Skip to main content
gunair
Up and Coming
September 28, 2014

Frame rate too high = judder! How to force only 75 frames???

Hello from Germany.

I have an unusual problem. I worked hard in the last weeks to optimize the performance of my demo scene to get 75 frames. Now I was nearly successfull - the judder is nearly gone. But now, in some areas of the scene (I'm flying through) the performance is too good - I get frame rates up to 100 and above. Equal to a frame rate below 75, the Rift reacts with judder. So my question:

How can I force Unity or the Rift (or the Nvidia GPU) to show only 75 frames, even if there is enough performance to do more???

Thanks in advance!

Greets, Gunair
    This topic has been closed for replies.

    3 replies

    Proton
    Up and Coming
    September 28, 2014
    I get best results in DX11
    Edit > Project Settings > Player
    > Other Settings
    > Use Direct3D 11

    The Oculus driver seems to handle VSync. So you can use code like this to turn it on and off:
                     if (OVRDevice.HMD != null) {
                        uint caps = OVRDevice.HMD.GetEnabledCaps();
                        if (!useVsync)
                            caps |= (uint)OVR.ovrHmdCaps.ovrHmdCap_NoVSync;
                        else
                            caps &= ~(uint)OVR.ovrHmdCaps.ovrHmdCap_NoVSync;

                        OVRDevice.HMD.SetEnabledCaps(caps);
                     }


    In DX9 mode, you could try going into:
    Edit > Project Settings > Quality
    Then for each Quality level you use, change VSync Count to Every VBlank. I think DX11 ignores it, not sure if DX9 uses it.
    Twitter - Time Rifters
    molton
    Up and Coming
    September 28, 2014
    DX9 doesn't ignore the vsync, I had a weird problem with the frame rate being too high in directx9 it would get so hign in some cases (300fps) that it would throw off the Time.deltatime based calcualtions. I put the vblank every frame option on and it solved the problem.
    CubicleNinjas
    Up and Coming
    October 7, 2014
    "Proton" wrote:
    I get best results in DX11
    Edit > Project Settings > Player
    > Other Settings
    > Use Direct3D 11

    The Oculus driver seems to handle VSync. So you can use code like this to turn it on and off:
                     if (OVRDevice.HMD != null) {
                        uint caps = OVRDevice.HMD.GetEnabledCaps();
                        if (!useVsync)
                            caps |= (uint)OVR.ovrHmdCaps.ovrHmdCap_NoVSync;
                        else
                            caps &= ~(uint)OVR.ovrHmdCaps.ovrHmdCap_NoVSync;

                        OVRDevice.HMD.SetEnabledCaps(caps);
                     }



    Thank you Proton! You've saved me twice in one day with these tips. Really appreciate it.

    When I use the above Unity loses its mind. I've probably implemented it incorrectly, but curious as to how it should be used as I'm not familiar with C#. Right now I'm defining a public class and using this in the start area, but that isn't working for me.

    And can confirm with Molton that DX9 requires every VBlank as well for best performance.
    Cubicle Ninjas Custom VR App Development Guided Meditation VR for Rift, Gear, and Go
    Terms & ConditionsAccessibility statement