Are you saying its a bug in the steam VR version that only effects 4.14.1 then? can you still not reproduce it?
Is it not the case that the Steam api has changed by design that effected 4.14.1?
Seems a little strange for us to contact steam and say
***"Hey Valve I am having trouble developing my VR game in ue4, I keep getting this strange fps lag when ever I look at a 3D UMG Widget in world space but it only happens in 4.14.1, so if you could just change your api to work with this version that would be great.
Many Thanks
Mr wishful"***
you do support steam VR right? so would it not be better for it to come from you guys as its a very specific bug that only effects UE4’s latest version under certain conditions.
I will address you as my questions seem to be getting ignored as I guess because you opened the bug, not sure what the process is, am I supposed to open my own identical bug report to get my questions answered?
anyway…
I have been looking into this a little and it seems that interleaved reprojection was the original way of reprojection that steamVR was using, it lowers the frame rate to 45 fps if the frame rate drops below 90 fps. there was a new reprojection released in Nov called asynchronous reprojection that handles the slight dip in fps without applying the 45 fps cap.
Now if it has been replaced should it even be activated?? So maybe the bug is that its activated and it should not be, arguable still is should it even be a option now…
The trouble is it still does not answer the question of why it only effects 4.14.1 and that there seems to be an extra performance hit on looking at UMG / slate UI’s in this version, also do you see any frame drop when looking at UI with interleaved reprojection deactivated or do you stay at a solid 90fps?
I will check this with my project tonight when I get home.
yep it is getting quiet frustrating as as the last respose was just to contact steamVR… oh and just a heads up you have posted this as an answer to the question…
After doing a bit more digging and testing I was able to find the following information. The issue does not appear to have started with the introduction of 4.14.1 but rather closer to the time of the 4.12 version’s release (or at least not for the issue in the report that I referenced before (UE-30406)). I have provided a link to the public tracker for the issue that I referenced in a previous post. That being said, I cannot reproduce this issue on our end. You will see that the issue was closed as “Cannot Reproduce”. This means that we are unable to reproduce this issue any longer on our end. From what I can find the solution appears to be due to an update to SteamVR put out (SteamVR update 1467410709).
I would be more than happy to reopen the issue, provided that I can reproduce it on our end. If you could provide a test case or project that reproduces this issue, I will continue to investigate to that end.
Thank you for the reply and the update, I was under the impression that Awatr had reproduced this in a new project and supplied the project for you? I will try to reproduce this in a clean project as well.
I created a project from scratch using the VR template, I added a blueprint actor and a widget component with a few controls and dropped it to MotionController.Map. Whenever you look at the blueprint, my FPS drops to 45FPS, as soon as I look away or remove the blueprint actor from the level it goes up to 90 FPS again."
Have you checked that project? Did you try to open it and look at the WMG widget? I didn’t see your answer after I posted this.
I can reproduce this in a new project just as describes, this is with “Allow Interleaved projection” turn on.
Obviously when you turn it off you get 90 fps again when looking at the Widget. so there is something wrong here as its only designed to drop to 45 fps when you dont hit 90fps.
Ii was working fine in 4.13 to 4.14 and only broke in 4.14.1 so this might actually be a new bug related to UI only.
I can confirm that the test project that provided successfully replicates the bug in 14.1. Opening the project in a source build of 14.0 runs smoothly at 90fps.
Rudy, the level to open is ‘Motion Controller Map’ and make sure that ‘Allow interleaved reprojection’ is checked in your SteamVR settings. Also, if you’re testing on an Oculus it’s not going to cause the bug.
Can I add that I am also experience this issue with my widget blueprints. Turning off re projection does indeed fix it but surly this is a bug with 14.1?
Thank you for the additional information. I have already run those tests and cannot reproduce this issue on our end. I have tested with an oculus as well and got the same results as you did. As for the test project that was provided and the setting on my Steam VR, I have already run the tests as you have suggested, however there has been no change in the results (cannot reproduce). If you could provide your dxdiag information this may help provide more insight into the issue.
After looking over the dxdiags I was able to find a common difference between my test case. I was able to reproduce this issue on our end. I have updated and reopened the issue that was mentioned above (Unreal Engine Issues and Bug Tracker (UE-30406)) Please feel free to use the link provided for future updates.
I’m also experiencing this problem. The same project runs flawless in 14.0 while in 14.3 (and 14.1) I have to turn off interleaved reprojection in SteamVR to get 90FPS again, although I still see occasional hiccups, whereas in 14.0 it runs completely smooth. I’m using video textures (and no widgets) in this project and it seems that when removed from the scene the problem goes away in 14.3 (with reprojection on).