unity AR模型显示、交互和解决模型闪烁问题

创新实训第一周：实现AR模型显示和交互

（1）下载vuforia

到 vuforia官网下载扩展包

选择Download Unity Extension

将下载好的包导入到新建的U3D项目中

（2）vuforia的简单使用

①首先在官网注册vuforia账号

②在Develop选项下的License Manager中，点击Get Development Key获取许可码

③在Target Manager中点击Add Database中创建由于存储识别图片的库

其中这里的Width为实际识别时的图片宽度（如打印在纸上的图片或者显示在电脑屏幕上的图片大小），根据实际情况填写，单位是米

添加图片时尽量选择复杂不对称的图片作为识别图

选中所需图片，点击Download Database(1)下载该unitypackage导入到unity工程中

④在工程里使用ARCamera和ImageTarget替换原有的MainCamera

⑤将导入的图片设为ImageTarget的识别图

这里可能会出现导入的图片（材质）为白色的情况，解决如下：

在Asset中找到该图片，设置为2d，并点击Apply

然后单击ImageTarget就可以将该图片应用到Target上

⑥将所要显示的模型拖到Imagetarget中作为子物体

调整模型的大小和位置（为了防止模型的显示为俯视图，需要将模型绕x轴旋转到贴近图片的位置）

调整照相机位置和角度

（3）交互（改变动画和伸缩模型）

①给模型添加5个动画，并自定义显示动画的控制变量wait（float类型）

实现点击屏幕切换动画的效果

给模型挂上控制脚本，实现点击屏幕改变wait变量的值

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

public class ChanMove : MonoBehaviour {
    private Animator m_animator;
	// Use this for initialization
	void Start () {
        m_animator = this.GetComponent<Animator>();
	}
	
	// Update is called once per frame
	void FixedUpdate () {

        if (Input.touchCount == 1)// 手指按下
        {
            if (Input.touches[0].phase == TouchPhase.Began)
            {
                float f = Random.value;//返回一个0~1之间的数
                m_animator.SetFloat("wait", f);
            }
        }
    }
}

②伸缩模型

对ImageTarget下的脚本DefaultTrackableEventHandler进行更改，实现手指在屏幕中上下拖动伸缩模型的效果

public class DefaultTrackableEventHandler : MonoBehaviour,
                                                ITrackableEventHandler
    {
        #region PRIVATE_MEMBER_VARIABLES
 
        private TrackableBehaviour mTrackableBehaviour;

        #region 添加交互
        private GameObject chopper;
        private Vector3 originScale;//表示三个方向的缩放因子
        private Vector3 newScale;//表示三个方向的缩放因子
        private Quaternion originRotation;
        private float x;
        private Vector3 center;
        private Quaternion newRotation;
        private bool isTracked;//表示识别图是否被追踪到
        #endregion

        #endregion // PRIVATE_MEMBER_VARIABLES


        #region UNTIY_MONOBEHAVIOUR_METHODS

        void Start()
        {
            #region 添加交互
        chopper = GameObject.Find("unitychan");
        originScale = chopper.transform.localScale;
        newScale = originScale;
        originRotation = this.GetComponent<Transform>().localRotation;
        newRotation = originRotation;
        isTracked = false;
        center = new Vector3(0, 0, 0);
            #endregion

            mTrackableBehaviour = GetComponent<TrackableBehaviour>();
            if (mTrackableBehaviour)
            {
                mTrackableBehaviour.RegisterTrackableEventHandler(this);
            }
        }

        #endregion // UNTIY_MONOBEHAVIOUR_METHODS

        #region 添加交互

        void Update()
        {
            if (isTracked)
            {
                if (Input.touchCount == 1)//手指在屏幕上滑动
                {
                    if (Input.touches[0].phase == TouchPhase.Moved)
                    {
                        // 手指滑动时，要触发的代码 
                        //float s01 = Input.GetAxis("Mouse X");    //手指水平移动的距离
                        //float s02 = Input.GetAxis("Mouse Y");    //手指垂直移动的距离
                        if (newScale.x > 0.05)
                            if (Input.GetAxis("Mouse Y") > 0)
                                newScale += new Vector3(0.005f, 0.005f, 0.005f);
                            else if (Input.GetAxis("Mouse Y") < 0)
                                newScale -= new Vector3(0.005f, 0.005f, 0.005f);
                        chopper.transform.localScale = newScale;
                    }
                }
            }
            else
                chopper.transform.localScale = originScale;
        }
        #endregion

        #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)
        {
            if (newStatus == TrackableBehaviour.Status.DETECTED ||
                newStatus == TrackableBehaviour.Status.TRACKED ||
                newStatus == TrackableBehaviour.Status.EXTENDED_TRACKED)
            {
                isTracked = true;

                OnTrackingFound();
            }
            else
            {
                isTracked = false;

                OnTrackingLost();//脱卡不消失
            }
        }

        #endregion // PUBLIC_METHODS



        #region PRIVATE_METHODS


        private void OnTrackingFound()
        {
            Renderer[] rendererComponents = GetComponentsInChildren<Renderer>(true);
            Collider[] colliderComponents = GetComponentsInChildren<Collider>(true);
            
            // Enable rendering:
            foreach (Renderer component in rendererComponents)
            {
                component.enabled = true;
               // component.transform.parent = VuforiaManager.Instance.ARCameraTransform;
            }

            // Enable colliders:
            foreach (Collider component in colliderComponents)
            {
                component.enabled = true;
                //component.transform.parent = VuforiaManager.Instance.ARCameraTransform;
            }

            Debug.Log("Trackable " + mTrackableBehaviour.TrackableName + " found");
        }


        private void OnTrackingLost()
        {
            Renderer[] rendererComponents = GetComponentsInChildren<Renderer>(true);
            Collider[] colliderComponents = GetComponentsInChildren<Collider>(true);

            // Disable rendering:
            foreach (Renderer component in rendererComponents)
            {
                component.enabled = false;
            }

            // Disable colliders:
            foreach (Collider component in colliderComponents)
            {
                component.enabled = false;
            }

            Debug.Log("Trackable " + mTrackableBehaviour.TrackableName + " lost");
        }

        #endregion // PRIVATE_METHODS
    }
}

（4）发布

①选择菜单File-BuildSettings