constructor( near, far, renderTarget ) {

		super();

		this.type = 'CubeCamera';

		/**
		 * A reference to the cube render target.
		 *
		 * @type {WebGLCubeRenderTarget}
		 */
		this.renderTarget = renderTarget;

		/**
		 * The current active coordinate system.
		 *
		 * @type {?(WebGLCoordinateSystem|WebGPUCoordinateSystem)}
		 * @default null
		 */
		this.coordinateSystem = null;

		/**
		 * The current active mipmap level
		 *
		 * @type {number}
		 * @default 0
		 */
		this.activeMipmapLevel = 0;

		const cameraPX = new PerspectiveCamera( fov, aspect, near, far );
		cameraPX.layers = this.layers;
		this.add( cameraPX );

		const cameraNX = new PerspectiveCamera( fov, aspect, near, far );
		cameraNX.layers = this.layers;
		this.add( cameraNX );

		const cameraPY = new PerspectiveCamera( fov, aspect, near, far );
		cameraPY.layers = this.layers;
		this.add( cameraPY );

		const cameraNY = new PerspectiveCamera( fov, aspect, near, far );
		cameraNY.layers = this.layers;
		this.add( cameraNY );

		const cameraPZ = new PerspectiveCamera( fov, aspect, near, far );
		cameraPZ.layers = this.layers;
		this.add( cameraPZ );

		const cameraNZ = new PerspectiveCamera( fov, aspect, near, far );
		cameraNZ.layers = this.layers;
		this.add( cameraNZ );

	}
Constructs a new cube camera.

@param {number} near - The camera's near plane.
@param {number} far - The camera's far plane.
@param {WebGLCubeRenderTarget} renderTarget - The cube render target.