audio #

The current version of Hydra can use the default microphone as an input, it uses Meyda in order to analyze the sound and get values for audio reactivity. This works internally using the FFT algorithm.

the a object #

The a object gives you access to all of the audio functionality. Please follow along on the Hydra editor:

a.show #

Show the FFT bins near the canvas.

a.show()

a.setBins #

Set the number of FFT bins. A bin is a part of the audible spectrum Hydra will analyze on the mic input.

a.setBins(6)

a.fft[] #

You can access the value of the leftmost (lowest frequency) bin by calling the first element in the a.fft array. Using higher numbers will get you the higher frequency bins.

a.fft[0]

Usage #

These should be used inside arrow functions, this way Hydra will check their value each time a frame is rendered, making the audio reactivity happen.

osc(10, 0, () => a.fft[0]*4)
  .out()

a.setCutoff #

It is possible to calibrate the responsiveness by changing the minimum and maximum value detected. (Represented by blur lines over the fft). To set minimum value detected:

a.setCutoff(4)

a.setScale #

Setting the scale changes the range that is detected. The a.fft[] array will return a value between 0 and 1, where 0 represents the cutoff and 1 corresponds to the maximum.

a.setScale(2)

a.setSmooth #

You can set smoothing between audio level readings (values between 0 and 1). 0 corresponds to no smoothing (more jumpy, faster reaction time), while 1 means that the value will never change.

a.setSmooth(0.8)

a.hide #

To hide the FFT bins:

a.hide()

Example #

a.setBins(5) // amount of bins (bands) to separate the audio spectrum

noise(2)
	.modulate(o0,()=>a.fft[1]*.5) // listening to the 2nd band
	.out()

a.setSmooth(.8) // audio reactivity smoothness from 0 to 1, uses linear interpolation
a.setScale(8)    // loudness upper limit (maps to 0)
a.setCutoff(0.1)   // loudness from which to start listening to (maps to 0)

a.show() // show what hydra's listening to
// a.hide()

render(o0)