feat: initialize project with core dependencies and game entry point

node_modules/three/examples/jsm/csm/CSM.js

@@ -0,0 +1,598 @@
+import {
+	Vector2,
+	Vector3,
+	DirectionalLight,
+	MathUtils,
+	ShaderChunk,
+	Matrix4,
+	Box3
+} from 'three';
+import { CSMFrustum } from './CSMFrustum.js';
+import { CSMShader } from './CSMShader.js';
+
+const _cameraToLightMatrix = new Matrix4();
+const _lightSpaceFrustum = new CSMFrustum( { webGL: true } );
+const _center = new Vector3();
+const _origin = new Vector3();
+const _bbox = new Box3();
+const _uniformArray = [];
+const _logArray = [];
+const _lightOrientationMatrix = new Matrix4();
+const _lightOrientationMatrixInverse = new Matrix4();
+const _up = new Vector3( 0, 1, 0 );
+
+/**
+ * An implementation of Cascade Shadow Maps (CSM).
+ *
+ * This module can only be used with {@link WebGLRenderer}. When using {@link WebGPURenderer},
+ * use {@link CSMShadowNode} instead.
+ *
+ * @three_import import { CSM } from 'three/addons/csm/CSM.js';
+ */
+export class CSM {
+
+	/**
+	 * Constructs a new CSM instance.
+	 *
+	 * @param {CSM~Data} data - The CSM data.
+	 */
+	constructor( data ) {
+
+		/**
+		 * The scene's camera.
+		 *
+		 * @type {Camera}
+		 */
+		this.camera = data.camera;
+
+		/**
+		 * The parent object, usually the scene.
+		 *
+		 * @type {Object3D}
+		 */
+		this.parent = data.parent;
+
+		/**
+		 * 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 shadow map size.
+		 *
+		 * @type {number}
+		 * @default 2048
+		 */
+		this.shadowMapSize = data.shadowMapSize || 2048;
+
+		/**
+		 * The shadow bias.
+		 *
+		 * @type {number}
+		 * @default 0.000001
+		 */
+		this.shadowBias = data.shadowBias || 0.000001;
+
+		/**
+		 * The light direction.
+		 *
+		 * @type {Vector3}
+		 */
+		this.lightDirection = data.lightDirection || new Vector3( 1, - 1, 1 ).normalize();
+
+		/**
+		 * The light intensity.
+		 *
+		 * @type {number}
+		 * @default 3
+		 */
+		this.lightIntensity = data.lightIntensity || 3;
+
+		/**
+		 * The light near value.
+		 *
+		 * @type {number}
+		 * @default 1
+		 */
+		this.lightNear = data.lightNear || 1;
+
+		/**
+		 * The light far value.
+		 *
+		 * @type {number}
+		 * @default 2000
+		 */
+		this.lightFar = data.lightFar || 2000;
+
+		/**
+		 * 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;
+
+		/**
+		 * The main frustum.
+		 *
+		 * @type {CSMFrustum}
+		 */
+		this.mainFrustum = new CSMFrustum( { webGL: true } );
+
+		/**
+		 * An array of frustums representing the cascades.
+		 *
+		 * @type {Array<CSMFrustum>}
+		 */
+		this.frustums = [];
+
+		/**
+		 * An array of numbers in the range `[0,1]` the defines how the
+		 * mainCSM frustum should be split up.
+		 *
+		 * @type {Array<number>}
+		 */
+		this.breaks = [];
+
+		/**
+		 * 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 = [];
+
+		/**
+		 * A Map holding enhanced material shaders.
+		 *
+		 * @type {Map<Material,Object>}
+		 */
+		this.shaders = new Map();
+
+		this._createLights();
+		this.updateFrustums();
+		this._injectInclude();
+
+	}
+
+	/**
+	 * Creates the directional lights of this CSM instance.
+	 *
+	 * @private
+	 */
+	_createLights() {
+
+		for ( let i = 0; i < this.cascades; i ++ ) {
+
+			const light = new DirectionalLight( 0xffffff, this.lightIntensity );
+			light.castShadow = true;
+			light.shadow.mapSize.width = this.shadowMapSize;
+			light.shadow.mapSize.height = this.shadowMapSize;
+
+			light.shadow.camera.near = this.lightNear;
+			light.shadow.camera.far = this.lightFar;
+			light.shadow.bias = this.shadowBias;
+
+			this.parent.add( light );
+			this.parent.add( light.target );
+			this.lights.push( light );
+
+		}
+
+	}
+
+	/**
+	 * 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 );
+
+	}
+
+	/**
+	 * Updates the shadow bounds of this CSM instance.
+	 *
+	 * @private
+	 */
+	_updateShadowBounds() {
+
+		const frustums = this.frustums;
+		for ( let i = 0; i < frustums.length; i ++ ) {
+
+			const light = this.lights[ i ];
+			const shadowCam = light.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();
+
+		}
+
+	}
+
+	/**
+	 * 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 );
+
+		}
+
+	}
+
+	/**
+	 * Updates the CSM. This method must be called in your animation loop before
+	 * calling `renderer.render()`.
+	 */
+	update() {
+
+		const camera = this.camera;
+		const frustums = this.frustums;
+
+		// 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( _origin, this.lightDirection, _up );
+		_lightOrientationMatrixInverse.copy( _lightOrientationMatrix ).invert();
+
+		for ( let i = 0; i < frustums.length; i ++ ) {
+
+			const light = this.lights[ i ];
+			const shadowCam = light.shadow.camera;
+			const texelWidth = ( shadowCam.right - shadowCam.left ) / this.shadowMapSize;
+			const texelHeight = ( shadowCam.top - shadowCam.bottom ) / this.shadowMapSize;
+			_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 );
+
+			light.position.copy( _center );
+			light.target.position.copy( _center );
+
+			light.target.position.x += this.lightDirection.x;
+			light.target.position.y += this.lightDirection.y;
+			light.target.position.z += this.lightDirection.z;
+
+		}
+
+	}
+
+	/**
+	 * Injects the CSM shader enhancements into the built-in materials.
+	 *
+	 * @private
+	 */
+	_injectInclude() {
+
+		ShaderChunk.lights_fragment_begin = CSMShader.lights_fragment_begin;
+		ShaderChunk.lights_pars_begin = CSMShader.lights_pars_begin;
+
+	}
+
+	/**
+	 * Applications must call this method for all materials that should be affected by CSM.
+	 *
+	 * @param {Material} material - The material to setup for CSM support.
+	 */
+	setupMaterial( material ) {
+
+		material.defines = material.defines || {};
+		material.defines.USE_CSM = 1;
+		material.defines.CSM_CASCADES = this.cascades;
+
+		if ( this.fade ) {
+
+			material.defines.CSM_FADE = '';
+
+		}
+
+		const breaksVec2 = [];
+		const scope = this;
+		const shaders = this.shaders;
+
+		material.onBeforeCompile = function ( shader ) {
+
+			const far = Math.min( scope.camera.far, scope.maxFar );
+			scope._getExtendedBreaks( breaksVec2 );
+
+			shader.uniforms.CSM_cascades = { value: breaksVec2 };
+			shader.uniforms.cameraNear = { value: scope.camera.near };
+			shader.uniforms.shadowFar = { value: far };
+
+			shaders.set( material, shader );
+
+		};
+
+		shaders.set( material, null );
+
+	}
+
+	/**
+	 * Updates the CSM uniforms.
+	 *
+	 * @private
+	 */
+	_updateUniforms() {
+
+		const far = Math.min( this.camera.far, this.maxFar );
+		const shaders = this.shaders;
+
+		shaders.forEach( function ( shader, material ) {
+
+			if ( shader !== null ) {
+
+				const uniforms = shader.uniforms;
+				this._getExtendedBreaks( uniforms.CSM_cascades.value );
+				uniforms.cameraNear.value = this.camera.near;
+				uniforms.shadowFar.value = far;
+
+			}
+
+			if ( ! this.fade && 'CSM_FADE' in material.defines ) {
+
+				delete material.defines.CSM_FADE;
+				material.needsUpdate = true;
+
+			} else if ( this.fade && ! ( 'CSM_FADE' in material.defines ) ) {
+
+				material.defines.CSM_FADE = '';
+				material.needsUpdate = true;
+
+			}
+
+		}, this );
+
+	}
+
+	/**
+	 * Computes the extended breaks for the CSM uniforms.
+	 *
+	 * @private
+	 * @param {Array<Vector2>} target - The target array that holds the extended breaks.
+	 */
+	_getExtendedBreaks( target ) {
+
+		while ( target.length < this.breaks.length ) {
+
+			target.push( new Vector2() );
+
+		}
+
+		target.length = this.breaks.length;
+
+		for ( let i = 0; i < this.cascades; i ++ ) {
+
+			const amount = this.breaks[ i ];
+			const prev = this.breaks[ i - 1 ] || 0;
+			target[ i ].x = prev;
+			target[ i ].y = amount;
+
+		}
+
+	}
+
+	/**
+	 * Applications must call this method every time they change camera or CSM settings.
+	 */
+	updateFrustums() {
+
+		this._getBreaks();
+		this._initCascades();
+		this._updateShadowBounds();
+		this._updateUniforms();
+
+	}
+
+	/**
+	 * Applications must call this method when they remove the CSM usage from their scene.
+	 */
+	remove() {
+
+		for ( let i = 0; i < this.lights.length; i ++ ) {
+
+			this.parent.remove( this.lights[ i ].target );
+			this.parent.remove( this.lights[ i ] );
+
+		}
+
+	}
+
+	/**
+	 * Frees the GPU-related resources allocated by this instance. Call this
+	 * method whenever this instance is no longer used in your app.
+	 */
+	dispose() {
+
+		const shaders = this.shaders;
+		shaders.forEach( function ( shader, material ) {
+
+			delete material.onBeforeCompile;
+			delete material.defines.USE_CSM;
+			delete material.defines.CSM_CASCADES;
+			delete material.defines.CSM_FADE;
+
+			if ( shader !== null ) {
+
+				delete shader.uniforms.CSM_cascades;
+				delete shader.uniforms.cameraNear;
+				delete shader.uniforms.shadowFar;
+
+			}
+
+			material.needsUpdate = true;
+
+		} );
+		shaders.clear();
+
+	}
+
+}
+
+/**
+ * Constructor data of `CSM`.
+ *
+ * @typedef {Object} CSM~Data
+ * @property {Camera} camera - The scene's camera.
+ * @property {Object3D} parent - The parent object, usually the scene.
+ * @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} [shadowMapSize=2048] - The shadow map size.
+ * @property {number} [shadowBias=0.000001] - The shadow bias.
+ * @property {Vector3} [lightDirection] - The light direction.
+ * @property {number} [lightIntensity=3] - The light intensity.
+ * @property {number} [lightNear=1] - The light near value.
+ * @property {number} [lightNear=2000] - The light far value.
+ * @property {number} [lightMargin=200] - The light margin.
+ **/

node_modules/three/examples/jsm/csm/CSMFrustum.js

@@ -0,0 +1,209 @@
+import { Vector3, Matrix4 } from 'three';
+
+const inverseProjectionMatrix = new Matrix4();
+
+/**
+ * Represents the frustum of a CSM instance.
+ *
+ * @three_import import { CSMFrustum } from 'three/addons/csm/CSMFrustum.js';
+ */
+class CSMFrustum {
+
+	/**
+	 * Constructs a new CSM frustum.
+	 *
+	 * @param {CSMFrustum~Data} [data] - The CSM data.
+	 */
+	constructor( data ) {
+
+		data = data || {};
+
+		/**
+		 * The zNear value. This value depends on whether the CSM
+		 * is used with WebGL or WebGPU. Both API use different
+		 * conventions for their projection matrices.
+		 *
+		 * @type {number}
+		 */
+		this.zNear = data.webGL === true ? - 1 : 0;
+
+		/**
+		 * An object representing the vertices of the near and
+		 * far plane in view space.
+		 *
+		 * @type {Object}
+		 */
+		this.vertices = {
+			near: [
+				new Vector3(),
+				new Vector3(),
+				new Vector3(),
+				new Vector3()
+			],
+			far: [
+				new Vector3(),
+				new Vector3(),
+				new Vector3(),
+				new Vector3()
+			]
+		};
+
+		if ( data.projectionMatrix !== undefined ) {
+
+			this.setFromProjectionMatrix( data.projectionMatrix, data.maxFar || 10000 );
+
+		}
+
+	}
+
+	/**
+	 * Setups this CSM frustum from the given projection matrix and max far value.
+	 *
+	 * @param {Matrix4} projectionMatrix - The projection matrix, usually of the scene's camera.
+	 * @param {number} maxFar - The maximum far value.
+	 * @returns {Object} An object representing the vertices of the near and far plane in view space.
+	 */
+	setFromProjectionMatrix( projectionMatrix, maxFar ) {
+
+		const zNear = this.zNear;
+		const isOrthographic = projectionMatrix.elements[ 2 * 4 + 3 ] === 0;
+
+		inverseProjectionMatrix.copy( projectionMatrix ).invert();
+
+		// 3 --- 0  vertices.near/far order
+		// |     |
+		// 2 --- 1
+		// clip space spans from [-1, 1]
+
+		this.vertices.near[ 0 ].set( 1, 1, zNear );
+		this.vertices.near[ 1 ].set( 1, - 1, zNear );
+		this.vertices.near[ 2 ].set( - 1, - 1, zNear );
+		this.vertices.near[ 3 ].set( - 1, 1, zNear );
+		this.vertices.near.forEach( function ( v ) {
+
+			v.applyMatrix4( inverseProjectionMatrix );
+
+		} );
+
+		this.vertices.far[ 0 ].set( 1, 1, 1 );
+		this.vertices.far[ 1 ].set( 1, - 1, 1 );
+		this.vertices.far[ 2 ].set( - 1, - 1, 1 );
+		this.vertices.far[ 3 ].set( - 1, 1, 1 );
+		this.vertices.far.forEach( function ( v ) {
+
+			v.applyMatrix4( inverseProjectionMatrix );
+
+			const absZ = Math.abs( v.z );
+			if ( isOrthographic ) {
+
+				v.z *= Math.min( maxFar / absZ, 1.0 );
+
+			} else {
+
+				v.multiplyScalar( Math.min( maxFar / absZ, 1.0 ) );
+
+			}
+
+		} );
+
+		return this.vertices;
+
+	}
+
+	/**
+	 * Splits the CSM frustum by the given array. The new CSM frustum are pushed into the given
+	 * target array.
+	 *
+	 * @param {Array<number>} breaks - An array of numbers in the range `[0,1]` the defines how the
+	 * CSM frustum should be split up.
+	 * @param {Array<CSMFrustum>} target - The target array that holds the new CSM frustums.
+	 */
+	split( breaks, target ) {
+
+		while ( breaks.length > target.length ) {
+
+			target.push( new CSMFrustum() );
+
+		}
+
+		target.length = breaks.length;
+
+		for ( let i = 0; i < breaks.length; i ++ ) {
+
+			const cascade = target[ i ];
+
+			if ( i === 0 ) {
+
+				for ( let j = 0; j < 4; j ++ ) {
+
+					cascade.vertices.near[ j ].copy( this.vertices.near[ j ] );
+
+				}
+
+			} else {
+
+				for ( let j = 0; j < 4; j ++ ) {
+
+					cascade.vertices.near[ j ].lerpVectors( this.vertices.near[ j ], this.vertices.far[ j ], breaks[ i - 1 ] );
+
+				}
+
+			}
+
+			if ( i === breaks.length - 1 ) {
+
+				for ( let j = 0; j < 4; j ++ ) {
+
+					cascade.vertices.far[ j ].copy( this.vertices.far[ j ] );
+
+				}
+
+			} else {
+
+				for ( let j = 0; j < 4; j ++ ) {
+
+					cascade.vertices.far[ j ].lerpVectors( this.vertices.near[ j ], this.vertices.far[ j ], breaks[ i ] );
+
+				}
+
+			}
+
+		}
+
+	}
+
+	/**
+	 * Transforms the given target CSM frustum into the different coordinate system defined by the
+	 * given camera matrix.
+	 *
+	 * @param {Matrix4} cameraMatrix - The matrix that defines the new coordinate system.
+	 * @param {CSMFrustum} target - The CSM to convert.
+	 */
+	toSpace( cameraMatrix, target ) {
+
+		for ( let i = 0; i < 4; i ++ ) {
+
+			target.vertices.near[ i ]
+				.copy( this.vertices.near[ i ] )
+				.applyMatrix4( cameraMatrix );
+
+			target.vertices.far[ i ]
+				.copy( this.vertices.far[ i ] )
+				.applyMatrix4( cameraMatrix );
+
+		}
+
+	}
+
+}
+
+/**
+ * Constructor data of `CSMFrustum`.
+ *
+ * @typedef {Object} CSMFrustum~Data
+ * @property {boolean} [webGL] - Whether this CSM frustum is used with WebGL or WebGPU.
+ * @property {Matrix4} [projectionMatrix] - A projection matrix usually of the scene's camera.
+ * @property {number} [maxFar] - The maximum far value.
+ **/
+
+export { CSMFrustum };

node_modules/three/examples/jsm/csm/CSMHelper.js

@@ -0,0 +1,243 @@
+import {
+	Group,
+	Mesh,
+	LineSegments,
+	BufferGeometry,
+	LineBasicMaterial,
+	Box3Helper,
+	Box3,
+	PlaneGeometry,
+	MeshBasicMaterial,
+	BufferAttribute,
+	DoubleSide
+} from 'three';
+
+/**
+ * A helper for visualizing the cascades of a CSM instance.
+ *
+ * @augments Group
+ * @three_import import { CSMHelper } from 'three/addons/csm/CSMHelper.js';
+ */
+class CSMHelper extends Group {
+
+	/**
+	 * Constructs a new CSM helper.
+	 *
+	 * @param {CSM|CSMShadowNode} csm - The CSM instance to visualize.
+	 */
+	constructor( csm ) {
+
+		super();
+
+		/**
+		 * The CSM instance to visualize.
+		 *
+		 * @type {CSM|CSMShadowNode}
+		 */
+		this.csm = csm;
+
+		/**
+		 * Whether to display the CSM frustum or not.
+		 *
+		 * @type {boolean}
+		 * @default true
+		 */
+		this.displayFrustum = true;
+
+		/**
+		 * Whether to display the cascade planes or not.
+		 *
+		 * @type {boolean}
+		 * @default true
+		 */
+		this.displayPlanes = true;
+
+		/**
+		 * Whether to display the shadow bounds or not.
+		 *
+		 * @type {boolean}
+		 * @default true
+		 */
+		this.displayShadowBounds = true;
+
+		const indices = new Uint16Array( [ 0, 1, 1, 2, 2, 3, 3, 0, 4, 5, 5, 6, 6, 7, 7, 4, 0, 4, 1, 5, 2, 6, 3, 7 ] );
+		const positions = new Float32Array( 24 );
+		const frustumGeometry = new BufferGeometry();
+		frustumGeometry.setIndex( new BufferAttribute( indices, 1 ) );
+		frustumGeometry.setAttribute( 'position', new BufferAttribute( positions, 3, false ) );
+		const frustumLines = new LineSegments( frustumGeometry, new LineBasicMaterial() );
+		this.add( frustumLines );
+
+		this.frustumLines = frustumLines;
+		this.cascadeLines = [];
+		this.cascadePlanes = [];
+		this.shadowLines = [];
+
+	}
+
+	/**
+	 * This method must be called if one of the `display*` properties is changed at runtime.
+	 */
+	updateVisibility() {
+
+		const displayFrustum = this.displayFrustum;
+		const displayPlanes = this.displayPlanes;
+		const displayShadowBounds = this.displayShadowBounds;
+
+		const frustumLines = this.frustumLines;
+		const cascadeLines = this.cascadeLines;
+		const cascadePlanes = this.cascadePlanes;
+		const shadowLines = this.shadowLines;
+		for ( let i = 0, l = cascadeLines.length; i < l; i ++ ) {
+
+			const cascadeLine = cascadeLines[ i ];
+			const cascadePlane = cascadePlanes[ i ];
+			const shadowLineGroup = shadowLines[ i ];
+
+			cascadeLine.visible = displayFrustum;
+			cascadePlane.visible = displayFrustum && displayPlanes;
+			shadowLineGroup.visible = displayShadowBounds;
+
+		}
+
+		frustumLines.visible = displayFrustum;
+
+	}
+
+	/**
+	 * Updates the helper. This method should be called in the app's animation loop.
+	 */
+	update() {
+
+		const csm = this.csm;
+		const camera = csm.camera;
+		const cascades = csm.cascades;
+		const mainFrustum = csm.mainFrustum;
+		const frustums = csm.frustums;
+		const lights = csm.lights;
+
+		const frustumLines = this.frustumLines;
+		const frustumLinePositions = frustumLines.geometry.getAttribute( 'position' );
+		const cascadeLines = this.cascadeLines;
+		const cascadePlanes = this.cascadePlanes;
+		const shadowLines = this.shadowLines;
+
+		if ( camera === null ) return;
+
+		this.position.copy( camera.position );
+		this.quaternion.copy( camera.quaternion );
+		this.scale.copy( camera.scale );
+		this.updateMatrixWorld( true );
+
+		while ( cascadeLines.length > cascades ) {
+
+			this.remove( cascadeLines.pop() );
+			this.remove( cascadePlanes.pop() );
+			this.remove( shadowLines.pop() );
+
+		}
+
+		while ( cascadeLines.length < cascades ) {
+
+			const cascadeLine = new Box3Helper( new Box3(), 0xffffff );
+			const planeMat = new MeshBasicMaterial( { transparent: true, opacity: 0.1, depthWrite: false, side: DoubleSide } );
+			const cascadePlane = new Mesh( new PlaneGeometry(), planeMat );
+			const shadowLineGroup = new Group();
+			const shadowLine = new Box3Helper( new Box3(), 0xffff00 );
+			shadowLineGroup.add( shadowLine );
+
+			this.add( cascadeLine );
+			this.add( cascadePlane );
+			this.add( shadowLineGroup );
+
+			cascadeLines.push( cascadeLine );
+			cascadePlanes.push( cascadePlane );
+			shadowLines.push( shadowLineGroup );
+
+		}
+
+		for ( let i = 0; i < cascades; i ++ ) {
+
+			const frustum = frustums[ i ];
+			const light = lights[ i ];
+			const shadowCam = light.shadow.camera;
+			const farVerts = frustum.vertices.far;
+
+			const cascadeLine = cascadeLines[ i ];
+			const cascadePlane = cascadePlanes[ i ];
+			const shadowLineGroup = shadowLines[ i ];
+			const shadowLine = shadowLineGroup.children[ 0 ];
+
+			cascadeLine.box.min.copy( farVerts[ 2 ] );
+			cascadeLine.box.max.copy( farVerts[ 0 ] );
+			cascadeLine.box.max.z += 1e-4;
+
+			cascadePlane.position.addVectors( farVerts[ 0 ], farVerts[ 2 ] );
+			cascadePlane.position.multiplyScalar( 0.5 );
+			cascadePlane.scale.subVectors( farVerts[ 0 ], farVerts[ 2 ] );
+			cascadePlane.scale.z = 1e-4;
+
+			this.remove( shadowLineGroup );
+			shadowLineGroup.position.copy( shadowCam.position );
+			shadowLineGroup.quaternion.copy( shadowCam.quaternion );
+			shadowLineGroup.scale.copy( shadowCam.scale );
+			shadowLineGroup.updateMatrixWorld( true );
+			this.attach( shadowLineGroup );
+
+			shadowLine.box.min.set( shadowCam.bottom, shadowCam.left, - shadowCam.far );
+			shadowLine.box.max.set( shadowCam.top, shadowCam.right, - shadowCam.near );
+
+		}
+
+		const nearVerts = mainFrustum.vertices.near;
+		const farVerts = mainFrustum.vertices.far;
+		frustumLinePositions.setXYZ( 0, farVerts[ 0 ].x, farVerts[ 0 ].y, farVerts[ 0 ].z );
+		frustumLinePositions.setXYZ( 1, farVerts[ 3 ].x, farVerts[ 3 ].y, farVerts[ 3 ].z );
+		frustumLinePositions.setXYZ( 2, farVerts[ 2 ].x, farVerts[ 2 ].y, farVerts[ 2 ].z );
+		frustumLinePositions.setXYZ( 3, farVerts[ 1 ].x, farVerts[ 1 ].y, farVerts[ 1 ].z );
+
+		frustumLinePositions.setXYZ( 4, nearVerts[ 0 ].x, nearVerts[ 0 ].y, nearVerts[ 0 ].z );
+		frustumLinePositions.setXYZ( 5, nearVerts[ 3 ].x, nearVerts[ 3 ].y, nearVerts[ 3 ].z );
+		frustumLinePositions.setXYZ( 6, nearVerts[ 2 ].x, nearVerts[ 2 ].y, nearVerts[ 2 ].z );
+		frustumLinePositions.setXYZ( 7, nearVerts[ 1 ].x, nearVerts[ 1 ].y, nearVerts[ 1 ].z );
+		frustumLinePositions.needsUpdate = true;
+
+	}
+
+	/**
+	 * Frees the GPU-related resources allocated by this instance. Call this
+	 * method whenever this instance is no longer used in your app.
+	 */
+	dispose() {
+
+		const frustumLines = this.frustumLines;
+		const cascadeLines = this.cascadeLines;
+		const cascadePlanes = this.cascadePlanes;
+		const shadowLines = this.shadowLines;
+
+		frustumLines.geometry.dispose();
+		frustumLines.material.dispose();
+
+		const cascades = this.csm.cascades;
+
+		for ( let i = 0; i < cascades; i ++ ) {
+
+			const cascadeLine = cascadeLines[ i ];
+			const cascadePlane = cascadePlanes[ i ];
+			const shadowLineGroup = shadowLines[ i ];
+			const shadowLine = shadowLineGroup.children[ 0 ];
+
+			cascadeLine.dispose(); // Box3Helper
+
+			cascadePlane.geometry.dispose();
+			cascadePlane.material.dispose();
+
+			shadowLine.dispose(); // Box3Helper
+
+		}
+
+	}
+
+}
+
+export { CSMHelper };

node_modules/three/examples/jsm/csm/CSMShader.js

@@ -0,0 +1,307 @@
+import { ShaderChunk } from 'three';
+
+/**
+ * @module CSMShader
+ * @three_import import { CSMShader } from 'three/addons/csm/CSMShader.js';
+ */
+
+/**
+ * The object that holds the GLSL enhancements to enable CSM. This
+ * code is injected into the built-in material shaders by {@link CSM}.
+ *
+ * @type {Object}
+ */
+const CSMShader = {
+	lights_fragment_begin: /* glsl */`
+vec3 geometryPosition = - vViewPosition;
+vec3 geometryNormal = normal;
+vec3 geometryViewDir = ( isOrthographic ) ? vec3( 0, 0, 1 ) : normalize( vViewPosition );
+
+vec3 geometryClearcoatNormal = vec3( 0.0 );
+
+#ifdef USE_CLEARCOAT
+
+	geometryClearcoatNormal = clearcoatNormal;
+
+#endif
+
+#ifdef USE_IRIDESCENCE
+	float dotNVi = saturate( dot( normal, geometryViewDir ) );
+	if ( material.iridescenceThickness == 0.0 ) {
+		material.iridescence = 0.0;
+	} else {
+		material.iridescence = saturate( material.iridescence );
+	}
+	if ( material.iridescence > 0.0 ) {
+		material.iridescenceFresnel = evalIridescence( 1.0, material.iridescenceIOR, dotNVi, material.iridescenceThickness, material.specularColor );
+		// Iridescence F0 approximation
+		material.iridescenceF0 = Schlick_to_F0( material.iridescenceFresnel, 1.0, dotNVi );
+	}
+#endif
+
+IncidentLight directLight;
+
+#if ( NUM_POINT_LIGHTS > 0 ) && defined( RE_Direct )
+
+	PointLight pointLight;
+	#if defined( USE_SHADOWMAP ) && NUM_POINT_LIGHT_SHADOWS > 0
+	PointLightShadow pointLightShadow;
+	#endif
+
+	#pragma unroll_loop_start
+	for ( int i = 0; i < NUM_POINT_LIGHTS; i ++ ) {
+
+		pointLight = pointLights[ i ];
+
+		getPointLightInfo( pointLight, geometryPosition, directLight );
+
+		#if defined( USE_SHADOWMAP ) && ( UNROLLED_LOOP_INDEX < NUM_POINT_LIGHT_SHADOWS )
+		pointLightShadow = pointLightShadows[ i ];
+		directLight.color *= ( directLight.visible && receiveShadow ) ? getPointShadow( pointShadowMap[ i ], pointLightShadow.shadowMapSize, pointLightShadow.shadowIntensity, pointLightShadow.shadowBias, pointLightShadow.shadowRadius, vPointShadowCoord[ i ], pointLightShadow.shadowCameraNear, pointLightShadow.shadowCameraFar ) : 1.0;
+
+		#endif
+
+		RE_Direct( directLight, geometryPosition, geometryNormal, geometryViewDir, geometryClearcoatNormal, material, reflectedLight );
+
+	}
+	#pragma unroll_loop_end
+
+#endif
+
+#if ( NUM_SPOT_LIGHTS > 0 ) && defined( RE_Direct )
+
+	SpotLight spotLight;
+ 	vec4 spotColor;
+	vec3 spotLightCoord;
+	bool inSpotLightMap;
+
+	#if defined( USE_SHADOWMAP ) && NUM_SPOT_LIGHT_SHADOWS > 0
+	SpotLightShadow spotLightShadow;
+	#endif
+
+	#pragma unroll_loop_start
+	for ( int i = 0; i < NUM_SPOT_LIGHTS; i ++ ) {
+
+		spotLight = spotLights[ i ];
+
+		getSpotLightInfo( spotLight, geometryPosition, directLight );
+
+  		// spot lights are ordered [shadows with maps, shadows without maps, maps without shadows, none]
+		#if ( UNROLLED_LOOP_INDEX < NUM_SPOT_LIGHT_SHADOWS_WITH_MAPS )
+		#define SPOT_LIGHT_MAP_INDEX UNROLLED_LOOP_INDEX
+		#elif ( UNROLLED_LOOP_INDEX < NUM_SPOT_LIGHT_SHADOWS )
+		#define SPOT_LIGHT_MAP_INDEX NUM_SPOT_LIGHT_MAPS
+		#else
+		#define SPOT_LIGHT_MAP_INDEX ( UNROLLED_LOOP_INDEX - NUM_SPOT_LIGHT_SHADOWS + NUM_SPOT_LIGHT_SHADOWS_WITH_MAPS )
+		#endif
+		#if ( SPOT_LIGHT_MAP_INDEX < NUM_SPOT_LIGHT_MAPS )
+			spotLightCoord = vSpotLightCoord[ i ].xyz / vSpotLightCoord[ i ].w;
+			inSpotLightMap = all( lessThan( abs( spotLightCoord * 2. - 1. ), vec3( 1.0 ) ) );
+			spotColor = texture2D( spotLightMap[ SPOT_LIGHT_MAP_INDEX ], spotLightCoord.xy );
+			directLight.color = inSpotLightMap ? directLight.color * spotColor.rgb : directLight.color;
+		#endif
+		#undef SPOT_LIGHT_MAP_INDEX
+
+		#if defined( USE_SHADOWMAP ) && ( UNROLLED_LOOP_INDEX < NUM_SPOT_LIGHT_SHADOWS )
+		spotLightShadow = spotLightShadows[ i ];
+		directLight.color *= ( directLight.visible && receiveShadow ) ? getShadow( spotShadowMap[ i ], spotLightShadow.shadowMapSize, spotLightShadow.shadowIntensity, spotLightShadow.shadowBias, spotLightShadow.shadowRadius, vSpotLightCoord[ i ] ) : 1.0;
+
+		#endif
+
+		RE_Direct( directLight, geometryPosition, geometryNormal, geometryViewDir, geometryClearcoatNormal, material, reflectedLight );
+
+	}
+	#pragma unroll_loop_end
+
+#endif
+
+#if ( NUM_DIR_LIGHTS > 0 ) && defined( RE_Direct ) && defined( USE_CSM ) && defined( CSM_CASCADES )
+
+	DirectionalLight directionalLight;
+	float linearDepth = (vViewPosition.z) / (shadowFar - cameraNear);
+	#if defined( USE_SHADOWMAP ) && NUM_DIR_LIGHT_SHADOWS > 0
+	DirectionalLightShadow directionalLightShadow;
+	#endif
+
+	#if defined( USE_SHADOWMAP ) && defined( CSM_FADE )
+		vec2 cascade;
+		float cascadeCenter;
+		float closestEdge;
+		float margin;
+		float csmx;
+		float csmy;
+
+		#pragma unroll_loop_start
+		for ( int i = 0; i < NUM_DIR_LIGHTS; i ++ ) {
+
+			directionalLight = directionalLights[ i ];
+			getDirectionalLightInfo( directionalLight, directLight );
+
+			#if ( UNROLLED_LOOP_INDEX < NUM_DIR_LIGHT_SHADOWS )
+				// NOTE: Depth gets larger away from the camera.
+				// cascade.x is closer, cascade.y is further
+				cascade = CSM_cascades[ i ];
+				cascadeCenter = ( cascade.x + cascade.y ) / 2.0;
+				closestEdge = linearDepth < cascadeCenter ? cascade.x : cascade.y;
+				margin = 0.25 * pow( closestEdge, 2.0 );
+				csmx = cascade.x - margin / 2.0;
+				csmy = cascade.y + margin / 2.0;
+				if( linearDepth >= csmx && ( linearDepth < csmy || UNROLLED_LOOP_INDEX == CSM_CASCADES - 1 ) ) {
+
+					float dist = min( linearDepth - csmx, csmy - linearDepth );
+					float ratio = clamp( dist / margin, 0.0, 1.0 );
+
+					vec3 prevColor = directLight.color;
+					directionalLightShadow = directionalLightShadows[ i ];
+					directLight.color *= ( directLight.visible && receiveShadow ) ? getShadow( directionalShadowMap[ i ], directionalLightShadow.shadowMapSize, directionalLightShadow.shadowIntensity, directionalLightShadow.shadowBias, directionalLightShadow.shadowRadius, vDirectionalShadowCoord[ i ] ) : 1.0;
+
+					bool shouldFadeLastCascade = UNROLLED_LOOP_INDEX == CSM_CASCADES - 1 && linearDepth > cascadeCenter;
+					directLight.color = mix( prevColor, directLight.color, shouldFadeLastCascade ? ratio : 1.0 );
+
+					ReflectedLight prevLight = reflectedLight;
+					RE_Direct( directLight, geometryPosition, geometryNormal, geometryViewDir, geometryClearcoatNormal, material, reflectedLight );
+
+					bool shouldBlend = UNROLLED_LOOP_INDEX != CSM_CASCADES - 1 || UNROLLED_LOOP_INDEX == CSM_CASCADES - 1 && linearDepth < cascadeCenter;
+					float blendRatio = shouldBlend ? ratio : 1.0;
+
+					reflectedLight.directDiffuse = mix( prevLight.directDiffuse, reflectedLight.directDiffuse, blendRatio );
+					reflectedLight.directSpecular = mix( prevLight.directSpecular, reflectedLight.directSpecular, blendRatio );
+					reflectedLight.indirectDiffuse = mix( prevLight.indirectDiffuse, reflectedLight.indirectDiffuse, blendRatio );
+					reflectedLight.indirectSpecular = mix( prevLight.indirectSpecular, reflectedLight.indirectSpecular, blendRatio );
+
+				}
+			#endif
+
+		}
+		#pragma unroll_loop_end
+	#elif defined (USE_SHADOWMAP)
+
+		#pragma unroll_loop_start
+		for ( int i = 0; i < NUM_DIR_LIGHTS; i ++ ) {
+
+			directionalLight = directionalLights[ i ];
+			getDirectionalLightInfo( directionalLight, directLight );
+
+			#if ( UNROLLED_LOOP_INDEX < NUM_DIR_LIGHT_SHADOWS )
+
+				directionalLightShadow = directionalLightShadows[ i ];
+				if(linearDepth >= CSM_cascades[UNROLLED_LOOP_INDEX].x && linearDepth < CSM_cascades[UNROLLED_LOOP_INDEX].y) directLight.color *= ( directLight.visible && receiveShadow ) ? getShadow( directionalShadowMap[ i ], directionalLightShadow.shadowMapSize, directionalLightShadow.shadowIntensity, directionalLightShadow.shadowBias, directionalLightShadow.shadowRadius, vDirectionalShadowCoord[ i ] ) : 1.0;
+
+				if(linearDepth >= CSM_cascades[UNROLLED_LOOP_INDEX].x && (linearDepth < CSM_cascades[UNROLLED_LOOP_INDEX].y || UNROLLED_LOOP_INDEX == CSM_CASCADES - 1)) RE_Direct( directLight, geometryPosition, geometryNormal, geometryViewDir, geometryClearcoatNormal, material, reflectedLight );
+
+			#endif
+
+		}
+		#pragma unroll_loop_end
+
+	#elif ( NUM_DIR_LIGHT_SHADOWS > 0 )
+		// note: no loop here - all CSM lights are in fact one light only
+		getDirectionalLightInfo( directionalLights[0], directLight );
+		RE_Direct( directLight, geometryPosition, geometryNormal, geometryViewDir, geometryClearcoatNormal, material, reflectedLight );
+
+	#endif
+
+	#if ( NUM_DIR_LIGHTS > NUM_DIR_LIGHT_SHADOWS)
+		// compute the lights not casting shadows (if any)
+
+		#pragma unroll_loop_start
+		for ( int i = NUM_DIR_LIGHT_SHADOWS; i < NUM_DIR_LIGHTS; i ++ ) {
+
+			directionalLight = directionalLights[ i ];
+
+			getDirectionalLightInfo( directionalLight, directLight );
+
+			RE_Direct( directLight, geometryPosition, geometryNormal, geometryViewDir, geometryClearcoatNormal, material, reflectedLight );
+
+		}
+		#pragma unroll_loop_end
+
+	#endif
+
+#endif
+
+
+#if ( NUM_DIR_LIGHTS > 0 ) && defined( RE_Direct ) && !defined( USE_CSM ) && !defined( CSM_CASCADES )
+
+	DirectionalLight directionalLight;
+	#if defined( USE_SHADOWMAP ) && NUM_DIR_LIGHT_SHADOWS > 0
+	DirectionalLightShadow directionalLightShadow;
+	#endif
+
+	#pragma unroll_loop_start
+	for ( int i = 0; i < NUM_DIR_LIGHTS; i ++ ) {
+
+		directionalLight = directionalLights[ i ];
+
+		getDirectionalLightInfo( directionalLight, directLight );
+
+		#if defined( USE_SHADOWMAP ) && ( UNROLLED_LOOP_INDEX < NUM_DIR_LIGHT_SHADOWS )
+		directionalLightShadow = directionalLightShadows[ i ];
+		directLight.color *= ( directLight.visible && receiveShadow ) ? getShadow( directionalShadowMap[ i ], directionalLightShadow.shadowMapSize, directionalLightShadow.shadowIntensity, directionalLightShadow.shadowBias, directionalLightShadow.shadowRadius, vDirectionalShadowCoord[ i ] ) : 1.0;
+		#endif
+
+		RE_Direct( directLight, geometryPosition, geometryNormal, geometryViewDir, geometryClearcoatNormal, material, reflectedLight );
+
+	}
+	#pragma unroll_loop_end
+
+#endif
+
+#if ( NUM_RECT_AREA_LIGHTS > 0 ) && defined( RE_Direct_RectArea )
+
+	RectAreaLight rectAreaLight;
+
+	#pragma unroll_loop_start
+	for ( int i = 0; i < NUM_RECT_AREA_LIGHTS; i ++ ) {
+
+		rectAreaLight = rectAreaLights[ i ];
+		RE_Direct_RectArea( rectAreaLight, geometryPosition, geometryNormal, geometryViewDir, geometryClearcoatNormal, material, reflectedLight );
+
+	}
+	#pragma unroll_loop_end
+
+#endif
+
+#if defined( RE_IndirectDiffuse )
+
+	vec3 iblIrradiance = vec3( 0.0 );
+
+	vec3 irradiance = getAmbientLightIrradiance( ambientLightColor );
+
+	#if defined( USE_LIGHT_PROBES )
+
+		irradiance += getLightProbeIrradiance( lightProbe, geometryNormal );
+
+	#endif
+
+	#if ( NUM_HEMI_LIGHTS > 0 )
+
+		#pragma unroll_loop_start
+		for ( int i = 0; i < NUM_HEMI_LIGHTS; i ++ ) {
+
+			irradiance += getHemisphereLightIrradiance( hemisphereLights[ i ], geometryNormal );
+
+		}
+		#pragma unroll_loop_end
+
+	#endif
+
+#endif
+
+#if defined( RE_IndirectSpecular )
+
+	vec3 radiance = vec3( 0.0 );
+	vec3 clearcoatRadiance = vec3( 0.0 );
+
+#endif
+`,
+	lights_pars_begin: /* glsl */`
+#if defined( USE_CSM ) && defined( CSM_CASCADES )
+uniform vec2 CSM_cascades[CSM_CASCADES];
+uniform float cameraNear;
+uniform float shadowFar;
+#endif
+	` + ShaderChunk.lights_pars_begin
+};
+
+export { CSMShader };

node_modules/three/examples/jsm/csm/CSMShadowNode.js

@@ -0,0 +1,599 @@
+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 };
+		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;
+
+		} )();
+
+	}
+
+	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 );
+
+		}
+
+	}
+
+	/**
+	 * 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;
+
+			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 };