i was just about to try the HTC vive trackers with the new OpenXR backend. unfortunately, unlike the OpenVR backend they are not being registered as additional “tracked items” and therefore not usable. with OpenVR it was also possible to give them a “purpose” in the SteamVR settings (e.g. handheld-right) and one could then use the touch controller output for the right hand to get the transform-pose (apart from accessing them as tracked item) (thanks to @julian for this hint here). however, this workaround apparently not possible any more with the openxr backend (they won’t show up as a controller). there is however an openxr extension for the vive trackers that would probably solve the issue:
actually i’d need this functionality rather soon for a course i’m doing in the beginning of june and just found out about this right now. the easy solution would be to just not use the OpenXR backend and just use OpenVR. however, there is no way of choosing the backend explicitly and the StrideRuntime does not pick up OpenVR, even when no OpenXR compatible headset is connected (I’ve done this by setting the OpenXR backend to WindowsMixedReality and leaving SteamVR as an OpenVR host). this is something I consider a bug because other backends are impossible to use right now. if the fallback to OpenVR as backend would work, my issue would be solved :)
Of course the other clean solution would be to implement the OpenXR Extension. I probably could raise part of a funding, maybe there is somebody else who would take part in this?