to a later time than you want or if the value of the audio *(-5) is giving you a y value that doesn’t move the layer. Try changing your multiplier to something else and see if that fixes it.
“|_ (°_0) _|”
Sincerely,
George
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The multiplier only directs the amount of movement the y position will have. I’m asking what I would need to do in order to get it to start when I want it to, or sooner rather than later. The multiplier will not do that.
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Right I understand that, but if your multiplier is -5 and your value of the slider at the time you want it to start is 1, you’re only going to see a change of -5 which may not be enough for you to notice. This is why I told you to change your multiplier. If you make it something large like 100 or 200 you should see a change even if that value is low. Then you would know that it was just a matter of the slider value.
Your expression doesn’t indicate a start or end time, which means it is always active. Either you don’t have a value for your audio where you want it to start, or its too low. The expression is correct.
“|_ (°_0) _|”
Sincerely,
George
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You might be looking for something like this (not tested, but should be close):
tStart = 5; // start at 5 seconds
t = time - tStart;
if (t > 0){
multiplier = -5;
audio = thisComp.layer("Audio Amplitude").effect("Both Channels")("Slider").valueAtTime(t);
value + [0,audio*multiplier]
}else
value
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ok, thank you! the audio does actually FADE in & I want the action to happen right away, so I think I’m going to start with that.
I appreciate the clarification also. -
it’s saying expression result must be of dimension 2 not 1. Expression disabled.
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Hmmm… It works for me. You do have it applied to the position property, correct?
Also, I think I got the start time backwards. If you wanted the motion to start sooner you would do something like this:
tStart = -1;
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yea, it’s still doing the same thing. here’s a screen shot of the expression
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Ah, you probably need to reformat it with carriage returns so that it looks like this after you paste it in:
tStart = -1; // start at -1 seconds
t = time - tStart;
if (t > 0){
multiplier = -5;
audio = thisComp.layer("Audio Amplitude").effect("Both Channels")("Slider").valueAtTime(t);
value + [0,audio*multiplier] }
else
value
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This works perfectly!! Thank you kindly Dan I greatly appreciate it! I have another question for you if you don’t mind. I have a double bass instrument I’d like to have vibrate to audio.
I was on your website that had the string vibration expression but it wasn’t to audio for one & when I tried it anyway it gave a weird jerky motion that was all over the place.
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