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Gomoto's avatar
Gomoto
Honored Guest
12 years ago

UE 4.5.1 / SDK 0.4.3 direct to rift and hmd mirror off

With direct to rift mode do not use: hmd mirror off

With "hmd mirror off" direct to rift mode does not work correctly, 0 FPS.
With mirroring the direct to rift mode works very good here, 75 FPS, 13 ms.

(UE 4.5.1 / SDK 0.4.3 / GTX 970)

8 Replies

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  • Well Direct mode with mirroring off doesn't work for me either; with mirroring on it kind of works but it's unusable in my case.. Places where i'm getting solid 75 fps in Extended mode (eg SunTemple demo with sp=135), i get about 37 fps in Direct mode.

    (UE 4.5.1 / SDK 0.4.3 / R9 290)

    I think i'll have to wait for UE 4.6 before updating to Oculus 0.4.3, shame 4.5 has just come out..
  • Gomoto's avatar
    Gomoto
    Honored Guest
    Do you have Aero enabled. Iracing for example is only playable in direct mode if Aero is enabled here.
  • "Gomoto" wrote:
    Do you have Aero enabled. Iracing for example is only playable in direct mode if Aero is enabled here.

    Yep with Aero off it didn't even work, with Aero on and Direct mode i get 1/2 the framerate.

    Can i ask, are you working against the standard 4.5.1 or did you compile from GitHub? That might be another option for me to try..

    Anyway I think it's probably more due to my AMD card, since both Oculus and Epic clearly favor NVidia. Would be cool to know if anyone with AMD has managed to get it working!
  • Ok did a few more quick tests and managed to get Direct mode working both with Aero on and off, and both with mirroring on and off, not sure what is different from before though..

    What i think might be happening in my case is that the overall performance is only slightly worse than in 0.4.2, BUT they seem to have implemented a new method which forces half the refresh rate if you don't reach full 75 fps; i assume they've done this in order to avoid crazy judder and to play nicely with vsync, which kind of makes sense.

    Problem is if you were just about hitting 75 fps before (0.4.2), then the small hit in performance of 0.4.3 in combination with this new "snap fps" method means you are now constantly jumping from 75 to 33 fps, which makes the experience really terrible. Still, need to do some more testing. :geek:

    On the plus side, when everything is working the lower latency is really awesome, you can really feel it! :o
  • knack's avatar
    knack
    Honored Guest
    i lost 25fps in my application from 100 to 76, from 0.4.2->0.4.3
    i try keep up 90fps for CV1 now i fucked again, anyway i wait for integration of 0.4.3 with unreal and hope my fps going back again before suicide my oculus dropping from a bridge

    if not, that going to be very annoying. my knowledge are very limited i can't develop with this problems with every release.

    not happy :/
  • owenwp's avatar
    owenwp
    Expert Protege
    That "snap" is vsync, its nothing new. Low persistence and timewarp don't really work without it, so its unavoidable.
  • "owenwp" wrote:
    That "snap" is vsync, its nothing new. Low persistence and timewarp don't really work without it, so its unavoidable.

    Well the snap to 37.5 fps is new to this version; with 0.4.2 i could have low persistence with vsync on, if i went below 75 i would simply get judder. I guess it's more related to timewarp..

    What i find strange (by testing turning vsync on and off in the same places of a level) is that it seems to snap to 37.5 as soon as i get below 85 fps, not 75 fps, which makes the clear performance reduction of 0.4.3 even worse to swallow.
  • owenwp's avatar
    owenwp
    Expert Protege
    With vsync, if your frame takes longer than the display refresh time to render, the framerate must drop to half (and if even that is too long, half of that, etc). That is how all vsync works, not just in the rift.

    Now, if your performance is borderline, maybe it only drops below the refresh rate occasionally, so the app isn't continuously running at half rate, so yes that could be indicative of just overall longer render times.