DirectX VR issues in 4.20

anonymous_user_eec879e41 · August 28, 2018, 8:00pm

I’m getting this weird graphical issue after starting my game in VR mode. There’s a sort of pattern across my screen, and it affects most 3D graphics: The VR preview window, the editor, thumbnails and packaged builds. 2D images also seem to be affected.

The pattern looks a lot like the distortion the Unreal Engine applies to VR games.

The preview builds for 4.20 worked just fine, and right now I’m using version 4.19. But I can’t get 4.20 to work properly.

I’ve tried reinstalling the Unreal Engine, creating blank new projects, deleting all light sources, updating my graphics card driver and clearing my DerivedDataCache.

Does anyone have an idea what might be causing this? I’m using Windows 10, and AMD R9 390 graphics card and an Oculus Rift. Was there some big change in the release build of 4.20?

Thanks!

Edit: Taking a HighResScreenshot (while not in VR mode) resolves the issue until I enter VR mode again. Which doesn’t really help, but still…

Another edit: Vulkan and OpenGl do not have the issue I described. However, unlike DirectX 11 or 12, But some materials do not compile and I get frequent crashes - so I can’t simply switch to using Vulkan.

More edits (Not giving up yet): 4.20 introduced some mixed reality features, which seems like the only new VR feature. But all the mixed reality features are part of a new plugin… so it’s probably not related…?

Edit 4: [Click to view my DxDiag][2]. Tried rolling back my drivers, hasn’t helped. :<

Edit 5: Here’s another picture.

Final edit: I’ve submitted a new question in the rendering section of the Answerhub. [You can find it here][4]. It contains some new things I’ve learned. Hopefully I’ll get a few more replies as well - ortroll, you’ve been very helpful. Thank you for reading though my stuff.

anonymous_user_eec879e41 · August 30, 2018, 9:03am

Thank you for the answer. As I said in the post, I’m using an AMD R9 390 and the latest graphics drivers (18.8.2). I’m only having trouble when using DirectX and the release build of 4.20. (Edit: Vulkan breaks some materials, but the pattern’s disappeared)

anonymous_user_98092ca1 · August 30, 2018, 8:57am

What driver version you’re using? Is this Nvidia or AMD GPU?

anonymous_user_98092ca1 · September 4, 2018, 2:30pm

4.20 actually introduced translucency support for instanced stereo rendering. I’m still thinking for what might be the reason.

anonymous_user_eec879e41 · September 4, 2018, 7:02pm

Wow, that’s interesting. Instanced stereo is disabled on my system, but that might explain why my depth buffer also looks messed up. (Edit: To clarify, the instanced stereo setting has no effect on my problem)

anonymous_user_942e8e52 · September 12, 2018, 7:31pm

Thank you for submitting a bug report. I have reproduced this issue and logged a report for it here Unreal Engine Issues and Bug Tracker (UE-64034) . You can track the report’s status as the issue is reviewed by our development staff.

christianled59 · September 14, 2018, 11:55pm

I’m having this exact same issue. I can confirm its an issue with 4.21 as well and only seems to affect AMD cards. I’m currently stuck waiting for a fix since there is no way for me to really downgrade.

anonymous_user_eec879e41 · September 15, 2018, 9:03am

Glad to hear I’m not alone.

As said, they’re working on it. But consider upvoting the issue (UE-64034), maybe it’ll get fixed sooner

anonymous_user_9dc5d7981 · October 10, 2018, 8:50pm

I’m having this issue as well. I really hope a fix is found soon… It’s already been almost a month since the most recent answer… This is the best I could get the corruption to look after much experimentation.

anonymous_user_eec879e41 · October 14, 2018, 10:00am

Epic have closed the issue, saying they won’t fix it.

I’m messaging them right now, hopefully they’ll revisit this. I’d love to develop in a UE version newer than 4.19.

I’d at least be happy to find out the reason why they’re not willing to fix it. Perhaps there’s an issue reproducing the issue, but your screenshot shows exactly the same issue I’m having. Have you been in contact with Epic yet?

anonymous_user_eec879e41 · October 14, 2018, 8:01pm

(Duplicate answer from my other post)

Edit: It’s an AMD driver bug. Disable “Flags.bCompositeDepth” in “Oculus\OculusVR\Source\OculusHMD\Private\OculusHMD_Settings.cpp”

After the issue was marked as “Won’t fix”, as a last resort, I tried to find the bug myself.

I found it. So here it is. Reverse this commit and compile your own version of the Unreal Engine.

EpicGames/UnrealEngine/commit/bd51b2429fb5512e30d21d6e9199843c400c1557

Here are the instructions for getting GitHub access to the source code.

anonymous_user_9dc5d7981 · October 15, 2018, 3:40am

One temporary solution I’ve found is to use the previous version. If you use 4.19 it works. The only issue is whether this will persist into future updates. If so that is pretty bogus considering I bought this computer to be Oculus ready and start developing games. It would be a shame if they just lost support for us out of the blue like that.

anonymous_user_eec879e41 · October 15, 2018, 10:02am

I’m using 4.19 as well at the moment. Check my other answer for a way to get newer version to run without the bug.

I hope Epic reopens the issue and fixes it.

JUDGE_DREDD_VR · February 5, 2019, 10:21pm

I change Flags.bCompositeDepth to false and Build new Release but problem not fix