[Solved] Can Tobii 4C Extend view range outside of screen?

[Jianhong]

Hi,
I want to develop my WPF application based on tobii 4c to display real-time eye-gaze. Generally, the tracked eye’s view range is within a PC’s screen. And now, I want to extend the view range,that means when head turns a bigger angle, for example, 30 degree or more, the eye-gaze can still be projected within PC’s screen(My application’s main window).

Thanks a lot for your help.

[Grant [Tobii]]

Hi @chengjh1 and thanks for your query. The gaze co-ordinates as reported by the Core SDK are reported as normalised in reference to the screen area itself, namely the values of x,y lie between 0,1 therefore values outside the screen area are not necessarily viable for use.

Did you mean to suggest that when you turn your head more than 30 degrees, the eyes are no longer captured? So long as the eyes are looking within the screen area, then trackability should still be OK.

It would be helpful if you could kindly describe in more detail the scenario you are working with and we will do our best to help you out!

[Jianhong]

Hi Grant,I appreciate your response and explanations.Right,the gaze within the screen area, the trackability works well. Moreover, 1)I expect wider areas can be mapped into my app’s main win and presented visibly,thus,the gaze outside the usual screen area can also be seen, that’s just like a kind of scale. And also, the current calibration mode can only be at the bottom of the screen, 2)I think it wonderful to provide more flexible modes, such on the top of the screen, and so on. At last, as my investigation, the 4c is still able to capture the gaze outside the usual screen area, but only very narrow area. If more, the trackability will be lost, so, once header turn a small degree,the gaze will lose, that should be the 4c’s work scope..Thanks again.

[Grant [Tobii]]

Hi @chengjh1, The Tobii 4C calibration setup is indeed locked into being at the bottom of the screen only as this is the most optimal position to avoid interference for artifacts such as user eye lashes which can seriously impact trackability. Should you need a customised setup however, then it would be necessary to look at the Tobii Pro range of trakers for which some can offer alternative mounting scenarios.

I am afraid that the tracking area is very much dependent on the internal camera of the eye tracker and are designed to operate only within a maximum distance as specified by the screen being used (maximum is nominally 27 inches). Accordingly, there is no methodology for mapping gaze data outside this area scaled back onto the screen although you can of course use any gaze data captured that is outside the normalised screen coordinates and apply your own custom transformation.
Hopefully you can find a workaround for your needs in this regard. Please let us know of any further info we can provide.

[Jianhong]

I see,thanks a lot.

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