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  3. ULightComponent

ULightComponent

API > API/Runtime > API/Runtime/Engine

   
Name ULightComponent
Type class
Header File /Engine/Source/Runtime/Engine/Classes/Components/LightComponent.h
Include Path #include "Components/LightComponent.h"

Syntax

UCLASS (Abstract, HideCategories=(Trigger, Activation, "Components|Activation", Physics),  
       ShowCategories=(Mobility), MinimalAPI)  
class ULightComponent : public ULightComponentBase

Inheritance Hierarchy

Implements Interfaces

Derived Classes

Constructors

Name Remarks Include Path Unreal Specifiers

ULightComponent ( const FObjectInitializer& ObjectInitializer
)

 Updates/ resets light GUIDs. Components/LightComponent.h  

Typedefs

Name Type Remarks Include Path
FOnUpdateColorAndBrightness TMulticastDelegate_OneParam< void, ULightComponent & >   Components/LightComponent.h

Constants

Name Type Remarks Include Path
UpdateColorAndBrightnessEvent FOnUpdateColorAndBrightness Called When light color or brightness needs update Components/LightComponent.h

Variables

Public

Name Type Remarks Include Path Unreal Specifiers
bAddedToSceneVisible uint32 True when this light component has been added to the scene as a normal visible light. Components/LightComponent.h  
bAllowMegaLights uint32 Whether to allow this light to use MegaLights, if it is enabled in the project settings or Post Process Volume. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • Meta=(DisplayName="Allow MegaLights")
  • AdvancedDisplay
bCastShadowsFromCinematicObjectsOnly uint32 Whether the light should only cast shadows from components marked as bCastCinematicShadows. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • AdvancedDisplay
bEnableLightShaftBloom uint32 Whether to render light shaft bloom from this light. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=LightShafts
  • Meta=(DisplayName="Light Shaft Bloom")
bForceCachedShadowsForMovablePrimitives uint32 Enables cached shadows for movable primitives for this light even if r.shadow.cachedshadowscastfrommovableprimitives is 0 Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • AdvancedDisplay
BloomMaxBrightness float After exposure is applied, scene color brightness larger than BloomMaxBrightness will be rescaled down to BloomMaxBrightness. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=LightShafts
  • Meta=(UIMin="0", UIMax="100", SliderExponent=20.0)
BloomScale float Scales the additive color. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=LightShafts
  • Meta=(UIMin="0", UIMax="10")
BloomThreshold float Scene color must be larger than this to create bloom in the light shafts. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=LightShafts
  • Meta=(UIMin="0", UIMax="4")
BloomTint FColor Multiplies against scene color to create the bloom color. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=LightShafts
bOverrideRayEndBias uint32   Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • Meta=(InlineEditConditionToggle)
  • AdvancedDisplay
bUseIESBrightness uint32 True: take light brightness from IES profile, false: use the light brightness - the maximum light in one direction is used to define no masking. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=LightProfiles
  • Meta=(DisplayName="Use IES Intensity", EditCondition="IESTexture!=nullptr")
bUseRayTracedDistanceFieldShadows bool Whether to use ray traced distance field area shadows. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=DistanceFieldShadows
  • Meta=(DisplayName="Distance Field Shadows")
bUseTemperature uint32 False: use white (D65) as illuminant. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • Meta=(DisplayName="Use Temperature", ShouldShowInViewport=true)
CastTranslucentShadows uint32 Whether the light is allowed to cast dynamic shadows from translucency. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • AdvancedDisplay
ContactShadowCastingIntensity float Intensity of the shadows cast by primitives with "cast contact shadow" enabled. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=Light
  • AdvancedDisplay
  • Meta=(ClampMin=0.0, ClampMax=1.0, UIMin="0.0", UIMax="1.0")
ContactShadowLength float Length of screen space ray trace for sharp contact shadows. Zero is disabled. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=Light
  • AdvancedDisplay
  • Meta=(UIMin="0.0", UIMax="0.1")
ContactShadowLengthInWS uint32 Where Length of screen space ray trace for sharp contact shadows is in world space units or in screen space units. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=Light
  • AdvancedDisplay
  • Meta=(DisplayName="Contact Shadow Length In World Space Units")
ContactShadowNonCastingIntensity float Intensity of the shadows cast by primitives with "cast contact shadow" disabled. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category=Light
  • AdvancedDisplay
  • Meta=(ClampMin=0.0, ClampMax=1.0)
DestroyFence FRenderCommandFence Fence used to track progress of render resource destruction. Components/LightComponent.h  
DiffuseScale float Multiplier on diffuse lighting. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • AdvancedDisplay
  • Meta=(UIMin="0", UIMax="1")
DisabledBrightness float Brightness factor applied to the light when the light function is specified but disabled, for example in scene captures that use SceneCapView_LitNoShadows. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=LightFunction
  • Meta=(UIMin="0.0", UIMax="1.0")
IESBrightnessScale float Global scale for IES brightness contribution. Components/LightComponent.h
  • BlueprintReadOnly
  • Interp
  • Category=LightProfiles
  • Meta=(UIMin="0.0", UIMax="10.0", DisplayName="IES Intensity Scale")
IESTexture TObjectPtr< class UTextureLightProfile > IES texture (light profiles from real world measured data) Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=LightProfiles
  • Meta=(DisplayName="IES Texture")
LightFunctionFadeDistance float Distance at which the light function should be completely faded to DisabledBrightness. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=LightFunction
  • Meta=(DisplayName="Fade Distance")
LightFunctionMaterial TObjectPtr< class UMaterialInterface > The light function material to be applied to this light. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=LightFunction
LightFunctionScale FVector Scales the light function projection. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=LightFunction
  • Meta=(AllowPreserveRatio="true")
LightingChannels FLightingChannels Channels that this light should affect. Components/LightComponent.h
  • EditAnywhere
  • AdvancedDisplay
  • BlueprintReadOnly
  • Category=Light
MaxDistanceFadeRange float Fade the light out as it approaches MaxDrawDistance. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Performance
  • Meta=(EditCondition="MaxDrawDistance > 0.0")
MaxDrawDistance float World distance to where the light stops rendering (lighting & shadows). Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Performance
MegaLightsShadowMethod TEnumAsByte< EMegaLightsShadowMethod::Type > Selects which shadowing method should MegaLights use for this light. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • Meta=(DisplayName="MegaLights Shadow Method")
  • AdvancedDisplay
PreviewShadowMapChannel int32 Transient shadowmap channel used to preview the results of stationary light shadowmap packing. Components/LightComponent.h
  • NonPIEDuplicateTransient
RayEndBias float   Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • Meta=(EditCondition="bOverrideRayEndBias", ClampMin="0", UIMax="100")
  • AdvancedDisplay
RayStartOffsetDepthScale float Controls how large of an offset ray traced shadows have from the receiving surface as the camera gets further away. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=DistanceFieldShadows
  • Meta=(UIMin="0", UIMax=".1")
  • AdvancedDisplay
SceneProxy FLightSceneProxy * The light's scene info. Components/LightComponent.h  
ShadowBias float Controls how accurate self shadowing of whole scene shadows from this light are. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • AdvancedDisplay
  • Meta=(UIMin="0", UIMax="1")
ShadowResolutionScale float Scales the resolution of shadowmaps used to shadow this light. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • AdvancedDisplay
  • Meta=(UIMin=".125", UIMax="8")
ShadowSharpen float Amount to sharpen shadow filtering Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • AdvancedDisplay
  • Meta=(UIMin="0.0", UIMax="1.0", DisplayName="Shadow Filter Sharpen")
ShadowSlopeBias float Controls how accurate self shadowing of whole scene shadows from this light are. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • AdvancedDisplay
  • Meta=(UIMin="0", UIMax="1")
SpecularScale float Multiplier on specular highlights. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Category=Light
  • AdvancedDisplay
  • Meta=(UIMin="0", UIMax="1")
StashedLightFunctionMaterial TObjectPtr< class UMaterialInterface > When clearing the light func, e.g. because the light is made static, this field remembers the last value Components/LightComponent.h
  • Transient
StaticShadowDepthMap FStaticShadowDepthMap   Components/LightComponent.h  
Temperature float Color temperature in Kelvin of the blackbody illuminant. White (D65) is 6500K. Components/LightComponent.h
  • EditAnywhere
  • BlueprintReadOnly
  • Interp
  • Category=Light
  • Meta=(UIMin="1700.0", UIMax="12000.0", ShouldShowInViewport=true, DisplayAfter="bUseTemperature")
ViewLightingChannels FViewLightingChannels View / light masking support. Controls which views this light should affect. Components/LightComponent.h
  • EditAnywhere
  • AdvancedDisplay
  • BlueprintReadOnly
  • Category=Light

Functions

Public

Name Remarks Include Path Unreal Specifiers

virtual bool AffectsBounds ( const FBoxSphereBounds& InBounds
) const

 Test whether the light affects the given bounding volume. Components/LightComponent.h  

bool AffectsPrimitive ( const UPrimitiveComponent* Primitive
) const

 Test whether this light affects the given primitive. Components/LightComponent.h  

void ApplyComponentInstanceData ( FPrecomputedLightInstanceData* ComponentInstanceData
)

   Components/LightComponent.h  

void ClearLightFunctionMaterial()

 Set the light func to null, but remember the current value so it can be restored later Components/LightComponent.h  

virtual float ComputeLightBrightness()

 Compute current light brightness based on whether there is a valid IES profile texture attached, and whether IES brightness is enabled Components/LightComponent.h  

virtual FLightSceneProxy * CreateSceneProxy()

   Components/LightComponent.h  

virtual FLinearColor GetAtmosphereSunDiskColorScale()

   Components/LightComponent.h  

virtual uint8 GetAtmosphereSunLightIndex()

   Components/LightComponent.h  

virtual FBox GetBoundingBox()

 Return the world-space bounding box of the light's influence. Components/LightComponent.h  

virtual FSphere GetBoundingSphere()

   Components/LightComponent.h  

FLinearColor GetColoredLightBrightness()

   Components/LightComponent.h  

FLinearColor GetColorTemperature()

 Get the color temperature in the working color space. Components/LightComponent.h  

FVector GetDirection()

 Script interface to retrieve light direction. Components/LightComponent.h  

const FLightComponentMapBuildData * GetLightComponentMapBuildData()

   Components/LightComponent.h  

virtual FLightmassLightSettings GetLightmassSettings()

   Components/LightComponent.h  

virtual FVector4 GetLightPosition()

 Return the homogenous position of the light. Components/LightComponent.h  

virtual ELightComponentType GetLightType()

   Components/LightComponent.h  

virtual ELightUnits GetLightUnits()

   Components/LightComponent.h  

virtual UMaterialInterface * GetMaterial ( int32 ElementIndex
) const

   Components/LightComponent.h  

virtual int32 GetNumMaterials()

   Components/LightComponent.h  

virtual float GetUniformPenumbraSize()

   Components/LightComponent.h  

void InitializeStaticShadowDepthMap()

   Components/LightComponent.h  

bool IsShadowCast ( UPrimitiveComponent* Primitive
) const

 Check whether a given primitive will cast shadows from this light. Components/LightComponent.h  

virtual bool IsUsedAsAtmosphereSunLight()

 Whether to consider light as a sunlight for atmospheric scattering. Components/LightComponent.h  

void PushSelectionToProxy()

 Pushes new selection state to the render thread light proxy Components/LightComponent.h  

void SetAffectTranslucentLighting ( bool bNewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetBloomMaxBrightness ( float NewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetBloomScale ( float NewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetBloomThreshold ( float NewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetBloomTint ( FColor NewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetDiffuseScale ( float NewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetEnableLightShaftBloom ( bool bNewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetForceCachedShadowsForMovablePrimitives ( bool bNewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetIESBrightnessScale ( float NewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"
  • Meta=(DisplayName="Set IES Intensity Scale")

void SetIESTexture ( UTextureLightProfile* NewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"
  • Meta=(DisplayName="Set IES Texture")

void SetIndirectLightingIntensity ( float NewIntensity
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetIntensity ( float NewIntensity
)

 Set intensity of the lightSet brightness of the light Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

virtual void SetLightBrightness ( float InBrightness
)

 Set the Intensity using the brightness. The unit of brightness depends on the light type. Components/LightComponent.h  

void SetLightColor ( FLinearColor NewLightColor,
bool bSRGB
)

 Set color of the light Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetLightFColor ( FColor NewLightColor
)

 Set color of the light Components/LightComponent.h
  • Category="Rendering|Components|Light"

void SetLightFunctionDisabledBrightness ( float NewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetLightFunctionFadeDistance ( float NewLightFunctionFadeDistance
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetLightFunctionMaterial ( UMaterialInterface* NewLightFunctionMaterial
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetLightFunctionScale ( FVector NewLightFunctionScale
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetLightingChannels ( bool bChannel0,
bool bChannel1,
bool bChannel2
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

virtual void SetMaterial ( int32 ElementIndex,
UMaterialInterface* InMaterial
)

 Set the MaterialInterface to use for the given element index (if valid) Components/LightComponent.h  

void SetMaxDistanceFadeRange ( float NewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetMaxDrawDistance ( float NewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetShadowBias ( float NewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetShadowSlopeBias ( float NewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetSpecularScale ( float NewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetTemperature ( float NewTemperature
)

 Set color temperature of the light Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetTransmission ( bool bNewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetUseIESBrightness ( bool bNewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"
  • Meta=(DisplayName="Set Use IES Intensity")

void SetUseRayTracedDistanceFieldShadows ( bool bNewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetUseTemperature ( bool bNewValue
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void SetVolumetricScatteringIntensity ( float NewIntensity
)

   Components/LightComponent.h
  • BlueprintCallable
  • Category="Rendering|Components|Light"

void UpdateColorAndBrightness()

 Script interface to update the color and brightness on the render thread. Components/LightComponent.h  

Overridden from ULightComponentBase

Name Remarks Include Path Unreal Specifiers

virtual void UpdateLightSpriteTexture()

 Update the texture used on the editor sprite Components/LightComponent.h  

Overridden from USceneComponent

Name Remarks Include Path Unreal Specifiers

virtual bool IsPrecomputedLightingValid()

 True if our precomputed lighting is up to date Components/LightComponent.h  

virtual void PropagateLightingScenarioChange()

 Updates any visuals after the lighting has changed Components/LightComponent.h  

Overridden from UActorComponent

Name Remarks Include Path Unreal Specifiers

virtual void CheckForErrors ()

 Function that gets called from within Map_Check to allow this actor component to check itself for any potential errors and register them with map check dialog. Components/LightComponent.h  

virtual TStructOnScope< FActorComponentInstanceData > GetComponentInstanceData()

 Called before we throw away components during RerunConstructionScripts, to cache any data we wish to persist across that operation Components/LightComponent.h  

virtual FBox GetStreamingBounds()

   Components/LightComponent.h  

virtual void InvalidateLightingCacheDetailed ( bool bInvalidateBuildEnqueuedLighting,
bool bTranslationOnly
)

 Called when this actor component has moved, allowing it to discard statically cached lighting information. Components/LightComponent.h  

Overridden from UObject

Name Remarks Include Path Unreal Specifiers

virtual void BeginDestroy()

   Components/LightComponent.h  

virtual bool CanEditChange ( const FProperty* InProperty
) const

   Components/LightComponent.h  

virtual bool IsReadyForFinishDestroy()

   Components/LightComponent.h  

virtual void PostEditChangeProperty ( FPropertyChangedEvent& PropertyChangedEvent
)

   Components/LightComponent.h  

virtual void PostLoad()

 Called after this UObject has been serialized Components/LightComponent.h  

virtual void PreSave ( FObjectPreSaveContext ObjectSaveContext
)

   Components/LightComponent.h  

virtual void Serialize ( FArchive& Ar
)

   Components/LightComponent.h  

Protected

Name Remarks Include Path Unreal Specifiers

void UpdateProxy ( FUpdateLightProxyCallback&& Func
)

   Components/LightComponent.h  

Overridden from USceneComponent

Name Remarks Include Path Unreal Specifiers

virtual bool GetMaterialPropertyPath ( int32 ElementIndex,
UObject*& OutOwner,
FString& OutPropertyPath,
FProperty*& OutProperty
)

 Returns full material property path and UObject owner property object Path examples: Material property path with array element and inner struct Materials[0].InnerStruct.Material Material property path with array element Materials[0] Simple material property path Materials Components/LightComponent.h  

Overridden from UActorComponent

Name Remarks Include Path Unreal Specifiers
Used to create any rendering thread information for this component Components/LightComponent.h  
Used to shut down any rendering thread structure for this component Components/LightComponent.h  

virtual void OnRegister()

 UActorComponent Interface Components/LightComponent.h  
Called to send a transform update for this component to the rendering thread Components/LightComponent.h  

Static

Name Remarks Include Path Unreal Specifiers

static void ReassignStationaryLightChannels ( UWorld* TargetWorld,
bool bAssignForLightingBuild,
FStaticLightingBuildContext* LightingContext
)

 Iterates over ALL stationary light components in the target world and assigns their preview shadowmap channel, and updates light icons accordingly. Components/LightComponent.h  

Deprecated Variables

Name Type Remarks Include Path Unreal Specifiers
InverseSquaredFalloff_DEPRECATED uint32   Components/LightComponent.h  
MinRoughness_DEPRECATED float Min roughness effective for this light. Used for softening specular highlights. Components/LightComponent.h  
ShadowMapChannel_DEPRECATED int32 Legacy shadowmap channel from the lighting build, now stored in FLightComponentMapBuildData. Components/LightComponent.h  

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