AR模型脱卡unity端实现具体步骤
AR模型脱卡的原理
利用一些unity端AR插件做AR应用。通常会有一个需求，当识别物消失的时候，将3D模型从识别物这个父物体上移除，显示在屏幕中央。那么原理就显而易见了，就是在识别物追踪方法中，写一些模型的操作（判定当前模型显示、隐藏非当前模型）
实现方式
- 两个摄像机，丢失追踪后。移除父物体关联，用另一个相机进行渲染。其实就是一个相机坐标系的转换。（稍显复杂）
- 丢失追踪后，在主相机中创建一个空物体放置模型。（比较简单）
核心文件的编辑(简单点的)
NotFound.cs文件的编辑
using UnityEngine;
using System.Collections;
using Vuforia;
using System;
//拿到当前追踪识别
using UnityEngine;
using System.Collections;
using Vuforia;
using System;
using UnityEngine.SceneManagement;
public class NotFound : MonoBehaviour , ITrackableEventHandler
{
#region PRIVATE_MEMBER_VARIABLES
private TrackableBehaviour mTrackableBehaviour;
//判断是否是第一次识别是否完成，防止开启程序未放入识别图也在屏幕中央出现模型
bool firstfound = false;
public bool imageIsOut = false;//识别成功的图片是否已经出现过
//模型起始位置，值为起始模型组件中Transform.Position
//Vector3 origposition = new Vector3 (0, 0.25f, 0);
public Vector3 originPosition;
public Vector3 rotation;
public Vector3 it_position;
public Vector3 it_rotation;
//当前imagetarget对应的模型等target
public Transform[] localTargets;
//其他非当前imagetarget对应的模型等targets
public Transform[] otherTargets;
//Camera Object
GameObject gObject;
//Camera Object的Creat Empty脚本
CreatEmpty cempty;
//表示ImageTarget父物体那个组件
public GameObject[] otherImageTargets;
#region 自定义的协程延时函数
//定义一个延时函数
public static IEnumerator DelayToInvokeDo(Action action, float delaySeconds)
{
yield return new WaitForSeconds(delaySeconds);
action();
}
#endregion //自定义的协程延时函数
void Start()
{
//相机自动对焦
Vuforia.CameraDevice.Instance.SetFocusMode(Vuforia.CameraDevice.FocusMode.FOCUS_MODE_CONTINUOUSAUTO);
mTrackableBehaviour = GetComponent<TrackableBehaviour>();
if (mTrackableBehaviour)
{
mTrackableBehaviour.RegisterTrackableEventHandler(this);
}
//获取Camera中组件的CreatEmpty脚本
gObject = GameObject.FindWithTag("MainCamera");
cempty = gObject.GetComponent<CreatEmpty> ();
if(cempty != null)
{
//杀死空物体
cempty.destoryempty ();
}
}
#endregion // UNTIY_MONOBEHAVIOUR_METHODS
#region PUBLIC_METHODS
/// <summary>
/// Implementation of the ITrackableEventHandler function called when the
/// tracking state changes.
/// </summary>
public void OnTrackableStateChanged(
TrackableBehaviour.Status previousStatus,
TrackableBehaviour.Status newStatus)
{
//Vector3 orirotation = new Vector3 (270, 0, 0);
if (newStatus == TrackableBehaviour.Status.DETECTED ||
newStatus == TrackableBehaviour.Status.TRACKED ||
newStatus == TrackableBehaviour.Status.EXTENDED_TRACKED)
{
//如果识别成功图片没有出现过，则执行下面的代码，显示并延时0.5秒后消失
if(!imageIsOut)
{
for(int i = 0; i < otherTargets.Length; i++)
{
//但是隐藏其他imagetarget对应的模型，目的是防止在该imagetarget对应的模型出现在屏幕中央的时候不受其他imagetarget对应的模型的影响
//otherTargets[i].gameObject.SetActive (false);
setShow (otherTargets [i], false);
}
for(int i = 0; i < localTargets.Length; i++)
{
//localTargets[i].gameObject.SetActive (false);
setShow (localTargets [i], false);
}
//需要延时0.3s，让图片多显示0.3s后消失(执行outImage函数)
//Invoke ("outImage", 0.5f);//如果这样，并不影响下面代码的执行。
StartCoroutine(DelayToInvokeDo(() =>
{
outImage(newStatus);
//识别成功图片已经显示过了
imageIsOut = true;
}, 0.4f));
}
else
{
OnTrackingFound ();
}
}
else
{
OnTrackingLost ();
}
}
#endregion // PUBLIC_METHODS
//识别成功图片显示并消失之后
private void outImage(TrackableBehaviour.Status newStatus)
{
for(int i = 0; i < otherTargets.Length; i++)
{
//但是隐藏其他imagetarget对应的模型，目的是防止在该imagetarget对应的模型出现在屏幕中央的时候不受其他imagetarget对应的模型的影响
//otherTargets[i].gameObject.SetActive (false);
setShow (otherTargets [i], false);
}
for(int i = 0; i < localTargets.Length; i++)
{
//localTargets[i].gameObject.SetActive (false);
setShow (localTargets [i], false);
}
//显示并消失之后在一次判断图片是否处于追踪状态
if (newStatus == TrackableBehaviour.Status.TRACKED ||
newStatus == TrackableBehaviour.Status.DETECTED ||
newStatus == TrackableBehaviour.Status.EXTENDED_TRACKED)
{
OnTrackingFound ();
firstfound = true;
}
else
{
//OnTrackingLost ();
for(int i = 0; i < otherTargets.Length; i++)
{
//但是隐藏其他imagetarget对应的模型，目的是防止在该imagetarget对应的模型出现在屏幕中央的时候不受其他imagetarget对应的模型的影响
//otherTargets[i].gameObject.SetActive (false);
setShow (otherTargets [i], false);
}
for(int i = 0; i < localTargets.Length; i++)
{
//localTargets[i].gameObject.SetActive (false);
setShow (localTargets [i], false);
}
}
}
private void OnTrackingFound()
{
Debug.Log ("it is found");
for(int i = 0; i < otherImageTargets.Length; i++)
{
//让其他的识别图在执行一次状态识别成功的代码，使得模型归位到imagetarget子物体
otherImageTargets[i].GetComponent<NotFound> ().homing ();
//当前图片识别成功时，关闭其他图片的识别
// otherImageTargets[i].SetActive (false);
//将其他识别图中的识别成功图片设置成未显示过
otherImageTargets [i].GetComponent<NotFound> ().imageIsOut = false;
}
for(int i = 0; i < localTargets.Length; i++)
{
//setShow (localTargets [i], true);
//othertargetmodel.gameObject.SetActive (false);
localTargets[i].parent = this.transform;
localTargets[i].localPosition = it_position;
localTargets[i].rotation = Quaternion.Euler (it_rotation);
//开启当前图片对应的模型，因为在识别其他图片的时候有可能关闭了这个图片对应的模型
//localTargets[i].gameObject.SetActive (true);
setShow (localTargets [i], true);
}
//杀死空物体
cempty.destoryempty ();
//因为杀死了空物体，所以一旦丢失跟踪，模型就没地方放了，所以就加一个判断，丢失的话就不显示模型
if(mTrackableBehaviour.CurrentStatus ==TrackableBehaviour.Status.NOT_FOUND)
{
for(int i = 0;i < localTargets.Length; i++)
{
setShow (localTargets [i], false);
}
}
//target.rotation = Quaternion.Euler(orirotation);
//firstfound = true;
}
private void OnTrackingLost()
{
Debug.Log ("it is lost");
for(int i = 0; i < localTargets.Length; i++)
{
//localTargets[i].gameObject.SetActive (false);
setShow (localTargets [i], false);
}
if (firstfound == true)
{
//创建空物体
cempty.creatempty ();
for(int i = 0; i < otherTargets.Length; i++)
{
//但是隐藏其他imagetarget对应的模型，目的是防止在该imagetarget对应的模型出现在屏幕中央的时候不受其他imagetarget对应的模型的影响
//otherTargets[i].gameObject.SetActive (false);
setShow (otherTargets [i], false);
}
GameObject emptyobject = GameObject.Find ("empty");
Transform cameraPos = emptyobject.transform;
for(int i = 0; i < localTargets.Length; i++)
{
//将target作为cameraPos的子物体，cameraPos就是emptyobject(即空物体)的Transform表现形式
localTargets[i].parent = cameraPos;
localTargets[i].localPosition = originPosition;
//target.localRotation = Quaternion.Euler (orirotation);
// localTargets[i].localRotation = Quaternion.Euler (Vector3.zero);
// localTargets[i].localRotation = Quaternion.Euler(rotation);
//localTargets[i].gameObject.SetActive (true);
setShow (localTargets [i], true);
}
}
else
{
for(int i = 0; i < otherTargets.Length; i++)
{
//但是隐藏其他imagetarget对应的模型，目的是防止在该imagetarget对应的模型出现在屏幕中央的时候不受其他imagetarget对应的模型的影响
//otherTargets[i].gameObject.SetActive (false);
setShow (otherTargets [i], false);
}
for(int i = 0; i < localTargets.Length; i++)
{
print ("local Targets set active false");
//localTargets[i].gameObject.SetActive (false);
setShow (localTargets [i], false);
}
}
}
//方便其他脚本调用的接口函数，使this.中模型归位
public void homing()
{
for(int i = 0; i < localTargets.Length; i++)
{
localTargets[i].position = new Vector3(0,0,0);
localTargets[i].rotation = Quaternion.Euler (Vector3.zero);
localTargets[i].parent = this.transform;
}
}
//自己写的隐藏模型代码,仅模型可用
void setShow(Transform target,bool IsShow)
{
Renderer[] targetrendererComponents = target.GetComponentsInChildren<Renderer>(true);
Collider[] targetcolliderComponents = target.GetComponentsInChildren<Collider>(true);
if(IsShow)
{
// enable rendering:
foreach (Renderer component in targetrendererComponents)
{
component.enabled = true;
}
// enable colliders:
foreach (Collider component in targetcolliderComponents)
{
component.enabled = true;
}
}
else
{
// Disable rendering:
foreach (Renderer component in targetrendererComponents)
{
component.enabled = false;
}
// Disable colliders:
foreach (Collider component in targetcolliderComponents)
{
component.enabled = false;
}
}
}
}
CreatEmpty.cs文件的编写
using UnityEngine;
using System.Collections;
using Vuforia;
public class CreatEmpty : MonoBehaviour {
Vector3 emptyposition = new Vector3 (16, -62, 120);
public void creatempty()
{
//定义一个空物体，并将他作为Camera的子物体，并设置其坐标和旋转角度
GameObject emptyObject = new GameObject ();
emptyObject.transform.parent = GameObject.FindWithTag ("MainCamera").transform;
emptyObject.name = "empty";
emptyObject.transform.localPosition = emptyposition;
emptyObject.transform.localRotation = Quaternion.Euler (Vector3.zero);
}
//杀死camera组件中名字为“empty”的物体
public void destoryempty()
{
if (GameObject.Find ("empty"))
GameObject.Destroy (GameObject.Find ("empty"));
else
print ("没有empty！");
}
}
实现步骤（复杂点的）
-
添加新的Camera,并将Camera配置如下：
这里有个坑就是，图层的depth属性的设置。值越高图层显示优先级越高。 -
对于预制体添加标志Compent
这里添加两个组件Rotate是控制模型旋转的，另外一个是一个标志。方便我们通过组件查找到我们要访问的Object。 -
核心追踪的方法实现,挂靠到imageTarget上
public string ObjectName;
private void OnTrackingFound()
{
//初始化模型
TrackObjectFree[] objs = FindObjectsOfType<TrackObjectFree> ();
foreach (TrackObjectFree to in objs) {
Destroy (to.gameObject);
}
Resources.UnloadUnusedAssets ();
//创建模型
GameObject o = GameObject.Instantiate (Resources.Load (ObjectName)) as GameObject;
o.transform.parent = this.transform;
o.transform.position = this.transform.position;
}
private void OnTrackingLost()
{
TrackObjectFree to = GetComponentInChildren<TrackObjectFree> ();
if (to != null)
{
to.gameObject.transform.parent = this.transform.parent;
to.gameObject.layer = 10;
}
}