Audio Editor: Nodes – Arma Reforger

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TODO: Add images

Nodes are the fundamental building blocks that are used within the Audio Editor to create audio signal chains. There are a variety of different nodes, each with a specific purpose that modifies the sound or introduces some logic at its respective position in the chain.

Connecting a series of nodes together allows to create chains that produce sounds with varying degrees of complexity. This page serves as a reference for the usage of each type of node.

Note that there are certain fundamental nodes that must be present in a chain in order for a sound to be playable. These are namely:

• a node that outputs an audio waveform: either a Bank or a Generator
• a Sound node

Audio Editor Node Types

Nodes can be grouped into two main categories: resource and local. A node of the resource type is saved as a separate resource file and can be shared between multiple .acp files, while a node of the local type is stored in the .acp file itself and cannot be shared with other .acps.

Nodes of the resource type will appear on the design canvas with sharp corners, while nodes of the local type will appear with rounded corners.

Resource

Signal

Extension: .sig

Description: Takes one or more inputs and transforms them into one or more outputs that can be used to feed the inputs to other nodes. The internal logic that defines the input/output behavior can be edited inside the Signal Editor - BIKI by double-clicking on the node.

Input ports: Variable

Item detail:

Category	Attribute Name	Description
Inputs	Name	Input name (non-editable, defined inside the Signal Editor) *
	Value	Value of the input in case nothing is connected (otherwise this value is overridden by whatever is connected)
	Min	Minimum value of the signal input **
	Max	Maximum value of the signal output **
	ValRT	Slider that controls Value

* For connection with in-game signals, the name of the signal should correspond to the one defined in gamecode/script.

** This parameter has no effect on in-game signals or anything else connected to the signal input.

Mixer

Alias: OutputState, FinalMix

Extension: .afm

Description: This node serves as a way to group sounds based on type so that they can be processed as a unit before being sent to the final output(s). As with the Signal node, this node contains some internal logic that defines how each sound group is processed. This internal logic can be edited by double-clicking on the node.

Input ports: Variable depending on the value of the Inputs parameter

Local

BankLocal

Description: A collection of raw audio samples, of which one is selected to be played based on some selection method.

Input ports:

Name	Type	Description
Volume	Signal	Volume modifier [dB]
Pitch	Signal	Pitch modifier [semitones]
Replacer	Special-purpose node	Allows bank to be controlled by a Replacer. Hidden by default unless Enable replacer port attribute is checked.
Offset	Signal	Start position defined in milliseconds. Hidden by default unless Enable offset port attribute is checked.

Item detail:

Category	Attribute Name	Description	Value Range
General	Volume	Volume [dB], applied to all samples in the bank	[-60, +12] dB
	Volume variance	Volume randomization factor; maximum deviation from the value of Volume	[0, +12] dB
	Pitch	Pitch shift in semitones applied to all samples in the bank	[-12, +12] semitones
	Pitch variance	Pitch randomization factor; maximum deviation in semitones from the value of Pitch	[0, 2] semitones
	Loop count	Number of times that the played sample is repeated	[0, 255]
	Loop begin	The first sample of the region to be looped	Loop count defines the number of repetition When Offset is used, then the value must be greater than Offset
	Loop length	Length of the loop region, in samples.	The value of Loop begin + Loop length must be greater than Offset length
	Infinite Loop	If enabled, the played sample is repeated infinitely until the sound is stopped	True/False
	Selection	Method for selecting a sample	RandomNoRepeat: Samples selected at random, with the exception that the same sample is not repeated twice in a row Random: Samples selected at random SequenceFromFirst: Samples played in sequence, starting with the first sample FirstRandomAndSequence: Samples played in sequence, starting with a randomly-selected sample RandomNoRepeatGlobal: Ensures that the RandomNoRepeat condition is fulfilled when multiple game entities can play the same sample CustomSignalIndex: When this option is selected, a new input port is added to the bank that allows a sample to be selected based on the signal value
	Resampler	Resampling method, for converting between different sample rates [1]	Point: No interpolation (fastest, least accurate) [2] Linear: Interpolation (slower, but more accurate than point) [2] FIR (4/8/16): FIR filter that implements resampling (slowest but most accurate) [3]
	Fade	Fade-in/out function	Defines the "shape" of the volume change during fade-in/out Linear: TODO: link to visual plot SCurve: TODO: link to visual plot
Fade-in/out time		Time that it takes for the fade to complete (0: no fade in/out)	[0, 10000] ms
Flags	Disable streaming	When the size of the file is >256kB, then the sample is streamed in 16kB blocks. This flag suppresses streaming and the sample is loaded into memory (a single block of data). The flag is ignored when the size of the file is >16MB.	True/False
	Disable updating	Disables updating of bank inputs (Volume and Pitch) during playback if true. Recommended if: The Volume & Pitch inputs are not connected to anything The Volume & Pitch ports have signal inputs that are static	True/False
	Preload	Loads all samples into memory before any of them are played for the first time	True/False
	Enable replacer port	If enabled, creates a new input port for a Replacer node	True/False
Samples	Samples	List of audio samples	n/a
	Samples/Filename	Link to the sample (.wav format)	n/a
	Samples/Probability	In case of a randomized selection method, this parameter defines the probability that the sample will be selected.*	[0, 100]
	Samples/Index	Custom signal index	[0, inf+]
	Samples/Metadata

* Note that this value does not indicate the probability as a percentage. The probability in % can be obtained by dividing this value by the sum of the probabilities of all samples in the bank, then multiplying by 100.

Bus

Description: Mixes down all audio streams fed to the "In" port to a single output

Input ports:

Name	Type	Description
In	Audio	Accepts one or more audio streams
Volume	Signal	Volume modifier [dB]
DSP	Special-purpose node	Accepts a Filter or FilterChain

Item detail:

Category	Attribute Name	Description	Value Range
Limitation	Source Limit	Max number of inputs playing at a time. Quietest ones muted if limit exceeded.	[0, 255]
	Source Limit Type	Specifies when the Source Limit is evaluated	Static: Limit is evaluated once at the beginning of playback Dynamic: Limit is evaluated continuously during playback
Unsorted	Channels	Number of output channels	[1, 8]
	Sample Rate	Sample rate [Hz]	{8000, 11025, 16000, 32000, 44100, 48000, 64000, 96000, 192000} Hz
	Volume	Volume modifier [dB]	[-60, 12] dB
	Resampler	Resampling method, for converting between different sample rates [1]	Point: No interpolation (fastest, least accurate) [2] Linear: Interpolation (slower, but more accurate than point) [2] FIR (4/8/16): FIR filter that implements resampling (slowest but most accurate) [3]

Sound

Description: The root node of a signal chain. Must be present in every chain in order for sound to be playable.

Input ports:

Name	Type	Description
In	Audio	Accepts the audio output from one or more branches
Volume	Signal	Volume modifier [dB]
Trigger	Signal	Accepts a signal whose value can be used to trigger playback of the sound
DSP	Special-purpose node	Accepts a Filter or FilterChain
Master	Sound node	Accepts a Sound node that controls the start/stop behavior of this node

Item detail:

Category	Attribute Name	Description	Value Range
General	Volume	Volume modifier [dB]	[-60, 12] dB
	Priority	Factor that is taken into account when determining which sources to keep or destroy in case the limit of playing sources is exceeded. Sounds with lower priority are more likely to be destroyed than sounds with higher priority.	[0, 100]
	Delay Time	Delay time [ms] before sound is played	[0, 10000] ms
	No-Repeat Time	Time [ms] below which sound events with the same name will be ignored	[0, 1000] ms
Flags	Skip Inaudible	If enabled, sounds below the threshold of audibility are not played	True/False
	Bypass Volume Test	If enabled, volume is not considered when determining which sources to destroy in case the limit of playing sources is exceeded	True/False
	Speed of Sound	Simulates delayed playback due to the speed of sound Warning: only the playback start time is delayed - other sound-related parameters (i.e. signals and transformation) are not delayed which may cause a mismatch between audio and visuals.	True/False
	Updating disabled	Performance optimization: only Shader node is updated during playback; any other nodes in the chain remain in their "initialization" states.	True/False
	Early Reflections	Simulates early reflections from this sound	True/False
Transformation	Transformation	Specifies the position from which this sound is played	Entity: Sound is played from the position of the entity which the .acp file is attached to Bone: Sound is played from the bone specified in Bone Name on the entity which the .acp file is attached to
	Bone Name	Name of the bone on the entity on which sound is played (hidden if Transformation ≠ Bone)	String
	Static	If enabled, transformation is not updated during playback	True/False
Trigger	Type	Trigger type	Continuous: Sound is triggered and continues to repeat if the value of the signal connected to the Trigger port ≠ 0. One shot: Sound is triggered once based on the values of Threshold and Reset.
	Threshold	Value that the signal connected to the Trigger port needs to exceed before sound is triggered	Threshold >= Reset
	Reset	Value below which the signal needs to be before a new sound can be triggered	Reset <= Threshold
Slave	Event Type	If this sound is a slave (i.e. if the Master port is connected to another sound), this parameter defines its start/stop behavior in response to the master.	Start-Stop: Slave starts/stops when Master starts/stops OnStart-Start: Slave starts when Master starts OnStart-Stop: Slave stops when Master starts

Selector

Description: This node gives the user the ability to split the signal chain into multiple branches. On playback, the Selector will select one branch to connect to the chain, and leave the others disconnected based on the value of the control signal.

Input ports:

Name	Type	Description
Signal	Signal	Control signal whose value decides which of the following ports will be selected
(Varying number of user-defined ports)	Audio	The branch connected to this port becomes the output if the control signal falls within the Min/Max range defined for this port

Item detail:

Category	Attribute Name	Description	Value Range
Ports	Min	Lower bound of this port's range	(Unlimited)
	Max	Upper bound of this port's range	(Unlimited)
	Volume	Volume modifier [dB] applied to the branch connected to this port	[-60, 12] dB
	Default	If enabled, this port will be selected if the control signal does not fall within the range of any of the ports	True/False

Generator

Description: Outputs a variety of different waveforms as audio. Used primarily for testing/prototyping purposes.

Input ports:

Name	Type	Description
Time	Signal	Controls the Time parameter

Item detail:

Category	Attribute Name	Description	Value Range
Default	Function	Specifies the function/shape of the waveform that is output	Sine Square Sawtooth Triangle White noise Pink noise Brownian noise Silence
	Channels	Number of output channels	(Unlimited)
	Sample Rate	Sample rate [Hz]	{8000, 11025, 16000, 32000, 44100, 48000, 64000, 96000, 192000} Hz
	Time	Length of time [ms] that the sound lasts	[0, 10000] ms
	Volume	Volume modifier [dB]	[-60, 12] dB
	Loop Count	Number of times that the sound is repeated	[0, 255]
	Frequency	Frequency of the tone (hidden if not applicable to the Type)	[1, 20000]
Envelope	Attack Curve	Defines the curvature/shape of the attack (fade in).	Linear SCurve
	Attack Time	Length of the attack to reach the desired volume.	[0, 10000] ms
	Release Curve	Defines the curvature/shape of the release (fade out).	Linear SCurve
	Release Time	Length of the release to "fade out" after the generator time.	[0, 10000] ms

Constants

Description: A set of constant signal values

Shader

Description: Applies panning and attenuation based on the spatial relation between the in-game listener and emitter

Input ports:

Name	Type	Description
In	Audio	Accepts the audio output from one or more branches
Spatial factor	Special-purpose node	Accepts a Spatiality node that defines the spatial factor (i.e. the blend between the unprocessed and panned versions of the sound) based on the distance / spatial relation between the listener and emitter
Amplitude	Special-purpose node	Accepts an Amplitude node that defines how amplitude attenuation is applied based on the distance between the listener and emitter
Frequency	Special-purpose node	Accepts a Frequency node that defines how frequency attenuation is applied based on the distance between the listener and emitter
Incident angle (azimuth)	Signal	This port can be used to define the direction that the sound is perceived to be coming from. Utilising this feature overrides the default panning calculated from the positions of the listener and emitter. The value of the input is assumed to be in radians with a counter-clockwise rotation convention. This port is hidden unless Override Panning is enabled.

Item detail:

Category	Attribute Name	Description	Value Range
Unsorted	Override Panning	If enabled, a new input port is added that allows the user to override the default panning calculated from the positions of the listener and emitter.	True/False
	Reverse Panning	If enabled, the panning applied by the Shader is reversed (i.e. sounds coming from the left are panned to the right and vice-versa)	True/False
	ITD	If enabled, a short delay is applied to one channel based on the spatial relation between the listener and emitter. This simulates the interaural time difference (ITD) that humans rely on for localizing sounds. Note that ITD is only applied if headphones mode is enabled in the game's settings.	True/False

Amplitude

Description: Special-purpose node designed for use with Shader. Contains the parameters that control the degree of amplitude attenuation that is applied by the Shader.

Item detail:

Category	Attribute Name	Description	Value Range
Unsorted	Curve	Defines how the attenuation changes with distance - that is, the function that the attenuation vs. distance curve adheres to	Linear SCurve Logarithm 1/r

Frequency

Description: Special-purpose node designed for use with Shader. Contains the parameters that control the degree of frequency attenuation that is applied by the Shader.

From a physical standpoint, this node models the attenuation of high frequencies due to:

1. Distance between the listener and emitter
2. Directivity of the emitter: the degree to which the "clarity" of the sound produced by the emitter changes based on the direction it's facing with respect to the listener; sound is most clear when the emitter is facing the listener and least clear when the emitter is facing away from the listener.

Input ports:

Name	Type	Description
Directivity factor	Signal	Controls the Directivity Factor parameter

Item detail:

Category	Attribute Name	Description	Value Range
General	Dynamic Update	If enabled, the filter is updated during playback	Linear SCurve Logarithm 1/r
Distance Attenuation	Enable	If enabled, low-pass filtering due to distance attenuation is applied	True/Flase
	Type	Type of filter applied	AirAbsorption: Applies a custom filter that models the physical effect of distance on the frequency content of sound propagating through air Lowpass: Applies a generic lowpass filter with tweakable parameters that allows for greater flexibility, but is physically less accurate
	Filter Strength (AirAbsorption only)	Scaling factor for AirAbsorption filter	[0, 2]
	Inner Range (Lowpass only)	Distance [m] at which the filter's cutoff frequency is at the maximum value specified by Cutoff Max	[0, 100] m
	Outer Range (Lowpass only)	Distance at which the filter's cutoff frequency is at the minimum value specified by Cutoff Min	[0, 10000] m
	Slope Factor (Lowpass only)	Controls the slope of the filter; analogous to the "Q factor" of the filter	[0.01, 100]
	Cutoff Max (Lowpass only)	Maximum cutoff frequency of the filter when distance <= Inner Range	[100, 16000] Hz
	Cutoff Min (Lowpass only)	Minimum cutoff frequency of the filter when distance >= Outer Range	[100, 16000] Hz
Directivity	Enable	If enabled, low-pass filtering due to source directivity is applied	True/False
	Cutoff Frequency	Cutoff frequency of the directivity filter	[100, 250] Hz
	Directivity Factor	The degree to which sound is affected by the filter (0 = no filtering)	[0, 1]

Filter

Description: Special-purpose node that applies a specified DSP effect to the node (Sound or Bus) that it is connected to

Input ports:

Name	Type	Description
Wet/Dry	Signal	Controls the Wet/Dry parameter
Volume	Audio	The branch connected to this port becomes the output if the control signal falls within the Min/Max range defined for this port

Item detail:

Category	Attribute Name	Description	Value Range
Unsorted	Wet/Dry	Blend of the dry (unprocessed) and wet (processed) versions of the input sound	[0, 1]
	Volume	Volume modifier [dB]	[-60, 12]
	DSP Effect	Stores the parameters of one of the DSP Effects listed in the DSP Effects table	(See: DSP Effects)

DSP Effects:

DSP Type	Description	Attribute Name	Description	Value Range
Base	Abstract type that all DSP effects inherit from	n/a	n/a	n/a
Biquad	Biquad filter [4]	Biquad Type	Type of filter	LowPass HighPass BandPass Notch PeakingEQ LowShelf HighShelf AllPass
		Fc	Cutoff/center frequency of the filter	[20, 16000]
		Q	Factor that controls the slope of the filter shape	[0.1, 20]
		Gain (PeakingEQ, LowShelf, HighShelf, and AllPass only)	Gain [dB] of the filter	[-18, 18]
BitCrusher	Introduces distortion by reducing the bit depth of the audio input to 8-bit [5]	Bit Mask	An 8-digit string of '0's or '1's that specifies which of the 8 bits of the bit-crushed signal should be "enabled" (1) or "disabled" (0)	String
Compressor	Implements dynamic range compression; reduces the volume of the input signal if the specified threshold value is exceeded [6]	Threshold	Threshold value of the input level above which the gain begins to be reduced	[-50, 0] dB
		Ratio	Specifies the value of n in the ratio n:1. This value controls the amount of gain reduction (e.g. a ratio of 2:1 tells us that if the input signal is 2 dB over the value of Threshold, the resulting output level is reduced to 1 dB).	[1, 50]
		Attack	Specifies the amount of time [ms] that the output level takes to reach the value defined by Ratio	[1, 1000] ms
		Release	Specifies the amount of time [ms] that the compressor takes to "undo" gain reduction in the case that the signal level has decreased	[1, 1000] ms
		Knee Width	Controls the sharpness of the compressor's "knee"	[0, 20]
		Makeup Gain	Additional gain applied to the output signal. Typically used to compensate for the reduction in gain by the compressor.	[-24, 24]
		Clip	If enabled, the amplitude of the output signal is clipped to the range [-1, 1]	True/False
Limiter	Same as Compressor, but with Ratio set to ∞	(Same as Compressor)
Noise Gate	Mutes the input signal if its level is below the specified Threshold	Threshold	Threshold value of the input level below which the signal is muted	[-50, 0] dB

FilterChain

Description: Enables the grouping of multiple DSP nodes together in series. The individual DSP effects are applied in the order that they are connected to the FilterChain.

Input ports: Variable depending on the value of the Ports parameter

Replacer

Description: Special-purpose node designed to be used with Banks; enables the user to replace a string, if present, in the filepaths of all samples in the connected Bank.

Input ports:

Name	Type	Description
Control signal	Signal	Controls what the String to replace should be replaced with

Item detail:

Category	Attribute Name	Description	Value Range
Strings	String to replace	The string, searched for in the filepaths of all samples in the connected Bank, that we wish to replace	String
	Replacement strings	A list of candidate replacement strings and signal value pairs. A Replacement string from the list replaces String to replace in the filepaths of the connected bank's samples if its corresponding signal value matches that of the Control signal.	n/a

Stream

Description: Abstract node used for connecting streaming audio (e.g. voice chat) to a signal chain created in the audio editor

Item detail:

Category	Attribute Name	Description	Value Range
Unsorted	ID	ID string corresponding to the target stream ID defined in gamecode	String

Spatiality

Description: Special-purpose node designed for use with Shader. The purpose of this node is to provide the connected Shader(s) with a spatial factor value that controls how spatialized the output from the Shader(s) are.

ⓘ

Spatial factor controls the blending between unprocessed and spatialized (i.e. panned) sound. A value of 0 informs the connected Shader that no panning should be applied while a value of 1 indicates that the sound should be fully panned.

Input ports:

Name	Type	Description
Spatial Factor	Signal	The value of the spatial factor is taken from the signal connected to this port. This port is hidden unless the Spatial Factor Source is set to "Signal".

Item detail:

Category	Attribute Name	Description	Value Range
Spatiality	Spatial Factor Source	Defines where the spatial factor is taken from.	Value: When this option is selected, the spatial factor is defined by a constant value in the range [0, 1] Curve: When this option is selected, the spatial factor is defined by the distance between the listener and emitter. The user can define the relationship between distance and spatial factor via the curve property that becomes visible when this option is selected. Signal: When this option is selected, the spatial factor is defined by the value of the signal connected to the Spatial Factor input port. AzimuthCurve: This option is similar to the Curve option, but provides the user with an additional curve so that sounds to the side of the listener can have a different distance-to-spatial-factor relationship. When selected, Curve0 defines the distance-to-spatial-factor relationship for sounds directly in front (or behind) the listener and Curve90 defines the relationship for sounds 90 degrees to the left (or right) of the listener. For sounds partially to the side, a value is selected based on a linear interpolation between Curve0 and Curve90.

AuxOut

Description: Accepts the one or more Sound nodes as input and routes the output of those node(s) to the connected OutputState port.

Input ports:

Name	Type	Description
Sound	Sound node	The output from the sound node(s) connected to this port will be mixed down and sent to the output
Volume	Signal	Volume [dB] to be applied to the output
Mono Mix	Signal	Value between 0 and 1 that controls the mix between the unaltered output and a mono-downmixed version of the output

Signal Editor Node Types

Convertor

Description: Converts input values into output values based on defined ranges for input values.

Category	Attribute	Description
Unsorted	Input as default	True: If input is not defined in any range, that output = input False: If input is not defined in any range, that output = Default value
	Default
Ranges	Min
	Max
	Output	Output value for defined range [Min, Max)

Note: Ranges have to be in order. So 1-2, 2-3, 3-4 will work, but 1-2, 3-4, 2-3 will not.

Smoother

Category	Attribute	Description
Unsorted	Fade–in time	Time of interpolation, when input is ascending
	Fade-in type	Interpolation curve type
	Fade–out time	Time of interpolation, when input is descending
	Fade-out type	Interpolation curve type
	Input reset time	Resets interpolation time, when lastInput != currentInput
	Always interpolate	Output is always interpolated, even when Input reset time = true.

Interpolate

Category	Attribute	Description
Unsorted	X min
	X max
	Y min
	Y max
	Fade-in type	Interpolation curve type, Used, when input is ascending.
	Fade-out type	Interpolation curve type, Used, when input is descending.

Envelope

Category	Attribute	Description	Tips
Unsorted	A		if (A == B && C = D) { if (input >= A && input < C) output = 1; else output = 0; }
	B
	C
	D
	Fade-in type	Interpolation curve type. Between A and B
	Fade-out type	Interpolation curve type. Between C and D

Random

Category	Attribute	Description
Unsorted	Min
	Max
	Update rate	Every get Every frame

External References

1. https://en.wikipedia.org/wiki/Sample-rate_conversion
2. https://en.wikipedia.org/wiki/Interpolation
3. https://ccrma.stanford.edu/~jos/resample/resample.pdf
4. https://www.earlevel.com/main/2013/10/13/biquad-calculator-v2/
5. https://en.wikipedia.org/wiki/Audio_bit_depth
6. https://en.wikipedia.org/wiki/Dynamic_range_compression