[Solved] delay inroduced by the filter

[dynamite]

Hello.

I’m going to develop a gaze-controlled game in which targets will be moving and a high user reaction speed may be required.

I will used Tobii Eyetracker 4C and Tobii Core SDK.

The developer’s documentation mentions that “The data is lightly filtered for stability”.

Could you tell me please, how long can be the delay inroduced by the filter?

Thanks in advance,
Evgeniy

[Grant [Tobii]]

Hi @dynamite, in fact you have a number of options available to you when receiving the gaze data stream via the Tobii Core SDK:

“Lightly filtered” (i.e. the default) is an adaptive filter which is weighted based on the age of the gaze data points GazePointData and the velocity of the eye movements. This filter is designed to remove noise and in the same time being responsive to quick eye movements, so hopefully this option should not pose an issue for your application in terms of responsiveness.

However, should you find any delay a hindrance you may select “Unfiltered” where no filtering is performed by the Interaction Engine (except for the removal of invalid data points and the averaging of the gaze points from both eyes).

Selecting this option however is not without it’s drawback as the gaze point is an intrinsically noisy signal, as so the filters are used to stabilize the signal. There is therefore a trade-off between stability and responsiveness, so I would recommend you test out your application with both options and decide which suits you best for your own particular needs.

[dynamite]

Thank you for your reply!

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