3.0 Alpha 2 Direct to HMD Judder

[reject]

Hey there,

I appreciate the amazing work you guys are doing. Previously I was using Runtime 4.4 with Virieo 2.16. In extended mode, it was working great.

I went ahead to try out the new alpha(updated my rift runtime to 6.01) on my DK2 and I noticed a huge performance dip instead of performance increase. Is it possible the issue is because there it now broadcasts the game on both the rift and your monitor? Is there plans to disable this option?

I tried Mirror's Edge and Fallout NV, both were fine in the "billboard" mode but as soon as I went into VR mode(enabling head tracking), the judder was unbearable(about 40 fps, before I was getting 70-75). Additionally I had the 350.12 nVidia drivers, I tried the newest ones, neither made any difference. Any thoughts?

My specs are the following:

Windows 8.1 x64
i5-2500k
GTX 970
12GB DDR 1600
256GB SSD

[DrBeef]

Could you check you haven't inadvertently turned on SDK Pose Prediction (which isn't working at the moment). It shouldn't have horrific judder without it switched on (I think, off the top of my head, the hot-key to turn it on/off is LSHIFT+DEL).

Really, even at 40FPS, it should be largely judder free, due to the timewarping, there might be the occasional glitch, but nothing too serious.

[reject]

That did it! It was enabled. Looks like I'm going to need to upgrade my CPU, my computer is struggling between 20-40fps on it-- however you're right, after I disabled Pose Prediction, head tracking is judder free.

Is there any way to disable the streaming monitor, or plans to have that option incorporated?

[DrBeef]

Excellent!, glad to hear it was easily solved.

There shouldn't be much impact of having it rendering on the monitor.. Pretty sure it can't be disabled either. What you see on the monitor is the actual game rendering device.. what is shown in the rift is merely a DX11 "scene" containing a simple rectangle that uses the left and right eye buffers as textures. It seems counter intuitive, but the monitor isn't really showing a "mirror", it is the rift that is the mirror of sorts (to a specially implemented DX11 scene) the game that is being played on the monitor. As such, it has to be there.

Part of the problem may also be the introduction of the post-present sleep, which is used to reduce flickering, as the GPU isn't necessarily finished rendering at the point the textures are copied to the DX11 scene, the sleep (which is configured through Overall Settings) ensures that there's a high chance of it having finished. You might find you can increase the FPS a bit by reducing the number, but it will be at the cost of aesthetics.