How is the roll, pitch,yaw defined?

[eugenfunk]

Dear Agisoft team,

I would like to import a txt file in the reference pane with the full camera pose (position and orientation).
My orientation is defined in quaternions and I can convert it to any format, which can be used by Photoscan for image alignment.

I assume further, that roll, pitch, yaw are defined as euler angles. Thus, converting the quaternion to euler might be the way to go.
However, when I pass the euler angles (e.g. roll=z, pitch=x, yaw=y), (n DEG) the angle errors after the camera alignment process are very high.

* How do I map the euler angles( x,y,z) to roll, pitch, yaw assuming that my image local coordinate frame looks like this (z-front, y, down, x: right) : http://www.mathworks.com/help/vision/gs/triangulate_worldcoordinate.png

* If your roll,pitch,yaw is some sort of euler angles, is it defined as xyz or as a zyx rotation?


Thank you very much!

[Alexey Pasumansky]

Hello eugenfunk,

Assuming that camera is mounted under the plane looking vertically down and the direction bottom -> top on the image corresponds to the aircraft flying direction, Y axis is looking forward (flight direction), X-axis is pointing to the right wing and Z is looking to the sky (opposing to the camera pointing direction).

In this system yaw is rotation angle around Z-axis (zero means north), pitch - rotation around X-axis (zero means that nose-tail vector and wings are parallel to the ground), roll - rotation around Y-axis.

[eugenfunk]

Hi Alexey,

thank you very much! However, before I can verify this in my own, I need also the rotation order.
What would it be?
 
Rx*Ry*Rz
or
Rz*Ry*Rx?


Thanks again!

[Alexey Pasumansky]

Hello eugenfunk,

PhotoScan uses the following rotation order for the Euler's angles: yaw (in negative direction, pitch and then roll.