Audio: Multiphase Destruction – Arma Reforger

The Multiphase Destruction (MPD) system handles environmental destruction (e.g., breaking signs, crumbling walls, etc.). Each MPD entity transitions through "damage phases", altering its model, spawning debris and particle effects, or emitting sounds.

For efficiency, sounds are managed by the Audio: SCR SoundManagerEntity system, not individual entities. Entities reference enums in SCR_DestructionMultiPhaseComponent for sound definitions.
Sounds are triggered:
1. When an entity's damage phase changes (using SCR_EMaterialSoundTypeBreak).
2. When spawned debris collides with the environment or other entities (using SCR_EMaterialSoundTypeDebris).
When triggering a sound:
1. The enum string (e.g., "METAL_HEAVY") combines with "SOUND_MPD_" to form the sound name (e.g., "SOUND_MPD_METAL_HEAVY").
2. The system plays the sound from the .acp file linked to the MPDestructionManager.

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In order for Multiphase Destruction to work, a Multiphase Destruction Manager must be present within the world.

Design

All sound events are defined in one .acp: Sounds\Destruction\Multiphase\Destruction_Multiphase.acp
A "manager" needs to be present in the gameworld: Prefabs\MP\MPDestructionManager.et
Available sound types are defined via enums (SCR_EMaterialSoundTypeDebris and SCR_EMaterialSoundTypeBreak)

MPD Enum Overview

Sounds use enum values. Pick one of the following two to mod:

SCR_EMaterialSoundTypeBreak if the sound is supposed to play when the entity changes its damage phase.
In this case, the enum must start with "BREAK_", e.g. "BREAK_GLASSBOTTLE";
SCR_EMaterialSoundTypeDebris if the sound is supposed to play when debris collides with the environment

Add the desired name to the correct enum through modding - make sure to choose a descriptive one. Example:

Copy

modded enum SCR_EMaterialSoundTypeBreak { BREAK_GLASSBOTTLE, }

Break Sounds

Debris Sounds

SCR_EMaterialSoundTypeBreak

SCR_EMaterialSoundTypeDebris

Defined via the "Material Sound Type" entry in the "Unsorted" category .

These sounds will play once when the entity breaks OR changes its damage phase (PhasesToDestroyed Signal).

Example: A wooden fence breaking and playing a snapping/splintering sound.

Defined in the "Small Debris" classes of the destructible entity. This sound will trigger when the spawned debris collides with something else and a certain impact threshold is exceeded.

Example: Broken off wooden fence plank falls over and impacts with the ground.

Enum Value	Description
NONE	No sound, default
BREAK_GLASS	Small glass objects, e.g. a glass or bottle
BREAK_GLASS_PANE	Larger glass objects, e.g. car or building windows
BREAK_GROUNDRADAR	Dedicated sound for breaking ground radars
BREAK_MATRESS	Soft thump, used for soft, cloth-like sounds
BREAK_METAL	General metal break sound
BREAK_METAL_GENERATOR	When a generator breaks down
BREAK_METAL_NETFENCE	Metal-ish sound with elements of netfence rattling
BREAK_METAL_POLE	Resonant pole break sound
BREAK_PIANO	Dedicated sound for breaking pianos
BREAK_PLASTIC	Sharp smaller-scale plastic cracking
BREAK_ROCK	Break sound for larger rock/stone/asphalt objects, e.g. a massive wall
BREAK_SANDBAG	Soft and plastic-y
BREAK_TENT	Dedicated sound for tents
BREAK_WATERHYDRANT	Dedicated sound for waterhydrants
BREAK_WOOD_SOLID	Universal wooden break sound

Enum Name	Description
NONE	No sound, default
BELL_SMALL	Dedicated sound for small bells
GLASS	Small glass objects, e.g. bottles
MATRESS	Dedicated sound for matresses and pillows
METAL_HEAVY	Heavy metal impacts
METAL_LIGHT	Light, crisp metal impacts
METAL_NETFENCE	Metal-y impacts with netfence rattling
METAL_POLE	Resonant, medium-sized metal
PLASTIC_HOLLOW	E.g. a tube or food container
PLASTIC_SOLID	E.g. an old telephone
ROCK	Concrete chunks
ROCK_SMALL	More brick-like, slightly hollow
SANDBAG	Soft and plastic-y
WOOD_PLANK_SMALL	For small, wooden objects, e.g. fence boards
WOOD_PLANK_LARG	For large(r) wooden objects, such as smaller tree trunks

Signals

Not all signals are available for each type of sound.

Signal Name	Description	Available for Break Sounds	Available for Impact Sounds
PhasesToDestroyed	An integer indicating how damaged the entity is. 0 = Total destruction 1 = Broken > 1 = Anything else
EntitySize	The entity's mass, usually used in order to "scale" sounds.
CollisionDV	A value reflecting the change in speed of an entity upon contact (how fast was it before, how much was it slowed down?)

Debugging

If any issues arise, the first step should always be to make sure an MPDestructionManager entity exists in the world. Check if the SCR_DestructionMultiPhaseComponent is actually enabled (if it is an Entity with integrated MPD functionality, make sure "Enabled" is checked in the "Unsorted" tab). Entities with integrated MPD functionality will always use the values stored in their Prefabs - meaning a per-instance change will not work. A Prefab change also requires a reload of the current world.

Diag Menu

If a DestructionMPDestructionManager.et is present in the world, a Diag Menu entry can be found:

Diag Menu \ Sounds \ Show MPD Impulse Values

Upon colliding, the debris entity will then display the impulse data in the format <impulse value>/<impulse threshold>/<mass>.

Sound Definition Check

In the main Workbench Window (not World Editor), the "Multiphase Destruction Soundless Prefab Search" tool can be accessed via Plugins → Prefabs. The tool will go through all prefabs and list in the debug console log those which do not have a "Break" or "Impact" sound defined.