paulm

Actually for collecting the eye data I do still use an almost unaltered eye data callback function like described in https://forum.vive.com/topic/9341-vive-eye-tracking-at-120hz/ . I do still use the timestamp which comes with it as I suppose that it is an altered system timestamp. Using Windows & Unity: private void Update() { long timestamp = 0; SRanipal_Eye_API.SRanipal_GetSystemTime(ref long timestamp) Vector3 headPose = Camera.main.transform.rotation.eulerAngles; timestamp = SRanipalSystemToEyeTrackerTimeStamp(long timeStamp) } I am proposing that the timestamp above can now be compared with eyeData.timestamp which you get through the eye data callback function for synchronizing purposes. Cheers. 😃

I assume that SRanipal_Eye_API.SRanipal_GetSystemTime(ref long timestamp) gives you the you the tick count since system start. To get it along the EyeData.timeStamp you could use this: int SRanipalSystemToEyeTrackerTimeStamp(long timeStamp) { // Value is generated by observation long maxEyeDataTimestampValue = uint.MaxValue; timeStamp %= maxEyeDataTimestampValue; // Magic trick to round the integer at the fourth last digit timeStamp += 500; // Cutting of the last three digits timeStamp /= 1000; return (int) timeStamp; }

I guess SRanipal_Eye_API.SRanipal_UpdateTimeSync(); should do the trick.