<!-- NEW4 — TEST 4 · THE QUILT · part 246 -->
	const coefficients = this.coefficients;

		for ( let i = 0; i < 9; i ++ ) {

			coefficients[ i ].fromArray( array, offset + ( i * 3 ) );

		}

		return this;

	}

	/**
	 * Returns an array with the SH coefficients, or copies them into the provided
	 * array. The coefficients are represented as numbers.
	 *
	 * @param {Array<number>} [array=[]] - The target array.
	 * @param {number} [offset=0] - The array offset where to start copying.
	 * @return {Array<number>} An array with flat SH coefficients.
	 */
	toArray( array = [], offset = 0 ) {

		const coefficients = this.coefficients;

		for ( let i = 0; i < 9; i ++ ) {

			coefficients[ i ].toArray( array, offset + ( i * 3 ) );

		}

		return array;

	}

	/**
	 * Computes the SH basis for the given normal vector.
	 *
	 * @param {Vector3} normal - The normal.
	 * @param {Array<number>} shBasis - The target array holding the SH basis.
	 */
	static getBasisAt( normal, shBasis ) {

		// normal is assumed to be unit length

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

		// band 0
		shBasis[ 0 ] = 0.282095;

		// band 1
		shBasis[ 1 ] = 0.488603 * y;
		shBasis[ 2 ] = 0.488603 * z;
		shBasis[ 3 ] = 0.488603 * x;

		// band 2
		shBasis[ 4 ] = 1.092548 * x * y;
		shBasis[ 5 ] = 1.092548 * y * z;
		shBasis[ 6 ] = 0.315392 * ( 3 * z * z - 1 );
		shBasis[ 7 ] = 1.092548 * x * z;
		shBasis[ 8 ] = 0.546274 * ( x * x - y * y );

	}

}

/**
 * Light probes are an alternative way of adding light to a 3D scene. Unlike
 * classical light sources (e.g. directional, point or spot lights), light
 * probes do not emit light. Instead they store information about light
 * passing through 3D space. During rendering, the light that hits a 3D
 * object is approximated by using the data from the light probe.
 *
 * Light probes are usually created from (radiance) environment maps. The
 * class {@link LightProbeGenerator} can be used to create light probes from
 * cube textures or render targets. However, light estimation data could also
 * be provided in other forms e.g. by WebXR. This enables the rendering of
 * augmented reality content that reacts to real world lighting.
 *
 * The current probe implementation in three.js supports so-called diffuse
 * light probes. This type of light probe is functionally equivalent to an
 * irradiance environment map.
 *
 * @augments Light
 */
class LightProbe extends Light {

	/**
	 * Constructs a new light probe.
	 *
	 * @param {SphericalHarmonics3} sh - The spherical harmonics which represents encoded lighting information.
	 * @param {number} [intensity=1] - The light's strength/intensity.
	 */
	constructor( sh = new SphericalHarmonics3(), intensity = 1 ) {

		super( undefined, intensity );

		/**
		 * This flag can be used for type testing.
		 *
		 * @type {boolean}
		 * @readonly
		 * @default true
		 */
		this.isLightProbe = true;

		/**
		 * A light probe uses spherical harmonics to encode lighting information.
		 *
		 * @type {SphericalHarmonics3}
		 */
		this.sh = sh;

	}

	copy( source ) {

		super.copy( source );

		this.sh.copy( source.sh );

		return this;

	}

	toJSON( meta ) {

		const data = super.toJSON( meta );

		data.object.sh = this.sh.toArray();

		return data;

	}

}

const _customMaterials = {};

/**
 * Class for loading materials. The files are internally
 * loaded via {@link FileLoader}.
 *
 * ```js
 * const loader = new THREE.MaterialLoader();
 * const material = await loader.loadAsync( 'material.json' );
 * ```
 * This loader does not support node materials. Use {@link NodeMaterialLoader} instead.
 *
 * @augments Loader
 */
class MaterialLoader extends Loader {

	/**
	 * Constructs a new material loader.
	 *
	 * @param {LoadingManager} [manager] - The loading manager.
	 */
	constructor( manager ) {

		super( manager );

		/**
		 * A dictionary holding textures used by the material.
		 *
		 * @type {Object<string,Texture>}
		 */
		this.textures = {};

	}

	/**
	 * Starts loading from the given URL and pass the loaded material to the `onLoad()` callback.
	 *
	 * @param {string} url - The path/URL of the file to be loaded. This can also be a data URI.
	 * @param {function(Material)} onLoad - Executed when the loading process has been finished.
	 * @param {onProgressCallback} onProgress - Executed while the loading is in progress.
	 * @param {onErrorCallback} onError - Executed when errors occur.
	 */
	load( url, onLoad, onProgress, onError ) {

		const scope = this;

		const loader = new FileLoader( scope.manager );
		loader.setPath( scope.path );
		loader.setRequestHeader( scope.requestHeader );
		loader.setWithCredentials( scope.withCredentials );
		loader.load( url, function ( text ) {

			try {

				onLoad( scope.parse( JSON.parse( text ) ) );

			} catch ( e ) {

				if ( onError ) {

					onError( e );

				} else {

					error( e );

				}

				scope.manager.itemError( url );

			}

		}, onProgress, onError );

	}

	/**
	 * Parses the given JSON object and returns a