Hololens入門之手勢識別(使用Navigation gesture控制物體縮放)
本文示例在 Hololens入門之手勢識別(手檢測反饋) 示例的基礎上進行修改Navigation gesture ：保持點擊手勢，在一個標準3D立方空間內相對運動導航手勢就像一個虛擬的操縱桿，能夠用于UI控件導航，例如弧形菜單。通過點擊開始手勢，然后在以點擊處為中心的標準立方空間中移動手部。你可以沿著X、Y、Z軸移動手部，這會帶來數(shù)值-1到1的變化，初始位置的值為0.1、修改HandsManager.cs，添加InteractionManager.SourcePressed，InteractionManager.SourceReleased處理函數(shù)，用于識別物體被點擊和被釋放的事件HandsManager.cs完整代碼如下：

[csharp] view plain copy

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License. See LICENSE in the project root for license information.

using UnityEngine;  
using UnityEngine.VR.WSA.Input;  
  
namespace HoloToolkit.Unity  
{  
    /// <summary>  
    /// HandsManager determines if the hand is currently detected or not.  
    /// </summary>  
    public partial class HandsManager : Singleton<HandsManager>  
    {  
        /// <summary>  
        /// HandDetected tracks the hand detected state.  
        /// Returns true if the list of tracked hands is not empty.  
        /// </summary>  
        public bool HandDetected  
        {  
            get { return trackedHands.Count > 0; }  
        }  
  
        private HashSet<uint> trackedHands = new HashSet<uint>();  
  
        public GameObject FocusedGameObject { get; private set; }  
  
        void Awake()  
        {  
            InteractionManager.SourceDetected += InteractionManager_SourceDetected;  
            InteractionManager.SourceLost += InteractionManager_SourceLost;  
            //來源被按下    
            InteractionManager.SourcePressed += InteractionManager_SourcePressed;  
            //被釋放    
            InteractionManager.SourceReleased += InteractionManager_SourceReleased;  
  
            FocusedGameObject = null;  
        }  
  
        //手勢釋放時，將被關注的物體置空    
        private void InteractionManager_SourceReleased(InteractionSourceState state)  
        {  
            FocusedGameObject = null;  
        }  
        //識別到手指按下時，將凝視射線關注的物體置為當前手勢操作的對象    
        private void InteractionManager_SourcePressed(InteractionSourceState state)  
        {  
            if (GazeManager.Instance.FocusedObject != null)  
            {  
                FocusedGameObject = GazeManager.Instance.FocusedObject;  
            }  
        }  
  
        private void InteractionManager_SourceDetected(InteractionSourceState state)  
        {  
            // Check to see that the source is a hand.  
            if (state.source.kind != InteractionSourceKind.Hand)  
            {  
                return;  
            }  
  
            trackedHands.Add(state.source.id);  
        }  
  
        private void InteractionManager_SourceLost(InteractionSourceState state)  
        {  
            // Check to see that the source is a hand.  
            if (state.source.kind != InteractionSourceKind.Hand)  
            {  
                return;  
            }  
  
            if (trackedHands.Contains(state.source.id))  
            {  
                trackedHands.Remove(state.source.id);  
            }  
            FocusedGameObject = null;  
        }  
  
        void OnDestroy()  
        {  
            InteractionManager.SourceDetected -= InteractionManager_SourceDetected;  
            InteractionManager.SourceLost -= InteractionManager_SourceLost;  
  
            InteractionManager.SourceReleased -= InteractionManager_SourceReleased;  
            InteractionManager.SourcePressed -= InteractionManager_SourcePressed;  
        }  
    }  
}  

2、修改GestureManager.cs，訂閱Navigation手勢事件****[csharp] view plain copy

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License. See LICENSE in the project root for license information.

using UnityEngine.VR.WSA.Input;  
  
namespace HoloToolkit.Unity  
{  
    /// <summary>  
    /// GestureManager creates a gesture recognizer and signs up for a tap gesture.  
    /// When a tap gesture is detected, GestureManager uses GazeManager to find the game object.  
    /// GestureManager then sends a message to that game object.  
    /// </summary>  
    [RequireComponent(typeof(GazeManager))]  
    public partial class GestureManager : Singleton<GestureManager>  
    {  
        /// <summary>  
        /// Key to press in the editor to select the currently gazed hologram  
        /// </summary>  
        public KeyCode EditorSelectKey = KeyCode.Space;  
  
        /// <summary>  
        /// To select even when a hologram is not being gazed at,  
        /// set the override focused object.  
        /// If its null, then the gazed at object will be selected.  
        /// </summary>  
        public GameObject OverrideFocusedObject  
        {  
            get; set;  
        }  
  
        /// <summary>  
        /// Gets the currently focused object, or null if none.  
        /// </summary>  
        public GameObject FocusedObject  
        {  
            get { return focusedObject; }  
        }  
  
        public bool IsNavigating { get; private set; }  
        public Vector3 NavigationPosition { get; private set; }  
  
        private GestureRecognizer gestureRecognizer;  
        private GameObject focusedObject;  
  
        void Start()  
        {  
            //  創(chuàng)建GestureRecognizer實例    
            gestureRecognizer = new GestureRecognizer();  
            //  注冊指定的手勢類型    
            gestureRecognizer.SetRecognizableGestures(GestureSettings.Tap  
                | GestureSettings.NavigationX);  
            //  訂閱手勢事件    
            gestureRecognizer.TappedEvent += GestureRecognizer_TappedEvent;  
  
            //添加Navigation手勢事件    
            gestureRecognizer.NavigationStartedEvent += GestureRecognizer_NavigationStartedEvent;  
            gestureRecognizer.NavigationUpdatedEvent += GestureRecognizer_NavigationUpdatedEvent;  
            gestureRecognizer.NavigationCompletedEvent += GestureRecognizer_NavigationCompletedEvent;  
            gestureRecognizer.NavigationCanceledEvent += GestureRecognizer_NavigationCanceledEvent;  
            //  開始手勢識別    
            gestureRecognizer.StartCapturingGestures();  
        }  
  
        private void GestureRecognizer_NavigationCanceledEvent(InteractionSourceKind source, Vector3 normalizedOffset, Ray headRay)  
        {  
            IsNavigating = false;  
        }  
  
        private void GestureRecognizer_NavigationCompletedEvent(InteractionSourceKind source, Vector3 normalizedOffset, Ray headRay)  
        {  
            IsNavigating = false;  
        }  
  
        private void GestureRecognizer_NavigationUpdatedEvent(InteractionSourceKind source, Vector3 normalizedOffset, Ray headRay)  
        {  
            if (HandsManager.Instance.FocusedGameObject != null)  
            {  
                IsNavigating = true;  
                NavigationPosition = normalizedOffset;  
                HandsManager.Instance.FocusedGameObject.SendMessageUpwards("PerformZoomUpdate", normalizedOffset, SendMessageOptions.DontRequireReceiver);  
            }  
        }  
  
        private void GestureRecognizer_NavigationStartedEvent(InteractionSourceKind source, Vector3 normalizedOffset, Ray headRay)  
        {  
            if (HandsManager.Instance.FocusedGameObject != null)  
            {  
                IsNavigating = true;  
                NavigationPosition = normalizedOffset;  
                HandsManager.Instance.FocusedGameObject.SendMessageUpwards("PerformNavigationStart", normalizedOffset, SendMessageOptions.DontRequireReceiver);  
            }  
        }  
  
        private void OnTap()  
        {  
            if (focusedObject != null)  
            {  
                focusedObject.SendMessage("OnSelect", SendMessageOptions.DontRequireReceiver);  
            }  
        }  
  
        private void GestureRecognizer_TappedEvent(InteractionSourceKind source, int tapCount, Ray headRay)  
        {  
            OnTap();  
        }  
  
        void LateUpdate()  
        {  
            GameObject oldFocusedObject = focusedObject;  
  
            if (GazeManager.Instance.Hit &&  
                OverrideFocusedObject == null &&  
                GazeManager.Instance.HitInfo.collider != null)  
            {  
                // If gaze hits a hologram, set the focused object to that game object.  
                // Also if the caller has not decided to override the focused object.  
                focusedObject = GazeManager.Instance.HitInfo.collider.gameObject;  
            }  
            else  
            {  
                // If our gaze doesn't hit a hologram, set the focused object to null or override focused object.  
                focusedObject = OverrideFocusedObject;  
            }  
  
            //if (focusedObject != oldFocusedObject)  
            //{  
            //    // If the currently focused object doesn't match the old focused object, cancel the current gesture.  
            //    // Start looking for new gestures.  This is to prevent applying gestures from one hologram to another.  
            //    gestureRecognizer.CancelGestures();  
            //    gestureRecognizer.StartCapturingGestures();  
            //}  
 
#if UNITY_EDITOR  
            if (Input.GetMouseButtonDown(1) || Input.GetKeyDown(EditorSelectKey))  
            {  
                OnTap();  
            }  
#endif  
        }  
  
        void OnDestroy()  
        {  
            gestureRecognizer.StopCapturingGestures();  
            gestureRecognizer.TappedEvent -= GestureRecognizer_TappedEvent;  
            gestureRecognizer.NavigationStartedEvent -= GestureRecognizer_NavigationStartedEvent;  
            gestureRecognizer.NavigationUpdatedEvent -= GestureRecognizer_NavigationUpdatedEvent;  
            gestureRecognizer.NavigationCompletedEvent -= GestureRecognizer_NavigationCompletedEvent;  
            gestureRecognizer.NavigationCanceledEvent -= GestureRecognizer_NavigationCanceledEvent;  
        }  
    }  
}  

3、新增測試用Cube
[圖片上傳中。。。（1）]

4、新增修改CubeScript.cs，添加物體縮放函數(shù)，當選中物體，左右移動時，物體進行縮放[csharp] view plain copy

using System.Collections;  
using HoloToolkit.Unity;  
  
public class CubeScript : MonoBehaviour {  
  
    private Vector3 navigationPreviousPosition;  
    public float MaxScale = 2f;  
    public float MinScale = 0.1f;  
      
    // Use this for initialization  
    void Start () {  
      
    }  
      
    // Update is called once per frame  
    void Update () {  
      
    }  
  
    void PerformNavigationStart(Vector3 position)  
    {  
        //設置初始位置    
        navigationPreviousPosition = position;  
    }  
  
    void PerformZoomUpdate(Vector3 position)  
    {  
        if (GestureManager.Instance.IsNavigating && HandsManager.Instance.FocusedGameObject == gameObject)  
        {  
            Vector3 deltaScale = Vector3.zero;  
            float ScaleValue = 0.01f;  
            //設置每一幀縮放的大小  
            if (position.x < 0)  
            {  
                ScaleValue = -1 * ScaleValue;  
            }  
            //當縮放超出設置的最大，最小范圍時直接返回  
            if (transform.localScale.x >= MaxScale && ScaleValue > 0)  
            {  
                return;  
            }  
            else if (transform.localScale.x <= MinScale && ScaleValue < 0)  
            {  
                return;  
            }  
            //根據(jù)比例計算每個方向上的縮放大小  
            deltaScale.x = ScaleValue;  
            deltaScale.y = (transform.localScale.y / transform.localScale.x) * ScaleValue;  
            deltaScale.z = (transform.localScale.z / transform.localScale.x) * ScaleValue;  
            transform.localScale += deltaScale;  
        }  
    }  
}  

5、運行測試啟動后手勢向左滑動，物體縮小
[圖片上傳中。。。（2）]
手勢向右滑動，物體放大
[圖片上傳中。。。（3）]