📄 threejs/Core/Lights/LightShadow

File: LightShadow.md | Updated: 11/15/2025


title: LightShadow category: Core layout: docs

LightShadow

Abstract base class for light shadow classes. These classes represent the shadow configuration for different light types.

Constructor

new LightShadow( camera : Camera ) (abstract)

Constructs a new light shadow.

camera | The light's view of the world.
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Properties

.autoUpdate : boolean

Enables automatic updates of the light's shadow. If you do not require dynamic lighting / shadows, you may set this to false.

Default is true.

.bias : number

Shadow map bias, how much to add or subtract from the normalized depth when deciding whether a surface is in shadow.

The default is 0. Very tiny adjustments here (in the order of 0.0001) may help reduce artifacts in shadows.

Default is 0.

.blurSamples : number

The amount of samples to use when blurring a VSM shadow map.

Default is 8.

.camera : Camera

The light's view of the world.

.intensity : number

The intensity of the shadow. The default is 1. Valid values are in the range [0, 1].

Default is 1.

.map : RenderTarget

The depth map generated using the internal camera; a location beyond a pixel's depth is in shadow. Computed internally during rendering.

Default is null.

.mapPass : RenderTarget

The distribution map generated using the internal camera; an occlusion is calculated based on the distribution of depths. Computed internally during rendering.

Default is null.

.mapSize : Vector2

Defines the width and height of the shadow map. Higher values give better quality shadows at the cost of computation time. Values must be powers of two.

Default is (512,512).

.mapType : number

The type of shadow texture. The default is UnsignedByteType.

Default is UnsignedByteType.

.matrix : Matrix4

Model to shadow camera space, to compute location and depth in shadow map. This is computed internally during rendering.

.needsUpdate : boolean

When set to true, shadow maps will be updated in the next render call. If you have set LightShadow#autoUpdate to false, you will need to set this property to true and then make a render call to update the light's shadow.

Default is false.

.normalBias : number

Defines how much the position used to query the shadow map is offset along the object normal. The default is 0. Increasing this value can be used to reduce shadow acne especially in large scenes where light shines onto geometry at a shallow angle. The cost is that shadows may appear distorted.

Default is 0.

.radius : number

Setting this to values greater than 1 will blur the edges of the shadow. High values will cause unwanted banding effects in the shadows - a greater map size will allow for a higher value to be used here before these effects become visible.

The property has no effect when the shadow map type is PCFSoftShadowMap and and it is recommended to increase softness by decreasing the shadow map size instead.

The property has no effect when the shadow map type is BasicShadowMap.

Default is 1.

Methods

.clone() : LightShadow

Returns a new light shadow instance with copied values from this instance.

Returns: A clone of this instance.

.copy( source : LightShadow ) : LightShadow

Copies the values of the given light shadow instance to this instance.

source | The light shadow to copy.
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Returns: A reference to this light shadow instance.

.dispose()

Frees the GPU-related resources allocated by this instance. Call this method whenever this instance is no longer used in your app.

.getFrameExtents() : Vector2

Returns the frame extends.

Returns: The frame extends.

.getFrustum() : Frustum

Gets the shadow cameras frustum. Used internally by the renderer to cull objects.

Returns: The shadow camera frustum.

.getViewport( viewportIndex : number ) : Vector4

Returns a viewport definition for the given viewport index.

viewportIndex | The viewport index.
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Returns: The viewport.

.getViewportCount() : number

Used internally by the renderer to get the number of viewports that need to be rendered for this shadow.

Returns: The viewport count.

.toJSON() : Object

Serializes the light shadow into JSON.

See:

Returns: A JSON object representing the serialized light shadow.

.updateMatrices( light : Light )

Update the matrices for the camera and shadow, used internally by the renderer.

light | The light for which the shadow is being rendered.
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Source

src/lights/LightShadow.js