📄 `CSM.js`¶

📊 Analysis Summary¶

Metric	Count
🔧 Functions	15
🧱 Classes	1
📦 Imports	9
📊 Variables & Constants	39

📚 Table of Contents¶

Imports
Variables & Constants
Functions
Classes

🛠️ File Location:¶

📂 examples/jsm/csm/CSM.js

📦 Imports¶

Name	Source
`Vector2`	`three`
`Vector3`	`three`
`DirectionalLight`	`three`
`MathUtils`	`three`
`ShaderChunk`	`three`
`Matrix4`	`three`
`Box3`	`three`
`CSMFrustum`	`./CSMFrustum.js`
`CSMShader`	`./CSMShader.js`

Variables & Constants¶

Name	Type	Kind	Value	Exported
`_cameraToLightMatrix`	`any`	let/var	`new Matrix4()`	✗
`_lightSpaceFrustum`	`CSMFrustum`	let/var	`new CSMFrustum( { webGL: true } )`	✗
`_center`	`any`	let/var	`new Vector3()`	✗
`_bbox`	`any`	let/var	`new Box3()`	✗
`_uniformArray`	`any[]`	let/var	`[]`	✗
`_logArray`	`any[]`	let/var	`[]`	✗
`_lightOrientationMatrix`	`any`	let/var	`new Matrix4()`	✗
`_lightOrientationMatrixInverse`	`any`	let/var	`new Matrix4()`	✗
`_up`	`any`	let/var	`new Vector3( 0, 1, 0 )`	✗
`light`	`any`	let/var	`new DirectionalLight( 0xffffff, this.lightIntensity )`	✗
`camera`	`Camera`	let/var	`this.camera`	✗
`frustums`	`CSMFrustum[]`	let/var	`this.frustums`	✗
`light`	`DirectionalLight`	let/var	`this.lights[ i ]`	✗
`shadowCam`	`any`	let/var	`light.shadow.camera`	✗
`frustum`	`CSMFrustum`	let/var	`this.frustums[ i ]`	✗
`nearVerts`	`any`	let/var	`frustum.vertices.near`	✗
`farVerts`	`any`	let/var	`frustum.vertices.far`	✗
`point1`	`any`	let/var	`farVerts[ 0 ]`	✗
`point2`	`any`	let/var	`not shown`	✗
`camera`	`Camera`	let/var	`this.camera`	✗
`linearDepth`	`number`	let/var	`frustum.vertices.far[ 0 ].z / ( far - camera.near )`	✗
`margin`	`number`	let/var	`0.25 * Math.pow( linearDepth, 2.0 ) * ( far - camera.near )`	✗
`camera`	`Camera`	let/var	`this.camera`	✗
`camera`	`Camera`	let/var	`this.camera`	✗
`frustums`	`CSMFrustum[]`	let/var	`this.frustums`	✗
`light`	`DirectionalLight`	let/var	`this.lights[ i ]`	✗
`shadowCam`	`any`	let/var	`light.shadow.camera`	✗
`texelWidth`	`number`	let/var	`( shadowCam.right - shadowCam.left ) / this.shadowMapSize`	✗
`texelHeight`	`number`	let/var	`( shadowCam.top - shadowCam.bottom ) / this.shadowMapSize`	✗
`nearVerts`	`any`	let/var	`_lightSpaceFrustum.vertices.near`	✗
`farVerts`	`any`	let/var	`_lightSpaceFrustum.vertices.far`	✗
`breaksVec2`	`any[]`	let/var	`[]`	✗
`scope`	`this`	let/var	`this`	✗
`shaders`	`Map<Material, any>`	let/var	`this.shaders`	✗
`shaders`	`Map<Material, any>`	let/var	`this.shaders`	✗
`uniforms`	`any`	let/var	`shader.uniforms`	✗
`amount`	`number`	let/var	`this.breaks[ i ]`	✗
`prev`	`number`	let/var	`this.breaks[ i - 1 ] \\|\\| 0`	✗
`shaders`	`Map<Material, any>`	let/var	`this.shaders`	✗

Functions¶

`CSM._createLights(): void`¶

JSDoc:

/**
     * Creates the directional lights of this CSM instance.
     *
     * @private
     */

Returns: void

Calls:

this.parent.add
this.lights.push

Code

_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 );

        }

    }

`CSM._initCascades(): void`¶

JSDoc:

/**
     * Inits the cascades according to the scene's camera and breaks configuration.
     *
     * @private
     */

Returns: void

Calls:

camera.updateProjectionMatrix
this.mainFrustum.setFromProjectionMatrix
this.mainFrustum.split

Code

_initCascades() {

        const camera = this.camera;
        camera.updateProjectionMatrix();
        this.mainFrustum.setFromProjectionMatrix( camera.projectionMatrix, this.maxFar );
        this.mainFrustum.split( this.breaks, this.frustums );

    }

`CSM._updateShadowBounds(): void`¶

JSDoc:

/**
     * Updates the shadow bounds of this CSM instance.
     *
     * @private
     */

Returns: void

Calls:

point1.distanceTo
Math.max
Math.pow
shadowCam.updateProjectionMatrix

Internal Comments:

// Get the two points that represent that furthest points on the frustum assuming (x2)
// that's either the diagonal across the far plane or the diagonal across the whole (x2)
// frustum itself. (x2)
// expand the shadow extents by the fade margin if fade is enabled. (x2)

Code

_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();

        }

    }

`CSM._getBreaks(): void`¶

JSDoc:

/**
     * Computes the breaks of this CSM instance based on the scene's camera, number of cascades
     * and the selected split mode.
     *
     * @private
     */

Returns: void

Calls:

Math.min
uniformSplit
logarithmicSplit
practicalSplit
console.error
this.customSplitsCallback
target.push
MathUtils.lerp

Code

_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 );

        }

    }

`CSM.update(): void`¶

JSDoc:

/**
     * Updates the CSM. This method must be called in your animation loop before
     * calling `renderer.render()`.
     */

Returns: void

Calls:

_lightOrientationMatrix.lookAt
_lightOrientationMatrixInverse.copy( _lightOrientationMatrix ).invert
_cameraToLightMatrix.multiplyMatrices
frustums[ i ].toSpace
_bbox.makeEmpty
_bbox.expandByPoint
_bbox.getCenter
Math.floor
_center.applyMatrix4
light.position.copy
light.target.position.copy

Internal Comments:

// for each frustum we need to find its min-max box aligned with the light orientation (x4)
// the position in _lightOrientationMatrix does not matter, as we transform there and back (x4)

Code

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( new Vector3(), 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;

        }

    }

`CSM._injectInclude(): void`¶

JSDoc:

/**
     * Injects the CSM shader enhancements into the built-in materials.
     *
     * @private
     */

Returns: void

Code

_injectInclude() {

        ShaderChunk.lights_fragment_begin = CSMShader.lights_fragment_begin;
        ShaderChunk.lights_pars_begin = CSMShader.lights_pars_begin;

    }

`CSM.setupMaterial(material: Material): void`¶

JSDoc:

/**
     * Applications must call this method for all materials that should be affected by CSM.
     *
     * @param {Material} material - The material to setup for CSM support.
     */

Parameters:

material Material

Returns: void

Calls:

Math.min
scope._getExtendedBreaks
shaders.set

Code

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 );

    }

`CSM._updateUniforms(): void`¶

JSDoc:

/**
     * Updates the CSM uniforms.
     *
     * @private
     */

Returns: void

Calls:

Math.min
shaders.forEach
this._getExtendedBreaks

Code

_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 );

    }

`CSM._getExtendedBreaks(target: Vector2[]): void`¶

JSDoc:

/**
     * Computes the extended breaks for the CSM uniforms.
     *
     * @private
     * @param {Array<Vector2>} target - The target array that holds the extended breaks.
     */

Parameters:

target Vector2[]

Returns: void

Calls:

target.push

Code

_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;

        }

    }

`CSM.updateFrustums(): void`¶

JSDoc:

/**
     * Applications must call this method every time they change camera or CSM settings.
     */

Returns: void

Calls:

this._getBreaks
this._initCascades
this._updateShadowBounds
this._updateUniforms

Code

updateFrustums() {

        this._getBreaks();
        this._initCascades();
        this._updateShadowBounds();
        this._updateUniforms();

    }

`CSM.remove(): void`¶

JSDoc:

/**
     * Applications must call this method when they remove the CSM usage from their scene.
     */

Returns: void

Calls:

this.parent.remove

Code

remove() {

        for ( let i = 0; i < this.lights.length; i ++ ) {

            this.parent.remove( this.lights[ i ].target );
            this.parent.remove( this.lights[ i ] );

        }

    }

`CSM.dispose(): void`¶

JSDoc:

/**
     * Frees the GPU-related resources allocated by this instance. Call this
     * method whenever this instance is no longer used in your app.
     */

Returns: void

Calls:

shaders.forEach
shaders.clear

Code

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();

    }

`uniformSplit(amount: any, near: any, far: any, target: any): void`¶

Parameters:

amount any
near any
far any
target any

Returns: void

Calls:

target.push

Code

function uniformSplit( amount, near, far, target ) {

            for ( let i = 1; i < amount; i ++ ) {

                target.push( ( near + ( far - near ) * i / amount ) / far );

            }

            target.push( 1 );

        }

`logarithmicSplit(amount: any, near: any, far: any, target: any): void`¶

Parameters:

amount any
near any
far any
target any

Returns: void

Calls:

target.push

Code

function logarithmicSplit( amount, near, far, target ) {

            for ( let i = 1; i < amount; i ++ ) {

                target.push( ( near * ( far / near ) ** ( i / amount ) ) / far );

            }

            target.push( 1 );

        }

`practicalSplit(amount: any, near: any, far: any, lambda: any, target: any): void`¶

Parameters:

amount any
near any
far any
lambda any
target any

Returns: void

Calls:

logarithmicSplit
uniformSplit
target.push
MathUtils.lerp

Code

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 );

        }

Classes¶

`CSM`¶

Class Code

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( new Vector3(), 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();

    }

}

Methods¶

`_createLights(): void`¶

Code

_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 );

        }

    }

`_initCascades(): void`¶

Code

_initCascades() {

        const camera = this.camera;
        camera.updateProjectionMatrix();
        this.mainFrustum.setFromProjectionMatrix( camera.projectionMatrix, this.maxFar );
        this.mainFrustum.split( this.breaks, this.frustums );

    }

`_updateShadowBounds(): void`¶

Code

_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();

        }

    }

`_getBreaks(): void`¶

Code

_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 );

        }

    }

`update(): void`¶

Code

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( new Vector3(), 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;

        }

    }

`_injectInclude(): void`¶

Code

_injectInclude() {

        ShaderChunk.lights_fragment_begin = CSMShader.lights_fragment_begin;
        ShaderChunk.lights_pars_begin = CSMShader.lights_pars_begin;

    }

`setupMaterial(material: Material): void`¶

Code

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 );

    }

`_updateUniforms(): void`¶

Code

_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 );

    }

`_getExtendedBreaks(target: Vector2[]): void`¶

Code

_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;

        }

    }

`updateFrustums(): void`¶

Code

updateFrustums() {

        this._getBreaks();
        this._initCascades();
        this._updateShadowBounds();
        this._updateUniforms();

    }

`remove(): void`¶

Code

remove() {

        for ( let i = 0; i < this.lights.length; i ++ ) {

            this.parent.remove( this.lights[ i ].target );
            this.parent.remove( this.lights[ i ] );

        }

    }

`dispose(): void`¶

Code

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();

    }

📄 CSM.js¶

📊 Analysis Summary¶

📚 Table of Contents¶

🛠️ File Location:¶

📦 Imports¶

Variables & Constants¶

Functions¶

CSM._createLights(): void¶

CSM._initCascades(): void¶

CSM._updateShadowBounds(): void¶

CSM._getBreaks(): void¶

CSM.update(): void¶

CSM._injectInclude(): void¶

CSM.setupMaterial(material: Material): void¶

CSM._updateUniforms(): void¶

CSM._getExtendedBreaks(target: Vector2[]): void¶

CSM.updateFrustums(): void¶

CSM.remove(): void¶

CSM.dispose(): void¶

uniformSplit(amount: any, near: any, far: any, target: any): void¶

logarithmicSplit(amount: any, near: any, far: any, target: any): void¶

practicalSplit(amount: any, near: any, far: any, lambda: any, target: any): void¶

Classes¶

CSM¶

Methods¶

_createLights(): void¶

_initCascades(): void¶

_updateShadowBounds(): void¶

_getBreaks(): void¶

update(): void¶

_injectInclude(): void¶

setupMaterial(material: Material): void¶

_updateUniforms(): void¶

_getExtendedBreaks(target: Vector2[]): void¶

updateFrustums(): void¶

remove(): void¶

dispose(): void¶

📄 `CSM.js`¶

`CSM._createLights(): void`¶

`CSM._initCascades(): void`¶

`CSM._updateShadowBounds(): void`¶

`CSM._getBreaks(): void`¶

`CSM.update(): void`¶

`CSM._injectInclude(): void`¶

`CSM.setupMaterial(material: Material): void`¶

`CSM._updateUniforms(): void`¶

`CSM._getExtendedBreaks(target: Vector2[]): void`¶

`CSM.updateFrustums(): void`¶

`CSM.remove(): void`¶

`CSM.dispose(): void`¶

`uniformSplit(amount: any, near: any, far: any, target: any): void`¶

`logarithmicSplit(amount: any, near: any, far: any, target: any): void`¶

`practicalSplit(amount: any, near: any, far: any, lambda: any, target: any): void`¶

`CSM`¶

`_createLights(): void`¶

`_initCascades(): void`¶

`_updateShadowBounds(): void`¶

`_getBreaks(): void`¶

`update(): void`¶

`_injectInclude(): void`¶

`setupMaterial(material: Material): void`¶

`_updateUniforms(): void`¶

`_getExtendedBreaks(target: Vector2[]): void`¶

`updateFrustums(): void`¶

`remove(): void`¶

`dispose(): void`¶