/** * Simply returns {@code log(a. inverse() * b)}. * * <p>Useful for {@link #squadTangent(Quaternion, Quaternion, Quaternion)}. * * @param a the first Quaternion * @param b the second Quaternion */ public static final Quaternion lnDif(Quaternion a, Quaternion b) { Quaternion dif = a.inverse(); dif.multiply(b); dif.normalize(); return dif.log(); }