Latency in virtual reality (VR) and mixed reality (XR)
Low latency is extremely important for mixed, augmented, and virtual reality content. The main reasons why lower latency is better are the elimination of cybersickness and achieving a deeper immersion.
As a person moves their head, a headset should display the resulting changes almost immediately. If there is a significant delay, the user’s brain will reject the virtual world, causing them to lose immersion. This can, in turn, cause nausea and reduce the effectiveness of learning outcomes, for example.
In research, a meaningful latency threshold for virtual and mixed reality has been determined to be around 20 milliseconds. While humans can detect very small relative delays in parts of the visual field, when absolute delays are below approximately 20 milliseconds, they are generally imperceptible. Going below this threshold eliminates a major cause of cybersickness and achieves much deeper immersion, especially when combined with high resolution.
Achieving this is somewhat easier in virtual reality, where the user is shut out from the real world and only sees digital content. It is much more challenging in mixed reality. Mixed reality using video pass-through uses cameras to digitize the world in real-time. That data is then combined with virtual content inside our GPU and shown to users through the mixed reality device – completely blurring the lines between real and virtual. where digital objects blend with the real world, and the digital content needs to react to the real world fast enough so immersion does not break.