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  3. ULightComponent

ULightComponent

Unreal Engine C++ API Reference > Runtime > Engine > Components

Inheritance Hierarchy

References

   
Module Engine
Header /Engine/Source/Runtime/Engine/Classes/Components/LightComponent.h
Include #include "Components/LightComponent.h"

Syntax

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

Variables

  Type Name Description
Public variable uint32: 1 bAddedToSceneVisible True when this light component has been added to the scene as a normal visible light.
Public variable UProperty Category, EditAnywhere, AdvancedDisplay BlueprintReadOnly uint32: 1 bCastShadowsFromCinematicObjectsOnly Whether the light should only cast shadows from components marked as bCastCinematicShadows.
Public variable UProperty Category, EditAnywhere, Meta BlueprintReadOnly uint32: 1 bEnableLightShaftBloom Whether to render light shaft bloom from this light.
Public variable UProperty Category, EditAnywhere, AdvancedDisplay BlueprintReadOnly uint32: 1 bForceCachedShadowsForMovablePrimitives Enables cached shadows for movable primitives for this light even if r.shadow.cachedshadowscastfrommovableprimitives is 0
Public variable UProperty Category, EditAnywhere, Meta BlueprintReadOnly float BloomMaxBrightness After exposure is applied, scene color brightness larger than BloomMaxBrightness will be rescaled down to BloomMaxBrightness.
Public variable UProperty Category, EditAnywhere, Meta BlueprintReadOnly float BloomScale Scales the additive color.
Public variable UProperty Category, EditAnywhere, Meta BlueprintReadOnly float BloomThreshold Scene color must be larger than this to create bloom in the light shafts.
Public variable UProperty Category, EditAnywhere BlueprintReadOnly FColor BloomTint Multiplies against scene color to create the bloom color.
Public variable UProperty Category, EditAnywhere, Meta BlueprintReadOnly uint32: 1 bUseIESBrightness True: take light brightness from IES profile, false: use the light brightness - the maximum light in one direction is used to define no masking.
Public variable UProperty Category, EditAnywhere, Meta BlueprintReadOnly bool bUseRayTracedDistanceFieldShadows Whether to use ray traced distance field area shadows.
Public variable UProperty Category, EditAnywhere, Meta BlueprintReadOnly uint32: 1 bUseTemperature False: use white (D65) as illuminant.
Public variable UProperty Category, EditAnywhere, AdvancedDisplay BlueprintReadOnly uint32: 1 CastTranslucentShadows Whether the light is allowed to cast dynamic shadows from translucency.
Public variable UProperty Category, EditAnywhere, AdvancedDisplay, Meta BlueprintReadWrite float ContactShadowCastingIntensity Intensity of the shadows cast by primitives with "cast contact shadow" enabled.
Public variable UProperty Category, EditAnywhere, AdvancedDisplay, Meta BlueprintReadWrite float ContactShadowLength Length of screen space ray trace for sharp contact shadows. Zero is disabled.
Public variable UProperty Category, EditAnywhere, AdvancedDisplay, Meta BlueprintReadWrite uint32: 1 ContactShadowLengthInWS Where Length of screen space ray trace for sharp contact shadows is in world space units or in screen space units.
Public variable UProperty Category, EditAnywhere, AdvancedDisplay, Meta BlueprintReadWrite float ContactShadowNonCastingIntensity Intensity of the shadows cast by primitives with "cast contact shadow" disabled.
Public variable FRenderCommandFence DestroyFence Fence used to track progress of render resource destruction.
Public variable UProperty Category, EditAnywhere, Meta BlueprintReadOnly float DisabledBrightness Brightness factor applied to the light when the light function is specified but disabled, for example in scene captures that use SceneCapView_LitNoShadows.
Public variable UProperty Category, Interp, Meta BlueprintReadOnly float IESBrightnessScale Global scale for IES brightness contribution.
Public variable UProperty Category, EditAnywhere, Meta BlueprintReadOnly TObjectPtr< class UTextureLightProfile > IESTexture IES texture (light profiles from real world measured data)
Public variable UProperty Category, EditAnywhere, Meta BlueprintReadOnly float LightFunctionFadeDistance Distance at which the light function should be completely faded to DisabledBrightness.
Public variable UProperty Category, EditAnywhere BlueprintReadOnly TObjectPtr< class UMaterialInterface > LightFunctionMaterial The light function material to be applied to this light.
Public variable UProperty Category, EditAnywhere, Meta BlueprintReadOnly FVector LightFunctionScale Scales the light function projection.
Public variable UProperty Category, EditAnywhere, AdvancedDisplay BlueprintReadOnly FLightingChannels LightingChannels Channels that this light should affect.
Public variable UProperty Category, EditAnywhere float MaxDistanceFadeRange  
Public variable UProperty Category, EditAnywhere float MaxDrawDistance  
Public variable int32 PreviewShadowMapChannel Transient shadowmap channel used to preview the results of stationary light shadowmap packing.
Public variable UProperty Category, EditAnywhere, AdvancedDisplay, Meta BlueprintReadOnly float RayStartOffsetDepthScale Controls how large of an offset ray traced shadows have from the receiving surface as the camera gets further away.
Public variable FLightSceneProxy * SceneProxy The light's scene info.
Public variable UProperty Category, EditAnywhere, AdvancedDisplay, Meta BlueprintReadOnly float ShadowBias Controls how accurate self shadowing of whole scene shadows from this light are.
Public variable UProperty Category, EditAnywhere, AdvancedDisplay, Meta BlueprintReadOnly float ShadowResolutionScale Scales the resolution of shadowmaps used to shadow this light.
Public variable UProperty Category, EditAnywhere, AdvancedDisplay, Meta BlueprintReadOnly float ShadowSharpen Amount to sharpen shadow filtering
Public variable UProperty Category, EditAnywhere, AdvancedDisplay, Meta BlueprintReadOnly float ShadowSlopeBias Controls how accurate self shadowing of whole scene shadows from this light are.
Public variable UProperty Category, EditAnywhere, AdvancedDisplay, Meta BlueprintReadOnly float SpecularScale Multiplier on specular highlights.
Public variable UProperty Transient TObjectPtr< class UMaterialInterface > StashedLightFunctionMaterial When clearing the light func, e.g. because the light is made static, this field remembers the last value
Public variable FStaticShadowDepthMap StaticShadowDepthMap  
Public variable UProperty Category, EditAnywhere, Interp, Meta BlueprintReadOnly float Temperature Color temperature in Kelvin of the blackbody illuminant. White (D65) is 6500K.

Constructors

  Type Name Description
Public function  

ULightComponent ( const FObjectInitializer& ObjectInitializer
)

 Updates/ resets light GUIDs.

Functions

  Type Name Description
Public function Virtual Const bool

AffectsBounds ( const FBoxSphereBounds& InBounds
)

 Test whether the light affects the given bounding volume.
Public function Const bool

AffectsPrimitive ( const UPrimitiveComponent* Primitive
)

 Test whether this light affects the given primitive.
Public function void  
Public function void Set the light func to null, but remember the current value so it can be restored later
Public function Virtual Const float Compute current light brightness based on whether there is a valid IES profile texture attached, and whether IES brightness is enabled
Public function Virtual Const FLightSceneProxy *  
Public function Virtual Const FLinearColor  
Public function Virtual Const uint8  
Public function Virtual Const FBox Return the world-space bounding box of the light's influence.
Public function Virtual Const FSphere  
Public function Const FLinearColor  
Public function Const FLinearColor Get the color temperature in the working color space.
Public function Const FVector Script interface to retrieve light direction.
Public function Const const FLightComponentMapBuildData *  
Public function Virtual Const FLightmassLightSettings  
Public function Virtual Const FVector4 Return the homogenous position of the light.
Public function Virtual Const ELightComponentType  
Public function Virtual Const ELightUnits  
Public function Virtual Const UMaterialInterface *

GetMaterial ( int32 ElementIndex
)

  
Public function Virtual Const int32  
Public function Virtual Const float  
Public function void  
Public function Const bool Check whether a given primitive will cast shadows from this light.
Public function Virtual Const bool Whether to consider light as a sunlight for atmospheric scattering.
Public function void Pushes new selection state to the render thread light proxy
Public function Static void

ReassignStationaryLightChannels ( UWorld* TargetWorld,
bool bAssignForLightingBuild,
ULevel* LightingScenario
)

 Iterates over ALL stationary light components in the target world and assigns their preview shadowmap channel, and updates light icons accordingly.
Public function UFunction BlueprintCallable, Category void

SetAffectTranslucentLighting ( bool bNewValue
)

  
Public function UFunction BlueprintCallable, Category void

SetBloomMaxBrightness ( float NewValue
)

  
Public function UFunction BlueprintCallable, Category void

SetBloomScale ( float NewValue
)

  
Public function UFunction BlueprintCallable, Category void

SetBloomThreshold ( float NewValue
)

  
Public function UFunction BlueprintCallable, Category void

SetBloomTint ( FColor NewValue
)

  
Public function UFunction BlueprintCallable, Category void

SetEnableLightShaftBloom ( bool bNewValue
)

  
Public function UFunction BlueprintCallable, Category void  
Public function UFunction BlueprintCallable, Category, Meta void

SetIESBrightnessScale ( float NewValue
)

  
Public function UFunction BlueprintCallable, Category, Meta void  
Public function UFunction BlueprintCallable, Category void

SetIndirectLightingIntensity ( float NewIntensity
)

  
Public function UFunction BlueprintCallable, Category void

SetIntensity ( float NewIntensity
)

 Set intensity of the lightSet brightness of the light
Public function Virtual void

SetLightBrightness ( float InBrightness
)

 Set the Intensity using the brightness. The unit of brightness depends on the light type.
Public function UFunction BlueprintCallable, Category void

SetLightColor ( FLinearColor NewLightColor,
bool bSRGB
)

 Set color of the light
Public function UFunction Category void

SetLightFColor ( FColor NewLightColor
)

 Set color of the light
Public function UFunction BlueprintCallable, Category void  
Public function UFunction BlueprintCallable, Category void

SetLightFunctionFadeDistance ( float NewLightFunctionFadeDistance
)

  
Public function UFunction BlueprintCallable, Category void

SetLightFunctionMaterial ( UMaterialInterface* NewLightFunctionMaterial
)

  
Public function UFunction BlueprintCallable, Category void

SetLightFunctionScale ( FVector NewLightFunctionScale
)

  
Public function UFunction BlueprintCallable, Category void

SetLightingChannels ( bool bChannel0,
bool bChannel1,
bool bChannel2
)

  
Public function Virtual void

SetMaterial ( int32 ElementIndex,
UMaterialInterface* InMaterial
)

 Set the MaterialInterface to use for the given element index (if valid)
Public function UFunction BlueprintCallable, Category void

SetShadowBias ( float NewValue
)

  
Public function UFunction BlueprintCallable, Category void

SetShadowSlopeBias ( float NewValue
)

  
Public function UFunction BlueprintCallable, Category void

SetSpecularScale ( float NewValue
)

  
Public function UFunction BlueprintCallable, Category void

SetTemperature ( float NewTemperature
)

 Set color temperature of the light
Public function UFunction BlueprintCallable, Category void

SetTransmission ( bool bNewValue
)

  
Public function UFunction BlueprintCallable, Category, Meta void

SetUseIESBrightness ( bool bNewValue
)

  
Public function UFunction BlueprintCallable, Category void

SetUseTemperature ( bool bNewValue
)

  
Public function UFunction BlueprintCallable, Category void

SetVolumetricScatteringIntensity ( float NewIntensity
)

  
Public function void Script interface to update the color and brightness on the render thread.

Overridden from ULightComponentBase

  Type Name Description
Public function Virtual void Update the texture used on the editor sprite

Overridden from USceneComponent

  Type Name Description
Protected function 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
Public function Virtual Const bool True if our precomputed lighting is up to date
Public function Virtual void Updates any visuals after the lighting has changed

Overridden from UActorComponent

  Type Name Description
Protected function Virtual void Used to create any rendering thread information for this component
Protected function Virtual void Used to shut down any rendering thread structure for this component
Public function Virtual Const TStructOnScope< FActorComponentInstanceData > Called before we throw away components during RerunConstructionScripts, to cache any data we wish to persist across that operation
Public function Virtual Const FBox  
Public function Virtual void

InvalidateLightingCacheDetailed ( bool bInvalidateBuildEnqueuedLighting,
bool bTranslationOnly
)

 Called when this actor component has moved, allowing it to discard statically cached lighting information.
Protected function Virtual void UActorComponent Interface
Protected function Virtual void Called to send a transform update for this component to the rendering thread

Overridden from UObject

  Type Name Description
Public function Virtual void Called before destroying the object.
Public function Virtual Const bool

CanEditChange ( const FProperty* InProperty
)

 Called by the editor to query whether a property of this object is allowed to be modified.
Public function Virtual bool Called to check if the object is ready for FinishDestroy.
Public function Virtual void

PostEditChangeProperty ( FPropertyChangedEvent& PropertyChangedEvent
)

 Called when a property on this object has been modified externally
Public function Virtual void Called after this UObject has been serialized
Public function Virtual PRAGMA_ENABLE_DEPRECATION_WARNINGS void

PreSave ( FObjectPreSaveContext ObjectSaveContext
)

 Presave function.
Public function Virtual PRAGMA_DISABLE_DEPRECATION_WARNINGS void

PreSave ( const ITargetPlatform* TargetPlatform
)

  
Public function Virtual void Handles reading, writing, and reference collecting using FArchive.

Typedefs

Name Description
FOnUpdateColorAndBrightness  

Constants

Name Description
UpdateColorAndBrightnessEvent Called When light color or brightness needs update

Deprecated Variables

  Type Name Description
Public variable UProperty uint32: 1 InverseSquaredFalloff_DEPRECATED  
Public variable UProperty float MinRoughness_DEPRECATED Min roughness effective for this light. Used for softening specular highlights.
Public variable UProperty int32 ShadowMapChannel_DEPRECATED Legacy shadowmap channel from the lighting build, now stored in FLightComponentMapBuildData.

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