public static double[] createUnitVectorFromTranslations(double[] first,
			double[] second) {

		double xfirst = first[0];
		double yfirst = first[1];
		double zfirst = first[2];

		double xsecond = second[0];
		double ysecond = second[1];
		double zsecond = second[2];

		double xextended = xsecond - xfirst;
		double yextended = ysecond - yfirst;
		double zextended = zsecond - zfirst;

		double[] extended = new double[] { xextended, yextended, zextended };

		double[] normalised = normaliseVector(extended);

		return normalised;

	}