Accueil / npm / three@0.172.0 / examples / jsm / tsl / display / SSAAPassNode.js
SSAAPassNode.js
import { AdditiveBlending, Color, Vector2, RendererUtils, PassNode, QuadMesh, NodeMaterial } from 'three/webgpu';
import { nodeObject, uniform, mrt, texture, getTextureIndex } from 'three/tsl';
/** @module SSAAPassNode **/
const _size = /*@__PURE__*/ new Vector2();
let _rendererState;
/**
* 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: {@link https://en.wikipedia.org/wiki/Supersampling}
*
* @augments PassNode
*/
class SSAAPassNode extends PassNode {
static get type() {
return 'SSAAPassNode';
}
/**
* Constructs a new SSAA pass node.
*
* @param {Scene} scene - The scene to render.
* @param {Camera} camera - The camera to render the scene with.
*/
constructor( scene, camera ) {
super( PassNode.COLOR, scene, camera );
/**
* This flag can be used for type testing.
*
* @type {Boolean}
* @readonly
* @default true
*/
this.isSSAAPassNode = true;
/**
* The sample level specified as n, where the number of samples is 2^n,
* so sampleLevel = 4, is 2^4 samples, 16.
*
* @type {Number}
* @default 4
*/
this.sampleLevel = 4;
/**
* Whether rounding errors should be mitigated or not.
*
* @type {Boolean}
* @default true
*/
this.unbiased = true;
/**
* The clear color of the pass.
*
* @type {Color}
* @default 0x000000
*/
this.clearColor = new Color( 0x000000 );
/**
* The clear alpha of the pass.
*
* @type {Number}
* @default 0
*/
this.clearAlpha = 0;
/**
* A uniform node representing the sample weight.
*
* @type {UniformNode<float>}
* @default 1
*/
this.sampleWeight = uniform( 1 );
/**
* Reference to the internal render target that holds the current sample.
*
* @private
* @type {RenderTarget?}
*/
this._sampleRenderTarget = null;
/**
* Reference to the internal quad mesh.
*
* @private
* @type {QuadMesh}
*/
this._quadMesh = new QuadMesh();
}
/**
* This method is used to render the SSAA effect once per frame.
*
* @param {NodeFrame} frame - The current node frame.
*/
updateBefore( frame ) {
const { renderer } = frame;
const { scene, camera } = this;
_rendererState = RendererUtils.resetRendererAndSceneState( renderer, scene, _rendererState );
//
this._pixelRatio = renderer.getPixelRatio();
const size = renderer.getSize( _size );
this.setSize( size.width, size.height );
this._sampleRenderTarget.setSize( this.renderTarget.width, this.renderTarget.height );
//
this._cameraNear.value = camera.near;
this._cameraFar.value = camera.far;
renderer.setMRT( this.getMRT() );
renderer.autoClear = false;
const jitterOffsets = _JitterVectors[ Math.max( 0, Math.min( this.sampleLevel, 5 ) ) ];
const baseSampleWeight = 1.0 / jitterOffsets.length;
const roundingRange = 1 / 32;
const viewOffset = {
fullWidth: this.renderTarget.width,
fullHeight: this.renderTarget.height,
offsetX: 0,
offsetY: 0,
width: this.renderTarget.width,
height: this.renderTarget.height
};
const originalViewOffset = Object.assign( {}, camera.view );
if ( originalViewOffset.enabled ) Object.assign( viewOffset, originalViewOffset );
// render the scene multiple times, each slightly jitter offset from the last and accumulate the results.
for ( let i = 0; i < jitterOffsets.length; i ++ ) {
const jitterOffset = jitterOffsets[ i ];
if ( camera.setViewOffset ) {
camera.setViewOffset(
viewOffset.fullWidth, viewOffset.fullHeight,
viewOffset.offsetX + jitterOffset[ 0 ] * 0.0625, viewOffset.offsetY + jitterOffset[ 1 ] * 0.0625, // 0.0625 = 1 / 16
viewOffset.width, viewOffset.height
);
}
this.sampleWeight.value = baseSampleWeight;
if ( this.unbiased ) {
// the theory is that equal weights for each sample lead to an accumulation of rounding errors.
// The following equation varies the sampleWeight per sample so that it is uniformly distributed
// across a range of values whose rounding errors cancel each other out.
const uniformCenteredDistribution = ( - 0.5 + ( i + 0.5 ) / jitterOffsets.length );
this.sampleWeight.value += roundingRange * uniformCenteredDistribution;
}
renderer.setClearColor( this.clearColor, this.clearAlpha );
renderer.setRenderTarget( this._sampleRenderTarget );
renderer.clear();
renderer.render( scene, camera );
// accumulation
renderer.setRenderTarget( this.renderTarget );
if ( i === 0 ) {
renderer.setClearColor( 0x000000, 0.0 );
renderer.clear();
}
this._quadMesh.render( renderer );
}
renderer.copyTextureToTexture( this._sampleRenderTarget.depthTexture, this.renderTarget.depthTexture );
// restore
if ( camera.setViewOffset && originalViewOffset.enabled ) {
camera.setViewOffset(
originalViewOffset.fullWidth, originalViewOffset.fullHeight,
originalViewOffset.offsetX, originalViewOffset.offsetY,
originalViewOffset.width, originalViewOffset.height
);
} else if ( camera.clearViewOffset ) {
camera.clearViewOffset();
}
//
RendererUtils.restoreRendererAndSceneState( renderer, scene, _rendererState );
}
/**
* This method is used to setup the effect's MRT configuration and quad mesh.
*
* @param {NodeBuilder} builder - The current node builder.
* @return {PassTextureNode}
*/
setup( builder ) {
if ( this._sampleRenderTarget === null ) {
this._sampleRenderTarget = this.renderTarget.clone();
}
let sampleTexture;
const passMRT = this.getMRT();
if ( passMRT !== null ) {
const outputs = {};
for ( const name in passMRT.outputNodes ) {
const index = getTextureIndex( this._sampleRenderTarget.textures, name );
if ( index >= 0 ) {
outputs[ name ] = texture( this._sampleRenderTarget.textures[ index ] ).mul( this.sampleWeight );
}
}
sampleTexture = mrt( outputs );
} else {
sampleTexture = texture( this._sampleRenderTarget.texture ).mul( this.sampleWeight );
}
this._quadMesh.material = new NodeMaterial();
this._quadMesh.material.fragmentNode = sampleTexture;
this._quadMesh.material.transparent = true;
this._quadMesh.material.depthTest = false;
this._quadMesh.material.depthWrite = false;
this._quadMesh.material.premultipliedAlpha = true;
this._quadMesh.material.blending = AdditiveBlending;
this._quadMesh.material.name = 'SSAA';
return super.setup( builder );
}
/**
* Frees internal resources. This method should be called
* when the pass is no longer required.
*/
dispose() {
super.dispose();
if ( this._sampleRenderTarget !== null ) {
this._sampleRenderTarget.dispose();
}
}
}
export default SSAAPassNode;
// These jitter vectors are specified in integers because it is easier.
// I am assuming a [-8,8) integer grid, but it needs to be mapped onto [-0.5,0.5)
// before being used, thus these integers need to be scaled by 1/16.
//
// Sample patterns reference: https://msdn.microsoft.com/en-us/library/windows/desktop/ff476218%28v=vs.85%29.aspx?f=255&MSPPError=-2147217396
const _JitterVectors = [
[
[ 0, 0 ]
],
[
[ 4, 4 ], [ - 4, - 4 ]
],
[
[ - 2, - 6 ], [ 6, - 2 ], [ - 6, 2 ], [ 2, 6 ]
],
[
[ 1, - 3 ], [ - 1, 3 ], [ 5, 1 ], [ - 3, - 5 ],
[ - 5, 5 ], [ - 7, - 1 ], [ 3, 7 ], [ 7, - 7 ]
],
[
[ 1, 1 ], [ - 1, - 3 ], [ - 3, 2 ], [ 4, - 1 ],
[ - 5, - 2 ], [ 2, 5 ], [ 5, 3 ], [ 3, - 5 ],
[ - 2, 6 ], [ 0, - 7 ], [ - 4, - 6 ], [ - 6, 4 ],
[ - 8, 0 ], [ 7, - 4 ], [ 6, 7 ], [ - 7, - 8 ]
],
[
[ - 4, - 7 ], [ - 7, - 5 ], [ - 3, - 5 ], [ - 5, - 4 ],
[ - 1, - 4 ], [ - 2, - 2 ], [ - 6, - 1 ], [ - 4, 0 ],
[ - 7, 1 ], [ - 1, 2 ], [ - 6, 3 ], [ - 3, 3 ],
[ - 7, 6 ], [ - 3, 6 ], [ - 5, 7 ], [ - 1, 7 ],
[ 5, - 7 ], [ 1, - 6 ], [ 6, - 5 ], [ 4, - 4 ],
[ 2, - 3 ], [ 7, - 2 ], [ 1, - 1 ], [ 4, - 1 ],
[ 2, 1 ], [ 6, 2 ], [ 0, 4 ], [ 4, 4 ],
[ 2, 5 ], [ 7, 5 ], [ 5, 6 ], [ 3, 7 ]
]
];
/**
* TSL function for creating a SSAA pass node for Supersampling Anti-Aliasing.
*
* @function
* @param {Scene} scene - The scene to render.
* @param {Camera} camera - The camera to render the scene with.
* @returns {SSAAPassNode}
*/
export const ssaaPass = ( scene, camera ) => nodeObject( new SSAAPassNode( scene, camera ) );