[4.19 VIVE] VR performance issues

Hello,

I was wondering if anyone has experienced performance issues with 4.19 and VR. I have a somewhat complex project that works great on 4.18 with mostly solid 90fps but the same project on 4.19 has a lot of frame drops and stuttering. In 4.18 I have r.ScreenPercentage set to 140 and for 4.19 I set it to 100 and set vr.PixelDensity to 1. Lower vr.PixelDensity values still show stuttering so I wonder if this is a Vive/SteamVR related issue, also since both 4.18 and 4.19 show the same frame timing (11ms). On the other hand, I can notice a visual improvement in 4.19 (and also a different color grading) so I wonder if there has been some deeper changes to the rendering pipeline that might be producing this difference in performance.

Thanks!

Same! I migrated a project from 4.18 and matched the settings and I’m getting a lot of frame stuttering when in the 4.18 it runs at solid 120fps. Did you manage a way to fix this??

Same with simple project on Gear VR.

No, I had to abort trying to upgrade to 4.19 and keep the project in 4.18 where it runs smoothly.

Same here, SteamVR Vive project runs great on 4.18.3, but poor performance in 4.19.2. I’m guessing this might have something to do with the changes in VR resolution settings in 4.19… would be great to get someone explain what we have to do/consider when upgrading from 4.18>4.19.

Just had another read here: Significant Changes Coming To VR Resolution Settings in 4.19 - Unreal Engine

“When making this change, keep in mind that defaulted vr.PixelDensity=1 specifies a resolution that is larger than 4.18’s r.ScreenPercentage=100, so make sure to do extensive performance testing.”

According to the table on that page, a game would by default run on 140% ScreenPercentage for the Vive, which would explain a drop in performance. However, mine is set to 100% by default, but I sometimes test it in 160%, which runs fine. So there might be more to this… will have to test when I get the time.

I also struggle with framedrops in 4.19 where in 4.18 everything was fine. In my 4.18 i did extensive testing with both Vive and Oculus with 140/130 SS respectively. On 4.19, i reset it to 100 as recommended and PD to 1, which technically (as i understand it) should yield the same result. Hope someone could suggest a solution, or how to locate the cause. Im currently going through the profiler, but that just shows that in gpu bound, which i know already… but doesnt show me what is the main cause.

I’ve noticed the same thing with 4.19.2. Same level, same settings (except changed the r.ScreenResolution value to give the same results) and the performance its noticably worse on 4.19 compared with 4.16 and 4.18. There is definitely a bug in 4.19 somewhere

I just did a test in 4.20p5 seems very promising. I can’t say for sure though, since i can currently not package due to a plugin that isn’t compatible with the unreleased 4.20, but the PIE hitching seem to be either gone or much better. I really cross my fingers this is finally fixed… whatever it was.