public boolean isYOriented() {
		if (geometry != null && geometry instanceof CylindricalSurface) {
			return Math.abs(y) == 0 && (x != 0 || z != 0);
		} else if (geometry != null && geometry instanceof Plane) {
			return (x == 0) && (Math.abs(y) == 1) && (z == 0);
		} 			
		return false;
	}