How can you test for VR latency?

1 Measure the motion-to-photon latency

One way to test for VR latency is to measure the motion-to-photon latency, which is the time it takes for a user's head movement to be reflected on the VR display. This can be done using a high-speed camera and a sensor attached to the VR headset. The camera captures the frames of the VR display, while the sensor records the orientation and position of the headset. By comparing the timestamps of the camera and the sensor, you can calculate the motion-to-photon latency. Ideally, this should be below 20 milliseconds to avoid noticeable lag.

2 Use a latency tester device

Another way to test for VR latency is to use a latency tester device, which is a hardware tool that simulates the user's input and output in VR. The device consists of a LED, a photodiode, and a microcontroller. The LED flashes a signal to the VR display, while the photodiode detects the response from the display. The microcontroller measures the time difference between the LED and the photodiode, which is the VR latency. This method can test for different types of latency, such as rendering, display, and network latency.

3 Apply a software-based tool

A third way to test for VR latency is to apply a software-based tool, which is a program that runs on the VR device and measures the latency internally. The tool can use various techniques, such as injecting a synthetic frame, tracking the frame rate, or analyzing the GPU performance. The tool can also generate reports and graphs that show the latency over time and under different conditions. Some examples of software-based tools are Oculus Latency Tester, SteamVR Performance Test, and VRMark.

4 Conduct a subjective test

A fourth way to test for VR latency is to conduct a subjective test, which is a method that involves asking the users to rate their VR experience based on their perception of latency. The subjective test can use different scales, such as Likert scale, numerical scale, or verbal scale, to measure the users' satisfaction, comfort, and presence in VR. The subjective test can also include questions about the users' symptoms, such as nausea, headache, or dizziness, which can indicate high VR latency. The subjective test can complement the objective methods and provide valuable feedback.

5 Compare different VR platforms

A fifth way to test for VR latency is to compare different VR platforms, such as PC-based, mobile-based, or standalone VR devices. The VR platforms can have different levels of latency depending on their hardware specifications, software optimization, and network connectivity. By testing the same VR application or content on different platforms, you can evaluate how they perform in terms of VR latency. You can also compare the results with the recommended or acceptable VR latency standards, such as those from the International Telecommunication Union (ITU).

6 Optimize the VR application

A sixth way to test for VR latency is to optimize the VR application, which is the process of improving the efficiency and quality of the VR content. The optimization can involve reducing the complexity of the graphics, audio, and physics, as well as adjusting the resolution, frame rate, and rendering settings. The optimization can also involve using techniques such as asynchronous timewarp, reprojection, or foveated rendering, which can compensate for the fluctuations in VR latency. The optimization can help to achieve a consistent and low VR latency, as well as a better VR experience.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?