UDirectionalLightComponent | Unreal Engine 4.27 Documentation

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

Inheritance Hierarchy

References


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

Syntax

class UDirectionalLightComponent : public ULightComponent

Remarks

A light component that has parallel rays. Will provide a uniform lighting across any affected surface (eg. The Sun). This will affect all objects in the defined light-mass importance volume.

Variables

Type	Name	Description
FLinearColor	AtmosphereSunDiskColorScale	A color multiplied with the sun disk luminance.
int32	AtmosphereSunLightIndex	Two atmosphere lights are supported. For instance: a sun and a moon, or two suns.
uint32: 1	bAtmosphereSunLight	Whether the directional light can interact with the atmosphere, cloud and generate a visual disk.
uint32: 1	bCastCloudShadows	Whether the light should cast any shadows from clouds onto the atmosphere and other scene elements.
uint32: 1	bCastModulatedShadows	Whether the light should cast modulated shadows from dynamic objects (mobile only).
uint32: 1	bCastShadowsOnAtmosphere	Whether the light should cast any shadows from opaque meshes onto the atmosphere.
uint32: 1	bCastShadowsOnClouds	Whether the light should cast any shadows from opaque meshes onto clouds.
uint32: 1	bEnableLightShaftOcclusion	Whether to occlude fog and atmosphere inscattering with screenspace blurred occlusion from this light.
uint32: 1	bPerPixelAtmosphereTransmittance	Whether to apply atmosphere transmittance per pixel on opaque meshes, instead of using the light global transmittance.
uint32: 1	bUseInsetShadowsForMovableObjects	Stationary lights only: Whether to use per-object inset shadows for movable components, even though cascaded shadow maps are enabled.
float	CascadeDistributionExponent	Controls whether the cascades are distributed closer to the camera (larger exponent) or further from the camera (smaller exponent).
float	CascadeTransitionFraction	Proportion of the fade region between cascades.
FLinearColor	CloudScatteredLuminanceScale	Scales the lights contribution when scattered in cloud participating media.
float	CloudShadowDepthBias	The bias applied to the shadow front depth of the volumetric cloud shadow map.
float	CloudShadowExtent	The world space radius of the cloud shadow map around the camera in kilometers.
float	CloudShadowMapResolutionScale	Scale the cloud shadow map resolution, base resolution is 512.
float	CloudShadowOnAtmosphereStrength	The strength of the shadow on atmosphere. Disabled when 0.
float	CloudShadowOnSurfaceStrength	The strength of the shadow on opaque and transparent meshes. Disabled when 0.
float	CloudShadowRaySampleCountScale	Scale the shadow map tracing sample count.
float	CloudShadowStrength	The overall strength of the cloud shadow, higher value will block more light.
float	DistanceFieldShadowDistance	Distance at which the ray traced shadow cascade should end.
int32	DynamicShadowCascades	Number of cascades to split the view frustum into for the whole scene dynamic shadow.
float	DynamicShadowDistanceMovableLight	How far Cascaded Shadow Map dynamic shadows will cover for a movable light, measured from the camera.
float	DynamicShadowDistanceStationaryLight	How far Cascaded Shadow Map dynamic shadows will cover for a stationary light, measured from the camera.
int32	FarShadowCascadeCount	0: no Far Shadow Cascades, otherwise the number of cascades between DynamicShadowDistance and FarShadowDistance that are covered by Far Shadow Cascades.
float	FarShadowDistance	Distance at which the far shadow cascade should end.
int32	ForwardShadingPriority	Forward lighting priority for the single directional light that will be used for forward shading, translucent, single layer water and volumetric fog.
FLightmassDirectionalLightSettings	LightmassSettings	The Lightmass settings for this object.
FVector	LightShaftOverrideDirection	Can be used to make light shafts come from somewhere other than the light's actual direction.
float	LightSourceAngle	Angle subtended by light source in degrees (also known as angular diameter).
float	LightSourceSoftAngle	Angle subtended by soft light source in degrees.
FColor	ModulatedShadowColor	Color to modulate against the scene color when rendering modulated shadows. (mobile only)
float	OcclusionDepthRange	Everything closer to the camera than this distance will occlude light shafts.
float	OcclusionMaskDarkness	Controls how dark the occlusion masking is, a value of 1 results in no darkening term.
float	ShadowAmount	Control the amount of shadow occlusion. A value of 0 means no occlusion, thus no shadow.
float	ShadowCascadeBiasDistribution	Controls the depth bias scaling across cascades.
float	ShadowDistanceFadeoutFraction	Controls the size of the fade out region at the far extent of the dynamic shadow's influence.
float	ShadowSourceAngleFactor	Shadow source angle factor, relative to the light source angle.
float	TraceDistance	Determines how far shadows can be cast, in world units. Larger values increase the shadowing cost.

Constructors

	Type	Name	Description
		UDirectionalLightComponent ( const FObjectInitializer& ObjectInitializer )

Functions

	Type	Name	Description
	void	SetAtmosphereSunLight ( bool bNewValue )
	void	SetAtmosphereSunLightIndex ( int32 NewValue )
	void	SetCascadeDistributionExponent ( float NewValue )
	void	SetCascadeTransitionFraction ( float NewValue )
	void	SetDynamicShadowCascades ( int32 NewValue )
	void	SetDynamicShadowDistanceMovableLight ( float NewValue )
	void	SetDynamicShadowDistanceStationaryLight ( float NewValue )
	void	SetEnableLightShaftOcclusion ( bool bNewValue )
	void	SetForwardShadingPriority ( int32 NewValue )
	void	SetLightShaftOverrideDirection ( FVector NewValue )
	void	SetLightSourceAngle ( float NewValue )
	void	SetLightSourceSoftAngle ( float NewValue )
	void	SetOcclusionDepthRange ( float NewValue )
	void	SetOcclusionMaskDarkness ( float NewValue )
	void	SetShadowAmount ( float NewValue )
	void	SetShadowCascadeBiasDistribution ( float NewValue )
	void	SetShadowDistanceFadeoutFraction ( float NewValue )
	void	SetShadowSourceAngleFactor ( float NewValue )

Overridden from ULightComponent

Type	Name	Description
FLightSceneProxy *	CreateSceneProxy ()
FLinearColor	GetAtmosphereSunDiskColorScale ()
uint8	GetAtmosphereSunLightIndex ()
FLightmassLightSettings	GetLightmassSettings ()
FVector4	GetLightPosition ()	Return the homogenous position of the light.
ELightComponentType	GetLightType ()
ELightUnits	GetLightUnits ()
float	GetUniformPenumbraSize ()
bool	IsUsedAsAtmosphereSunLight ()	Whether to consider light as a sunlight for atmospheric scattering.

Overridden from UActorComponent

	Type	Name	Description
	bool	ForceActorNonSpatiallyLoaded ()
	void	InvalidateLightingCacheDetailed ( bool bInvalidateBuildEnqueuedLighting, bool bTranslationOnly )	Called when this actor component has moved, allowing it to discard statically cached lighting information.

Overridden from UObject

Type	Name	Description
bool	CanEditChange ( const FProperty* InProperty )	Called by the editor to query whether a property of this object is allowed to be modified.
void	PostEditChangeProperty ( FPropertyChangedEvent& PropertyChangedEvent )	Called after property has changed via e.g. property window or set command.
void	Serialize ( FArchive& Ar )	Handles reading, writing, and reference collecting using FArchive.