Kinect+Unity之手势识别初探

前几天环境配好了，连上Ｋｉｎｅｃｔ能跑示例项目ＫｉｎｅｃｔＶｉｅｗ。花了很大的力气找插件的ＡＰＩ手册，原来插件并没有官方手册，目前官网也只有两个示例项目。于是自己看代码，想首先学会怎样写一个手势触发特定事件。主要看了ＢｏｄｙＳｏｕｒｃｅＭａｎａｇｅｒ．ｃｓ和ＢｏｄｙＳｏｕｒｃｅＶｉｅｗ．ｃｓ，中午成功写出了如果左手高过头顶，自动截屏保存图片。

思路是ｉｆ判断，如果左手的ｙ坐标值大于等于头顶的ｙ坐标值条件为真，触发事件，调用Ｕｎｉｔｙ的一个ＡＰＩ叫Ａｐｐｌｉｃａｔｉｏｎ．Ｃａｐｔｕｒｅｓｃｒｅｅｎｓｈｏｔ（）。在ＢｏｄｙＳｏｕｒｃｅＶｉｅｗ．ｃｓ中的ＲｅｆｒｅｓｈＢｏｄｙＯｂｊｅｃｔ（）函数中修改，这个函数会在Ｕｐｄａｔｅ（）中调用，每一帧都会更新。红框部分是自己添加的代码，其余均为无改动的示例源码。

Ｋｉｎｅｃｔ．ＪｏｉｎＴｙｐｅ可以按Ｆ１２查看插件中的源代码，可知是枚举类型，如图

                                                           

简要分析一下示例程序中的ＲｅｆｒｅｓｈＢｏｄｙＯｂｅｊｃｔ函数。这个函数主要做的是获取关节点坐标，在Ｕｎｉｔｙ中画出人体骨骼。画骨骼直接用Ｕｎｉｔｙ的线渲染ＬｉｎｅＲｅｎｄｅｒ（在前面代码中已经调用它的ＳｅｔＶｅｒｔｅｘＣｏｕｎｔ方法设置画得线有两个端点）。遍历Ｄｉｃｔｉｏｎａｒｙ类型的＿Ｂｏｎｅｍａｐ（保存的是Ｋｅｙ－Ｖａｌｕｅ键值对，Ｖａｌｕｅ是Ｋｅｙ的下一个关联结点），ｋｅｙ就是画线段的源位置，ｖａｌｕｅ就是线段的目标位置。

完整代码如下

BodySourceManager.cs
using UnityEngine;
using System.Collections;
using Windows.Kinect;

public class BodySourceManager : MonoBehaviour 
{

    private KinectSensor _Sensor;
    private BodyFrameReader _Reader;
    private Body[] _Data = null;
    
    public Body[] GetData()
    {
        return _Data;
    }
    

    void Start () 
    {
        _Sensor = KinectSensor.GetDefault();

        if (_Sensor != null)
        {
            _Reader = _Sensor.BodyFrameSource.OpenReader();
            
            if (!_Sensor.IsOpen)
            {
                _Sensor.Open();
            }
        }   
    }
    
    void Update () 
    {
        if (_Reader != null)
        {
            var frame = _Reader.AcquireLatestFrame();
            if (frame != null)
            {
                if (_Data == null)
                {
                    _Data = new Body[_Sensor.BodyFrameSource.BodyCount];
                }
           
                frame.GetAndRefreshBodyData(_Data);
                frame.Dispose();
                frame = null;
            }
        }    

    }
    
    void OnApplicationQuit()
    {
        if (_Reader != null)
        {
            _Reader.Dispose();
            _Reader = null;
        }
        
        if (_Sensor != null)
        {
            if (_Sensor.IsOpen)
            {
                _Sensor.Close();
            }
            
            _Sensor = null;
        }
    }


}

BodySourceView.cs
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using Kinect = Windows.Kinect;

public class BodySourceView : MonoBehaviour 
{
    public Material BoneMaterial;
    public GameObject BodySourceManager;
    
    private Dictionary _Bodies = new Dictionary();
    private BodySourceManager _BodyManager;
    
    private Dictionary _BoneMap = new Dictionary()
    {
        { Kinect.JointType.FootLeft, Kinect.JointType.AnkleLeft },
        { Kinect.JointType.AnkleLeft, Kinect.JointType.KneeLeft },
        { Kinect.JointType.KneeLeft, Kinect.JointType.HipLeft },
        { Kinect.JointType.HipLeft, Kinect.JointType.SpineBase },
        
        { Kinect.JointType.FootRight, Kinect.JointType.AnkleRight },
        { Kinect.JointType.AnkleRight, Kinect.JointType.KneeRight },
        { Kinect.JointType.KneeRight, Kinect.JointType.HipRight },
        { Kinect.JointType.HipRight, Kinect.JointType.SpineBase },
        
        { Kinect.JointType.HandTipLeft, Kinect.JointType.HandLeft },
        { Kinect.JointType.ThumbLeft, Kinect.JointType.HandLeft },
        { Kinect.JointType.HandLeft, Kinect.JointType.WristLeft },
        { Kinect.JointType.WristLeft, Kinect.JointType.ElbowLeft },
        { Kinect.JointType.ElbowLeft, Kinect.JointType.ShoulderLeft },
        { Kinect.JointType.ShoulderLeft, Kinect.JointType.SpineShoulder },
        
        { Kinect.JointType.HandTipRight, Kinect.JointType.HandRight },
        { Kinect.JointType.ThumbRight, Kinect.JointType.HandRight },
        { Kinect.JointType.HandRight, Kinect.JointType.WristRight },
        { Kinect.JointType.WristRight, Kinect.JointType.ElbowRight },
        { Kinect.JointType.ElbowRight, Kinect.JointType.ShoulderRight },
        { Kinect.JointType.ShoulderRight, Kinect.JointType.SpineShoulder },
        
        { Kinect.JointType.SpineBase, Kinect.JointType.SpineMid },
        { Kinect.JointType.SpineMid, Kinect.JointType.SpineShoulder },
        { Kinect.JointType.SpineShoulder, Kinect.JointType.Neck },
        { Kinect.JointType.Neck, Kinect.JointType.Head },
    };
    
    void Update () 
    {
        if (BodySourceManager == null)
        {
            return;
        }
        
        _BodyManager = BodySourceManager.GetComponent();
        if (_BodyManager == null)
        {
            return;
        }
        
		Kinect.Body[] data = _BodyManager.GetData();//GetData();
        if (data == null)
        {
            return;
        }
        
        List trackedIds = new List();
        foreach(var body in data)
        {
            if (body == null)
            {
                continue;
              }
                
            if(body.IsTracked)
            {
                trackedIds.Add (body.TrackingId);
            }
        }
        
        List knownIds = new List(_Bodies.Keys);
        
        // First delete untracked bodies
        foreach(ulong trackingId in knownIds)
        {
            if(!trackedIds.Contains(trackingId))//List方法测试一个元素是否在List内
            {
                Destroy(_Bodies[trackingId]);//先Destroy掉GameObject
                _Bodies.Remove(trackingId);//再将键值对从_Bodies字典中移除
            }
        }

        foreach(var body in data)
        {
            if (body == null)
            {
                continue;
            }
            
            if(body.IsTracked)
            {
                if(!_Bodies.ContainsKey(body.TrackingId))
                {
                    _Bodies[body.TrackingId] = CreateBodyObject(body.TrackingId);
                }
                
                RefreshBodyObject(body, _Bodies[body.TrackingId]);
            }
        }
    }
    
    private GameObject CreateBodyObject(ulong id)
    {
        GameObject body = new GameObject("Body:" + id);
        
        for (Kinect.JointType jt = Kinect.JointType.SpineBase; jt <= Kinect.JointType.ThumbRight; jt++)
        {
            GameObject jointObj = GameObject.CreatePrimitive(PrimitiveType.Cube);
            
            LineRenderer lr = jointObj.AddComponent();
            lr.SetVertexCount(2);//设置线段数
            lr.material = BoneMaterial;//物体的材质
            lr.SetWidth(0.05f, 0.05f);//设置线的开始和结束宽度
            
            jointObj.transform.localScale = new Vector3(0.3f, 0.3f, 0.3f);
            jointObj.name = jt.ToString();
            jointObj.transform.parent = body.transform;
        }
        
        return body;
    }
    
    private void RefreshBodyObject(Kinect.Body body, GameObject bodyObject)
    {
        for (Kinect.JointType jt = Kinect.JointType.SpineBase; jt <= Kinect.JointType.ThumbRight; jt++)
        {

            Kinect.Joint sourceJoint = body.Joints[jt];
            Kinect.Joint? targetJoint = null;
            
            if(_BoneMap.ContainsKey(jt))
            {
                targetJoint = body.Joints[_BoneMap[jt]];//所以之前字典中设置就是一个一个关节连起来
            }
            
            Transform jointObj = bodyObject.transform.FindChild(jt.ToString());
            jointObj.localPosition = GetVector3FromJoint(sourceJoint);
            
            LineRenderer lr = jointObj.GetComponent();
            if(targetJoint.HasValue)
            {
				//Debug.Log (jointObj.localPosition);ok
                lr.SetPosition(0, jointObj.localPosition);
                lr.SetPosition(1, GetVector3FromJoint(targetJoint.Value));
                lr.SetColors(GetColorForState (sourceJoint.TrackingState), GetColorForState(targetJoint.Value.TrackingState));
            }
            else
            {
                lr.enabled = false;
            }
			if(body.Joints[Kinect.JointType.HandLeft].Position.Y>=body.Joints[Kinect.JointType.Head].Position.Y){
				Debug.Log("handleft:"+body.Joints[Kinect.JointType.HandLeft].Position.Y);
				Debug.Log("head:"+body.Joints[Kinect.JointType.Head].Position.Y);
				Debug.Log("My LeftHand is Higher than head!~");
				Application.CaptureScreenshot ("Screenshoot.png", 0);
			}
        }
    }
    
    private static Color GetColorForState(Kinect.TrackingState state)
    {
        switch (state)
        {
        case Kinect.TrackingState.Tracked:
            return Color.green;

        case Kinect.TrackingState.Inferred:
            return Color.red;

        default:
            return Color.black;
        }
    }
    
    private static Vector3 GetVector3FromJoint(Kinect.Joint joint)
    {
        return new Vector3(joint.Position.X * 10, joint.Position.Y * 10, joint.Position.Z * 10);
    }
}
 
  
 
  
 
  
 
  
 
  
 
  
自己琢磨代码还是很开心的，代码值得完整的分析在此不赘述了。写博文是有点折腾，但是今天看到别人的技术博客和心得分享真的是很励志（http://www.the5fire.com/  http://blog.csdn.net/the_fire?viewmode=list）。