About Mixed Reality Toolkit Input Manager
The HoloToolkit Input Manager prefab is an empty (nongraphical) object that includes the components Gaze Manager, Input Manager, and (in a child object) Gestures Input, as well as others. You can open these scripts to read through them and see in detail what they do and how they're implemented.
Gaze Manager
The GazeManager provides a useful Unity interface for managing the gaze ray-the user's camera view direction-and its interaction with other objects in the scene. This includes the current HitInfo (see https://docs.unity3d.com/ScriptReference/RaycastHit.html). GazeManager is a singleton class, ensuring that there is only one instance in the scene. In each game update, it gathers the current gaze info and does a physics raycast to see if any objects are at the center of the user's view. It also includes some magic goodness to stabilize the gaze pose for comfort, compensating for the fact that it's tied to your head movement, which may not be as smooth...
