measure device pitch yaw and roll relative to the target

Question

I am newbie to vuforia, I would like to measure the device orientation relative to the target.

My idea was to use the projection matrix to get the rotation matrix decomposed from the projection matrix and then compute the orientation values.

Is there a simpler way or am I doing it wrong?

Answer 1

I could solve it using this matrix

https://developer.vuforia.com/resources/dev-guide/pose-matrix-explained

I got the rotation matrix from the pose matrix and calculated the orientation from http://planning.cs.uiuc.edu/node103.html

Hope this helps someone.