Depth Buffer sampling is "late" on right eye with Multi Pass Stereo Rendering VR and URP

Hi guys,

I have an issue when sampling the depth buffer in a VR project using URP.
I use Unity 2020.1.15 (but the issue occurs in older Unity versions) with XR plugin Oculus (but the problem occurs also with other plugins like OpenVR).

To sample depth, I use a basic Shader Graph shader:


When using the Stereo Rendering Mode "Single Pass Instanced", everything is fine: the depth sampling is perfectly in sync in both eyes.

But when using the Stereo Rendering Mode "Multi Pass", the sampling on the left eye is OK, while the right eye is late by a few frames. It might not be very visible in the video, but it's very ugly when moving the head in the HMD. Just pause the video and check the alignment between the depth sampling and the regular rendering:

Here is a screenshot from the video showing that the sampling in the left eye is OK, while the right eye is not aligned with the regular rendering:


Here is the test project I made if you want to give it a try: https://www.dropbox.com/s/pvkujbf1mkvjxmb/Test_URP_VR_ShowDepth.zip?dl=0

Is it a known issue? Is there any workaround (apart from switching to Single Pass Instanced)?

Thank you

 

Hi,

I have been having the same issue, except that I am not even able to get a normal depth with single pass instanced. I really can't figure it out, one eye being late on only this one buffer...

 

Disabling the "Shared depth buffer" option in the Oculus XR settings does the trick for me. Though as far as I could tell, this also occurs when using Single Pass Instanced