What's the Fixation Thresholds in Magic Leap 2 Gaze Recognition

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Hi everyone,

I'm working with the eye tracking system on the Magic Leap 2. I'm trying to figure out what thresholds or parameters the system uses to determine a fixation.

Does anyone have insights on:

  • Velocity Thresholds: What's the eye movement speed below which a fixation is detected?
  • Duration Thresholds: How long does the gaze need to stay in one area to count as a fixation?
  • Spatial Dispersion Thresholds: What's the maximum allowable movement within a fixation zone?
    Thank you!
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Hey @KaiZ,

Welcome to the Magic Leap Developer Forums!

These values are currently not published anywhere publicly.
I have shared this request with the Voice of Customer team to see if we can share these values or not.

I will update here once I have a definite answer for you!

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@KaiZ

After collaborating with the team, we concluded that we are able to publish some of this information!

Directly from our Computer Vision team:

We don't have an explicit velocity threshold, fixation classification is made by a process of exclusion: We check to see if it is a saccade (using a variation of this paper https://www.researchgate.net/profile/Dorion-Liston-2/publication/256970171_Saccade_detection_during_smooth_tracking/links/5a01e0e9aca272e53ebe8d9c/Saccade-detection-during-smooth-tracking.pdf). If it's not a saccade but the movement exceeds the spatial dispersion threshold (0.6 degrees of movement in an 80ms window) then it's a pursuit and otherwise it's a fixation.

Also, some of the values were tuned a little bit for our particular system (for example the size of the window depends on the frame rate of the camera)

The research paper linked above should give you more details.
I hope this helps! Please let me know if you have any more questions.

1 Like
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thank you so much! that's very helpful