Light

The Light class extends Actor and simplifies the process of spawning and configuring dynamic lights in Unreal Engine. It supports three light types -- Point, Spot, and Rect -- and automatically sets up location, rotation, color, intensity, attenuation, and shadow settings.

tip

Light is an Actor, so it inherits all functions from Actor.

Light Profiles

• Point lights act as a light bulb, casting light in all directions from a single point.
• Spot lights emit light from a single point in a direction limited by a set of cones.
• Rect lights emit light from a rectangular surface in a direction.

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Constructor

Blueprint

// Lights are spawned via Lua scripting.

Lua

-- Spawn a spot light
local myLight = Light(
    Vector(0, 0, 300),           -- location
    Rotator(45, 0, 0),           -- rotation
    LinearColor(1, 0.5, 0.5, 1), -- color
    LightType.Spot,              -- light type
    8000,                        -- intensity
    1200,                        -- attenuation radius
    30,                          -- cone angle
    0.2,                         -- inner cone percent
    5000,                        -- max draw distance
    true,                        -- use inverse squared falloff
    true,                        -- cast shadows
    true                         -- visible
)

JavaScript

// Light spawning follows the same pattern via PuerTS or Helix JS bindings.
// Refer to the Lua examples for constructor parameters.

Constructor Parameters

Name	Type	Default	Description
Location	Vector	(0,0,0)	Spawn position in world space.
Rotation	Rotator	(0,0,0)	Initial rotation of the light.
Color	LinearColor	white	Light color and alpha.
LightTypeParam	enum	LightType.Point	LightType.Point, .Spot, or .Rect.
Intensity	number	5000	Light brightness (in lumens).
AttenuationRadius	number	1000	Distance the light affects (Point/Spot only).
ConeAngle	number	44	Outer angle for Spot lights.
InnerConePercent	number	0	Inner angle as a percent of outer angle.
MaxDrawDistance	number	0	Fade out distance (0 = infinite).
UseInverseSquaredFalloff	boolean	true	Use physically accurate light falloff.
CastShadows	boolean	true	Enable shadow casting.
Visible	boolean	true	Whether the light is visible.

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Methods

General

Method	Parameters	Return Type	Description
ToggleEnabled	--	void	Enables or disables the light.
IsEnabled	--	boolean	Returns the enabled status of the light.
GetLightColor	--	Color	Returns the current color of the light.
GetBrightness	--	number	Returns the brightness amount.

Color and Intensity

Method	Parameters	Return Type	Description
SetLightFColor	NewLightColor: Color	void	Sets the light color using a Color value.
SetLightColor	NewLightColor: LinearColor	void	Sets the light color using a LinearColor value.
SetIntensityUnits	NewIntensityUnits: ELightUnits	void	Sets how the light's intensity is measured (unitless, lumens, candelas, or EV).
SetAttenuationRadius	NewRadius: number	void	Sets the distance at which the light has no effect.
SetCastShadows	bNewValue: boolean	void	Sets whether the light casts shadows.
SetCastVolumetricShadow	bNewValue: boolean	void	Enables or disables volumetric shadow casting.
SetAffectReflection	bNewValue: boolean	void	Enables or disables the light's influence on reflections.
SetAffectGlobalIllumination	bNewValue: boolean	void	Enables or disables the light's contribution to global illumination.
SetVolumetricScatteringIntensity	NewIntensity: number	void	Controls the light's contribution to volumetric lighting.
SetUseTemperature	bNewValue: boolean	void	Enables or disables using Kelvin temperature for light color.
SetTemperature	NewTemperature: number	void	Sets the color temperature in Kelvin (requires SetUseTemperature(true)).

Light Function

Method	Parameters	Return Type	Description
SetLightFunctionScale	NewLightFunctionScale: Vector	void	Sets the scale of the light function projection.
SetLightFunctionMaterial	NewLightFunctionMaterial: UMaterialInterface	void	Sets a material to use as the light function (gobo effect).
SetLightFunctionFadeDistance	NewLightFunctionFadeDistance: number	void	Controls how far the light function effect fades out.

Spot Light

Method	Parameters	Return Type	Description
SetOuterConeAngle	NewOuterConeAngle: number	void	Sets the outer cone angle for spot lights.
SetInnerConeAngle	NewInnerConeAngle: number	void	Sets the inner cone angle for spot lights.

Rect Light

Method	Parameters	Return Type	Description
SetSourceWidth	NewValue: number	void	Sets the width of the source rectangle.
SetSourceHeight	NewValue: number	void	Sets the height of the source rectangle.
SetSourceTexture	NewValue: UTexture	void	Assigns a texture to the rect light source.
SetBarnDoorLength	NewValue: number	void	Controls the length of the barn doors.
SetBarnDoorAngle	NewValue: number	void	Controls the angle of the barn doors.

Point Light

Method	Parameters	Return Type	Description
SetSourceRadius	NewValue: number	void	Sets the radius of the source for point lights.
SetSoftSourceRadius	NewValue: number	void	Sets the radius of the soft source effect.
SetSourceLength	NewValue: number	void	Sets the source length for tube-style light emission.

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Examples

Dynamic Spotlight

Blueprint

// Lights are spawned and configured via Lua scripting.

Lua

local myLight = Light(
    Vector(0, 0, 300),
    Rotator(45, 0, 0),
    LinearColor(1, 0.5, 0.5, 1),
    LightType.Spot,
    8000, 1200, 30, 0.2, 5000, true, true, true
)

-- Change color at runtime
myLight:SetLightColor(LinearColor(1.0, 0.0, 0.5, 1.0))

-- Toggle the light off
myLight:ToggleEnabled()

-- Check if enabled
local isEnabled = myLight:IsEnabled()

JavaScript

// Light configuration follows the same pattern via PuerTS or Helix JS bindings.
// Refer to the Lua examples for function signatures.

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Performance

Dynamic shadow-casting lights are expensive. Use SetCastShadows(false) for ambient or decorative lights that do not need shadows.