Orientation Gone Awry

[adhocdown]

When we initially calibrate the PPT, our orientation is perfect. However, after the first run the orientation changes, seemingly at random.

For example, when the person attempts to walk straight, she will move to the right or completely backwards in the environment.

As a side note, we are transferring tracking data wirelessly, but latency is not an issue.

[Jeff]

Can you describe how you are getting the orientation data? Is it with an inertial sensor or PPT Eyes?

[adhocdown]

We receive information via the HMD (Oculus Rift), which uses an inertial sensor.

[Jeff]

If you're getting yaw drift you can correct that by adding the optical heading plug-in in vizconnect. This setup requires that you have two PPT markers mounted above the HMD.

[johnallen]

If you're getting yaw drift you can correct that by adding the optical heading plug-in in vizconnect. This setup requires that you have two PPT markers mounted above the HMD.

I have this same problem and I'm considering 2 possible solutions.

1/ I have 6 tracking lights/markers in all but usually only use one for tracking the participant's head so have I understood you correctly that I could use two of my spare ones to orient the yaw for the rift? (in a similar way to your eyes 2014 product?)

I usually try to use vizconnect to configure my hardware setup. Can you advise how I could integrate my markers with this please for yaw control? and how I get Vizard to take the yaw settings from the markers but to take the pitch and roll setting from the rift.

Also, should I always fix them a set, fixed separation?

2/ Or, alternatively, I have a spare intersense wireless inertiacube3. Would I be better to get Vizard to use this for the yaw, pitch and roll settings and to use the rift as a dumb display. Again, advice on configuraton in Vizconnect would be much appreciated.

I would favour whichever approach gave me the best responsiveness.

Thanks,
John

[Jeff]

To use optical heading in vizconnect, go to the trackers tab and:

1) Add the two PPT trackers
2) Add the orientation sensor of the rift
3) Add the optical heading tracker and specify the left/right position trackers, orientation tracker, and distance between position trackers

The inertiaCube3 may also have the same drift. However, intersense provides two calibration procedures with their ISDemo software which may help reduce or eliminate it.