Nodes: Add DenoiseNode. (mrdoob#28879)

* Nodes: Add `DenoiseNode`.

* Clean up.

src/nodes/Nodes.js

@@ -135,6 +135,7 @@ export { default as RGBShiftNode, rgbShift } from './display/RGBShiftNode.js';
 export { default as FilmNode, film } from './display/FilmNode.js';
 export { default as Lut3DNode, lut3D } from './display/Lut3DNode.js';
 export { default as GTAONode, ao } from './display/GTAONode.js';
+export { default as DenoiseNode, denoise } from './display/DenoiseNode.js';
 export { default as FXAANode, fxaa } from './display/FXAANode.js';
 export { default as RenderOutputNode, renderOutput } from './display/RenderOutputNode.js';
 export { default as PixelationPassNode, pixelationPass } from './display/PixelationPassNode.js';

src/nodes/display/DenoiseNode.js

@@ -0,0 +1,183 @@
+import TempNode from '../core/TempNode.js';
+import { uv } from '../accessors/UVNode.js';
+import { addNodeElement, tslFn, nodeObject, float, int, vec2, vec3, vec4, mat2, If } from '../shadernode/ShaderNode.js';
+import { NodeUpdateType } from '../core/constants.js';
+import { uniform } from '../core/UniformNode.js';
+import { uniforms } from '../accessors/UniformsNode.js';
+import { abs, dot, sin, cos, PI, pow, max } from '../math/MathNode.js';
+import { loop } from '../utils/LoopNode.js';
+import { luminance } from './ColorAdjustmentNode.js';
+import { textureSize } from '../accessors/TextureSizeNode.js';
+import { Vector2 } from '../../math/Vector2.js';
+import { Vector3 } from '../../math/Vector3.js';
+
+class DenoiseNode extends TempNode {
+
+	constructor( textureNode, depthNode, normalNode, noiseNode, camera ) {
+
+		super();
+
+		this.textureNode = textureNode;
+		this.depthNode = depthNode;
+		this.normalNode = normalNode;
+		this.noiseNode = noiseNode;
+
+		this.cameraProjectionMatrixInverse = uniform( camera.projectionMatrixInverse );
+		this.lumaPhi = uniform( 5 );
+		this.depthPhi = uniform( 5 );
+		this.normalPhi = uniform( 5 );
+		this.radius = uniform( 5 );
+		this.index = uniform( 0 );
+
+		this._resolution = uniform( new Vector2() );
+		this._sampleVectors = uniforms( generatePdSamplePointInitializer( 16, 2, 1 ) );
+
+		this.updateBeforeType = NodeUpdateType.RENDER;
+
+	}
+
+	updateBefore() {
+
+		const map = this.textureNode.value;
+
+		this._resolution.value.set( map.image.width, map.image.height );
+
+	}
+
+	setup() {
+
+		const uvNode = uv();
+
+		const sampleTexture = ( uv ) => this.textureNode.uv( uv );
+		const sampleDepth = ( uv ) => this.depthNode.uv( uv ).x;
+		const sampleNormal = ( uv ) => this.normalNode.uv( uv );
+		const sampleNoise = ( uv ) => this.noiseNode.uv( uv );
+
+		const getViewPosition = tslFn( ( [ screenPosition, depth ] ) => {
+
+			screenPosition = vec2( screenPosition.x, screenPosition.y.oneMinus() ).mul( 2.0 ).sub( 1.0 );
+
+			const clipSpacePosition = vec4( vec3( screenPosition, depth ), 1.0 );
+			const viewSpacePosition = vec4( this.cameraProjectionMatrixInverse.mul( clipSpacePosition ) );
+
+			return viewSpacePosition.xyz.div( viewSpacePosition.w );
+
+		} );
+
+		const denoiseSample = tslFn( ( [ center, viewNormal, viewPosition, sampleUv ] ) => {
+
+			const texel = sampleTexture( sampleUv );
+			const depth = sampleDepth( sampleUv );
+			const normal = sampleNormal( sampleUv ).rgb.normalize();
+			const neighborColor = texel.rgb;
+			const viewPos = getViewPosition( sampleUv, depth );
+
+			const normalDiff = dot( viewNormal, normal ).toVar();
+			const normalSimilarity = pow( max( normalDiff, 0 ), this.normalPhi ).toVar();
+			const lumaDiff = abs( luminance( neighborColor ).sub( luminance( center ) ) ).toVar();
+			const lumaSimilarity = max( float( 1.0 ).sub( lumaDiff.div( this.lumaPhi ) ), 0 ).toVar();
+			const depthDiff = abs( dot( viewPosition.sub( viewPos ), viewNormal ) ).toVar();
+			const depthSimilarity = max( float( 1.0 ).sub( depthDiff.div( this.depthPhi ) ), 0 );
+			const w = lumaSimilarity.mul( depthSimilarity ).mul( normalSimilarity );
+
+			return vec4( neighborColor.mul( w ), w );
+
+		} );
+
+		const denoise = tslFn( () => {
+
+			const depth = sampleDepth( uvNode );
+			const viewNormal = sampleNormal( uvNode ).rgb.normalize();
+
+			depth.greaterThanEqual( 1.0 ).discard();
+			dot( viewNormal, viewNormal ).equal( 0.0 ).discard();
+
+			const texel = sampleTexture( uvNode );
+			const center = vec3( texel.rgb );
+
+			const viewPosition = getViewPosition( uvNode, depth );
+
+			const noiseResolution = textureSize( this.noiseNode, 0 );
+			let noiseUv = vec2( uvNode.x, uvNode.y.oneMinus() );
+			noiseUv = noiseUv.mul( this._resolution.div( noiseResolution ) );
+			const noiseTexel = sampleNoise( noiseUv );
+
+			const x = sin( noiseTexel.element( this.index.mod( 4 ).mul( 2 ).mul( PI ) ) );
+			const y = cos( noiseTexel.element( this.index.mod( 4 ).mul( 2 ).mul( PI ) ) );
+
+			const noiseVec = vec2( x, y );
+			const rotationMatrix = mat2( noiseVec.x, noiseVec.y.negate(), noiseVec.x, noiseVec.y );
+
+			const totalWeight = float( 1.0 ).toVar();
+			const denoised = vec3( texel.rgb ).toVar();
+
+			loop( { start: int( 0 ), end: int( 16 ), type: 'int', condition: '<' }, ( { i } ) => {
+
+				const sampleDir = this._sampleVectors.element( i ).toVar();
+				const offset = rotationMatrix.mul( sampleDir.xy.mul( float( 1.0 ).add( sampleDir.z.mul( this.radius.sub( 1 ) ) ) ) ).div( this._resolution ).toVar();
+				const sampleUv = uvNode.add( offset ).toVar();
+
+				const result = denoiseSample( center, viewNormal, viewPosition, sampleUv );
+
+				denoised.addAssign( result.xyz );
+				totalWeight.addAssign( result.w );
+
+			} );
+
+			If( totalWeight.greaterThan( float( 0 ) ), () => {
+
+				denoised.divAssign( totalWeight );
+
+			} );
+
+			return vec4( denoised, 1.0 );
+
+
+		} );
+
+		const outputNode = denoise();
+
+		return outputNode;
+
+	}
+
+}
+
+function generatePdSamplePointInitializer( samples, rings, radiusExponent ) {
+
+	const poissonDisk = generateDenoiseSamples( samples, rings, radiusExponent );
+
+	const array = [];
+
+	for ( let i = 0; i < samples; i ++ ) {
+
+		const sample = poissonDisk[ i ];
+		array.push( sample );
+
+	}
+
+	return array;
+
+}
+
+function generateDenoiseSamples( numSamples, numRings, radiusExponent ) {
+
+	const samples = [];
+
+	for ( let i = 0; i < numSamples; i ++ ) {
+
+		const angle = 2 * Math.PI * numRings * i / numSamples;
+		const radius = Math.pow( i / ( numSamples - 1 ), radiusExponent );
+		samples.push( new Vector3( Math.cos( angle ), Math.sin( angle ), radius ) );
+
+	}
+
+	return samples;
+
+}
+
+export const denoise = ( node, depthNode, normalNode, noiseNode, camera ) => nodeObject( new DenoiseNode( nodeObject( node ).toTexture(), nodeObject( depthNode ), nodeObject( normalNode ), nodeObject( noiseNode ), camera ) );
+
+addNodeElement( 'denoise', denoise );
+
+export default DenoiseNode;