VR headset delay (Regression)

When using a Vive in 2018.2.0b5 and b4 I've noticed that there's a severe delay in moving your head and having the screen react to your movement. I've noticed this in our project where we use TrackedPoseDriver, but using the SteamVR tracked object for the headset does not solve the issue. The only thing that has solved the issue is to use the Camera by itself with no TrackedPoseDriver or SteamVR components attached to it. The problem is incredibly easy to reproduce.

Steps to reproduce:

• Open any project, or start a new project using Unity Hub, selecting "3D with extras" or "[XR] VR Lightweight RP"
• Open the SampleScene
• Add a Tracked Pose Driver to the camera (important)
• Turn on VR in Player settings, make sure OpenVR is in the list
• Hit Play
• Put on Vive headset and move your head around, notice the delay in the visuals

To solve temporarily:

• Exit playmode
• Remove any Tracked Pose Driver or SteamVR components from your camera
• Hit play
• Notice no delay

This is a straight regression from 2017 and 2018.1 into 2018.2

Setting "Update Type" to any value does not change the behavior.

 

Unity staff is probably going to ask you to submit a bug-report, following this document, as they don't use the forum to track bugs. Don't forget to post the bug-report Case number in this thread, so Unity can pick up your report even faster.

 

Unfortunately video will not show off this issue and is only noticeable inside the headset. Looking at your computer monitor will not show any obvious delay, but having the headset and moving your head around (especially shaking your head quickly) will produce a noticeable delay in the reaction time of the image.

 

Also I want to make sure I clarify this as a delay, and not lag. The visuals are smooth but the display will show visuals from an earlier time. But I do want to note that with all of the reprojection settings enabled in SteamVR, it totally trips that system out. Turning those settings off has 0 effect on the delay. The issue exists in editor and build with reprojection on or off, doesn't matter.

 

Yeah sorry I've had a bug report open and been talking to someone 1042158