Hey guys, let me start with the question and then explain after for the folks who don't TL;DR 😃
If the sensors inside the HMD were disabled, could the CV1 still track 6DOF without them? If so, how much loss of performance? It seems to me the answer should be that it would still be able to operate just fine, based on the quite decent 6DOF head tracking NaturalPoint gets out of just three LED's or even reflectors!
Why on Earth would you want to do such a thing Trip?! I'm glad you asked: Virtual Reality and full motion simulators are an incredibly obvious combination. I believe this so strongly that once I got my DK1 and confirmed for myself that VR was indeed for real this time I immediately started looking into a DIY motion simulator and have since invested considerably more than any sane person would on my budget in building a 6DOF motion sim platform!
Mounting the Rift camera to the moving platform the pilot/driver sits upon gives working positional tracking, the only fly in the ointment is that when the whole simulator tilts forward because you slam the brakes, your view tilts downward a bit because the accelerometers and/or gyro say you are looking down. The same goes for all pitch, roll, and yaw movement of the platform.
This is tolerable, but if all that would need to be done to fix it is disable the sensors in the HMD, that seems like an awful easy fix for Oculus to implement for the lucky few who own such a setup.
@cybereality Would this work? If so, am I correct that it would require very little effort for Oculus to implement a "disable on-board sensors" check box? I would love you guys forever and ever if you make the Rift more motion sim friendly. It also would likely convert any motion sim owners who may be going for "that other HMD". 😃
Thanks!
Trip
Edit for typo
Ray "Trip" Rodriguez III
R 'n' R Lawn Service
Lake Ariel PA
In theory it should work. You would have to tweak the software to poll the camera / IR sensors more often and not "look" for inputs from the accelerometer(s). You would most likely lose some finesse.
On the DK2 the camera runs at a lower rate than the IMU, so it can correct the orientation if it drifts but isn't fast enough for the 75Hz frame rate, and certainly not for time warp that requires multiple updates per frame. (Think the DK2 camera was maybe 60Hz)
I don't know that the CV1 camera is running at, but it's probably still slower than the IMU.
But in theory the camera alone would be enough to do all the tracking (assuming you didn't want time warp). However there's no way I know of to make the official sdk not use the IMU.
I think ideally your sim would know how the rig is moving and totate the view to counter it. Pitch down 45 degrees, camera pitches up 45. Cancelling out.
Thanks @kojack that is an excellent and thorough answer.
@TwoHedWlf That is exactly what we want, but I was looking for a quick fix Oculus could give us that would require nearly zero effort on their part. Really this shouldn't be that hard to solve properly, but Oculus so far seems strangely disinterested in supporting motion sims =(.
Ray "Trip" Rodriguez III
R 'n' R Lawn Service
Lake Ariel PA
Probably without the assistance of the IMU the tracking would be jittery. Those gyroscopes are very good at telling when your head is still, but optical tracking is unstable due to the micro-movements of the user turning into an annoying noise of slightly different poses. Just guessing. I only experimented with 3 points optical tracking. You can imagine that with that constellation of so many points tracking must be a lot more robust.
