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  • 35 Comments
Joined 2 years ago
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Cake day: July 19th, 2023

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  • You’ve just invented time travel.

    The basic flow is
    [user input -> render 33ms -> frame available]
    It is impossible to have a latency lower than this, a newer frame simply does not exist yet.

    But with interpolation you also need consistent time between frames. You can’t just present a new frame and the interpolated frame instantly after each other. First you present the interpolated frame, then you want half a frame and present the new frame it was interpolated to.

    So your minimum possible latency is 1.5 frames, or 33+16=59ms (which is horrible)

    One thing I wonder tho… could you use the motion vectors from the game engine that are available before a frame even exists?


  • It’s worse

    • render frame 1 - 33ms
    • render frame 2 -33ms
    • interpolate frame 1|2
    • show frame 1
    • start rendering frame 3…
    • wait 16ms
    • show frame 1|2
    • wait 16 ms
    • show frame 2
    • interpolate frame 2|3
    • start working on frame 4…
    • wait 16ms
    • show frame 2|3
    • wait 16 ms
    • show frame 3 -> this is a whole 33ms late!

    And that’s while ignoring the extra processing time of the interpolation and asynchronous workload. That’s so slow, that if you wiggle your joystick 15 times per second the image on the screen will be moving in the opposite direction