Chapter 478: SSAAPassNode

Core Idea

A special render pass node that renders the scene with SSAA (Supersampling Anti-Aliasing). This manual SSAA approach re-renders the scene ones for each sample with camera jitter and accumulates the results.

This node produces a high-quality anti-aliased output but is also extremely expensive because of its brute-force approach of re-rendering the entire scene multiple times.

Reference: https://en.wikipedia.org/wiki/Supersampling

Key Concepts

• isSSAAPassNode : boolean (readonly): This flag can be used for type testing.
• sampleLevel : number: The sample level specified as n, where the number of samples is 2^n, so sampleLevel = 4, is 2^4 samples, 16.
• sampleWeight : UniformNode.<float>: A uniform node representing the sample weight.
• unbiased : boolean: Whether rounding errors should be mitigated or not.

Code Examples

import { ssaaPass } from 'three/addons/tsl/display/SSAAPassNode.js';

• What it demonstrates: Typical usage of SSAAPassNode.

Reference Tables

Constructor

Signature
new SSAAPassNode( scene : Scene, camera : Camera )

Properties

Property	Description
.isSSAAPassNode : boolean (readonly)	This flag can be used for type testing.
.sampleLevel : number	The sample level specified as n, where the number of samples is 2^n, so sampleLevel = 4, is 2^4 samples, 16.
.sampleWeight : UniformNode.<float>	A uniform node representing the sample weight.
.unbiased : boolean	Whether rounding errors should be mitigated or not.

Methods

Method	Description
.dispose()	Frees internal resources. This method should be called when the pass is no longer required.
.setup( builder : NodeBuilder ) : PassTextureNode	This method is used to setup the effect's MRT configuration and quad mesh.
.updateBefore( frame : NodeFrame )	This method is used to render the SSAA effect once per frame.

Key Takeaways

1. SSAAPassNode extends: EventDispatcher → Node → TempNode → PassNode
2. Most relevant properties: isSSAAPassNode, sampleLevel, sampleWeight, unbiased.
3. Key methods: dispose, setup, updateBefore.

Connects To

• EventDispatcher: parent class
• Node: parent class
• TempNode: parent class
• PassNode: parent class
• Source: examples/jsm/tsl/display/SSAAPassNode.js