Why do you have a rotation of axes when converting to TF in aruco_ros_utils?

[balakumar-s]

Why do you have a rotation of axes when converting to TF in aruco_ros_utils?

[balakumar-s]

The ideal way to do that would be to set a TF transform between the camera frame and the world frame and then publishing the pose of the object with reference to the camera frame would get transformed. TF setup link. I was setting up a common world frame between robot and camera and your rotations caused trouble and I removed the rotations and now it works well. Thanks for the ROS port.

[bmagyar]

AFAIK I did that to publish a world-oriented coordinate frame, not a camera-oriented one. Camera frames often use Z as distance from camera pointing angle (depth) and X,Y align with the image axes.

Having Z pointing up made life much simpler for applications using these markers such as object manipulation or robot localisation.

[bmagyar]

Yes you are right, although I weighted the most common usages and went for the internal rotation solution to save head scratching for most users.

[kopp]

Actually, this started some head scratching for me: If I visualize the marker coordinate frame from the result topic with image_view, I get different coordinate systems than the rviz tf visualization:

(or is that a different issue?)

[bmagyar]

One is the internal aruco visualisation, the tf frame is the output I wanted in 2012 :)
There's no further explanation to that.
If you want to fix that, feel free to send in a pull request.

[kopp]

I'm fine with it -- I only use the ros tf output. I primarily wanted to document this issue :-)