constructor( radius = 1, phi = 0, theta = 0 ) {

		/**
		 * The radius, or the Euclidean distance (straight-line distance) from the point to the origin.
		 *
		 * @type {number}
		 * @default 1
		 */
		this.radius = radius;

		/**
		 * The polar angle in radians from the y (up) axis.
		 *
		 * @type {number}
		 * @default 0
		 */
		this.phi = phi;

		/**
		 * The equator/azimuthal angle in radians around the y (up) axis.
		 *
		 * @type {number}
		 * @default 0
		 */
		this.theta = theta;

	}
Constructs a new spherical.

@param {number} [radius=1] - The radius, or the Euclidean distance (straight-line distance) from the point to the origin.
@param {number} [phi=0] - The polar angle in radians from the y (up) axis.
@param {number} [theta=0] - The equator/azimuthal angle in radians around the y (up) axis.