UE4.9.1 does not recognise Rift with 0.6.0.1, and has game breaking performance with 0.7.0.0

[Sam_Deiter]

@mechanicalsnowman;385937

Thanks for replying Sam, I’ll get on that troubleshooting right now and get back to you within an hour or so –

My GPU is a GTX680 4GB,

One thing though, your driver is not the onerecommended by Oculus for the runtime 0.7:

Does this mean that the direct driver mode is not actually necessary? My technical knowledge of this kind of thing is admittedly lacking, I assumed that the two (runtime and nVidia driver) needed to go hand-in-hand.

Edit - r.ScreenPercentage does not change anything in stereo, the command there is HMD SP, right? Should I be using that instead?

Edit 2 - showlog window states that HMD SP is an unknown command when I type it on it’s own. Setting HMD SP to a number makes it work though, so I’ve deduced that the default HMD SP is 100, and setting it to 130 drops the framerate from a choppy 75 to a solid 50, as if it’s being synch’d. Bringing it down to 80 brings back the performance to how it was on 0.6 and 4.8 / 4.9.

I’m going to install 350.12 now to see if that increases performance.

Edit 3 - I made a mistake with Edit 2. After installing 350.12 and testing, and then re-installing 355.98, I can now reach a HMD SP of 110 with a solid 75 fps. I had forgotten to turn off a test feature I was working on that isn’t optimized yet.

So in summary

• Lowering HMD SP does make the game renderable. If 130 is the default value then setting this to 110 achieves the same performance as I had with 4.9.0
• A particularly CPU heavy feature that ran fine on 4.9.0 w/0.6 seems to hit performance harder in 4.9.1 w/0.7 (no matter the screen percentage value)
• 350.12 and 355.98 have comparable performance (though when there are frame drops in 350.12, there is a strange tearing artifact on the Rift’s right eye. Frame drops appear simply as jitter on 355.98 with no tearing. This visual artifact is only present in the Rift display and not on the monitor displaying the Rift’s feed)

Hey Mechanicalsnowman,

Thanks for testing this and getting back to me with the results. Let me clarify a few things as it looks like I did in fact give you some incorrect information.

Does this mean that the direct driver mode is not actually necessary? My technical knowledge of this kind of thing is admittedly lacking, I assumed that the two (runtime and nVidia driver) needed to go hand-in-hand.

I have no idea about direct driver mode but I can look into this and see what more info I can get about this.

One thing though, your driver is not the one recommended by Oculus for the runtime 0.7:

I tried the 355.83 drivers and I could not get my HMD to attach to UE4 in VR. I was able to get everything working using the 350.12 drivers so I just rolled back. I have not tried the latest ones again because I was in the middle of working on something so I just needed things to work and that is why I used the older version because I knew that one worked. When I get some more time to dig deeper into this I will have a look and see if I can figure out what is going on.

r.ScreenPercentage does not change anything in stereo, the command there is HMD SP, right? Should I be using that instead?

This is correct however what r.ScreenPercentage does is tell you the current screen percentage and that is what I wanted to know. However now that I am re-reading my post I was completely wrong in saying use r.ScreenPercentage to set your Screen Percentage and you should in fact be using HMD SP (Number you want to use) command. Sorry about that it completely did not register that I was using the wrong command when I was writing the response as I was thinking HMD SP in my head but was actually writing r.ScreenPercentage. Also adjusting the HMD SP should be the last thing that you do when trying to get your game to run at desired frame rate.

Thanks again for testing this out and positing such detailed results. If I figure anything else out I will make sure to let you know and if you figure anything else out please respond back to this thread so that I can track it.

Cheers-

Sam Deiter