clampPoint( point, target ) {

		const deltaLengthSq = this.center.distanceToSquared( point );

		target.copy( point );

		if ( deltaLengthSq > ( this.radius * this.radius ) ) {

			target.sub( this.center ).normalize();
			target.multiplyScalar( this.radius ).add( this.center );

		}

		return target;

	}
Clamps a point within the sphere. If the point is outside the sphere, it
will clamp it to the closest point on the edge of the sphere. Points
already inside the sphere will not be affected.

@param {Vector3} point - The plane to clamp.
@param {Vector3} target - The target vector that is used to store the method's result.
@return {Vector3} The clamped point.