Hello I try to setup a simple AR project that runs on PC with Oculus Link on a Quest Pro with a passthrough background and 3D objects over it. I have followed the official documentation https://developer.oculus.com/documentation/unreal/unreal-passthrough-overview/ and manage to have see a passthrough but it is always on top even if I configure it with "underlay" option.What I am missing to make it works? What are the important settings to have in mind (for instance I have Enable alpha channel through tonemapper)? Does Forward/defered rendering have an issue on the result? DX11/D12?Also is it necessary to use the Oculus fork of Unreal or a regular Unreal with MetaXR plugin is ok?

Thank you for the update! Just know there's at least one other person out here trying to create quest link AR experiences in 5.1.1 haha.I was about to write about my experience, namely that I used to be able to use passthrough in P.I.E. less than a week ago, but that got me thinking about what could've changed across all projects since then.I've found the culprit on my end, I had my scalability settings set to low. "Effects" MUST be set to at least "Epic" in order for passthrough to work in-editor. Let me know if this works for you!

that's a great info! Yes Effects scalability change something and now it is working in the editor!Thank you.

hugoar wrote:Yes I am using a Quest Pro.I had an issue like that once. Passthrough need alpha. you have to check that in your project setting.Hey - found that out also ... allow alpha through tonemapper / rendering post processing options... is your performance using passthrough also really bad? Used PT and Spacial Anchors wirh Quest2 already and it was a lot better... any hints to improve?

I fpund put, that next to the rendering settings (allow theough tonemapper) it was actually me being an idiot ... i was connected via usb 2 - so the stream was just not fast enough to render ok quality ... maybe thats your issue also ... check usb connection in the oculus app ...

I was able to run full screen Passthrough in a fork from oculus. And in order for it to work in the mesh, it is necessary to enable Allow CPU ACCESS in the mesh

Passthrough with Unreal Engine 5.1.1. underlay | Meta Community Forums

27 Replies

Alighieri2000
Explorer
3 years ago
Also having this issue. Any update would be appreciated!
hugoar
Protege
3 years ago
I have seen that I have different result when I run it in editor and when I package the project. On a package project the underlay seems to work. Anyway it is really a problem not to have it in editor because right now I have to remove the passthrough and then put it back just before package. Also I would love more control on how it is composited, all the glow bloom on object is cutout, some small particules seems to disappears.
Alighieri2000
Explorer
3 years ago
Thank you for the update! Just know there's at least one other person out here trying to create quest link AR experiences in 5.1.1 haha.
I was about to write about my experience, namely that I used to be able to use passthrough in P.I.E. less than a week ago, but that got me thinking about what could've changed across all projects since then.

I've found the culprit on my end, I had my scalability settings set to low. "Effects" MUST be set to at least "Epic" in order for passthrough to work in-editor. Let me know if this works for you!
hugoar
Protege
3 years ago
that's a great info! Yes Effects scalability change something and now it is working in the editor!
Thank you.
hugoar
Protege
3 years ago
have you tried to use passthrought throught an object, like a window?
I have tried to use PokeAhole material (which is kind of strange, with a lot a nodes not connected, like if it was a working shader) but without success. I seen that I have to change framebuffer's alpha channel but I dont know exactly where to change it.
- LeeBlue181
  Explorer
  3 years ago
  Hey there - i got a different issue - in the paathrough sample i can ONLY see the PT not the objects - doesnt matter if under or overlay for the passthrough layers ... using a quest pro through ... any idea?
hugoar
Protege
3 years ago
Yes I am using a Quest Pro.
I had an issue like that once. Passthrough need alpha. you have to check that in your project setting.
- LeeBlue181
  Explorer
  3 years ago
  hugoar wrote:
  Yes I am using a Quest Pro.
  I had an issue like that once. Passthrough need alpha. you have to check that in your project setting.
  Hey - found that out also ... allow alpha through tonemapper / rendering post processing options... is your performance using passthrough also really bad? Used PT and Spacial Anchors wirh Quest2 already and it was a lot better... any hints to improve?
  - CasualCapybara
    Explorer
    2 years ago
    This worked for me! Thank you so much!
    There was nothing in any Meta tutorial or documentation that mentions that you need to allow alpha through tonemapper in the Rendering > Post processing settings to be able to see objects in passthrough!
    I spent hours trying to figure out why my objects appeared in the editor, but not in passthrough on my Quest 3 and this finally worked for me.
    
    Cheers! 😀
sunroot.o2
Protege
3 years ago
I'm also trying to do passthrough in PIE mode but the quality of it is too bad.
Could you let me know how to improve it?
I'm doing on UE5.1 with Quest Pro by PIE.
Each time i turn my head, the field of view is re-rendered.
- vrmobility2
  Explorer
  2 years ago
  Hello,
  
  Hello,
  I have the same issue with objects not appearing ontop of the Underlay.
  
  I enabled Alpha channel but it does not work more.
  
  Do we need to do PostprocessVolume and PostprocessMaterials ?
  
  I really tried alot of option with little success yet.
  - amx95
    Explorer
    2 years ago
    I was able to run full screen Passthrough in a fork from oculus. And in order for it to work in the mesh, it is necessary to enable Allow CPU ACCESS in the mesh
LeeBlue181
Explorer
3 years ago
I fpund put, that next to the rendering settings (allow theough tonemapper) it was actually me being an idiot ... i was connected via usb 2 - so the stream was just not fast enough to render ok quality ... maybe thats your issue also ... check usb connection in the oculus app ...
- sunroot.o2
  Protege
  3 years ago
  Um. I'm experiencing the low camera frame rate when playing in editor(UE5.1) by airlink for the passthrough underlay. Do you also have this problem? In the installing page of meta xr, there was saying this issue, but the latest version of meta xr 54.0 has released, and there is no saying that issue anymore, that means that problem has solved? when i tried with the new plugin, problem still appears.
deimov
Honored Guest
3 years ago
Hello.... does anyone know where can i find a tutorial of how to correctly implement passtrough in Unreal Engine 5.1? but no the oculus documentation.... because i cant not do it :,(
- ysquall
  Protege
  3 years ago
  I'm also trying to implement it in ue 5.1
  We migrated our project from ue4.27 to ue5.1 and now everything appears black in the place where the passthrough should go
hugoar
Protege
2 years ago
I was using passthrought with XR API Oculus OVRplugin+openxr backend. I was working but now when I want to open the project it crashes. There has been an update somewhere that make it crashes.
If I setup the MetaXr plugin to Epic Native OpenXr I can launch the project again but no more passthrought. Probably it is not possible to use Oculus Passthrough with native OpenXr. The thing is Epic or Meta has to make a bug fix to make OVRplugin works again.