Hi @oleksandrdubyna88, can you kindly clarify which API of the Core SDK you are using please?
Firstly, with regard to the Sample Application Interaction_Interactors_102 not detecting gaze properly,
a number of causes spring to mind. Are you sure to have Tobii.EyeX.exe running? Check process explorer to be sure. I assume the Tobii Tray icon is present and you can calibrate successfully? Are you sure to be running the latest
version of the both the Tobii Core software and SDK?
The sample application is very simple, so the issue most likely lies in the Core software not running.
In terms of adding a fixation for an interactor, you could use the FixationDataStream to detect the presence
of a fixation for each individual element within wpf:Behaviors.HasGaze routine.
More details @ https://tobii.github.io/CoreSDK/articles/streams.html
I would first focus on getting the basic samples to run correctly first.. please go through the steps above and kindly
get back to me if you are still having troubles.