[quote author=Fu-Kwun Hwang link=topic=2084.msg8280#msg8280 date=1310269202]
The green circle moves when pitch value change (when you drag slider). The rotating axes is the green arrow.

Do rotational axes for raw,pitch and yaw are three orthogonal axes?
Please let me know the rotational axes for the pitch rotation you want.

Yes. Rotational axes for roll, pitch and yaw are 3 orthogonal axes or let say perpendicular to each other. Please make analogy with the airplane movings (attachments). Pich is simple up and down the nose of the plane; roll is wings up and down; yaw is rotation arround the vertical axis. Pitch is X axis; Yaw is Z and Roll is Y. I hope this will be helpful. Please note that my geometry is at the level of Medical University which is quite basic. I was waiting all the night at my office for your reply. Many thanks for your kindeness to reply very quickly.

Please have the second attachment (more clear view of the axes PRY). It was failed to appear by my previous submission.