hololens官方教程HoloToolKit中部分代码的理解

1.Gaze Manager

using HoloToolkit;using UnityEngine;/// <summary>/// GazeManager determines the location of the user's gaze, hit position and normals./// </summary>public class GazeManager : Singleton<GazeManager>{    [Tooltip("Maximum gaze distance for calculating a hit.")]    public float MaxGazeDistance = 5.0f;    //The maximum distance within which collides can be detected    [Tooltip("Select the layers raycast should target.")]    public LayerMask RaycastLayerMask = Physics.DefaultRaycastLayers;    /// <summary>    /// Physics.Raycast result is true if it hits a Hologram.    /// </summary>    public bool Hit { get; private set; }    /// <summary>    /// HitInfo property gives access    /// to RaycastHit public members.    /// </summary>    public RaycastHit HitInfo { get; private set; }    /// <summary>    /// Position of the user's gaze.    /// </summary>    public Vector3 Position { get; private set; }    /// <summary>    /// RaycastHit Normal direction.    /// </summary>    public Vector3 Normal { get; private set; }    private GazeStabilizer gazeStabilizer;    private Vector3 gazeOrigin;    private Vector3 gazeDirection;    void Awake()    {        gazeStabilizer = GetComponent<GazeStabilizer>();    }    private void Update()    {        gazeOrigin = Camera.main.transform.position;        gazeDirection = Camera.main.transform.forward;        gazeStabilizer.UpdateHeadStability(gazeOrigin, Camera.main.transform.rotation);        gazeOrigin = gazeStabilizer.StableHeadPosition;        UpdateRaycast();    }    /// <summary>    /// Calculates the Raycast hit position and normal.    /// </summary>    private void UpdateRaycast()    {        RaycastHit hitInfo;        Hit = Physics.Raycast(gazeOrigin,                       gazeDirection,                       out hitInfo,                       MaxGazeDistance,                       RaycastLayerMask);        HitInfo = hitInfo;        if (Hit)        {            // If raycast hit a hologram...            Position = hitInfo.point;            Normal = hitInfo.normal;        }        else        {            // If raycast did not hit a hologram...            // Save defaults ...            Position = gazeOrigin + (gazeDirection * MaxGazeDistance);            Normal = gazeDirection;        }    }}

bool Hit   光标是否与物体发生了碰撞；
        HitInfo   用来储存碰撞的信息；
        Position   碰撞点，就是gaze的坐标位置（发生了碰撞时，即Hit == true时），

或是gaze的最远的点（由MaxGazeDistance决定，不发生碰撞时，即Hit == false ）
        Normal 碰撞点的法线，就是gaze的点的法向量（Hit == true 时），或是gaze的方向（就是gazeDirection，当Hit == false时）。

2.Gesture Manager

    public GestureRecognizer NavigationRecognizer { get; private set; }    // Manipulation gesture recognizer.    public GestureRecognizer ManipulationRecognizer { get; private set; }    // Currently active gesture recognizer.    public GestureRecognizer ActiveRecognizer { get; private set; }    public bool IsNavigating { get; private set; }    public Vector3 NavigationPosition { get; private set; }    public bool IsManipulating { get; private set; }    public Vector3 ManipulationPosition { get; private set; }

两种识别器的声明：Navigation和Manipulation；分别声明两个bool类型，判断当前识别器是否在运行中；声明Vector3坐标；

void Awake()    {        /* TODO: DEVELOPER CODING EXERCISE 2.b */        // 2.b: Instantiate the NavigationRecognizer.        NavigationRecognizer = new GestureRecognizer();        // 2.b: Add Tap and NavigationX GestureSettings to the NavigationRecognizer's RecognizableGestures.        NavigationRecognizer.SetRecognizableGestures(            GestureSettings.Tap |            GestureSettings.NavigationX);        // 2.b: Register for the TappedEvent with the NavigationRecognizer_TappedEvent function.        NavigationRecognizer.TappedEvent += NavigationRecognizer_TappedEvent;        // 2.b: Register for the NavigationStartedEvent with the NavigationRecognizer_NavigationStartedEvent function.        NavigationRecognizer.NavigationStartedEvent += NavigationRecognizer_NavigationStartedEvent;        // 2.b: Register for the NavigationUpdatedEvent with the NavigationRecognizer_NavigationUpdatedEvent function.        NavigationRecognizer.NavigationUpdatedEvent += NavigationRecognizer_NavigationUpdatedEvent;        // 2.b: Register for the NavigationCompletedEvent with the NavigationRecognizer_NavigationCompletedEvent function.         NavigationRecognizer.NavigationCompletedEvent += NavigationRecognizer_NavigationCompletedEvent;        // 2.b: Register for the NavigationCanceledEvent with the NavigationRecognizer_NavigationCanceledEvent function.         NavigationRecognizer.NavigationCanceledEvent += NavigationRecognizer_NavigationCanceledEvent;        // Instantiate the ManipulationRecognizer.        ManipulationRecognizer = new GestureRecognizer();        // Add the ManipulationTranslate GestureSetting to the ManipulationRecognizer's RecognizableGestures.        ManipulationRecognizer.SetRecognizableGestures(            GestureSettings.ManipulationTranslate);        // Register for the Manipulation events on the ManipulationRecognizer.        ManipulationRecognizer.ManipulationStartedEvent += ManipulationRecognizer_ManipulationStartedEvent;        ManipulationRecognizer.ManipulationUpdatedEvent += ManipulationRecognizer_ManipulationUpdatedEvent;        ManipulationRecognizer.ManipulationCompletedEvent += ManipulationRecognizer_ManipulationCompletedEvent;        ManipulationRecognizer.ManipulationCanceledEvent += ManipulationRecognizer_ManipulationCanceledEvent;        ResetGestureRecognizers();    }

将navigation的可识别操作设置为单击以及横向移动（手指移动的横向分量将被检测），

将manipulation则设定为manipulationTranslate（大概是跟随手平移）

注册两种识别器的开始，更新，完成，撤销事件。

void OnDestroy()    {        // 2.b: Unregister the Tapped and Navigation events on the NavigationRecognizer.        NavigationRecognizer.TappedEvent -= NavigationRecognizer_TappedEvent;        NavigationRecognizer.NavigationStartedEvent -= NavigationRecognizer_NavigationStartedEvent;        NavigationRecognizer.NavigationUpdatedEvent -= NavigationRecognizer_NavigationUpdatedEvent;        NavigationRecognizer.NavigationCompletedEvent -= NavigationRecognizer_NavigationCompletedEvent;        NavigationRecognizer.NavigationCanceledEvent -= NavigationRecognizer_NavigationCanceledEvent;        // Unregister the Manipulation events on the ManipulationRecognizer.        ManipulationRecognizer.ManipulationStartedEvent -= ManipulationRecognizer_ManipulationStartedEvent;        ManipulationRecognizer.ManipulationUpdatedEvent -= ManipulationRecognizer_ManipulationUpdatedEvent;        ManipulationRecognizer.ManipulationCompletedEvent -= ManipulationRecognizer_ManipulationCompletedEvent;        ManipulationRecognizer.ManipulationCanceledEvent -= ManipulationRecognizer_ManipulationCanceledEvent;    }

注销上述事件

public void Transition(GestureRecognizer newRecognizer)    {        if (newRecognizer == null)        {            return;        }        if (ActiveRecognizer != null)        {            if (ActiveRecognizer == newRecognizer)            {                return;            }            ActiveRecognizer.CancelGestures();            ActiveRecognizer.StopCapturingGestures();        }        newRecognizer.StartCapturingGestures();        ActiveRecognizer = newRecognizer;    }

两种识别器之间的变换，比如当前为navigation识别模式，调用Transition（ManipulationRecognizer）可以使manipulation识别器开始工作。

 public void ResetGestureRecognizers()    {        // Default to the navigation gestures.        Transition(NavigationRecognizer);    }

重置识别器（官方Demo中默认操作是旋转，因此默认的识别器是navigation识别器）

private void NavigationRecognizer_NavigationStartedEvent(InteractionSourceKind source, Vector3 relativePosition, Ray ray)    {        // 2.b: Set IsNavigating to be true.        IsNavigating = true;        // 2.b: Set NavigationPosition to be relativePosition.        NavigationPosition = relativePosition;    }    private void NavigationRecognizer_NavigationUpdatedEvent(InteractionSourceKind source, Vector3 relativePosition, Ray ray)    {        // 2.b: Set IsNavigating to be true.        IsNavigating = true;        // 2.b: Set NavigationPosition to be relativePosition.        NavigationPosition = relativePosition;    }    private void NavigationRecognizer_NavigationCompletedEvent(InteractionSourceKind source, Vector3 relativePosition, Ray ray)    {        // 2.b: Set IsNavigating to be false.        IsNavigating = false;    }    private void NavigationRecognizer_NavigationCanceledEvent(InteractionSourceKind source, Vector3 relativePosition, Ray ray)    {        // 2.b: Set IsNavigating to be false.        IsNavigating = false;    }

各种navigation识别器发生事件之后执行的操作，此处操作是改变IsNavigating的值，即当前识别器的”工作状态“

 private void ManipulationRecognizer_ManipulationStartedEvent(InteractionSourceKind source, Vector3 position, Ray ray)    {        if (HandsManager.Instance.FocusedGameObject != null)        {            IsManipulating = true;            ManipulationPosition = position;            HandsManager.Instance.FocusedGameObject.SendMessageUpwards("PerformManipulationStart", position);        }    }    private void ManipulationRecognizer_ManipulationUpdatedEvent(InteractionSourceKind source, Vector3 position, Ray ray)    {        if (HandsManager.Instance.FocusedGameObject != null)        {            IsManipulating = true;            ManipulationPosition = position;            HandsManager.Instance.FocusedGameObject.SendMessageUpwards("PerformManipulationUpdate", position);        }    }    private void ManipulationRecognizer_ManipulationCompletedEvent(InteractionSourceKind source, Vector3 position, Ray ray)    {        IsManipulating = false;    }    private void ManipulationRecognizer_ManipulationCanceledEvent(InteractionSourceKind source, Vector3 position, Ray ray)    {        IsManipulating = false;    }    private void NavigationRecognizer_TappedEvent(InteractionSourceKind source, int tapCount, Ray ray)    {        GameObject focusedObject = InteractibleManager.Instance.FocusedGameObject;        if (focusedObject != null)        {            focusedObject.SendMessageUpwards("OnSelect");        }    }

manipulation识别事件发生后的操作略有不同，识别开始时让当前焦点物体执行方法PerformManipulationStart（GestureAction中）初始化物体位置信息，

更新事件发生后让当前焦点物体执行方法PerformManipulationUpdate（GestureAction中）进行物体的平移操作。单击事件将执行Interactible脚本中的OnSelect（）方法。