Accueil / npm / three@0.186.1 / examples / jsm / tsl / display / SSRNode.js
SSRNode.js
import { Break, Continue, Fn, If, Loop, abs, bool, cross, distance, div, dot, float, getScreenPosition, getViewPosition, int, logarithmicDepthToViewZ, luminance, max, min, mix, mul, nodeObject, normalize, orthographicDepthToViewZ, passTexture, perspectiveDepthToViewZ, reference, reflect, sub, texture, trunc, uniform, uv, vec2, vec3, vec4, viewZToPerspectiveDepth, context } from 'three/tsl';
import { HalfFloatType, LinearFilter, LinearMipmapLinearFilter, Matrix4, NodeMaterial, NodeUpdateType, QuadMesh, RenderTarget, RendererUtils, TempNode, Vector2, Vector3 } from 'three/webgpu';
import { bindAnalyticNoise } from '../utils/RNoise.js';
import { ENV_RAY_LENGTH, getSpecularDominantFactor, ggxReflectionSample } from '../utils/SpecularHelpers.js';
import { boxBlur } from './boxBlur.js';
import ImportanceSampledEnvironment from './ImportanceSampledEnvironment.js';
const _quadMesh = /*@__PURE__*/ new QuadMesh();
const _size = /*@__PURE__*/ new Vector2();
let _rendererState;
// Maximum ray-march step count; `quality` (0..1) scales it to a fixed per-ray count.
const MAX_STEPS = 64;
/**
* @typedef {Object} SSRNodeOptions
* @property {boolean} [stochastic=false] - When `false`, traces a single mirror reflection and softens roughness with a blur pass (first-generation SSR). When `true`, varies the reflection direction per pixel with stochastic GGX rays (second-generation SSR); higher quality on rough/glossy surfaces but noisier, so it expects a temporal/spatial denoiser downstream.
* @property {Node<float>} [metalnessNode=null] - Per-pixel metalness. Drives GGX reflection sampling and, with `reflectNonMetals=false`, the non-metal early-out.
* @property {Node<float>} [roughnessNode=null] - Per-pixel roughness. Drives GGX sampling and the blur mip selection.
* @property {boolean} [reflectNonMetals=false] - Only used when `stochastic=false`. When `false`, non-metallic surfaces are discarded for a noticeable performance gain; set `true` to also reflect dielectrics (e.g. marble, polished wood, plastic).
* @property {Texture} [environmentNode=null] - Equirectangular HDR environment map with CPU-side `image.data` (e.g. from RGBELoader). Not compatible with PMREM / `scene.environment` cubemaps.
* @property {boolean} [envImportanceSampling=false] - When `true`, precomputes env-luminance CDF tables and uses MIS for environment misses. Build-time only.
* @property {Node} [diffuseNode=null] - Scene diffuse / base color. Defaults to `vec3(1)` in the shader when omitted.
* @property {boolean} [binaryRefine=false] - Sub-step binary-search refinement of detected hits. Compile-time constant (baked into the shader at construction).
* @property {Camera} [camera=null] - Camera the scene is rendered with. Inferred from the color pass when omitted.
*/
/**
* Post processing node for computing screen space reflections (SSR).
*
* Reference: {@link https://lettier.github.io/3d-game-shaders-for-beginners/screen-space-reflection.html}
*
* @augments TempNode
* @three_import import { ssr } from 'three/addons/tsl/display/SSRNode.js';
*/
class SSRNode extends TempNode {
static get type() {
return 'SSRNode';
}
/**
* Constructs a new SSR node.
*
* @param {Node<vec4>} colorNode - The node that represents the beauty pass.
* @param {Node<float>} depthNode - A node that represents the beauty pass's depth.
* @param {Node<vec3>} normalNode - A node that represents the beauty pass's normals.
* @param {SSRNodeOptions} [options] - Optional inputs for material and environment data.
*/
constructor( colorNode, depthNode, normalNode, options = {} ) {
super( 'vec4' );
const {
stochastic = false,
metalnessNode = null,
roughnessNode = null,
reflectNonMetals = false,
environmentNode = null,
envImportanceSampling = false,
diffuseNode = null,
binaryRefine = false
} = options;
let camera = options.camera ?? null;
/**
* When `true`, the reflection direction is varied per pixel with stochastic GGX rays
* (second-generation SSR). When `false`, a single mirror reflection is traced and
* roughness is softened with a blur pass (first-generation SSR).
*
* @type {boolean}
*/
this.stochastic = stochastic;
/**
* When `true`, env-luminance CDF tables are built and MIS is used for environment misses.
* Fixed at construction time.
*
* @type {boolean}
*/
this.envImportanceSampling = envImportanceSampling;
/**
* The node that represents the beauty pass.
*
* @type {Node<vec4>}
*/
this.colorNode = colorNode;
/**
* A node that represents the scene's diffuse color (typically the MRT `diffuseColor` attachment).
* When `null`, the shader uses `vec3(1)`.
*
* @type {?Node<vec4>}
*/
this.diffuseNode = diffuseNode !== null ? nodeObject( diffuseNode ) : null;
/**
* A node that represents the beauty pass's depth.
*
* @type {Node<float>}
*/
this.depthNode = depthNode;
/**
* A node that represents the beauty pass's normals.
*
* @type {Node<vec3>}
*/
this.normalNode = normalNode;
/**
* Per-pixel metalness, used to drive the GGX reflection sampling and the non-metal
* early-out. When `null`, the shader treats surfaces as non-metallic.
*
* @type {?Node<float>}
*/
this.metalnessNode = metalnessNode;
/**
* Per-pixel roughness, used to drive the GGX reflection sampling and the blur mip
* selection. When `null`, the shader treats surfaces as fully smooth.
*
* @type {?Node<float>}
*/
this.roughnessNode = roughnessNode;
/**
* Only used when {@link SSRNode#stochastic} is `false`. When `false`, non-metallic
* surfaces are discarded for a noticeable performance gain; set `true` to also
* reflect dielectrics. Baked into the shader as a compile-time constant; assigning a
* new value recompiles the SSR material.
*
* @type {boolean}
* @default false
*/
this._reflectNonMetals = reflectNonMetals;
/**
* 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.
*
* @type {number}
* @default 1
*/
this.resolutionScale = 1;
/**
* The `updateBeforeType` is set to `NodeUpdateType.FRAME` since the node renders
* its effect once per frame in `updateBefore()`.
*
* @type {string}
* @default 'frame'
*/
this.updateBeforeType = NodeUpdateType.FRAME;
/**
* Controls how far a fragment can reflect. Increasing this value result in more
* computational overhead but also increases the reflection distance.
*
* @type {UniformNode<float>}
*/
this.maxDistance = uniform( 1 );
/**
* Controls the cutoff between what counts as a possible reflection hit and what does not.
*
* @type {UniformNode<float>}
*/
this.thickness = uniform( 0.1 );
/**
* A multiplier for the overall reflection intensity. `1` leaves the
* reflections unchanged, lower values dim them and higher values boost them.
*
* @type {UniformNode<float>}
* @default 1
*/
this.intensity = uniform( 1 );
/**
* Screen-edge fade width, in UV units. As a screen-space hit approaches a screen
* border, the reflection is faded over this distance — either toward the environment
* reflection ({@link SSRNode#screenEdgeFadeBlack} `false`) or to zero intensity
* (`true`). `0` disables it.
*
* @type {UniformNode<float>}
* @default 0.2
*/
this.screenEdgeFade = uniform( 0.2 );
/**
* When `true`, SSR fades to zero near screen borders instead of blending toward
* the environment map. Hits are faded by the reflection sample UV; misses are
* faded by the surface pixel UV.
*
* Baked into the shader as a compile-time constant so the unused fade branch is
* eliminated; assigning a new value recompiles the SSR material.
*
* @type {boolean}
* @default false
*/
this._screenEdgeFadeBlack = false;
/**
* Absolute env luminance cap. HDR env samples above this are scaled down (hue preserved).
*
* @type {UniformNode<float>}
* @default 10
*/
this.maxLuminance = uniform( 10 );
/**
* 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.
*
* @type {UniformNode<float>}
*/
this.quality = uniform( 0.5 );
/**
* Mirror bias for the stochastic GGX sampling. Concentrates the reflected rays toward
* the lobe's narrow (near-mirror) core, trading a small amount of bias for less noise.
* `0` samples the full VNDF lobe; values toward `1` tighten the cone. Range `[0,1]`.
*
* @type {UniformNode<float>}
* @default 0.5
*/
this.mirrorBias = uniform( 0.5 );
/**
* The quality of the blur. Must be an integer in the range `[1,3]`.
*
* Baked into the blur shader as a compile-time constant so the `(size*2+1)²`
* sample loop unrolls; assigning a new value recompiles the blur material.
*
* @type {number}
* @default 2
*/
this._blurQuality = 2;
/**
* Enables sub-step binary-search refinement of a detected hit. When on, a coarse
* crossing is bisected toward the exact intersection (sharper hits, less step
* aliasing) at the cost of extra depth samples. Baked into the shader as a
* compile-time constant; assigning a new value rebuilds the SSR material.
*
* @type {boolean}
* @default false
*/
this._binaryRefine = binaryRefine;
/**
* Non-linear step distribution exponent. `1` = uniform steps; `> 1` concentrates
* samples near the ray origin — where most short-range reflections are missed — and
* spaces them out toward maxDistance, as `s = (i / steps) ^ stepExponent`.
*
* Baked into the shader as a compile-time constant so `pow()` folds to a few
* multiplies; assigning a new value recompiles the SSR material. Only used by the
* stochastic reflection path.
*
* @type {number}
* @default 2
*/
this._stepExponent = 2;
/**
* HDR environment map for screen-space misses.
*
* @type {?Texture}
*/
this.environmentNode = environmentNode;
/**
* A node that represents the history texture for multi-bounce reflections.
*
* @type {?Texture}
*/
this.historyTexture = null;
/**
* A node that represents the velocity texture for reprojection.
*
* @type {?Node<vec2>}
*/
this.velocityTexture = null;
//
if ( camera === null ) {
if ( this.colorNode.passNode && this.colorNode.passNode.isPassNode === true ) {
camera = this.colorNode.passNode.camera;
} else {
throw new Error( 'THREE.SSRNode: No camera found. ssr() requires a camera.' );
}
}
/**
* The camera the scene is rendered with.
*
* @type {Camera}
*/
this.camera = camera;
/**
* The spread of the blur. Automatically set when generating mips.
*
* @private
* @type {UniformNode<int>}
*/
this._blurSpread = uniform( 1 );
/**
* Represents the projection matrix of the scene's camera.
*
* @private
* @type {UniformNode<mat4>}
*/
this._cameraProjectionMatrix = uniform( camera.projectionMatrix );
/**
* Represents the inverse projection matrix of the scene's camera.
*
* @private
* @type {UniformNode<mat4>}
*/
this._cameraProjectionMatrixInverse = uniform( camera.projectionMatrixInverse );
/**
* Represents the near value of the scene's camera.
*
* @private
* @type {ReferenceNode<float>}
*/
this._cameraNear = reference( 'near', 'float', camera );
/**
* Represents the far value of the scene's camera.
*
* @private
* @type {ReferenceNode<float>}
*/
this._cameraFar = reference( 'far', 'float', camera );
this._cameraWorldMatrix = uniform( new Matrix4().copy( camera.matrixWorld ) );
this._cameraWorldPosition = uniform( new Vector3().copy( camera.position ) );
this._cameraViewMatrix = uniform( new Matrix4().copy( camera.matrixWorld ) );
this._cameraViewMatrixInverse = uniform( new Matrix4().copy( camera.matrixWorldInverse ) );
/**
* The resolution of the pass.
*
* @private
* @type {UniformNode<vec2>}
*/
this._resolution = uniform( new Vector2() );
this._noiseIndex = uniform( 0 );
/**
* CDF-backed environment sampler. Created when {@link setEnvMap} is called.
*
* @private
* @type {?ImportanceSampledEnvironment}
*/
this._importanceEnvironment = null;
/**
* Intensity multiplier applied to environment-map reflections on screen-space
* misses and at screen edges. Defaults to π to match the former hardcoded multiplier.
*
* @type {UniformNode<float>}
* @default Math.PI
*/
this.environmentIntensity = uniform( Math.PI );
/**
* The render target the SSR is rendered into.
*
* @private
* @type {RenderTarget}
*/
this._ssrRenderTarget = new RenderTarget( 1, 1, { depthBuffer: false, type: HalfFloatType } );
this._ssrRenderTarget.texture.name = 'SSRNode.SSR';
/**
* The render target for the blurred SSR reflections.
*
* @private
* @type {RenderTarget}
*/
this._blurRenderTarget = new RenderTarget( 1, 1, { depthBuffer: false, type: HalfFloatType, minFilter: LinearMipmapLinearFilter, magFilter: LinearFilter } );
this._blurRenderTarget.texture.name = 'SSRNode.Blur';
this._blurRenderTarget.texture.mipmaps.push( {}, {}, {}, {}, {} );
/**
* The material that is used to render the effect.
*
* @private
* @type {NodeMaterial}
*/
this._ssrMaterial = new NodeMaterial();
this._ssrMaterial.name = 'SSRNode.SSR';
/**
* The SSR fragment `Fn` and its shared context, captured in {@link SSRNode#setup}.
* Re-invoking the `Fn` produces a fresh node graph, which is how the baked
* compile-time constants are re-applied when they change (see {@link SSRNode#_buildSSRMaterial}).
*
* @private
*/
this._ssrFn = null;
this._sharedContext = null;
/**
* The blur material.
*
* @private
* @type {NodeMaterial}
*/
this._blurMaterial = new NodeMaterial();
this._blurMaterial.name = 'SSRNode.Blur';
/**
* The copy material.
*
* @private
* @type {NodeMaterial}
*/
this._copyMaterial = new NodeMaterial();
this._copyMaterial.name = 'SSRNode.Copy';
/**
* The result of the effect is represented as a separate texture node.
*
* @private
* @type {PassTextureNode}
*/
this._textureNode = passTexture( this, this._ssrRenderTarget.texture );
let blurredTextureNode = null;
if ( this.stochastic === false && this.roughnessNode !== null ) {
const mips = this._blurRenderTarget.texture.mipmaps.length - 1;
const r = this.roughnessNode;
const lod = r.mul( r ).mul( mips ).clamp( 0, mips );
blurredTextureNode = passTexture( this, this._blurRenderTarget.texture ).level( lod );
}
/**
* Holds the blurred SSR reflections.
*
* @private
* @type {?PassTextureNode}
*/
this._blurredTextureNode = blurredTextureNode;
if ( environmentNode !== null && environmentNode.isTexture === true ) {
this.setEnvMap( environmentNode );
}
}
/**
* Non-linear step distribution exponent (compile-time constant). See the backing
* field for details. Assigning a new value recompiles the SSR material.
*
* @type {number}
*/
get stepExponent() {
return this._stepExponent;
}
set stepExponent( value ) {
if ( value !== this._stepExponent ) {
this._stepExponent = value;
this._buildSSRMaterial();
}
}
/**
* Blur kernel size (compile-time constant). Assigning a new value recompiles the
* blur material.
*
* @type {number}
*/
get blurQuality() {
return this._blurQuality;
}
set blurQuality( value ) {
if ( value !== this._blurQuality ) {
this._blurQuality = value;
// The size is baked into the boxBlur node tree, so rebuild it (recompiles the material).
if ( this.stochastic === false ) this._buildBlurMaterial();
}
}
/**
* Builds (or rebuilds) the blur material's node graph, baking the current
* {@link SSRNode#blurQuality} as the kernel size so the sample loop unrolls.
*
* @private
*/
_buildBlurMaterial() {
this._blurMaterial.fragmentNode = boxBlur( texture( this._ssrRenderTarget.texture ), { size: this._blurQuality, separation: this._blurSpread } );
this._blurMaterial.needsUpdate = true;
}
/**
* Whether SSR fades to black near screen borders (compile-time constant). Assigning
* a new value recompiles the SSR material.
*
* @type {boolean}
*/
get screenEdgeFadeBlack() {
return this._screenEdgeFadeBlack;
}
set screenEdgeFadeBlack( value ) {
if ( value !== this._screenEdgeFadeBlack ) {
this._screenEdgeFadeBlack = value;
this._buildSSRMaterial();
}
}
/**
* Whether sub-step binary-search hit refinement is enabled (compile-time constant).
* Assigning a new value rebuilds the SSR material.
*
* @type {boolean}
*/
get binaryRefine() {
return this._binaryRefine;
}
set binaryRefine( value ) {
if ( value !== this._binaryRefine ) {
this._binaryRefine = value;
this._buildSSRMaterial();
}
}
/**
* Whether dielectrics are reflected in the non-stochastic path (compile-time constant).
* Assigning a new value rebuilds the SSR material.
*
* @type {boolean}
*/
get reflectNonMetals() {
return this._reflectNonMetals;
}
set reflectNonMetals( value ) {
if ( value !== this._reflectNonMetals ) {
this._reflectNonMetals = value;
this._buildSSRMaterial();
}
}
/**
* Rebuilds the SSR material's node graph by re-invoking the fragment `Fn`, which
* re-bakes the compile-time constants ({@link SSRNode#binaryRefine},
* {@link SSRNode#stepExponent}, {@link SSRNode#screenEdgeFadeBlack}) at their current
* values. A no-op until {@link SSRNode#setup} has captured the `Fn`.
*
* @private
*/
_buildSSRMaterial() {
if ( this._ssrFn === null ) return;
this._ssrMaterial.contextNode = context( this._sharedContext );
this._ssrMaterial.fragmentNode = this._ssrFn();
this._ssrMaterial.needsUpdate = true;
}
/**
* Returns the result of the effect as a texture node.
*
* @return {PassTextureNode} A texture node that represents the result of the effect.
*/
getTextureNode() {
return ( this.stochastic === false && this.roughnessNode !== null ) ? this._blurredTextureNode : this._textureNode;
}
/**
* Sets the size of the effect.
*
* @param {number} width - The width of the effect.
* @param {number} height - The height of the effect.
*/
setSize( width, height ) {
width = Math.round( this.resolutionScale * width );
height = Math.round( this.resolutionScale * height );
this._resolution.value.set( width, height );
this._ssrRenderTarget.setSize( width, height );
this._blurRenderTarget.setSize( width, height );
}
/**
* Wires the feedback inputs for multi-bounce reflections: the previous frame's
* denoised result (`history`) and the velocity buffer used to reproject it
* (`velocity`). `history` accepts the producing node (e.g. a
* {@link RecurrentDenoiseNode}) — its output render target is used — or a raw
* texture. Pass `null` for both to disable multi-bounce.
*
* @param {Texture} history
* @param {Node<vec2>} velocity
*/
setHistory( history, velocity ) {
this.historyTexture = ( history && typeof history.getRenderTarget === 'function' )
? history.getRenderTarget().texture
: history;
this.velocityTexture = velocity;
}
/**
* Sets the environment map for importance-sampled env lighting when
* screen-space rays miss. Call this whenever the scene's env map changes.
*
* Uses {@link ImportanceSampledEnvironment} (CDF + MIS adapted from
* [three-gpu-pathtracer](https://github.com/gkjohnson/three-gpu-pathtracer)).
*
* @param {Texture|null} hdr - The equirectangular HDR environment map, or null to disable.
* @see {@link https://github.com/gkjohnson/three-gpu-pathtracer}
*/
setEnvMap( hdr ) {
if ( hdr === null ) {
if ( this._importanceEnvironment !== null ) {
this._importanceEnvironment.clear();
this._importanceEnvironment = null;
}
this._buildSSRMaterial();
return;
}
if ( hdr.image === undefined || hdr.image.data === undefined ) {
console.warn( 'SSRNode: `environmentNode` / `setEnvMap()` expects an equirectangular HDR texture with CPU-side image data (e.g. RGBELoader). PMREM cubemaps and `scene.environment` are not supported.' );
return;
}
if ( this._importanceEnvironment === null ) {
this._importanceEnvironment = new ImportanceSampledEnvironment( this.envImportanceSampling );
}
this._importanceEnvironment.updateFrom( hdr );
this._buildSSRMaterial();
}
/**
* Intensity multiplier for the importance-sampled env contribution.
* Only available after {@link setEnvMap} has been called.
*
* @type {?UniformNode<float>}
*/
get envMapIntensity() {
return this._importanceEnvironment !== null ? this._importanceEnvironment.intensity : null;
}
/**
* This method is used to render the effect once per frame.
*
* @param {NodeFrame} frame - The current node frame.
*/
updateBefore( frame ) {
const { renderer } = frame;
this._cameraWorldMatrix.value.copy( this.camera.matrixWorld );
this._cameraWorldPosition.value.copy( this.camera.position );
_rendererState = RendererUtils.resetRendererState( renderer, _rendererState );
const ssrRenderTarget = this._ssrRenderTarget;
const blurRenderTarget = this._blurRenderTarget;
const size = renderer.getDrawingBufferSize( _size );
_quadMesh.material = this._ssrMaterial;
this.setSize( size.width, size.height );
// Advance the noise index once per frame (matches SSGI / Denoise).
this._noiseIndex.value = ( this._noiseIndex.value + 1 ) % 0x7fffffff;
// clear
renderer.setMRT( null );
renderer.setClearColor( 0x000000, 0 );
// ssr
renderer.setRenderTarget( ssrRenderTarget );
_quadMesh.name = 'SSR [ Reflections ]';
_quadMesh.render( renderer );
// blur (optional)
if ( this.stochastic === false && this.roughnessNode !== null ) {
// blur mips but leave the base mip unblurred
for ( let i = 0; i < blurRenderTarget.texture.mipmaps.length; i ++ ) {
_quadMesh.material = ( i === 0 ) ? this._copyMaterial : this._blurMaterial;
this._blurSpread.value = i;
renderer.setRenderTarget( blurRenderTarget, 0, i );
_quadMesh.name = 'SSR [ Blur Level ' + i + ' ]';
_quadMesh.render( renderer );
}
}
// restore
RendererUtils.restoreRendererState( renderer, _rendererState );
}
/**
* This method is used to setup the effect's TSL code.
*
* @param {NodeBuilder} builder - The current node builder.
* @return {PassTextureNode}
*/
setup( builder ) {
const uvNode = uv();
const pointToLineDistance = Fn( ( [ point, linePointA, linePointB ] ) => {
// https://mathworld.wolfram.com/Point-LineDistance3-Dimensional.html
return cross( point.sub( linePointA ), point.sub( linePointB ) ).length().div( linePointB.sub( linePointA ).length() );
} );
const pointPlaneDistance = Fn( ( [ point, planePoint, planeNormal ] ) => {
// https://mathworld.wolfram.com/Point-PlaneDistance.html
// https://en.wikipedia.org/wiki/Plane_(geometry)
// http://paulbourke.net/geometry/pointlineplane/
// planeNormal is already normalized, so the denominator is 1.
const d = mul( planeNormal.x, planePoint.x ).add( mul( planeNormal.y, planePoint.y ) ).add( mul( planeNormal.z, planePoint.z ) ).negate().toVar();
const distance = mul( planeNormal.x, point.x ).add( mul( planeNormal.y, point.y ) ).add( mul( planeNormal.z, point.z ) ).add( d );
return distance;
} );
const getViewZ = Fn( ( [ depth ] ) => {
let viewZNode;
if ( this.camera.isPerspectiveCamera ) {
viewZNode = perspectiveDepthToViewZ( depth, this._cameraNear, this._cameraFar );
} else {
viewZNode = orthographicDepthToViewZ( depth, this._cameraNear, this._cameraFar );
}
return viewZNode;
} );
const sampleDepth = ( uv ) => {
const depth = this.depthNode.sample( uv ).r;
if ( builder.renderer.logarithmicDepthBuffer === true ) {
const viewZ = logarithmicDepthToViewZ( depth, this._cameraNear, this._cameraFar );
return viewZToPerspectiveDepth( viewZ, this._cameraNear, this._cameraFar );
}
return depth;
};
const sampleMarchNoise = this.stochastic === true ? bindAnalyticNoise( this._resolution, 47 ) : null;
const computeScreenBorderFactor = Fn( ( [ uvCoord, borderWidth ] ) => {
const border = borderWidth.max( 1e-4 );
// Distance to the nearest screen edge — uniform falloff at corners.
const edgeDist = min(
min( uvCoord.x, float( 1 ).sub( uvCoord.x ) ),
min( uvCoord.y, float( 1 ).sub( uvCoord.y ) )
);
// Two smoothsteps for a softer ease-in-out than a single ramp.
const t = edgeDist.smoothstep( 0, border );
return t.smoothstep( 0, 1 ).pow( 0.125 );
} ).setLayout( {
name: 'computeScreenBorderFactor',
type: 'float',
inputs: [
{ name: 'uvCoord', type: 'vec2' },
{ name: 'borderWidth', type: 'float' }
]
} );
const ssr = Fn( () => {
const noise = this.stochastic === true ? sampleMarchNoise( uvNode, this._noiseIndex ) : null;
const uvPos = uvNode.toVar();
const depth = sampleDepth( uvPos ).toVar();
// Skip background pixels (cleared far-plane depth); the target is cleared each frame.
depth.greaterThanEqual( 1.0 ).discard();
const viewPosition = getViewPosition( uvPos, depth, this._cameraProjectionMatrixInverse ).toVar();
const worldPosition = this._cameraWorldMatrix.mul( vec4( viewPosition, 1.0 ) ).xyz.toVar();
const viewNormal = this.normalNode.rgb.normalize().toVar();
const viewIncidentDir = ( ( this.camera.isPerspectiveCamera ) ? normalize( viewPosition ) : vec3( 0, 0, - 1 ) ).toVar();
// The node system samples the metalness/roughness textures at the current uv,
// so no explicit sample() is needed here.
const metalness = float( this.metalnessNode );
if ( this.stochastic === false && this._reflectNonMetals === false ) {
metalness.lessThanEqual( 0.0 ).discard();
}
const roughness = float( this.roughnessNode );
const glossiness = min( roughness.div( 0.25 ), 1 ).oneMinus();
// Only the fade-to-black miss path reads this, and that path is baked out otherwise.
const surfaceBorderFactor = this.screenEdgeFadeBlack ? computeScreenBorderFactor( uvPos, this.screenEdgeFade ) : null;
const hitBorderWidth = this.screenEdgeFade.mul( glossiness );
const V = viewIncidentDir.negate().normalize().toVar();
let viewReflectDir, finalSampleWeight, specDominantFactor;
const albedo = vec3( 1 ).toVar();
let sampleEnvReflection = null;
if ( this.stochastic === false ) {
viewReflectDir = reflect( viewIncidentDir, viewNormal ).normalize().toVar();
finalSampleWeight = vec3( metalness );
specDominantFactor = float( 1 );
} else {
const Xi = noise.toVar();
// Mirror-bias: pull `Xi.y` toward the cap top to tighten the GGX lobe and cut mid-roughness
// noise. Unbiased — bounded VNDF keeps brdf·cos/pdf ~constant (EA, "Stochastic SSR").
Xi.y.assign( mix( Xi.y, 0.0, this.mirrorBias.mul( Xi.w.sqrt() ) ) );
albedo.assign( ( this.diffuseNode !== null ? this.diffuseNode.sample( uvPos ).rgb : vec3( 1 ) ) );
const ggxSample = ggxReflectionSample( viewNormal, V, roughness, metalness, albedo, Xi ).toVar();
// Sometimes the GGX sample is facing away from the surface, so we need to re-sample.
If( ggxSample.get( 'reflectDir' ).dot( viewNormal ).lessThan( 0 ), () => {
ggxSample.assign( ggxReflectionSample( viewNormal, V, roughness, metalness, albedo, Xi.add( Xi.mul( 7 ) ).fract() ) );
} );
viewReflectDir = ggxSample.get( 'reflectDir' ).toVar();
finalSampleWeight = ggxSample.get( 'sampleWeight' ).toVar();
specDominantFactor = getSpecularDominantFactor( ggxSample.get( 'NdotV' ), roughness ).toVar();
sampleEnvReflection = () => {
if ( this._importanceEnvironment === null ) return vec3( 0 );
const envColor = vec3( 0 ).toVar();
if ( this.envImportanceSampling ) {
const Xi2 = bindAnalyticNoise( this._resolution, 59 )( uvPos, this._noiseIndex );
envColor.assign( this._importanceEnvironment.sampleEnvironmentMIS( {
cameraWorldMatrix: this._cameraWorldMatrix,
viewReflectDir,
N: viewNormal,
V,
alpha: ggxSample.get( 'alpha' ),
f0: ggxSample.get( 'f0' ),
Xi2
} ) );
} else {
envColor.assign( this._importanceEnvironment.sampleEnvironmentBRDF( {
cameraWorldMatrix: this._cameraWorldMatrix,
viewReflectDir,
N: viewNormal,
V,
alpha: ggxSample.get( 'alpha' ),
f0: ggxSample.get( 'f0' )
} ) );
}
return envColor;
};
}
// Multi-bounce: fold in the previous frame's reflection at the hit point, reprojected by its
// own motion. The (1 - history.a) decay damps the feedback. No-op until both textures are set.
const reprojectHitPointHistory = ( uvHit, color ) => {
if ( ! ( this.historyTexture && this.velocityTexture ) ) return color;
const velocity = this.velocityTexture.sample( uvHit ).xy;
const historyUV = uvHit.sub( velocity );
const historyBounce = texture( this.historyTexture, historyUV ).toVar();
const sampleDecay = historyBounce.a.oneMinus();
return color.add( historyBounce.rgb.mul( sampleDecay ) );
};
// Fades a screen-space hit near the screen borders, using the hit sample UV (where the
// screen-space data was read). `screenEdgeFadeBlack` is baked, so the two modes branch in
// JS: fade the reflection to black, or blend it toward the environment reflection.
const applyHitEdgeFade = ( reflectColor, uvS, hitBorderWidth ) => {
if ( this.screenEdgeFadeBlack ) {
const hitBorderFactor = computeScreenBorderFactor( uvS, this.screenEdgeFade );
reflectColor.rgb.mulAssign( hitBorderFactor );
} else {
const hitBorderFactor = computeScreenBorderFactor( uvS, hitBorderWidth );
If( hitBorderFactor.lessThan( 1 ), () => {
reflectColor.rgb.assign( mix( sampleEnvReflection().mul( this.environmentIntensity ), reflectColor.rgb, hitBorderFactor ) );
} );
}
};
const maxReflectRayLen = this.maxDistance.div( dot( viewIncidentDir.negate(), viewNormal ) ).toVar();
const d1viewPosition = viewPosition.add( viewReflectDir.mul( maxReflectRayLen ) ).toVar();
// Camera type is fixed at build time, so guard the near-plane clamp with a JS branch
// rather than a runtime uniform (the orthographic case compiles it out entirely).
if ( this.camera.isPerspectiveCamera ) {
If( d1viewPosition.z.greaterThan( this._cameraNear.negate() ), () => {
const t = sub( this._cameraNear.negate(), viewPosition.z ).div( viewReflectDir.z );
d1viewPosition.assign( viewPosition.add( viewReflectDir.mul( t ) ) );
} );
}
const d0 = uvPos.mul( this._resolution ).xy.toVar();
const d1 = getScreenPosition( d1viewPosition, this._cameraProjectionMatrix ).mul( this._resolution ).toVar();
const xLen = d1.x.sub( d0.x ).toVar();
const yLen = d1.y.sub( d0.y ).toVar();
// dominant-axis ray length in texels (used for the per-step floor below)
const rayLen = max( xLen.abs(), yLen.abs() ).max( 1 ).toVar();
// Blur traces a single mirror ray, so spend steps in proportion to the ray's screen-space
// length (cheap for the short rays that dominate). Scatter needs a fixed, bounded count for
// coherent stochastic sampling; each step then spans the whole ray as rayVec / totalStep.
const totalStep = int( this.stochastic === false
? trunc( max( abs( xLen ), abs( yLen ) ).mul( this.quality.clamp() ) ).max( int( 1 ) ).toConst()
: this.quality.clamp().mul( MAX_STEPS ).max( float( 1 ) ) ).toConst();
const xSpan = xLen.div( totalStep ).toVar();
const ySpan = yLen.div( totalStep ).toVar();
const stepVec = vec2( xSpan, ySpan ).toVar();
const invResolution = vec2( float( 1 ), float( 1 ) ).div( this._resolution ).toVar();
const uvPixelStepX = vec2( invResolution.x, float( 0 ) ).toVar();
const output = vec4( 0 ).toVar();
const hit = float( 0 ).toVar();
// Reflected-ray view-space Z at ray parameter s ∈ [0,1] (linear in 1/z for perspective),
// hoisted so the march and refinement evaluate it identically.
const recipVPZ = float( 1 ).div( viewPosition.z ).toConst();
const recipD1VPZ = float( 1 ).div( d1viewPosition.z ).toConst();
// Camera type is known at build time, so branch at compile time rather than via a runtime select.
const reflectRayZAt = this.camera.isPerspectiveCamera
? ( sVal ) => float( 1 ).div( recipVPZ.add( sVal.mul( recipD1VPZ.sub( recipVPZ ) ) ) )
: ( sVal ) => viewPosition.z.add( sVal.mul( d1viewPosition.z.sub( viewPosition.z ) ) );
// Screen-space position along the ray for a given s ∈ [0,1].
const screenPosAt = ( sVal ) => d0.add( stepVec.mul( sVal.mul( totalStep ) ) );
// Ray parameter s ∈ [0,1] for step `idx`. Blur marches uniformly (matching the original loop:
// one ~texel step per iteration). Scatter uses an exponential remap `(idx/steps)^stepExponent`
// that concentrates samples near the origin, floored to ≥1 texel/step; `jitter` dissolves banding.
const sampleFraction = this.stochastic === false
? ( idx ) => idx.div( totalStep )
: ( idx ) => max(
idx.add( noise.z.sub( 0.5 ) ).div( totalStep ).pow( this.stepExponent ),
idx.div( rayLen )
);
// Carry the hit out of the loop so refinement runs after the march, not nested inside it (a
// loop-inside-a-loop tripped shader-compiler bugs on some drivers). hitSLo/hitSHi bracket s.
const foundHit = bool( false ).toVar();
const hitSLo = float( 0 ).toVar();
const hitSHi = float( 0 ).toVar();
// Carry the coarse hit's UV/depth to skip a redundant fetch when refinement is off.
const hitUvS = vec2( 0 ).toVar();
const hitD = float( 0 ).toVar();
// March from d0 toward d1, looking for an intersection with the depth buffer.
Loop( { start: int( 1 ), end: totalStep }, ( { i } ) => {
// Exponentially-distributed ray parameter, shared by the sample position and ray depth.
const s = sampleFraction( float( i ) ).toVar();
const xy = screenPosAt( s ).toVar();
If( xy.x.lessThan( 0 ).or( xy.x.greaterThan( this._resolution.x ) ).or( xy.y.lessThan( 0 ) ).or( xy.y.greaterThan( this._resolution.y ) ), () => {
Break();
} );
const uvS = xy.mul( invResolution ).toVar();
const d = sampleDepth( uvS ).toVar();
const vZ = getViewZ( d ).toVar();
const viewReflectRayZ = reflectRayZAt( s ).toVar();
If( viewReflectRayZ.lessThanEqual( vZ ), () => {
// Depth crossing: ray went behind the depth buffer. Gate by thickness before stopping
// so an occluder gap doesn't end the march prematurely.
const vP = getViewPosition( uvS, d, this._cameraProjectionMatrixInverse ).toVar();
const away = pointToLineDistance( vP, viewPosition, d1viewPosition ).toVar();
const uvNeighbor = uvS.add( uvPixelStepX ).toVar();
const vPNeighbor = getViewPosition( uvNeighbor, d, this._cameraProjectionMatrixInverse ).toVar();
const minThickness = vPNeighbor.x.sub( vP.x ).mul( 3 ).toVar();
const tk = max( minThickness, this.thickness ).toVar();
If( away.lessThanEqual( tk ), () => {
const vN = this.normalNode.sample( uvS ).rgb.normalize().toVar();
// the reflected ray is pointing towards the same side as the fragment's normal (current ray position),
// which means it wouldn't reflect off the surface. The loop continues to the next step for the next ray sample.
if ( this.stochastic === false ) {
If( dot( viewReflectDir, vN ).greaterThanEqual( 0 ), () => {
Continue();
} );
// this distance represents the depth of the intersection point between the reflected ray and the scene.
const distance = pointPlaneDistance( vP, viewPosition, viewNormal ).toVar();
// Distance exceeding limit: The reflection is potentially too far away and
// might not contribute significantly to the final color
If( distance.greaterThan( this.maxDistance ), () => {
Break();
} );
}
foundHit.assign( true );
hitUvS.assign( uvS );
hitD.assign( d );
if ( this.binaryRefine ) {
hitSLo.assign( sampleFraction( float( i ).sub( 1 ) ) );
hitSHi.assign( s );
}
Break();
} );
} );
} );
If( foundHit, () => {
// Bisect the bracketed crossing toward the exact intersection. Run after the march, not
// nested (a loop-inside-a-loop tripped shader-compiler bugs on some drivers).
if ( this.binaryRefine ) {
Loop( { start: int( 0 ), end: int( 8 ), type: 'int', condition: '<' }, () => {
const sMid = hitSLo.add( hitSHi ).mul( 0.5 ).toVar();
const sceneZMid = getViewZ( sampleDepth( screenPosAt( sMid ).mul( invResolution ) ) );
If( reflectRayZAt( sMid ).lessThanEqual( sceneZMid ), () => {
hitSHi.assign( sMid );
} ).Else( () => {
hitSLo.assign( sMid );
} );
} );
// Refinement moved the crossing, so re-fetch UV/depth at the refined `s`.
hitUvS.assign( screenPosAt( hitSHi ).mul( invResolution ) );
hitD.assign( sampleDepth( hitUvS ) );
}
// Shade the hit, reusing the depth fetched during the march (or refinement).
const uvS = hitUvS;
const vP = getViewPosition( uvS, hitD, this._cameraProjectionMatrixInverse ).toVar();
// In blur mode the ratio² falloff re-grows past maxDistance, so over-range hits fall back
// to env. The scatter path bounds reach via ray length, so every hit shades.
const distancePointPlane = this.stochastic === false ? pointPlaneDistance( vP, viewPosition, viewNormal ).toVar() : float( 0 );
const withinRange = distancePointPlane.lessThanEqual( this.maxDistance );
If( withinRange, () => {
const hitWorldPosition = this._cameraWorldMatrix.mul( vec4( vP, 1.0 ) ).xyz.toVar();
const worldDistance = distance( worldPosition, hitWorldPosition ).mul( specDominantFactor ).toVar();
const reflectColor = this.colorNode.sample( uvS ).toVar();
// Multi-bounce: add the reprojected previous-frame reflection at the hit point.
reflectColor.rgb.assign( reprojectHitPointHistory( uvS, reflectColor.rgb ) );
if ( this.stochastic === true ) applyHitEdgeFade( reflectColor, uvS, hitBorderWidth );
// The scatter (GGX) path bakes distance/grazing response into finalSampleWeight.
// The mirror/blur path is a plain reflection, so reapply upstream's squared
// distance attenuation and grazing Fresnel here to match its falloff.
let weightedColor = reflectColor.rgb.mul( finalSampleWeight );
if ( this.stochastic === false ) {
const ratio = float( 1 ).sub( distancePointPlane.div( this.maxDistance ) ).toVar();
const attenuation = ratio.mul( ratio ).toVar();
const fresnelCoe = div( dot( viewIncidentDir, viewReflectDir ).add( 1 ), 2 ).toVar();
weightedColor = weightedColor.mul( attenuation.mul( fresnelCoe ) );
}
hit.assign( 1 );
output.assign( vec4( weightedColor, worldDistance ) );
} );
} );
// Screen-space ray missed: environment fallback (MIS when CDF env is set up).
If( hit.equal( 0 ), () => {
if ( this.stochastic === true ) {
output.assign( vec4( sampleEnvReflection().mul( this.environmentIntensity ), float( ENV_RAY_LENGTH ) ) );
// Misses fade by the surface pixel UV (where the reflection is being shaded).
if ( this.screenEdgeFadeBlack ) {
output.rgb.mulAssign( surfaceBorderFactor );
}
}
} );
const lum = luminance( output.rgb ).max( 1e-4 ).toVar();
output.rgb.mulAssign( this.maxLuminance.div( lum ).min( 1 ) );
// scale the reflection color by the user-controlled intensity
output.rgb.mulAssign( this.intensity );
return output.max( 0 );
} );
this._ssrFn = ssr;
this._sharedContext = builder.getSharedContext();
this._buildSSRMaterial();
const reflectionBuffer = texture( this._ssrRenderTarget.texture );
if ( this.stochastic === false ) {
this._buildBlurMaterial();
}
this._copyMaterial.fragmentNode = reflectionBuffer;
this._copyMaterial.needsUpdate = true;
//
return this.getTextureNode();
}
getRenderTarget() {
return this._ssrRenderTarget;
}
/**
* Frees internal resources. This method should be called
* when the effect is no longer required.
*/
dispose() {
super.dispose();
this._ssrRenderTarget.dispose();
this._blurRenderTarget.dispose();
this._ssrMaterial.dispose();
this._blurMaterial.dispose();
this._copyMaterial.dispose();
if ( this._importanceEnvironment !== null ) {
this._importanceEnvironment.dispose();
this._importanceEnvironment = null;
}
}
}
export default SSRNode;
/**
* TSL function for creating screen space reflections (SSR).
*
* @tsl
* @function
* @param {Node<vec4>} colorNode - The node that represents the beauty pass.
* @param {Node<float>} depthNode - A node that represents the beauty pass's depth.
* @param {Node<vec3>} normalNode - A node that represents the beauty pass's normals.
* @param {SSRNodeOptions} [options] - Optional inputs for material and environment data.
* @returns {SSRNode}
*/
export const ssr = ( colorNode, depthNode, normalNode, options = {} ) => nodeObject( new SSRNode(
nodeObject( colorNode ),
nodeObject( depthNode ),
nodeObject( normalNode ),
options
) );