Blowinwind

Based on game build 714014 | Last updated: 2026-03-03

Overview

Blowinwind is a component that models physics-based movement driven by a directional wind force. It accumulates velocity over time in the wind direction, modulates movement speed using sine-based variation, and applies the resulting speed and rotation to the entity’s locomotor component. It also manages a sound loop whose playback parameter scales with movement speed. The component is typically used for entities exposed to environmental wind (e.g., gusts in the Caves or outdoors). It interacts directly with locomotor to control forward movement speed and rotation.

Usage example

local inst = CreateEntity()
inst:AddComponent("blowinwind")
inst.components.blowinwind:SetAverageSpeed(8)
inst.components.blowinwind:SetMaxSpeedMult(1.3)
inst.components.blowinwind:SetMinSpeedMult(0.7)
inst.components.blowinwind:Start(math.rad(90), 1.0) -- wind from the right

Dependencies & tags

Components used: locomotor, SoundEmitter, Transform
Tags: None identified.

Properties

Property	Type	Default Value	Description
inst	entity	nil (assigned in constructor)	The entity instance the component is attached to.
maxSpeedMult	number	1.5	Maximum multiplier applied to base speed during sine-based variation.
minSpeedMult	number	0.5	Minimum multiplier applied to base speed during sine-based variation.
averageSpeed	number	(TUNING.WILSON_RUN_SPEED + TUNING.WILSON_WALK_SPEED)/2	Baseline speed used for remapping velocity magnitude to walkspeed.
speed	number	0	Current calculated walkspeed applied to locomotor.walkspeed.
windAngle	number	0	Wind direction angle in radians (XZ plane).
windVector	Vector3	(0,0,0)	Normalized wind direction vector derived from windAngle.
currentAngle	number	0	Current rotation angle of the entity, updated per-frame.
currentVector	Vector3	(0,0,0)	Normalized vector for current direction.
velocity	Vector3	(0,0,0)	Accumulated velocity in the wind direction, updated per-frame.
speedVarTime	number	0	Time elapsed since last reset of speed variation cycle.
speedVarPeriod	number	Random value near 5 (see constructor)	Duration of one full sine wave period for speed variation.
soundName	string or nil	nil	Name of sound loop to manage (if set externally).
soundPath	string or nil	nil	Path to sound asset (if set externally).
soundParameter	string or nil	nil	Name of sound parameter to modulate with speed (if set externally).
velocMult	number or nil	nil	Unused in current implementation; comment suggests future intent.

Main functions

Start(ang, vel)

• Description: Initializes wind-driven movement by setting the wind direction, updating the entity's rotation, and beginning the update loop. Starts the sound loop if configured.
• Parameters:
  ang (number, optional) — Wind direction in radians (XZ plane). If provided, sets windAngle, windVector, currentAngle, and currentVector.
  vel (number, optional) — Intended velocity multiplier (currently unused; assignment is commented out).
• Returns: Nothing.
• Error states: No explicit failure cases; silent no-op if ang/vel are omitted.

Stop()

• Description: Halts wind-driven movement by stopping the update loop and killing the sound loop.
• Parameters: None.
• Returns: Nothing.

ChangeDirection(ang, vel)

• Description: Updates the wind direction without affecting the update loop or sound. Updates windAngle and windVector only.
• Parameters:
  ang (number, optional) — New wind direction in radians.
  vel (number, optional) — Intended velocity multiplier (commented out in implementation; ignored).
• Returns: Nothing.

SetMaxSpeedMult(spd)

• Description: Sets the upper bound of speed variation multiplier during sine-based oscillation.
• Parameters: spd (number) — New maximum multiplier (e.g., 1.5).
• Returns: Nothing.

SetMinSpeedMult(spd)

• Description: Sets the lower bound of speed variation multiplier during sine-based oscillation.
• Parameters: spd (number) — New minimum multiplier (e.g., 0.5).
• Returns: Nothing.

SetAverageSpeed(spd)

• Description: Overrides the default baseline speed used for remapping velocity to walkspeed.
• Parameters: spd (number) — New average speed reference (e.g., 8).
• Returns: Nothing.

GetSpeed()

• Description: Returns the most recently calculated walkspeed applied to the locomotor.
• Parameters: None.
• Returns: number — Current speed.

GetVelocity()

• Description: Returns the accumulated velocity vector in the wind direction.
• Parameters: None.
• Returns: Vector3 — Current velocity.

OnUpdate(dt)

• Description: Core update function (called per frame while component is active). Accumulates velocity toward wind direction, remaps magnitude to a walkspeed, applies sine-based variation, updates rotation and sound, and drives locomotor:WalkForward().
• Parameters: dt (number) — Delta time in seconds.
• Returns: Nothing.
• Error states: Stops itself and returns early if inst is nil or destroyed.

OnEntityWake()

• Description: Reactivates movement when the entity wakes (e.g., after sleeping). Calls Start() using last-known windAngle and velocMult.
• Parameters: None.
• Returns: Nothing.

OnEntitySleep()

• Description: Deactivates movement when the entity sleeps. Calls Stop().
• Parameters: None.
• Returns: Nothing.

StartSoundLoop()

• Description: Starts the configured sound loop if emitter and sound are valid and not already playing.
• Parameters: None.
• Returns: Nothing.

StopSoundLoop()

• Description: Stops the configured sound loop if emitter and sound name are valid.
• Parameters: None.
• Returns: Nothing.

Events & listeners

• Listens to: None identified.
• Pushes: None identified.