constructor( degree1, degree2, knots1, knots2, controlPoints ) {

		/**
		 * The first NURBS degree.
		 *
		 * @type {number}
		 */
		this.degree1 = degree1;

		/**
		 * The second NURBS degree.
		 *
		 * @type {number}
		 */
		this.degree2 = degree2;

		/**
		 * The first knots as a flat array of numbers.
		 *
		 * @type {Array<number>}
		 */
		this.knots1 = knots1;

		/**
		 * The second knots as a flat array of numbers.
		 *
		 * @type {Array<number>}
		 */
		this.knots2 = knots2;

		/**
		 *  An array holding arrays of control points.
		 *
		 * @type {Array<Array<Vector2|Vector3|Vector4>>}
		 */
		this.controlPoints = [];

		const len1 = knots1.length - degree1 - 1;
		const len2 = knots2.length - degree2 - 1;

		// ensure Vector4 for control points
		for ( let i = 0; i < len1; ++ i ) {

			this.controlPoints[ i ] = [];

			for ( let j = 0; j < len2; ++ j ) {

				const point = controlPoints[ i ][ j ];
				this.controlPoints[ i ][ j ] = new Vector4( point.x, point.y, point.z, point.w );

			}

		}

	}
Constructs a new NURBS surface.

@param {number} degree1 - The first NURBS degree.
@param {number} degree2 - The second NURBS degree.
@param {Array<number>} knots1 - The first knots as a flat array of numbers.
@param {Array<number>} knots2 - The second knots as a flat array of numbers.
@param {Array<Array<Vector2|Vector3|Vector4>>} controlPoints - An array^2 holding control points.