Camera Location: (where are you) X Y Z
Look At Vector: (coordinates of the object you want to look at) X Y Z
Look Up Vector: (usually 0 1 0) X Y Z
Viewpoint Orientation (calculated): First three numbers = axis (unit vector), last number = angle (radians). The rotation transform the world coord frame into the viewpoint, with the original negative z axis looking into the direction of the look-at vector.