built-in phone's 3D orientation experiment

[pietropicerno]

The attitude sensor has been left out for a reason as explained on https://phyphox.org/wiki/index.php/Attitude_sensor and we would definitely need to recheck the validity of its results on a substantial number of devices. Problems like gimbal lock will always persist and the user base for quaternions is quite narrow, isn’t it?

Game rotation vector looks like a worse variant of attitude: for what purpose would this be necessary? AFAICS, there is no equivalent on iOS, so it would be pretty down the list then anyway…

Ad p.s.: check https://phyphox.org/forums/showthread.ph...45#pid3545 for an inclination experiment utilising the gravity vector.

Thanks Jens!
1) I got your point and your "policy". I know that type_rotation_vector is proprietary and it would differ from smartphone to smartphone, but I would just take it "as is". 
2) I understand the limits of Euler angles, but for teaching purposes they are fine though. 
3) I love your inclination experiment using the gravity vector so it can be used in case of an accelerating smartphone, but type_gravity is computed using the proprietary sensor fusion algorithm so we're back to the 1st point. Well, according to android type_gravity should be computed by subtracting type_linear_acceleration to type_accelerometer and, since type_linear_acceleration" is computed using the orientation of the phone with acc and gyro only (see Sensor types  |  Android Open Source Project ) then I suppose that type_gravity is computed using type_game_rotation_vector (and, infact, ythe inclination of your experiment is not disturbed by ferromagnetic pbjects).

Thanks for the support Jens! Now, lots of things are more clear to me.
Best,
Pietro