Skip to main content
hugoar
hugoar
Up and Coming
April 25, 2023

Passthrough with Unreal Engine 5.1.1. underlay

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?

 

    This topic has been closed for replies.

    27 replies

    Alighieri2000
    New Participant
    May 10, 2023

    Also having this issue. Any update would be appreciated! 

    hugoar
    hugoarAuthor
    Up and Coming
    May 11, 2023

    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
    New Participant
    May 11, 2023

    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
      hugoarAuthor
      Up and Coming
      May 12, 2023

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

        hugoar
        hugoarAuthor
        Up and Coming
        May 12, 2023

        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
        Participant
        June 23, 2023

        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
        hugoarAuthor
        Up and Coming
        June 23, 2023

        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
        Participant
        June 23, 2023
        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
          CasualCapybara
          New Participant
          November 17, 2023

          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! 😀

            sunrooto2
            Inspiring
            June 27, 2023

            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
            New Participant
            August 29, 2023

            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
            New Participant
            August 30, 2023

            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
              Participant
              June 27, 2023

              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 ... 

                sunrooto2
                Inspiring
                June 28, 2023

                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
                Participant
                June 30, 2023

                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
                Inspiring
                July 2, 2023

                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
                hugoarAuthor
                Up and Coming
                July 18, 2023

                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.

                Show more replies
                Terms & ConditionsAccessibility statement