Motion-to-Photon Latency Simulator

Head Tracking

Motion-to-photon latency 40 ms

Head turn speed 90°/s

Display refresh rate 90 Hz

Angular error

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Frame budget used

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Sensory-conflict risk

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Peak error (5s)

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How it works

Every VR frame is rendered from a head pose sampled slightly in the past. By the time the photons reach your eyes, the true head angle has moved on — that gap is the motion-to-photon latency. The faster you turn and the longer the pipeline delay, the further the image lags behind reality, and it is exactly this visual/vestibular mismatch that the inner ear flags as wrong.

angular error ≈ turnRate · latency
risk score   ≈ clamp(error / 8°, 0, 1)

Motion-to-photon latency — total delay from sensor sample to displayed photon; industry guidance targets under ~20 ms to stay below the perceptible threshold.
Head turn speed — how fast the simulated head yaws; faster turns amplify any fixed latency into a larger angular error.
Display refresh rate — how often a new frame can appear; a lower rate adds its own frame-interval delay on top of the pipeline latency.
Timewarp — asynchronous reprojection that re-orients the last rendered frame toward the very latest head pose just before scan-out, shrinking the visible error without re-rendering the scene.

The chart's dashed cyan needle is the true head angle right now; the solid orange needle is what the display is actually showing you. The gap between them, traced over time in the strip chart below, is the raw material of VR motion sickness.

True head angle Rendered (delayed) angle Error strip chart