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📄 LightProbeHelper.js

📊 Analysis Summary

Metric	Count
🔧 Functions	2
🧱 Classes	1
📦 Imports	3
📊 Variables & Constants	2

📚 Table of Contents

• Imports
• Variables & Constants
• Functions
• Classes

🛠️ File Location:

📂 examples/jsm/helpers/LightProbeHelper.js

📦 Imports

Name	Source
Mesh	three
ShaderMaterial	three
SphereGeometry	three

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Variables & Constants

Name	Type	Kind	Value	Exported
material	any	let/var	new ShaderMaterial( { type: 'LightProbeHelperMaterial', uniforms: { sh: { val...	✗
geometry	any	let/var	new SphereGeometry( 1, 32, 16 )	✗

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Functions

LightProbeHelper.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:

• this.geometry.dispose
• this.material.dispose

Code

dispose() {

        this.geometry.dispose();
        this.material.dispose();

    }

LightProbeHelper.onBeforeRender(): void

Returns: void

Calls:

• this.position.copy
• this.scale.set( 1, 1, 1 ).multiplyScalar

Code

onBeforeRender() {

        this.position.copy( this.lightProbe.position );

        this.scale.set( 1, 1, 1 ).multiplyScalar( this.size );

        this.material.uniforms.intensity.value = this.lightProbe.intensity;

    }

---

Classes

LightProbeHelper

Class Code

class LightProbeHelper extends Mesh {

    /**
     * Constructs a new light probe helper.
     *
     * @param {LightProbe} lightProbe - The light probe to visualize.
     * @param {number} [size=1] - The size of the helper.
     */
    constructor( lightProbe, size = 1 ) {

        const material = new ShaderMaterial( {

            type: 'LightProbeHelperMaterial',

            uniforms: {

                sh: { value: lightProbe.sh.coefficients }, // by reference

                intensity: { value: lightProbe.intensity }

            },

            vertexShader: /* glsl */`

                varying vec3 vNormal;

                void main() {

                    vNormal = normalize( normalMatrix * normal );

                    gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );

                }

            `,

            fragmentShader: /* glsl */`

                #define RECIPROCAL_PI 0.318309886

                vec3 inverseTransformDirection( in vec3 normal, in mat4 matrix ) {

                    // matrix is assumed to be orthogonal

                    return normalize( ( vec4( normal, 0.0 ) * matrix ).xyz );

                }

                // source: https://graphics.stanford.edu/papers/envmap/envmap.pdf,
                vec3 shGetIrradianceAt( in vec3 normal, in vec3 shCoefficients[ 9 ] ) {

                    // normal is assumed to have unit length,

                    float x = normal.x, y = normal.y, z = normal.z;

                    // band 0,
                    vec3 result = shCoefficients[ 0 ] * 0.886227;

                    // band 1,
                    result += shCoefficients[ 1 ] * 2.0 * 0.511664 * y;
                    result += shCoefficients[ 2 ] * 2.0 * 0.511664 * z;
                    result += shCoefficients[ 3 ] * 2.0 * 0.511664 * x;

                    // band 2,
                    result += shCoefficients[ 4 ] * 2.0 * 0.429043 * x * y;
                    result += shCoefficients[ 5 ] * 2.0 * 0.429043 * y * z;
                    result += shCoefficients[ 6 ] * ( 0.743125 * z * z - 0.247708 );
                    result += shCoefficients[ 7 ] * 2.0 * 0.429043 * x * z;
                    result += shCoefficients[ 8 ] * 0.429043 * ( x * x - y * y );
                    return result;

                }

                uniform vec3 sh[ 9 ]; // sh coefficients

                uniform float intensity; // light probe intensity

                varying vec3 vNormal;

                void main() {

                    vec3 normal = normalize( vNormal );

                    vec3 worldNormal = inverseTransformDirection( normal, viewMatrix );

                    vec3 irradiance = shGetIrradianceAt( worldNormal, sh );

                    vec3 outgoingLight = RECIPROCAL_PI * irradiance * intensity;

                    gl_FragColor = linearToOutputTexel( vec4( outgoingLight, 1.0 ) );

                }

            `,

        } );

        const geometry = new SphereGeometry( 1, 32, 16 );

        super( geometry, material );

        /**
         * The light probe to visualize.
         *
         * @type {LightProbe}
         */
        this.lightProbe = lightProbe;

        /**
         * The size of the helper.
         *
         * @type {number}
         * @default 1
         */
        this.size = size;
        this.type = 'LightProbeHelper';

        this.onBeforeRender();

    }

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

        this.geometry.dispose();
        this.material.dispose();

    }

    onBeforeRender() {

        this.position.copy( this.lightProbe.position );

        this.scale.set( 1, 1, 1 ).multiplyScalar( this.size );

        this.material.uniforms.intensity.value = this.lightProbe.intensity;

    }

}

Methods

dispose(): void

Code

dispose() {

        this.geometry.dispose();
        this.material.dispose();

    }

onBeforeRender(): void

Code

onBeforeRender() {

        this.position.copy( this.lightProbe.position );

        this.scale.set( 1, 1, 1 ).multiplyScalar( this.size );

        this.material.uniforms.intensity.value = this.lightProbe.intensity;

    }

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