ffffff, intensity, width, height ); * rectLight.position.set( 5, 5, 0 ); * rectLight.lookAt( 0, 0, 0 ); * scene.add( rectLight ) * ``` * * @augments Light */ class RectAreaLight extends Light { /** * Constructs a new area light. * * @param {(number|Color|string)} [color=0xffffff] - The light's color. * @param {number} [intensity=1] - The light's strength/intensity. * @param {number} [width=10] - The width of the light. * @param {number} [height=10] - The height of the light. */ constructor( color, intensity, width = 10, height = 10 ) { super( color, intensity ); /** * This flag can be used for type testing. * * @type {boolean} * @readonly * @default true */ this.isRectAreaLight = true; this.type = 'RectAreaLight'; /** * The width of the light. * * @type {number} * @default 10 */ this.width = width; /** * The height of the light. * * @type {number} * @default 10 */ this.height = height; } /** * The light's power. Power is the luminous power of the light measured in lumens (lm). * Changing the power will also change the light's intensity. * * @type {number} */ get power() { // compute the light's luminous power (in lumens) from its intensity (in nits) return this.intensity * this.width * this.height * Math.PI; } set power( power ) { // set the light's intensity (in nits) from the desired luminous power (in lumens) this.intensity = power / ( this.width * this.height * Math.PI ); } copy( source ) { super.copy( source ); this.width = source.width; this.height = source.height; return this; } toJSON( meta ) { const data = super.toJSON( meta ); data.object.width = this.width; data.object.height = this.height; return data; } } /** * Represents a third-order spherical harmonics (SH). Light probes use this class * to encode lighting information. * * - Primary reference: {@link https://graphics.stanford.edu/papers/envmap/envmap.pdf} * - Secondary reference: {@link https://www.ppsloan.org/publications/StupidSH36.pdf} */ class SphericalHarmonics3 { /** * Constructs a new spherical harmonics. */ constructor() { /** * This flag can be used for type testing. * * @type {boolean} * @readonly * @default true */ this.isSphericalHarmonics3 = true; /** * An array holding the (9) SH coefficients. * * @type {Array} */ this.coefficients = []; for ( let i = 0; i < 9; i ++ ) { this.coefficients.push( new Vector3() ); } } /** * Sets the given SH coefficients to this instance by copying * the values. * * @param {Array} coefficients - The SH coefficients. * @return {SphericalHarmonics3} A reference to this spherical harmonics. */ set( coefficients ) { for ( let i = 0; i < 9; i ++ ) { this.coefficients[ i ].copy( coefficients[ i ] ); } return this; } /** * Sets all SH coefficients to `0`. * * @return {SphericalHarmonics3} A reference to this spherical harmonics. */ zero() { for ( let i = 0; i < 9; i ++ ) { this.coefficients[ i ].set( 0, 0, 0 ); } return this; } /** * Returns the radiance in the direction of the given normal. * * @param {Vector3} normal - The normal vector (assumed to be unit length) * @param {Vector3} target - The target vector that is used to store the method's result. * @return {Vector3} The radiance. */ getAt( normal, target ) { // normal is assumed to be unit length const x = normal.x, y = normal.y, z = normal.z; const coeff = this.coefficients; // band 0 target.copy( coeff[ 0 ] ).multiplyScalar( 0.282095 ); // band 1 target.addScaledVector( coeff[ 1 ], 0.488603 * y ); target.addScaledVector( coeff[ 2 ], 0.488603 * z ); target.addScaledVector( coeff[ 3 ], 0.488603 * x ); // band 2 target.addScaledVector( coeff[ 4 ], 1.092548 * ( x * y ) ); target.addScaledVector( coeff[ 5 ], 1.092548 * ( y * z ) ); target.addScaledVector( coeff[ 6 ], 0.315392 * ( 3.0 * z * z - 1.0 ) ); target.addScaledVector( coeff[ 7 ], 1.092548 * ( x * z ) ); target.addScaledVector( coeff[ 8 ], 0.546274 * ( x * x - y * y ) ); return target; } /** * Returns the irradiance (radiance convolved with cosine lobe) in the * direction of the given normal. * * @param {Vector3} normal - The normal vector (assumed to be unit length) * @param {Vector3} target - The target vector that is used to store the method's result. * @return {Vector3} The irradiance. */ getIrradianceAt( normal, target ) { // normal is assumed to be unit length const x = normal.x, y = normal.y, z = normal.z; const coeff = this.coefficients; // band 0 target.copy( coeff[ 0 ] ).multiplyScalar( 0.886227 ); // π * 0.282095 // band 1 target.addScaledVector( coeff[ 1 ], 2.0 * 0.511664 * y ); // ( 2 * π / 3 ) * 0.488603 target.addScaledVector( coeff[ 2 ], 2.0 * 0.511664 * z ); target.a