unity3d 尝试 基于地理定位的 增强现实

首先说，这个尝试失败，属于死在去医院的路上那种。

基于地理定位的增强现实，AR全息实景，是一种高大上的说法，说直白点就是山寨类似随便走这样的应用。

打开应用，搜索周边信息，然后再把信息叠加在摄像头拍摄到的内容上面。

思路：用手机移动来控制unity中的camrea，将摄像头拍摄到的内容作为背景。获取地理信息，将信息转化成文字添加到unity的世界中。

1、用手机移动控制unity中的camrea。

这段代码中unity的论坛中找到，但是时间很久远，改了下发现能用。

​​http://forum.unity3d.com/threads/sharing-gyroscope-controlled-camera-on-iphone-4.98828/​​

using UnityEngine;
using System.Collections;

public class CameraManager : MonoBehaviour {



  private bool gyroBool;
  private Gyroscope gyro;
  private Quaternion rotFix;

  public void Start ()
  {
    Transform currentParent = transform.parent;
    GameObject camParent = new GameObject ("GyroCamParent");
    camParent.transform.position = transform.position;
    transform.parent = camParent.transform;
    GameObject camGrandparent = new GameObject ("GyroCamGrandParent");
    camGrandparent.transform.position = transform.position;
    camParent.transform.parent = camGrandparent.transform;
    camGrandparent.transform.parent = currentParent;

    gyroBool = SystemInfo.supportsGyroscope;

    if (gyroBool) {

      gyro = Input.gyro;
      gyro.enabled = true;

      if (Screen.orientation == ScreenOrientation.LandscapeLeft) {
        camParent.transform.eulerAngles = new Vector3 (90, 90, 0);
      } else if (Screen.orientation == ScreenOrientation.Portrait) {
        camParent.transform.eulerAngles = new Vector3 (90, 180, 0);
      } else if (Screen.orientation == ScreenOrientation.PortraitUpsideDown) {
        camParent.transform.eulerAngles = new Vector3 (90, 180, 0);
      } else if (Screen.orientation == ScreenOrientation.LandscapeRight) {
        camParent.transform.eulerAngles = new Vector3 (90, 180, 0);
      } else {
        camParent.transform.eulerAngles = new Vector3 (90, 180, 0);
      }

      if (Screen.orientation == ScreenOrientation.LandscapeLeft) {
        rotFix = new Quaternion (0, 0,0.7071f,0.7071f);
      } else if (Screen.orientation == ScreenOrientation.Portrait) {
        rotFix = new Quaternion (0, 0, 1, 0);
      } else if (Screen.orientation == ScreenOrientation.PortraitUpsideDown) {
        rotFix = new Quaternion (0, 0, 1, 0);
      } else if (Screen.orientation == ScreenOrientation.LandscapeRight) {
        rotFix = new Quaternion (0, 0, 1, 0);
      } else {
        rotFix = new Quaternion (0, 0, 1, 0);
      }

      //Screen.sleepTimeout = 0;
    } else {
      #if UNITY_EDITOR
      print("NO GYRO");
      #endif
    }
  }

  public void Update ()
  {
    if (gyroBool) {
      Quaternion quatMap;
      #if UNITY_IOS
      quatMap = gyro.attitude;
      #elif UNITY_ANDROID
      quatMap = new Quaternion(gyro.attitude.x,gyro.attitude.y,gyro.attitude.z,gyro.attitude.w);
      #endif
      transform.localRotation = quatMap * rotFix;
    }
  }
}

2、背景摄像头显示摄像机内容

摄像头的内容可以显示在guitexure上也可以显示在plan上，但是在guitexrue上显示的时候，方向转了90度，最后只好显示在plan上。

using UnityEngine;
using System.Collections;

public class WebCamManager : MonoBehaviour {

  // Use this for initialization
  void Start () {

    WebCamTexture webcamTexture = new WebCamTexture ();

    //如果有后置摄像头，调用后置摄像头
    for (int i = 0; i < WebCamTexture.devices.Length; i++) {
      if (!WebCamTexture.devices [i].isFrontFacing) {
        webcamTexture.deviceName = WebCamTexture.devices [i].name;
        break;
      }
    }

    Renderer renderer = GetComponent<Renderer>();  
    renderer.material.mainTexture = webcamTexture;  
    webcamTexture.Play();  
  }
}

3、调用高德地图的地理定位和搜索附近

4、当搜索到内容以后，将名称信息添加到unity的世界里。

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using UnityEngine.UI;

public class ARMange : MonoBehaviour {

  public List<PlaceInfo> places = new List<PlaceInfo>();
  public GameObject perfab;
  public PlaceInfo location = new PlaceInfo ();

  public void ShowPlaces(){
    ClearPlace ();

    for (int i = 0; i < places.Count; i++) {

      GameObject newPlace = Instantiate<GameObject> (perfab);
      newPlace.transform.parent = this.transform;

      double posZ = places [i].Latitude - location.Latitude;
      double posX = places [i].Longitude - location.Longitude;

      float z = 0;
      float x = 0;
      float y = 0;

      if (posZ > 0) {
        z = 500f;
      } else {
        z = -500f;
      }

      if (posX > 0) {
        x = 500f;
      } else {
        x = -500f;
      }

      z = z + (float)(posZ * 1000);
      x = x + (float)(posX * 1000);
      y = y + i * 20;

      newPlace.transform.position = new Vector3 (x, y, z);
      newPlace.transform.LookAt (this.transform);
      newPlace.transform.Rotate (new Vector3 (0f, 180f, 0f));

      newPlace.gameObject.GetComponentInChildren<Text> ().text = places [i].Name;
    }
  }

  private void ClearPlace(){
    GameObject[] oldPlaces = GameObject.FindGameObjectsWithTag ("Place");
    for (int i = 0; i < oldPlaces.Length; i++) {
      Destroy (oldPlaces [i].gameObject);
    }
  }

}

5、这个时候显示内容没问题，但是方向会偏移。于是加了个指南针来矫正方向

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class CompassManage : MonoBehaviour {

  public Transform cam;

  void Start () {
    Input.location.Start ();
    Input.compass.enabled = true;
  }
  
  // Update is called once per frame
  void Update () {
    transform.rotation = Quaternion.Euler(0, cam.eulerAngles.y-Input.compass.trueHeading, 0);
  }
}

6、最后遇到的，我无法解决的问题

简单一句话，就是滤波。这个应用需要准确稳定的判断出当前手机方向位置状态，但是，输入的内容，重力，罗盘，加速度都是在不断变化，并且会有偏移的量，需要滤波。

虽然大致知道了是应该用互补滤波和卡尔曼滤波，但是，我的水平只能看懂名字，看不懂内容。

数学无力的我只好放弃。等遇到别人写好的代码再抄下吧。

这是死在半路上的结果的样子

这样的结果呢，当然是不甘心的，但是没时间去仔细研究这个问题了，所以只好放弃。如果哪位大侠知道怎么根据重力，罗盘，加速判断手机状态的，在这里跪求先。

====================

在SearchManage.cs文件中，我把搜索范围限定在了昆明，

//txtInfo.text = txtInfo.text + "\r\n";
      AndroidJavaObject query = amapHelper.Call<AndroidJavaObject>("getPoiSearch",inputQuery.text,"","0871");
      txtInfo.text = txtInfo.text + "query get...";

将0871改成其他地方的区号就可以了，（为空是全国范围，但是没验证过）