Unreal running in standalone instead of VR Preview

[BRB_Jeff]

I want to run in standalone rather than VR Preview with Vive and can't get it to work.

Does anyone know the command line options to run Unreal on Vive in standalone mode?

[hoesing]

Have you tried hitting alt+enter in standalone mode? I think running with -fullscreen on the command line should also enter stereo mode, as well as 'stereo on' from the console.

[BRB_Jeff]

Thanks. Alt+Enter and -fullscreen in shortcut is working. I tried setting "stereo on" "fullscreen 1" etc in all the console ini files but that didn't work. I would rather it just start up in stereo mode without the shortcut trick. But will keep looking.

Also, it seems like while VR preview is running true to 90hz, standalone is capped to 45. I tried turning off bUseVSync didn't seem to make any difference. Any ideas on that?

[hoesing]

Have you tried minimizing the editor while running standalone?

[itemsix]

There's a few ways you can do this:

- Start with the -fullscreen commandline
- Put a ConsoleCommand in your level / game mode blueprint that calls "stereo on"
- You can edit your packaged build's UE4CommandlLine.txt to include the -fullscreen command

We tend to roll with option 2, because that allows a little more control.

[BRB_Jeff]

Thanks @itemsix will do.

Any idea about the 45hz issue in standalone? It feels artificially capped since in VR Preview it is 90. I verified it is actually running 45 and not just the ui reporting wrong. Definite choppiness.

[BRB_Jeff]

Standalone does seem to have serious performance issues compared with VR Preview.

I have now ruled out card and driver settings. I can force VSync off at the driver level and I get > 90FPS on VR Preview and ~50-55fps on standalone.

It clearly does something different in standalone mode than VR preview.

Any thoughts on other things to try?

[lfl_ben_peck]

Do you have GPU-CPU sync turned off? I think that is the "r.finishcurrentframe" console var. Should already be off though if you have recent code.

This probably isn't it, as I don't think it would cause a difference in preview vs standalone, but make sure your IStereoRendering::GetNumberOfBufferedFrames() returns 1. We integrated some code recently that returned 3, and it caused barfy tracking latency...


Not to hijack, but, any ideas how to disable the editor minimizing when you run a VR preview? It's kind of annoying because I like to have my blueprint editor visible in the background while I preview...

[BRB_Jeff]

@ben thanks, will check.

Looks like someone on Epic forums posted something to try on minimize workaround.

https://forums.unrealengine.com/showthread.php?78048-EPIC-Please-don-t-minimize-editor-during-VR-preview

[llatta]

Re: 45 Hz issue
We had performance trouble in standalone sometimes, because it wouldn't resize the window correctly when pressing Alt-Enter. At that point the D3D present for the window probably causes some crazy GDI blit or what not to rescale the window, and everything would chugg. One way to get the window to resize then is the "r.ScreenPercentage" command. Type it once to see what the current/recommended percentage is in the console (for us seems to be 140), and then just set it to the same number again, ie "r.ScreenPercentage 140". There are certainly proper ways to fix it, but for us this only happened on an older locked off demo build, so didn't look into it further than this workaround...

[76561198178603993]

Have you cooked content first? We notice a very large performance decrease when running in standalone builds w/o cooked content.

[BRB_Jeff]

Turned out it was a bug in VR preview not rendering correct resolution. Once fixed we had to optimize our rendering a bit.

[Miss Stabby]

Another trick to get fullscreen to work is to let a blueprint "check" for HMD's on startup, and then fire the fullscreen console command (along with some render settings overrides) so, when you run it on a regular non-vr workstation it remains windowed, but if a vr headset is detected it automatically goes fullscreen