So it seems it might be related to the Pimax missing a proximity sensor.
This is what I wrote to Cyan:
Hi again Lloyd.
I just had a thought. Are You using proximity sensor data to toggle headset display image on/off?
If yes, that might be the reason why it doesn’t work in the Pimax headsets as they have no proximity sensor.
If this is the case, I will suggest to the Pimax devs that they fake proximity sensor data using their gyro (to sense if headset is being worn (moved))…
And the response:
Yes, that’s essentially how it works, assuming the headset works as expected. Some headsets refuse to pick up on the signals if they have no sensor.
Let us know what you learn if you reach out to the Pimax devs.
If You can’t use the gyro for it, maybe just make a toggle for it in PiTool to let games/programs think it’s always “on” (i.e. headset is being worn).
It might be why there’s no image in-game in Obduction 1.8.0.
If You don’t think that’s the issue, could You try to run the game and see if You get any valuable debug data? The issue is there’s no image in the headset after starting the game but You can see that the tracking works when You look at the monitor and move the headset.