How to check left/right blinking

[Supachai Tengtrakul]

Hi,
I noticed that Tobii4C seems to know whether I blink my left/right eye, but I looked it up and it’s nowhere to be found in UnitySDK documentation. This is quite essential to my research so I want to know whether this feature is available in UnitySDK or not. I did look it up but I still found no clear answer.
Thank you.

[Grant [Tobii]]

Hi @me-supachai, thanks for your query. Unfortunately, the Unity SDK does not include a blink detection algorithm nor is individual eye validity exposed programmatically.

You could in theory create your own custom blink detection algorithm within using a loop counter of around 200ms based on gaze validity, but this may not provide the most accuracy for your needs. Accordingly, if you need access to individual eye validity data, you will need to use the Tobii Stream Engine API for these purposes.

Please also bear in mind that using either the Unity SDK or Stream Engine API for analysis or research requires the purchase of an analytical licence to do so.
You can read more about this @ https://analyticaluse.tobii.com/

If you could kindly describe in more detail your project intentions, we will do our best to help you out! Best Wishes.

[Supachai Tengtrakul]

I’m not sure whether I need an analytical license or not because I just want to make a system that recognizes individual eye blink then test whether it works well or not. I don’t think I need to store any of eye gazing data or transfer them anywhere to be analyzed or anything. Do I still need the license for this case? Also, can I use Stream Engine API without the licence and does it work with Unity?

[Grant [Tobii]]

Hi @me-supachai okay thanks for the clarification.

The stream engine API is not designed to work in conjunction with the Unity SDK so you will need to choose one or the other for your blink detection. As previously stated, if you use the Unity SDK, you will only be able to detect validity on both eyes captured which could still be used theoretically to capture blinks by creating a custom loop timer (of around 300-400ms) though this technique will be less reliable than if you have both eye validitys exposed and can introduce a more sophisticated algorithm for blink detection.

So long as your intention is for interaction, then you should not need worry about the analytical licence. We would recommend first trying with Unity a simple loop counter and let us know if you think it’s accurate enough for your needs.

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