three
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JavaScript 3D library
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JavaScript
import { RenderTarget, Vector2, TempNode, QuadMesh, NodeMaterial, RendererUtils, MathUtils } from 'three/webgpu';
import { clamp, normalize, reference, nodeObject, Fn, NodeUpdateType, uniform, vec4, passTexture, uv, logarithmicDepthToViewZ, viewZToPerspectiveDepth, getViewPosition, screenCoordinate, float, sub, fract, dot, vec2, rand, vec3, Loop, mul, PI, cos, sin, uint, cross, acos, sign, pow, luminance, If, max, abs, Break, sqrt, HALF_PI, div, ceil, shiftRight, convertToTexture, bool, getNormalFromDepth, countOneBits, interleavedGradientNoise } from 'three/tsl';
const _quadMesh = /*@__PURE__*/ new QuadMesh();
const _size = /*@__PURE__*/ new Vector2();
// From Activision GTAO paper: https://www.activision.com/cdn/research/s2016_pbs_activision_occlusion.pptx
const _temporalRotations = [ 60, 300, 180, 240, 120, 0 ];
const _spatialOffsets = [ 0, 0.5, 0.25, 0.75 ];
let _rendererState;
/**
* Post processing node for applying Screen Space Global Illumination (SSGI) to a scene.
*
* References:
* - {@link https://github.com/cdrinmatane/SSRT3}.
* - {@link https://cdrinmatane.github.io/posts/ssaovb-code/}.
* - {@link https://cdrinmatane.github.io/cgspotlight-slides/ssilvb_slides.pdf}.
*
* The quality and performance of the effect mainly depend on `sliceCount` and `stepCount`.
* The total number of samples taken per pixel is `sliceCount` * `stepCount` * `2`. Here are some
* recommended presets depending on whether temporal filtering is used or not.
*
* With temporal filtering (recommended):
*
* - Low: `sliceCount` of `1`, `stepCount` of `12`.
* - Medium: `sliceCount` of `2`, `stepCount` of `8`.
* - High: `sliceCount` of `3`, `stepCount` of `16`.
*
* Use for a higher slice count if you notice temporal instabilities like flickering. Reduce the sample
* count then to mitigate the performance lost.
*
* Without temporal filtering:
*
* - Low: `sliceCount` of `2`, `stepCount` of `6`.
* - Medium: `sliceCount` of `3`, `stepCount` of `8`.
* - High: `sliceCount` of `4`, `stepCount` of `12`.
*
* @augments TempNode
* @three_import import { ssgi } from 'three/addons/tsl/display/SSGINode.js';
*/
class SSGINode extends TempNode {
static get type() {
return 'SSGINode';
}
/**
* Constructs a new SSGI node.
*
* @param {TextureNode} beautyNode - A texture node that represents the beauty or scene pass.
* @param {TextureNode} depthNode - A texture node that represents the scene's depth.
* @param {TextureNode} normalNode - A texture node that represents the scene's normals.
* @param {PerspectiveCamera} camera - The camera the scene is rendered with.
*/
constructor( beautyNode, depthNode, normalNode, camera ) {
super( 'vec4' );
/**
* A texture node that represents the beauty or scene pass.
*
* @type {TextureNode}
*/
this.beautyNode = beautyNode;
/**
* A node that represents the scene's depth.
*
* @type {TextureNode}
*/
this.depthNode = depthNode;
/**
* A node that represents the scene's normals. If no normals are passed to the
* constructor (because MRT is not available), normals can be automatically
* reconstructed from depth values in the shader.
*
* @type {TextureNode}
*/
this.normalNode = normalNode;
/**
* 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;
/**
* Number of per-pixel hemisphere slices. This has a big performance cost and should be kept as low as possible.
* Should be in the range `[1, 4]`.
*
* @type {UniformNode<uint>}
* @default 1
*/
this.sliceCount = uniform( 1, 'uint' );
/**
* Number of samples taken along one side of a given hemisphere slice. This has a big performance cost and should
* be kept as low as possible. Should be in the range `[1, 32]`.
*
* @type {UniformNode<uint>}
* @default 12
*/
this.stepCount = uniform( 12, 'uint' );
/**
* Power function applied to AO to make it appear darker/lighter. Should be in the range `[0, 4]`.
*
* @type {UniformNode<float>}
* @default 1
*/
this.aoIntensity = uniform( 1, 'float' );
/**
* Intensity of the indirect diffuse light. Should be in the range `[0, 100]`.
*
* @type {UniformNode<float>}
* @default 10
*/
this.giIntensity = uniform( 10, 'float' );
/**
* Effective sampling radius in world space. AO and GI can only have influence within that radius.
* Should be in the range `[1, 25]`.
*
* @type {UniformNode<float>}
* @default 12
*/
this.radius = uniform( 12, 'float' );
/**
* Makes the sample distance in screen space instead of world-space (helps having more detail up close).
*
* @type {UniformNode<bool>}
* @default false
*/
this.useScreenSpaceSampling = uniform( true, 'bool' );
/**
* Controls samples distribution. It's an exponent applied at each step get increasing step size over the distance.
* Should be in the range `[1, 3]`.
*
* @type {UniformNode<float>}
* @default 2
*/
this.expFactor = uniform( 2, 'float' );
/**
* Constant thickness value of objects on the screen in world units. Allows light to pass behind surfaces past that thickness value.
* Should be in the range `[0.01, 10]`.
*
* @type {UniformNode<float>}
* @default 1
*/
this.thickness = uniform( 1, 'float' );
/**
* Whether to increase thickness linearly over distance or not (avoid losing detail over the distance).
*
* @type {UniformNode<bool>}
* @default false
*/
this.useLinearThickness = uniform( false, 'bool' );
/**
* How much light backface surfaces emit.
* Should be in the range `[0, 1]`.
*
* @type {UniformNode<float>}
* @default 0
*/
this.backfaceLighting = uniform( 0, 'float' );
/**
* Whether to use temporal filtering or not. Setting this property to
* `true` requires the usage of `TRAANode`. This will help to reduce noise
* although it introduces typical TAA artifacts like ghosting and temporal
* instabilities.
*
* If setting this property to `false`, a manual denoise via `DenoiseNode`
* is required.
*
* @type {boolean}
* @default true
*/
this.useTemporalFiltering = true;
// private uniforms
/**
* The resolution of the effect.
*
* @private
* @type {UniformNode<vec2>}
*/
this._resolution = uniform( new Vector2() );
/**
* Used to compute the effective step radius when viewSpaceSampling is `false`.
*
* @private
* @type {UniformNode<vec2>}
*/
this._halfProjScale = uniform( 1 );
/**
* Temporal direction that influences the rotation angle for each slice.
*
* @private
* @type {UniformNode<float>}
*/
this._temporalDirection = uniform( 0 );
/**
* Temporal offset added to the initial ray step.
*
* @private
* @type {UniformNode<float>}
*/
this._temporalOffset = uniform( 0 );
/**
* 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 );
/**
* A reference to the scene's camera.
*
* @private
* @type {PerspectiveCamera}
*/
this._camera = camera;
/**
* The render target the GI is rendered into.
*
* @private
* @type {RenderTarget}
*/
this._ssgiRenderTarget = new RenderTarget( 1, 1, { depthBuffer: false } );
this._ssgiRenderTarget.texture.name = 'SSGI';
/**
* The material that is used to render the effect.
*
* @private
* @type {NodeMaterial}
*/
this._material = new NodeMaterial();
this._material.name = 'SSGI';
/**
* The result of the effect is represented as a separate texture node.
*
* @private
* @type {PassTextureNode}
*/
this._textureNode = passTexture( this, this._ssgiRenderTarget.texture );
}
/**
* 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._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 ) {
this._resolution.value.set( width, height );
this._ssgiRenderTarget.setSize( width, height );
this._halfProjScale.value = height / ( Math.tan( this._camera.fov * MathUtils.DEG2RAD * 0.5 ) * 2 ) * 0.5;
}
/**
* This method is used to render the effect once per frame.
*
* @param {NodeFrame} frame - The current node frame.
*/
updateBefore( frame ) {
const { renderer } = frame;
_rendererState = RendererUtils.resetRendererState( renderer, _rendererState );
//
const size = renderer.getDrawingBufferSize( _size );
this.setSize( size.width, size.height );
// update temporal uniforms
if ( this.useTemporalFiltering === true ) {
const frameId = frame.frameId;
this._temporalDirection.value = _temporalRotations[ frameId % 6 ] / 360;
this._temporalOffset.value = _spatialOffsets[ frameId % 4 ];
} else {
this._temporalDirection.value = 1;
this._temporalOffset.value = 1;
}
//
_quadMesh.material = this._material;
_quadMesh.name = 'SSGI';
// clear
renderer.setClearColor( 0x000000, 1 );
// gi
renderer.setRenderTarget( this._ssgiRenderTarget );
_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 MAX_RAY = uint( 32 );
const globalOccludedBitfield = uint( 0 );
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 sampleNormal = ( uv ) => ( this.normalNode !== null ) ? this.normalNode.sample( uv ).rgb.normalize() : getNormalFromDepth( uv, this.depthNode.value, this._cameraProjectionMatrixInverse );
const sampleBeauty = ( uv ) => this.beautyNode.sample( uv );
// From Activision GTAO paper: https://www.activision.com/cdn/research/s2016_pbs_activision_occlusion.pptx
const spatialOffsets = Fn( ( [ position ] ) => {
return float( 0.25 ).mul( sub( position.y, position.x ).bitAnd( 3 ) );
} ).setLayout( {
name: 'spatialOffsets',
type: 'float',
inputs: [
{ name: 'position', type: 'vec2' }
]
} );
const GTAOFastAcos = Fn( ( [ value ] ) => {
const outVal = abs( value ).mul( float( - 0.156583 ) ).add( HALF_PI );
outVal.mulAssign( sqrt( abs( value ).oneMinus() ) );
const x = value.x.greaterThanEqual( 0 ).select( outVal.x, PI.sub( outVal.x ) );
const y = value.y.greaterThanEqual( 0 ).select( outVal.y, PI.sub( outVal.y ) );
return vec2( x, y );
} ).setLayout( {
name: 'GTAOFastAcos',
type: 'vec2',
inputs: [
{ name: 'value', type: 'vec2' }
]
} );
const horizonSampling = Fn( ( [ directionIsRight, RADIUS, viewPosition, slideDirTexelSize, initialRayStep, uvNode, viewDir, viewNormal, n ] ) => {
const STEP_COUNT = this.stepCount.toConst();
const EXP_FACTOR = this.expFactor.toConst();
const THICKNESS = this.thickness.toConst();
const BACKFACE_LIGHTING = this.backfaceLighting.toConst();
const stepRadius = float( 0 );
If( this.useScreenSpaceSampling.equal( true ), () => {
stepRadius.assign( RADIUS.mul( this._resolution.x.div( 2 ) ).div( float( 16 ) ) ); // SSRT3 has a bug where stepRadius is divided by STEP_COUNT twice; fix here
} ).Else( () => {
stepRadius.assign( max( RADIUS.mul( this._halfProjScale ).div( viewPosition.z.negate() ), float( STEP_COUNT ) ) ); // Port note: viewZ is negative so a negate is required
} );
stepRadius.divAssign( float( STEP_COUNT ).add( 1 ) );
const radiusVS = max( 1, float( STEP_COUNT.sub( 1 ) ) ).mul( stepRadius );
const uvDirection = directionIsRight.equal( true ).select( vec2( 1, - 1 ), vec2( - 1, 1 ) ); // Port note: Because of different uv conventions, uv-y has a different sign
const samplingDirection = directionIsRight.equal( true ).select( 1, - 1 );
const color = vec3( 0 );
const lastSampleViewPosition = vec3( viewPosition ).toVar();
Loop( { start: uint( 0 ), end: STEP_COUNT, type: 'uint', condition: '<' }, ( { i } ) => {
const offset = pow( abs( mul( stepRadius, float( i ).add( initialRayStep ) ).div( radiusVS ) ), EXP_FACTOR ).mul( radiusVS ).toConst();
const uvOffset = slideDirTexelSize.mul( max( offset, float( i ).add( 1 ) ) ).toConst();
const sampleUV = uvNode.add( uvOffset.mul( uvDirection ) ).toConst();
If( sampleUV.x.lessThanEqual( 0 ).or( sampleUV.y.lessThanEqual( 0 ) ).or( sampleUV.x.greaterThanEqual( 1 ) ).or( sampleUV.y.greaterThanEqual( 1 ) ), () => {
Break();
} );
const sampleViewPosition = getViewPosition( sampleUV, sampleDepth( sampleUV ), this._cameraProjectionMatrixInverse ).toConst();
const pixelToSample = sampleViewPosition.sub( viewPosition ).normalize().toConst();
const linearThicknessMultiplier = this.useLinearThickness.equal( true ).select( sampleViewPosition.z.negate().div( this._cameraFar ).clamp().mul( 100 ), float( 1 ) );
const pixelToSampleBackface = normalize( sampleViewPosition.sub( linearThicknessMultiplier.mul( viewDir ).mul( THICKNESS ) ).sub( viewPosition ) );
let frontBackHorizon = vec2( dot( pixelToSample, viewDir ), dot( pixelToSampleBackface, viewDir ) );
frontBackHorizon = GTAOFastAcos( clamp( frontBackHorizon, - 1, 1 ) );
frontBackHorizon = clamp( div( mul( samplingDirection, frontBackHorizon.negate() ).sub( n.sub( HALF_PI ) ), PI ) ); // Port note: subtract half pi instead of adding it
frontBackHorizon = directionIsRight.equal( true ).select( frontBackHorizon.yx, frontBackHorizon.xy ); // Front/Back get inverted depending on angle
// inline ComputeOccludedBitfield() for easier debugging
const minHorizon = frontBackHorizon.x.toConst();
const maxHorizon = frontBackHorizon.y.toConst();
const startHorizonInt = uint( frontBackHorizon.mul( float( MAX_RAY ) ) ).toConst();
const angleHorizonInt = uint( ceil( maxHorizon.sub( minHorizon ).mul( float( MAX_RAY ) ) ) ).toConst();
const angleHorizonBitfield = angleHorizonInt.greaterThan( uint( 0 ) ).select( uint( shiftRight( uint( 0xFFFFFFFF ), uint( 32 ).sub( MAX_RAY ).add( MAX_RAY.sub( angleHorizonInt ) ) ) ), uint( 0 ) ).toConst();
let currentOccludedBitfield = angleHorizonBitfield.shiftLeft( startHorizonInt );
currentOccludedBitfield = currentOccludedBitfield.bitAnd( globalOccludedBitfield.bitNot() );
globalOccludedBitfield.assign( globalOccludedBitfield.bitOr( currentOccludedBitfield ) );
const numOccludedZones = countOneBits( currentOccludedBitfield );
//
If( numOccludedZones.greaterThan( 0 ), () => { // If a ray hit the sample, that sample is visible from shading point
const lightColor = sampleBeauty( sampleUV );
If( luminance( lightColor ).greaterThan( 0.001 ), () => { // Continue if there is light at that location (intensity > 0)
const lightDirectionVS = normalize( pixelToSample );
const normalDotLightDirection = clamp( dot( viewNormal, lightDirectionVS ) );
If( normalDotLightDirection.greaterThan( 0.001 ), () => { // Continue if light is facing surface normal
const lightNormalVS = sampleNormal( sampleUV );
// Intensity of outgoing light in the direction of the shading point
let lightNormalDotLightDirection = dot( lightNormalVS, lightDirectionVS.negate() );
const d = sign( lightNormalDotLightDirection ).lessThan( 0 ).select( abs( lightNormalDotLightDirection ).mul( BACKFACE_LIGHTING ), abs( lightNormalDotLightDirection ) );
lightNormalDotLightDirection = BACKFACE_LIGHTING.greaterThan( 0 ).and( dot( lightNormalVS, viewDir ).greaterThan( 0 ) ).select( d, clamp( lightNormalDotLightDirection ) );
color.rgb.addAssign( float( numOccludedZones ).div( float( MAX_RAY ) ).mul( lightColor ).mul( normalDotLightDirection ).mul( lightNormalDotLightDirection ) );
} );
} );
} );
lastSampleViewPosition.assign( sampleViewPosition );
} );
return vec3( color );
} );
const gi = Fn( () => {
const depth = sampleDepth( uvNode ).toVar();
depth.greaterThanEqual( 1.0 ).discard();
const viewPosition = getViewPosition( uvNode, depth, this._cameraProjectionMatrixInverse ).toVar();
const viewNormal = sampleNormal( uvNode ).toVar();
const viewDir = normalize( viewPosition.xyz.negate() ).toVar();
//
const noiseOffset = spatialOffsets( screenCoordinate );
const noiseDirection = interleavedGradientNoise( screenCoordinate );
const noiseJitterIdx = this._temporalDirection.mul( 0.02 ); // Port: Add noiseJitterIdx here for slightly better noise convergence with TRAA (see #31890 for more details)
const initialRayStep = fract( noiseOffset.add( this._temporalOffset ) ).add( rand( uvNode.add( noiseJitterIdx ).mul( 2 ).sub( 1 ) ) );
const ao = float( 0 );
const color = vec3( 0 );
const ROTATION_COUNT = this.sliceCount.toConst();
const AO_INTENSITY = this.aoIntensity.toConst();
const GI_INTENSITY = this.giIntensity.toConst();
const RADIUS = this.radius.toConst();
Loop( { start: uint( 0 ), end: ROTATION_COUNT, type: 'uint', condition: '<' }, ( { i } ) => {
const rotationAngle = mul( float( i ).add( noiseDirection ).add( this._temporalDirection ), PI.div( float( ROTATION_COUNT ) ) ).toConst();
const sliceDir = vec3( vec2( cos( rotationAngle ), sin( rotationAngle ) ), 0 ).toConst();
const slideDirTexelSize = sliceDir.xy.mul( float( 1 ).div( this._resolution ) ).toConst();
const planeNormal = normalize( cross( sliceDir, viewDir ) ).toConst();
const tangent = cross( viewDir, planeNormal ).toConst();
const projectedNormal = viewNormal.sub( planeNormal.mul( dot( viewNormal, planeNormal ) ) ).toConst();
const projectedNormalNormalized = normalize( projectedNormal ).toConst();
const cos_n = clamp( dot( projectedNormalNormalized, viewDir ), - 1, 1 ).toConst();
const n = sign( dot( projectedNormal, tangent ) ).negate().mul( acos( cos_n ) ).toConst();
globalOccludedBitfield.assign( 0 );
color.addAssign( horizonSampling( bool( true ), RADIUS, viewPosition, slideDirTexelSize, initialRayStep, uvNode, viewDir, viewNormal, n ) );
color.addAssign( horizonSampling( bool( false ), RADIUS, viewPosition, slideDirTexelSize, initialRayStep, uvNode, viewDir, viewNormal, n ) );
ao.addAssign( float( countOneBits( globalOccludedBitfield ) ).div( float( MAX_RAY ) ) );
} );
ao.divAssign( float( ROTATION_COUNT ) );
ao.assign( pow( ao.clamp().oneMinus(), AO_INTENSITY ).clamp() );
color.divAssign( float( ROTATION_COUNT ) );
color.mulAssign( GI_INTENSITY );
// scale color based on luminance
const maxLuminance = float( 7 ).toConst(); // 7 represent a HDR luminance value
const currentLuminance = luminance( color );
const scale = currentLuminance.greaterThan( maxLuminance ).select( maxLuminance.div( currentLuminance ), float( 1 ) );
color.mulAssign( scale );
return vec4( color, ao );
} );
this._material.fragmentNode = gi().context( builder.getSharedContext() );
this._material.needsUpdate = true;
//
return this._textureNode;
}
/**
* Frees internal resources. This method should be called
* when the effect is no longer required.
*/
dispose() {
this._ssgiRenderTarget.dispose();
this._material.dispose();
}
}
export default SSGINode;
/**
* TSL function for creating a SSGI effect.
*
* @tsl
* @function
* @param {TextureNode} beautyNode - The texture node that represents the input of the effect.
* @param {TextureNode} depthNode - A texture node that represents the scene's depth.
* @param {TextureNode} normalNode - A texture node that represents the scene's normals.
* @param {Camera} camera - The camera the scene is rendered with.
* @returns {SSGINode}
*/
export const ssgi = ( beautyNode, depthNode, normalNode, camera ) => nodeObject( new SSGINode( convertToTexture( beautyNode ), depthNode, normalNode, camera ) );