Hi @rasa, whilst it is a nice idea, unfortunately the derivate of the raw gaze locations against their respective time points is not a reliable way to calculate saccadic amplitude as this metric relies on the distance travelled between gaze *fixations*.
To determine therefore Saccadic Amplitude within your program you would need to integrate a fixation filter yourself from the literature 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 perhaps translate for your purposes in Unity:
& one in R:
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 licence.