title: SSSNode category: Addons layout: docs

SSSNode

Post processing node for applying Screen-Space Shadows (SSS) to a scene.

Screen-Space Shadows (also known as Contact Shadows) should ideally be used to complement traditional shadow maps. They are best suited for rendering detailed shadows of smaller objects at a closer scale like intricate shadowing on highly detailed models. In other words: Use Shadow Maps for the foundation and Screen-Space Shadows for the details.

The shadows produced by this implementation might have too hard edges for certain use cases. Use a box, gaussian or hash blur to soften the edges before doing the composite with the beauty pass. Code example:

Limitations:

Ideally the maximum shadow length should not exceed 1 meter. Otherwise the effect gets computationally very expensive since more samples during the ray marching process are evaluated. You can mitigate this issue by reducing the quality paramter.
The effect can only be used with a single directional light, the main light of your scene. This main light usually represents the sun or daylight.
Like other Screen-Space techniques SSS can only honor objects in the shadowing computation that are currently visible within the camera's view.

References:

Code Example

const sssPass = sss( scenePassDepth, camera, mainLight );
const sssBlur = boxBlur( sssPass.r, { size: 2, separation: 1 } ); // optional blur

Import

SSSNode is an addon, and must be imported explicitly, see Installation#Addons.

import { sss } from 'three/addons/tsl/display/SSSNode.js';

Constructor

new SSSNode( depthNode : TextureNode, camera : Camera, mainLight : DirectionalLight )

Constructs a new SSS node.

depthNode | A texture node that represents the scene's depth.
---|---
camera | The camera the scene is rendered with.
mainLight | The main directional light of the scene.

Properties

.depthNode : TextureNode

A node that represents the beauty pass's depth.

.maxDistance : UniformNode.<float>

Maximum shadow length in world units. Longer shadows result in more computational overhead.

Default is 0.1.

.quality : UniformNode.<float>

This parameter controls how detailed the raymarching process works. The value ranges is [0,1] where 1 means best quality (the maximum number of raymarching iterations/samples) and 0 means no samples at all.

A quality of 0.5 is usually sufficient for most use cases. Try to keep this parameter as low as possible. Larger values result in noticeable more overhead.

Default is 0.5.

.resolutionScale : number

The resolution scale. Valid values are in the range [0,1]. 1 means best quality but also results in more computational overhead. Setting to 0.5 means the effect is computed in half-resolution.

Default is 1.

.shadowIntensity : UniformNode.<float>

Shadow intensity. Must be in the range [0, 1].

Default is 0.5.

.thickness : UniformNode.<float>

Depth testing thickness.

Default is 0.01.

.updateBeforeType : string

The updateBeforeType is set to NodeUpdateType.FRAME since the node renders its effect once per frame in updateBefore().

Default is 'frame'.

Overrides: TempNode#updateBeforeType

.useTemporalFiltering : boolean

Whether to use temporal filtering or not. Setting this property to true requires the usage of TRAANode. This will help to reduce noice although it introduces typical TAA artifacts like ghosting and temporal instabilities.

Default is false.