Matinee and Oculus RIFT DK2


I created a matinee inside unreal editor with a camera travel.

My question is how do I create a node tree in BP so I have a GUI button created inside Unreal that I need to look at it with Oculus Rift so then the matinee starts playing?

I dont know how it will detect user is looking at button to it activates the sequence.

Thank you for your help.