Unusual tracker sensor setup with Vizard

[Zhi]

Hi All,

Our lab uses hiball 3000 tracking system. The hiball tracker sensor is usually attached to the top of the HMD. However, a new project requires us to attach the tracker sensor to the left side of the HMD. That is, the tracker sensor is now tilted 90 deg to the left (roll rotation only) with respect to its original orientation. My question is how to recalibrate the tracker coordinate system to the vizard coordinate system. We used the following code to calibrate the hiball tracker coordinate with the upright sensor orienation.

HeadSensor.swapPos([1,3,2]) 
HeadSensor.swapQuat([-1,-3,-2,4])

Is there an easy way to recalibrate the system when the sensor is rotated 90 deg to the side (i.e. now hiball pitch is vizard yaw, and hiball yaw is vizard pitch, the hiball roll is vizard roll). That is, to find out the corresponding parameters of the swapPos and swapQuat methods.

Thanks in advance.
Zhi