constructor( degree, knots
			/* array of reals */
			, controlPoints
			/* array of Vector(2|3|4) */
			, startKnot
			/* index in knots */
			, endKnot
			/* index in knots */
		) {

			super();
			this.degree = degree;
			this.knots = knots;
			this.controlPoints = []; // Used by periodic NURBS to remove hidden spans

			this.startKnot = startKnot || 0;
			this.endKnot = endKnot || this.knots.length - 1;

			for ( let i = 0; i < controlPoints.length; ++ i ) {

				// ensure THREE.Vector4 for control points
				const point = controlPoints[ i ];
				this.controlPoints[ i ] = new THREE.Vector4( point.x, point.y, point.z, point.w );

			}

		}
NURBS curve object

Derives from THREE.Curve, overriding getPoint and getTangent.

Implementation is based on (x, y [, z=0 [, w=1]]) control points with w=weight.