How to use Unreal Engine to create AR application that works on CloudXR?

Hi Everyone,

Totally new to CloudXR , anyone know what is the process of creating OpenXR application in Unreal Engine that stream AR to mobile devices (Android and Iphone/Ipad)?

Thank you.

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I think you can create a app for steamvr by Unreal engine or other engine, and it will automaticall hooked up with CloudXR, since CloudXR is work with SteamVR

Finally tested myself, basically for creating XR application that stream AR to mobile device in Unreal Engine is pretty straight forward. I was using Unreal 4.26.2 for testing, steps listed below if anyone else is looking for information on this.

  1. Use the Virtual Reality template provided by unreal engine.
  2. Load the “MotionControllerMap”
  3. For AR, you can basically delete everything in the scene(most important thing to delete is the world sphere aka sphere map; it will enable you to see your device’s camera video feed) except the lighting and the VRPawn . (Do not enable OpenVR plugin, it seems to crash if enable)
  4. Build for windows and run steamVR, run the client app provided by Nvidia SDK on your device(android works best for now) and key in your IP and connect.
  5. Scan the surface and select a point(this point will be the camera start point, which you should see the motion controller hands by default)
  6. Run the package windows app created from UE4.Done.

Some observation I find was that object have translucency or transparency to them and it changes according to angles and distance to object, should be a rendering bug(I saw a separated thread that mentioned this in this forum, seems a fixed will be done in the next version of SDK).
I have not tested interactivity with UMG widget/btns at the moment, will update if I am able to test them.

Have you already tried to test it with the UE5 version of VR template?

AR on smartphone is alpha blended with camera (much more than unity exported project), all object seems semitransparent (depending on ArCore version on the phone)
For VR you don’t need the VR template, every base scene with a camera seems ok for a basic walkthrough

The blending issue is improved in the next release. Some conversions are causing the alpha to be lowered below 1.0. I recall someone in one thread noted if you manually boost alpha values, say multiply by 1.1, that can work around the issue.

using 4.26.2 I don’t get any image at all on the AR device (Phone). Unity and ar_test.exe seems to works fine.
Has anyone had success with this? It actually looks like UE has removed the opacity output on postprocessing materials all together now. I really hope I have missed something because the demo I have been building uses unreal and used to work (badly, semitransparent, bad tracking) on iphones before the summer.

Maybe I should add that this is with cxr 3.0 (including hotfix per aug 2021). I used to get output from Unreal using earlier versions. Have you had success using 3.0, Unreal and iPhone?

Have not have the chance to try out the new versions be it the CXR3.0 or even the recent UE4.27 releases and deployment to iphone/ipad. Probably would not be able to try soon due to other work.

I tried to lauch VR template build of version UE5. I found much more global problems. When running this build, Steam VR crashes and the device ejects from the CloudXR server.
Here are the logs:
CloudXR Server - SteamVR Log 2021-08-31 13.15.42.txt (637 Bytes)
Streamer Server Log 2021-08-31 13.14.49.txt (147.4 KB)
CloudXR Server - SteamVR Log 2021-08-31 13.14.49.txt (5.0 KB)
CloudXR Server - SteamVR Log 2021-08-31 13.14.45.txt (477 Bytes)
CloudXR Server - SteamVR Log 2021-08-31 13.03.04.txt (1.6 KB)
CloudXR Server - SteamVR Log 2021-08-31 13.03.02.txt (519 Bytes)
Streamer Server Log 2021-08-31 13.15.45.txt (15.4 KB)
CloudXR Server - SteamVR Log 2021-08-31 13.15.45.txt (1.7 KB)

Have you tried this with tethered VR? Or is the crash specific to CloudXR?