05-16-2018 10:18 PM - edited 05-17-2018 12:35 AM
I am noticing a slight warping of the displayed image as I turn my head in the Vive Focus. It seems as though the distortion correction shader is not entirely cancelling out the distortion from the lenses. The issue can be seen clearly near the edges of the view and is very visible when rotating the headset horizontally. Objects close to the outer edge of the view appear to warp further towards the periphery as the user rotates her head away from that side. There is also a smaller general warping in the middle of the view field that makes the virtual world sway slightly during rotation.
This issue is more pronounced after a session with the original Vive, which has no discernible distortion. Are there plans to refine the correction shader to more fully account for the distortion from the lenses? I think that might provide more comfort for all users and prevent nausea in those most susceptible.
05-17-2018 12:38 PM
05-17-2018 04:27 PM - edited 05-17-2018 05:09 PM
I was also unsure at first whether it was related to the sometimes floaty/jittery positional tracking of the Focus, after some testing I am convinced that is not the case. If you use the Focus in a well-lit room with good features for tracking you can still see warping as you rotate your head. It's easier to see the issue if you move away from virtual objects before looking around. The warping is visible even on distant objects indicating that the positional tracking is not the problem.
Switching back and forth between an original Vive and the Focus makes the issue very obvious. I do think it's worth fixing because the distortion is distracting and presence breaking. I'm curious to know what the team thinks and if a fix would be feasible.
05-19-2018 12:14 AM
Thank you for the response. I created a quick graphic to better show what I think is happening.
The blue arrows indicate the direction of the unwanted warping. The red areas show the location and intensity of the warping. Near the middle of the display the warping is weakest and causes only a slight waver to the image as the headset is rotated. The very red areas are where the warping is most intense. Towards the edge of the view the warping relaxes.
Basically the barrel distortion of the shader does not seem to be fully counteracting the pin-cushion effect of the lenses in certain areas of the image. I hope this is helpful to the team.
05-21-2018 03:25 AM
@thetrakynia Many thanks for your inputs.
To keep better FOV, less distortion and lense selection are always challenges and trade-off decision.
05-26-2018 03:41 AM
I confirm, it's VERY swimmy out there.
Especially easy to see in the UE4 level "sea of cube"
Pressing eye closer to the lens (having a thiner foam would help), makes it a little better.
This definitely needs to be addressed.
06-03-2018 09:31 PM
Thanks All for your analysis contribution, and our optical team and SDK software are working together to fine tune better parameters regarding this issue.
Could you help to provide ROM version and S/N from your side via below adb command?
So we can clarify more exactly the detail info. on our side.
ROM info: adb shell getprop ro.build.description
S/N: adb shell getprop ro.serialno
06-04-2018 11:54 AM
I've seen similar "swimming" issues especially when rotating your head slightly from left to right from other developers in person but only at certain locations - can everyone test to make sure that the inside-out tracking is not a factor at all (as well as if possible if it's reproducible across different Focus devices?
06-04-2018 12:19 PM
06-06-2018 02:19 AM - edited 06-06-2018 04:25 AM
Thank you for the progress update, good luck to the team as they iron out the issue. Here is the information for my Vive Focus:
1.22.1400.2 9.0_g CL1033707 release-keys
06-06-2018 04:23 AM - edited 06-06-2018 04:28 AM
I only have a single Vive Focus to test with but I am certain with my unit that the issue is caused by distortion and not tracking problems. The view warping occurs in different physical locations each with adequate lighting and good features for tracking. When the Focus has occasionally had trouble tracking the result is a clear erroneous move of the viewpoint itself before the software latches on to features within the physical space.
That is distinct from the persistent warping that I see generally. The issue is a lack of spatial coherence in the final presented images which makes objects within the virtual world appear to bend and change size as the headset is rotated.
06-06-2018 04:27 AM
All the VR developers I've shown the Focus to have immediately commented on this and they've mainly suggested that the final image isn't being distorted correctly for the optics.
Likewise - really pressing the headset into one's face mitigates the issue somewhat (and improves the FOV) but becomes uncomfortable over time. Even with this there's still some swimminess with horizontal head motion.
06-06-2018 09:58 AM