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renderingframe-rateunreal-engine4oculus

Oculus only Low FPS (UE4)

I am experiencing a weird issue developing with Unreal Engine 4.

I have a scene, containing some transparent object, forward rendering, using a second render camera (render to texture) that is 90fps proof on Vive, WMR, but is ~60fps using Oculus. Even weirder, I reduce GPU usage and it becomes 90fps in editor but is still ~60fps in shipping.

Do you have some hints about this Oculus only performance issue?

Thanks for any help.

Solution

  • Because of what is basically forced vsync in the headset, you are locked into integer fractions of 90hz. (2/3-60hz, 1/2-45hz, 1/3-30hz, etc). When frametimes are too high to maintain 90hz, the frame rate steps down to 60hz for at least a few frames.

    You might be right on the edge of performance for your app. You can verify this with the STAT UNIT or STAT DETAILED console commands.

    There might be extra CPU performance overhead for the Oculus‘ tracking software.