Skip to main content
Up and Coming
August 27, 2014

4.4.1: Anyone able to run 'Minimum Default' without judder?'

I'm fiddeling around with Unreal Engine 4's Oculus integration but I am not able to get this to work right (I use Direct HMD Mode) even with the most basic level (First Person Level Blueprint), here's a screenshot of the level:



Here's what I tried:
- Disabled mirroring (using console command 'hmd mirror off')
- Set 'Min Desired Frame Rate' in project settings to 75 fps
- Deactivated 'Smooth Frame Rate'
- Started game in own process

My System:
- Core i5 4750
- 8 GB RAM
- Win7x64
- NVidia GTX 760
- Unreal Engine 4.4.1
- Oculus Runtime 0.4.1

Game judders as hell like there is no tomorrow. What am I doing wrong here?

See attached logs for more details.

spyro

PS: Does anyone know how to show the average frame render time in gameplay so that I can view in in the Rift?
    This topic has been closed for replies.

    31 replies

    Up and Coming
    August 28, 2014
    What do you see if you use 'stat fps'?
    Up and Coming
    August 28, 2014
    Try also to reduce the quality by 'hmd sp 100' (use 'hmd sp reset' to reset screenpercentage back).
    Participant
    August 28, 2014
    Unfortunately only disabling the Dynamic Shadow will get you a smooth image .
    New Participant
    August 28, 2014
    I think I'm also seeing the same issue. When using the stats I see the render time spike approximately every second leading to the judder. This happens with the built in viewport, standalone preview windows and a fully built exe with the editor shut.

    This happens with a very basic scene, and does not change with render quality.

    The only way I've found to prevent the judder is to disable Direct mode on the oculus.

    Specs:

    i5 2500K
    8GB
    R9 290
    DK2
    Windows 8.1
    spyroAuthor
    Up and Coming
    August 28, 2014
    "artyom17" wrote:
    What do you see if you use 'stat fps'?


    I am not able to see any stats when in Rift mode. They are only visible in the viewport of the editor which can't be sent to Rift for some reason. I have to start the game as standalone for this - and all the stat information seems gone.

    When I reactivate mirroring I am able to see the stats partly on the right edge of the screen in Rift Mode.
    (EDIT: 'stat fps' seems ok, the problem remains with 'stat unit'.)

    The values change very fast but they go never over 60 fps. When using 'stat unit' I can clearly see that the render time for each frame is between 16 and 17 ms. So it seems to be a bug with the Direct HMD Mode implementation. The game locks on 60 fps.

    Here are my project's frame rate settings:



    In the editor's viewport it runs with a much higher framerate without problems, so it's no general frame lock:
    http://s1.directupload.net/images/140828/g87aqltu.png


    spyro
    spyroAuthor
    Up and Coming
    August 28, 2014
    "cryotex" wrote:
    I think I'm also seeing the same issue. When using the stats I see the render time spike approximately every second leading to the judder. This happens with the built in viewport, standalone preview windows and a fully built exe with the editor shut.


    How did you manage to view stats through the Rift? Is it possible to show stats the center of the screen like on Unity demos?

    "cryotex" wrote:

    The only way I've found to prevent the judder is to disable Direct mode on the oculus.


    Tried this, too. The judder remains, but I am not able to see the stats because they are too much on the right to focus them through the Rift (mirroring doesn't work in extended mode).

    spyro
    spyroAuthor
    Up and Coming
    August 28, 2014
    "ipas" wrote:
    Unfortunately only disabling the Dynamic Shadow will get you a smooth image .


    Nope, the judder remains even then...

    spyro
    New Participant
    August 28, 2014
    "spyro" wrote:

    How did you manage to view stats through the Rift? Is it possible to show stats the center of the screen like on Unity demos?


    Sorry I'm not sure, I haven't got that far yet. I'm getting this judder on my main display as well as the rift. For me it's definitely something to do with the rift being in direct mode.
    Up and Coming
    August 28, 2014
    It is true that Direct Mode steals about 10% of framerate in latest drivers/SDK. We are working on it and hopefully we will release a new integration/runtime soon. In a meantime use Extend mode.
    Like I said, you must check the FPS by 'stat fps' command to make sure it is not below 75.
    You also may check which part of rendering takes the most time by 'profilegpu' console command.
    spyroAuthor
    Up and Coming
    August 28, 2014
    Ok, did some stats. It seems that with default settings it's nearly impossible to reach 75 fps, regardless how simple my scene is. Here's a screenshot from the profiler: http://s1.directupload.net/images/140828/fxtaeabc.png

    I'm not really sure how to read this. Is the gray bar representing the whole frame = 13.3 ms? If so, does that mean that the GPU is doing nothing for several ms to the end of the time frame? So why is the game juddering (maybe an issue with timewarp scheduling or something...?)

    As you can see, the total rendertime is a little over the maximum 13.3 ms for 75 fps (13.61 ms) but that seems to be in contradiction with the picture of the bar... :?

    With 'HMD SP 100' the simple test scene runs fine.

    MobileTemple runs with > 75 fps then, too. But this is only when I cook/package it, running it from the PLAY menu in it's own process seems drastically lower the FPS, don't know why.

    spyro