Lightwave's default rotation order always used to be Bank, Pitch, Heading, and I suppose it probably still is. That's the order that the rotations are applied mathematically, but not necessarily how they are ordered in the user interface. Terragen uses the same rotation order internally: Bank, Pitch, Heading. However, the user interfaces of the two programs list the values in different orders. Terragen's user interface shows X, Y, Z from left to right, according to the axes of rotation. X = Pitch, Y = Heading, Z = Bank. So Terragen shows you Pitch, Heading, Bank. If Lightwave shows you Heading, Pitch, Bank then you can convert between Terragen and Lightwave rotations by swapping the first and second values.