Hi @rasa, no the method I described would not be suitable to calculate the saccadic amplitude as this metric is determined between *fixations* of eye movements, not raw gaze locations which are inherently noisy.
You would need to integrate a fixation filter yourself from the literature (we do not provide one) in the code and thereafter determine the distance travelled between the two fixation points over a time period.
A number of third parties have created Matlab fixation filters which perhaps you can translate for your purposes in Unity:
https://se.mathworks.com/matlabcentral/fileexchange/56236-djangraw-gazevistoolbox
& one in R:
https://github.com/davebraze/FDBeye/wiki/Researcher-Contributed-Eye-Tracking-Tools
So, either you create the Fixation Filter yourself or work with the Tobii Pro Lab Software (https://www.tobiipro.com/product-listing/tobii-pro-lab/) which will determine this data for you.
In any event, you need to be aware that any analysis of data undertaken using the EyeX and associated SDK’s (Unity, Core SDK, etc) in expressly prohibited without the purchase of a special analytical licence. More information regarding this can be found @ https://analyticaluse.tobii.com/