Hi @rasa, there would only be an issue if you were somehow using both the Core SDK and the Unity SDK within the same program which is not the case.
When developing in Unity you need only consider that their own co-ordinate system ie (0,0) bottom left.
he co-ordinates displayed by unity should be read as (0,0) from bottom left and co-ordinates displayed by Tobii Eye X be read as (0,0) from top left ?
I a not sure what you mean by co-ordinates displayed by EyeX… all gaze data reported within the Unity SDK will be using the same consistent co-ordinate system. ie (0,0) bottom left.