Rotation tracking only

[PW]

How am I supposed to decouple positional tracking with the Vive?? I see no settings in SteamVR that offer this as an option and the whole SteamVR system just fails if I cut power to the Lighthouses...

[zalo]

Rotation-only isn't a supported mode in SteamVR; it might cause motion sickness...

You can edit the Unity or UE4 assets to not set the position of the HMD... but you'll always need a lighthouse to keep the screen from blueing out.

They also help prevent rotational drift.

[PW]

Thanks zalo but we have tested rotation only with DK2 on a seated motion platform and there were no motion sickness issues at all (all about context).

We don't want to be saddled with hardware we are not utilizing... I hope there is an option in the future to escape this constraint.

[SnugglePilot]

The scripts that come with the SteamVR Unity project are meant to be modified to your needs. Take a look at the OnPoseReceived function; you can alter that data to simply not set the camera position.

[PW]

I understand that both Unity and Unreal can ignore the translation input if I want them to, that's not the issue... The real issue is (like zalo stated above) that steamVR requires the lighthouses to be plugged in and detected to run any content at all.

This is a potential issue for anyone using the Vive to develop for an event space/attraction. I don't want another point of failure from a device im not even utilizing!

[SnugglePilot]

Ah. without lighthouses you get no rotational nor positional tracking, so basically you just have a very very expensive, lower powered version of cardboard stuck to your face? I can totally see this being in the "can't/won't support this" category from Valve's perspective. lighthouses required.

And yeah, that can be trouble in events - lighthouse cross-interference is a thing that you have to worry about (needed some tarps put up at Vision Summit), but we just showed Fantastic Contraption on the GDC expo floor at a booth without walls (!) and had no problems whatsoever.

If you're showing at a public event and want to show something without any tracking or hands.. one wonders why use the vive at all? :)

[PW]

We do have our business reasons to use the Vive. Lower powered version of cardboard? Not sure what you mean; I'm not going to be acheiving a higher graphical fidelity on a cell phone system like cardboard (we have already looked at streaming options if that's what you were thinking).

The Vive has an internal gyroscope & accelerometer for rotation, not sure why those couldn't be used indipendantly from positional tracking...

I am currently looking at quick development for short, ticketed, full-motion ride run on high end computers. It will be a shame if Oculus is my only flexible option for this kind of thing.

[JCorvinus]

I also have a use-case that requires this. Basically, I'm working on a back-mounted setup that lets a user be completely mobile, with additional pass-through cameras mounted to the front of the headset. When the user leaves the tracked area I'd have the pass-through feed fill the background so that the user only keeps some virtual objects in their local vicinity with them. When they re-enter the tracked volume, the user will be given the option to exit the mixed-reality mode and jump straight back into full VR.

I've currently got this working on my Oculus DK2 outside of SteamVR, but I just did a test with SteamVR and it appears that even the DK2 stops rendering when tracking is lost despite the fact that HMD is perfectly capable of doing rotation-only tracking.

I haven't yet ported this project to SteamVR. It's high on my list of things to do, but if I can't get around the positional tracking loss fade out it's going to be a major headache.

[Entropy]

I need just rotational tracking only as well. I had a demo where I used a motion capture suit (perception neuron) with DK2 (just rotational data) and it worked well because I just locked the camera position to the mocap's head position. Without being able to turn off the positional tracking of Vive will make the head position of the mocap suit not line up with the HTC Vive. I'll try the above mentioned solution of editing the scripts but would hope this is added as an option in the future because VR has many uses, not just the copy/paste experience of room scale VR that is handed to us.

[Entropy]

Above mentioned solution does not work. There is no "OnPoseReceived" in the code. I will update if I find a solution, but so far, no luck.

[SnugglePilot]

Originally posted by Entropy:

Above mentioned solution does not work. There is no "OnPoseReceived" in the code. I will update if I find a solution, but so far, no luck.

Check: SteamVR > Scripts > SteamVR_TrackedObject.cs. This is where OnNewPoses() is in the current example code.

[Entropy]

Finally! ... Finally figured it out. I love Unity... but I also sometimes hate it. I made the mistake of first downloading Unity 5.4 beta, which of course editing the scripts does nothing since that is all native now. So downgraded to 5.3 but downloading the SteamVR plugin kept giving me errors. Finally realized I needed to go to "C:\Users\accountName\AppData\Roaming\Unity\Asset Store" Delete the SteamVR Plugin and redownload using 5.3 and no more errors and commenting out the positioning code now works! Thank you much!

[a.]

HI, didnt work for me :(

I didnt found "OnPoseReceived", but i did find OnNewPoses() . I commented
transform.localPosition = pose.pos;
but it still tracks the position. Seems like transform.localRotation = pose.rot; is doing both rotation and position, so am i doing something wrong ? is my steam vr version different than yours? thanks for the help!

[Noahzr]

Any updates on this? I'm having trouble overriding the position as well

[ChaosJ]

Originally posted by a.:

HI, didnt work for me :(

I didnt found "OnPoseReceived", but i did find OnNewPoses() . I commented
transform.localPosition = pose.pos;
but it still tracks the position. Seems like transform.localRotation = pose.rot; is doing both rotation and position, so am i doing something wrong ? is my steam vr version different than yours? thanks for the help!

commented transform.localPosition = pose.pos;and transform.localRotation = pose.rot; will work in 5.3,it does't work in 5.4

[Raxx]

Posting to help any future devs looking for an answer. Just add:

UnityEngine.XR.InputTracking.disablePositionalTracking = true;

in a script that will be run when you want to disable the position tracking.

Apparently may not be supported after 2019.3, see https://forum.unity.com/threads/completely-disable-position-tracking.450644/