Accueil / npm / three@0.186.1 / examples / jsm / csm / CSMShadowNode.js
CSMShadowNode.js
import {
Vector2,
Vector3,
MathUtils,
Matrix4,
Box3,
Object3D,
WebGLCoordinateSystem,
ShadowBaseNode
} from 'three/webgpu';
import { CSMFrustum } from './CSMFrustum.js';
import { viewZToOrthographicDepth, reference, uniform, float, vec4, vec2, If, Fn, min, renderGroup, positionView, shadow } from 'three/tsl';
const _cameraToLightMatrix = new Matrix4();
const _lightSpaceFrustum = new CSMFrustum();
const _center = new Vector3();
const _bbox = new Box3();
const _uniformArray = [];
const _logArray = [];
const _lightDirection = new Vector3();
const _lightOrientationMatrix = new Matrix4();
const _lightOrientationMatrixInverse = new Matrix4();
const _up = new Vector3( 0, 1, 0 );
class LwLight extends Object3D {
constructor() {
super();
this.target = new Object3D();
}
}
/**
* An implementation of Cascade Shadow Maps (CSM).
*
* This module can only be used with {@link WebGPURenderer}. When using {@link WebGLRenderer},
* use {@link CSM} instead.
*
* @augments ShadowBaseNode
* @three_import import { CSMShadowNode } from 'three/addons/csm/CSMShadowNode.js';
*/
class CSMShadowNode extends ShadowBaseNode {
/**
* Constructs a new CSM shadow node.
*
* @param {DirectionalLight} light - The CSM light.
* @param {CSMShadowNode~Data} [data={}] - The CSM data.
*/
constructor( light, data = {} ) {
super( light );
/**
* The scene's camera.
*
* @type {?Camera}
* @default null
*/
this.camera = null;
/**
* The number of cascades.
*
* @type {number}
* @default 3
*/
this.cascades = data.cascades || 3;
/**
* The maximum far value.
*
* @type {number}
* @default 100000
*/
this.maxFar = data.maxFar || 100000;
/**
* The frustum split mode.
*
* @type {('practical'|'uniform'|'logarithmic'|'custom')}
* @default 'practical'
*/
this.mode = data.mode || 'practical';
/**
* The light margin.
*
* @type {number}
* @default 200
*/
this.lightMargin = data.lightMargin || 200;
/**
* Custom split callback when using `mode='custom'`.
*
* @type {Function}
*/
this.customSplitsCallback = data.customSplitsCallback;
/**
* Whether to fade between cascades or not.
*
* @type {boolean}
* @default false
*/
this.fade = false;
/**
* An array of numbers in the range `[0,1]` the defines how the
* mainCSM frustum should be split up.
*
* @type {Array<number>}
*/
this.breaks = [];
this._cascades = [];
/**
* The main frustum.
*
* @type {?CSMFrustum}
* @default null
*/
this.mainFrustum = null;
/**
* An array of frustums representing the cascades.
*
* @type {Array<CSMFrustum>}
*/
this.frustums = [];
/**
* An array of directional lights which cast the shadows for
* the different cascades. There is one directional light for each
* cascade.
*
* @type {Array<DirectionalLight>}
*/
this.lights = [];
this._shadowNodes = [];
}
/**
* Inits the CSM shadow node.
*
* @private
* @param {NodeBuilder} builder - The node builder.
*/
_init( { camera, renderer } ) {
this.camera = camera;
const data = {
webGL: renderer.coordinateSystem === WebGLCoordinateSystem,
reversedDepth: renderer.reversedDepthBuffer
};
this.mainFrustum = new CSMFrustum( data );
const light = this.light;
for ( let i = 0; i < this.cascades; i ++ ) {
const lwLight = new LwLight();
lwLight.castShadow = true;
const lShadow = light.shadow.clone();
lShadow.bias = lShadow.bias * ( i + 1 );
this.lights.push( lwLight );
lwLight.shadow = lShadow;
this._shadowNodes.push( shadow( lwLight, lShadow ) );
this._cascades.push( new Vector2() );
}
this.updateFrustums();
}
/**
* Inits the cascades according to the scene's camera and breaks configuration.
*
* @private
*/
_initCascades() {
const camera = this.camera;
camera.updateProjectionMatrix();
this.mainFrustum.setFromProjectionMatrix( camera.projectionMatrix, this.maxFar );
this.mainFrustum.split( this.breaks, this.frustums );
}
/**
* Computes the breaks of this CSM instance based on the scene's camera, number of cascades
* and the selected split mode.
*
* @private
*/
_getBreaks() {
const camera = this.camera;
const far = Math.min( camera.far, this.maxFar );
this.breaks.length = 0;
switch ( this.mode ) {
case 'uniform':
uniformSplit( this.cascades, camera.near, far, this.breaks );
break;
case 'logarithmic':
logarithmicSplit( this.cascades, camera.near, far, this.breaks );
break;
case 'practical':
practicalSplit( this.cascades, camera.near, far, 0.5, this.breaks );
break;
case 'custom':
if ( this.customSplitsCallback === undefined ) console.error( 'CSM: Custom split scheme callback not defined.' );
this.customSplitsCallback( this.cascades, camera.near, far, this.breaks );
break;
}
function uniformSplit( amount, near, far, target ) {
for ( let i = 1; i < amount; i ++ ) {
target.push( ( near + ( far - near ) * i / amount ) / far );
}
target.push( 1 );
}
function logarithmicSplit( amount, near, far, target ) {
for ( let i = 1; i < amount; i ++ ) {
target.push( ( near * ( far / near ) ** ( i / amount ) ) / far );
}
target.push( 1 );
}
function practicalSplit( amount, near, far, lambda, target ) {
_uniformArray.length = 0;
_logArray.length = 0;
logarithmicSplit( amount, near, far, _logArray );
uniformSplit( amount, near, far, _uniformArray );
for ( let i = 1; i < amount; i ++ ) {
target.push( MathUtils.lerp( _uniformArray[ i - 1 ], _logArray[ i - 1 ], lambda ) );
}
target.push( 1 );
}
}
/**
* Sets the light breaks.
*
* @private
*/
_setLightBreaks() {
for ( let i = 0, l = this.cascades; i < l; i ++ ) {
const amount = this.breaks[ i ];
const prev = this.breaks[ i - 1 ] || 0;
this._cascades[ i ].set( prev, amount );
}
}
/**
* Updates the shadow bounds of this CSM instance.
*
* @private
*/
_updateShadowBounds() {
const frustums = this.frustums;
for ( let i = 0; i < frustums.length; i ++ ) {
const shadowCam = this.lights[ i ].shadow.camera;
const frustum = this.frustums[ i ];
// Get the two points that represent that furthest points on the frustum assuming
// that's either the diagonal across the far plane or the diagonal across the whole
// frustum itself.
const nearVerts = frustum.vertices.near;
const farVerts = frustum.vertices.far;
const point1 = farVerts[ 0 ];
let point2;
if ( point1.distanceTo( farVerts[ 2 ] ) > point1.distanceTo( nearVerts[ 2 ] ) ) {
point2 = farVerts[ 2 ];
} else {
point2 = nearVerts[ 2 ];
}
let squaredBBWidth = point1.distanceTo( point2 );
if ( this.fade ) {
// expand the shadow extents by the fade margin if fade is enabled.
const camera = this.camera;
const far = Math.max( camera.far, this.maxFar );
const linearDepth = frustum.vertices.far[ 0 ].z / ( far - camera.near );
const margin = 0.25 * Math.pow( linearDepth, 2.0 ) * ( far - camera.near );
squaredBBWidth += margin;
}
shadowCam.left = - squaredBBWidth / 2;
shadowCam.right = squaredBBWidth / 2;
shadowCam.top = squaredBBWidth / 2;
shadowCam.bottom = - squaredBBWidth / 2;
shadowCam.updateProjectionMatrix();
}
}
/**
* Applications must call this method every time they change camera or CSM settings.
*/
updateFrustums() {
this._getBreaks();
this._initCascades();
this._updateShadowBounds();
this._setLightBreaks();
}
/**
* Setups the TSL when using fading.
*
* @private
* @return {ShaderCallNodeInternal}
*/
_setupFade() {
const cameraNear = reference( 'camera.near', 'float', this ).setGroup( renderGroup );
const cascades = reference( '_cascades', 'vec2', this ).setGroup( renderGroup ).setName( 'cascades' );
const shadowFar = uniform( 'float' ).setGroup( renderGroup ).setName( 'shadowFar' )
.onRenderUpdate( () => Math.min( this.maxFar, this.camera.far ) );
const linearDepth = viewZToOrthographicDepth( positionView.z, cameraNear, shadowFar ).toVar( 'linearDepth' );
const lastCascade = this.cascades - 1;
return Fn( ( builder ) => {
this.setupShadowPosition( builder );
const ret = vec4( 1, 1, 1, 1 ).toVar( 'shadowValue' );
const cascade = vec2().toVar( 'cascade' );
const cascadeCenter = float().toVar( 'cascadeCenter' );
const margin = float().toVar( 'margin' );
const csmX = float().toVar( 'csmX' );
const csmY = float().toVar( 'csmY' );
for ( let i = 0; i < this.cascades; i ++ ) {
const isLastCascade = i === lastCascade;
cascade.assign( cascades.element( i ) );
cascadeCenter.assign( cascade.x.add( cascade.y ).div( 2.0 ) );
const closestEdge = linearDepth.lessThan( cascadeCenter ).select( cascade.x, cascade.y );
margin.assign( float( 0.25 ).mul( closestEdge.pow( 2.0 ) ) );
csmX.assign( cascade.x.sub( margin.div( 2.0 ) ) );
if ( isLastCascade ) {
csmY.assign( cascade.y );
} else {
csmY.assign( cascade.y.add( margin.div( 2.0 ) ) );
}
const inRange = linearDepth.greaterThanEqual( csmX ).and( linearDepth.lessThanEqual( csmY ) );
If( inRange, () => {
const dist = min( linearDepth.sub( csmX ), csmY.sub( linearDepth ) ).toVar();
let ratio = dist.div( margin ).clamp( 0.0, 1.0 );
if ( i === 0 ) {
// don't fade at nearest edge
ratio = linearDepth.greaterThan( cascadeCenter ).select( ratio, 1 );
}
ret.subAssign( this._shadowNodes[ i ].oneMinus().mul( ratio ) );
} );
}
return ret;
} )();
}
/**
* Setups the TSL when no fading (default).
*
* @private
* @return {ShaderCallNodeInternal}
*/
_setupStandard() {
const cameraNear = reference( 'camera.near', 'float', this ).setGroup( renderGroup );
const cascades = reference( '_cascades', 'vec2', this ).setGroup( renderGroup ).setName( 'cascades' );
const shadowFar = uniform( 'float' ).setGroup( renderGroup ).setName( 'shadowFar' )
.onRenderUpdate( () => Math.min( this.maxFar, this.camera.far ) );
const linearDepth = viewZToOrthographicDepth( positionView.z, cameraNear, shadowFar ).toVar( 'linearDepth' );
return Fn( ( builder ) => {
this.setupShadowPosition( builder );
const ret = vec4( 1, 1, 1, 1 ).toVar( 'shadowValue' );
const cascade = vec2().toVar( 'cascade' );
for ( let i = 0; i < this.cascades; i ++ ) {
cascade.assign( cascades.element( i ) );
If( linearDepth.greaterThanEqual( cascade.x ).and( linearDepth.lessThanEqual( cascade.y ) ), () => {
ret.assign( this._shadowNodes[ i ] );
} );
}
return ret;
} )();
}
build( builder ) {
// register before the shadow nodes so `updateBefore()` runs first
builder.addSequentialNode( this );
return super.build( builder );
}
setup( builder ) {
if ( this.camera === null ) this._init( builder );
return this.fade === true ? this._setupFade() : this._setupStandard();
}
updateBefore( /*builder*/ ) {
const light = this.light;
const parent = light.parent;
const camera = this.camera;
const frustums = this.frustums;
// make sure the placeholder light objects which represent the
// multiple cascade shadow casters are part of the scene graph
for ( let i = 0; i < this.lights.length; i ++ ) {
const lwLight = this.lights[ i ];
if ( lwLight.parent === null ) {
parent.add( lwLight.target );
parent.add( lwLight );
}
}
_lightDirection.subVectors( light.target.position, light.position ).normalize();
// for each frustum we need to find its min-max box aligned with the light orientation
// the position in _lightOrientationMatrix does not matter, as we transform there and back
_lightOrientationMatrix.lookAt( light.position, light.target.position, _up );
_lightOrientationMatrixInverse.copy( _lightOrientationMatrix ).invert();
for ( let i = 0; i < frustums.length; i ++ ) {
const lwLight = this.lights[ i ];
const shadow = lwLight.shadow;
const shadowCam = shadow.camera;
const texelWidth = ( shadowCam.right - shadowCam.left ) / shadow.mapSize.width;
const texelHeight = ( shadowCam.top - shadowCam.bottom ) / shadow.mapSize.height;
_cameraToLightMatrix.multiplyMatrices( _lightOrientationMatrixInverse, camera.matrixWorld );
frustums[ i ].toSpace( _cameraToLightMatrix, _lightSpaceFrustum );
const nearVerts = _lightSpaceFrustum.vertices.near;
const farVerts = _lightSpaceFrustum.vertices.far;
_bbox.makeEmpty();
for ( let j = 0; j < 4; j ++ ) {
_bbox.expandByPoint( nearVerts[ j ] );
_bbox.expandByPoint( farVerts[ j ] );
}
_bbox.getCenter( _center );
_center.z = _bbox.max.z + this.lightMargin;
_center.x = Math.floor( _center.x / texelWidth ) * texelWidth;
_center.y = Math.floor( _center.y / texelHeight ) * texelHeight;
_center.applyMatrix4( _lightOrientationMatrix );
lwLight.position.copy( _center );
lwLight.target.position.copy( _center );
lwLight.target.position.add( _lightDirection );
lwLight.updateMatrixWorld();
lwLight.target.updateMatrixWorld();
}
}
/**
* Frees the GPU-related resources allocated by this instance. Call this
* method whenever this instance is no longer used in your app.
*/
dispose() {
for ( let i = 0; i < this.lights.length; i ++ ) {
const light = this.lights[ i ];
const parent = light.parent;
if ( parent !== null ) {
parent.remove( light.target );
parent.remove( light );
}
}
super.dispose();
}
}
/**
* Constructor data of `CSMShadowNode`.
*
* @typedef {Object} CSMShadowNode~Data
* @property {number} [cascades=3] - The number of cascades.
* @property {number} [maxFar=100000] - The maximum far value.
* @property {('practical'|'uniform'|'logarithmic'|'custom')} [mode='practical'] - The frustum split mode.
* @property {Function} [customSplitsCallback] - Custom split callback when using `mode='custom'`.
* @property {number} [lightMargin=200] - The light margin.
**/
export { CSMShadowNode };