constructor( envNode ) {

		super( 'vec3' );

		/**
		 * The node representing the environment map.
		 *
		 * @type {Node}
		 */
		this.envNode = envNode;

		/**
		 * A reference to the internal cube texture.
		 *
		 * @private
		 * @type {?CubeTexture}
		 * @default null
		 */
		this._cubeTexture = null;

		/**
		 * A reference to the internal cube texture node.
		 *
		 * @private
		 * @type {CubeTextureNode}
		 */
		this._cubeTextureNode = cubeTexture( null );

		const defaultTexture = new CubeTexture();
		defaultTexture.isRenderTargetTexture = true;

		/**
		 * A default cube texture that acts as a placeholder.
		 * It is used when the conversion from equirectangular to cube
		 * map has not finished yet for a given texture.
		 *
		 * @private
		 * @type {CubeTexture}
		 */
		this._defaultTexture = defaultTexture;

		/**
		 * The `updateBeforeType` is set to `NodeUpdateType.RENDER` since the node updates
		 * the texture once per render in its {@link CubeMapNode#updateBefore} method.
		 *
		 * @type {string}
		 * @default 'render'
		 */
		this.updateBeforeType = NodeUpdateType.RENDER;

	}
Constructs a new cube map node.

@param {Node} envNode - The node representing the environment map.