Channel

Descriptions

Allow for creation of value channels

Remarks

This class is only for channel and creation, and is NOT actually a channel.

Methods

---

named(name)

Descriptions

Change the name of channels created with this object.

Parameters

Name	Type	Description
name	string	The name of the channel(s)

Return types

Channel

Remarks

This is almost always used in a chain to create named channel.

Example

local channel = Channel.named("something").keyframe()

---

keyframe()

Descriptions

Create a key channel.

Return types

KeyChannel

Remarks

This is almost always used in a chain to create named channel.

Example

local channel = Channel.keyframe()
local namedChannel = Channel.named("keyframeChannel").keyframe()

---

fft(freqBandMin, freqBandMax, min, max, smoothness = 0.1, scalar = 1)

Descriptions

Create a FFT (Fast Fourier Transform) channel, that calculates the loudness of currently playing audio within the frequency band.

Parameters

Name	Type	Description
freqBandMin	number	The mininum frequency band to sample
freqBandMax	number	The maxinum frequency band to sample
min	number	Minimum value output
max	number	Maxinum value output
smoothness	number	Smoothness of return value over time (0-1)
scalar	number	Value output multiplier

Return types

ValueChannel

Remarks

freqBandMin and freqBandMax are in the unit of frequency bands, not hertz. By default the audio is sampled in 256 frequency bands. You can change this number with Channel.setGlobalFFTResolution()

Internally the channel tries it best to make sure output stays consistent with different FFT resolution. However the output value range can still be quite unpredictable, therefore the min and max parameters are not guaranteed to be accurate. Please use scalar to manually tune the channel if you run into trouble with this.

Example

local channel = Channel.fft(0, 30, 0, 1, 0.5)

---

setGlobalFFTResolution(resolution, windowDetail = 1)

Descriptions

Configures all subsequently created fft channels' frequency resolution.

Parameters

Name	Type	Description
resolution	number	The number of frequency bands to sample in
windowDetail	number	The window detail. Higher is more accurate but more expensive to calculate

Return types

nil

Remarks

resolution must be a square integer that's no smaller than 64 and no larger than 8192. E.g: 64, 128, 256, 512,...

windowDetail should be an integer number from 0 to 5.

Example

Channel.setGlobalFFTResolution(512)
local channel = Channel.fft(300, 512, 0, 1, 0.5)

---

constant(value)

Descriptions

Creates a constant value channel.

Parameters

Name	Type	Description
value	number	The constant value

Return types

ValueChannel

Remarks

_

Example

Scene.track.colorA = Channel.constant(127)

---

random(min, max, seed = 0)

Descriptions

Creates a channel that returns random value everytime.

Parameters

Name	Type	Description
min	number	Minimum value output
max	number	Maximum value output
seed	number	The randomizer's seed

Return types

ValueChannel

Remarks

Although you can set the randomizer's seed, the behaviour is still unpredictable because it's unclear how much time the randomizer has generated values at any point in time.

This channel also returns different values at the same timing point.

Example

sprite.colorR = Channel.random(200, 255)

---

noise(frequency, min, max, offset = 0, octave = 1)

Descriptions

Creates a perlin noise channel.

Parameters

Name	Type	Description
frequency	number	The perlin noise's frequency
min	number	Mininum value output
max	number	Maximum value output
offset	number	How much to offset the noise by
octave	number	The perlin noise's octave value

Return types

ValueChannel

Remarks

This channel is not actually random, although it may appear so. Two different perlin noise channels will return the same value, which may not be what you're trying to do. Use the offset parameter to mitigate this.

Multiple octave perlin noise essentially behaves like multiple perlin noises added on top of each other. The output value range is not well defined in this case, so min and max may not be accurate for octaves higher than 1.

Example

track.translationX = Channel.noise(10, -1, 1)
track.translationY = Channel.noise(10, -1, 1, 30)

---

sine(period, min, max, offset)

Descriptions

Creates a sine wave channel.

Parameters

Name	Type	Description
period	number	Looping duration
min	number	Mininum value output
max	number	Maximum value output
offset	number	How much to offset the wave by

Return types

ValueChannel

Remarks

The formula used to calculate this is min + (max-min) * sin(2*pi*(timing+offset)/period)

Example

sprite.colorA = Channel.sine(2000, 180, 255)

---

saw(easing, period, min, max, offset)

Descriptions

Creates a saw wave channel with easing method used at each interval.

Parameters

Name	Type	Description
easing	string	The easing to use
period	number	Looping duration
min	number	Mininum value output
max	number	Maximum value output
offset	number	How much to offset the wave by

Return types

ValueChannel

Remarks

For each duration, the value starts at max, then transition to min according to the provided easing.

Example

sprite.colorA = Channel.saw(2000, 255, 0)

---

min(channelA, channelB)

Descriptions

Creates a channel that take the minimum of two other channels.

Parameters

Name	Type	Description
channelA	ValueChannel	The first channel
channelB	ValueChannel	The second channel

Return types

ValueChannel

Remarks

_

Example

local keyChannel = Channel.keyframe()
sprite.colorA = Channel.minimum(Channel.constant(255), keyChannel)

---

max(channelA, channelB)

Descriptions

Creates a channel that take the maximum of two other channels.

Parameters

Name	Type	Description
channelA	ValueChannel	The first channel
channelB	ValueChannel	The second channel

Return types

ValueChannel

Remarks

_

Example

local keyChannel = Channel.keyframe()
sprite.translationZ = Channel.maximum(Channel.constant(0), keyChannel)

---

clamp(channelValue, channelMin, channelMax)

Descriptions

Creates a channel that limits the value of a channel between two other.

Parameters

Name	Type	Description
channelValue	ValueChannel	The lower bound channel
channelMin	ValueChannel	The lower bound channel
channelMax	ValueChannel	The upper bound channel

Return types

ValueChannel

Remarks

_

Example

local keyChannel = Channel.keyframe()
sprite.colorA = Channel.clamp(keyChannel, Channel.constant(50), Channel.constant(200))