Maths and QMatrix Help Required

webzoid

This question is more of a general maths-related question rather than a Qt-specific question, however the implementation is in Qt so maybe that makes it valid for this forum (if not, please let me know and I'll move it).

Ok, so I have the following problem...

I have a sensor which reports its orientation in the form of pitch, roll and yaw angles (in degrees). This sensor will be physically attached to another object (like a motorbike, bicycle or a car, etc) and this object knows its own yaw orientation.

If the sensor yaw is, say, -90 degrees offset from the yaw of the object, how can I recompute the pitch and roll from the sensor in order to be axis aligned (i.e. +90 degree yaw corrected) with the object?

As a (possibly) better example:

Sensor (Raw):
Pitch: 20 degrees
Roll: 15 degrees
Yaw: 90 degrees

Object:
Yaw: 180 degrees

Sensor > Object Yaw Delta: 90 degrees

Sensor (Object Aligned):
Pitch: 15 degrees (corrected by the delta yaw)
Roll: 20 degrees (corrected by the delta yaw)
Yaw: 180 degrees (same as the object)

Maths and matrix maths is really not my strong point.

Does this question even work? Is what I'm trying to do, the right way to go about things? Do I even know what I'm trying to do?!

So to begin, I assume I need a QMatrix3x3...

Please, send help!