constructor( light, size, color ) {

		super();

		/**
		 * The light being visualized.
		 *
		 * @type {HemisphereLight}
		 */
		this.light = light;

		this.matrix = light.matrixWorld;
		this.matrixAutoUpdate = false;

		/**
		 * The color parameter passed in the constructor.
		 * If not set, the helper will take the color of the light.
		 *
		 * @type {number|Color|string}
		 */
		this.color = color;

		this.type = 'HemisphereLightHelper';

		const geometry = new OctahedronGeometry( size );
		geometry.rotateY( Math.PI * 0.5 );

		this.material = new MeshBasicMaterial( { wireframe: true, fog: false, toneMapped: false } );
		if ( this.color === undefined ) this.material.vertexColors = true;

		const position = geometry.getAttribute( 'position' );
		const colors = new Float32Array( position.count * 3 );

		geometry.setAttribute( 'color', new BufferAttribute( colors, 3 ) );

		this.add( new Mesh( geometry, this.material ) );

		this.update();

	}
Constructs a new hemisphere light helper.

@param {HemisphereLight} light - The light to be visualized.
@param {number} [size=1] - The size of the mesh used to visualize the light.
@param {number|Color|string} [color] - The helper's color. If not set, the helper will take
the color of the light.