26 VR开发—— HTC Vive瞬移功能的实现

一、为什么要实现瞬移这个功能##

因为HTC Vive活动范围有限制（3m * 5m），所以我们在实际的使用中，为了更好的浏览场景，查看场景，会使用这种移动的方式，达到游戏中的视野移动。
一般来说就是手柄选取一个位置，通过扳机键确认移动。
移动的方式有两种：一种是水平移动即X，Z轴移动;另一种就是垂直移动,即Y轴移动。

二、实现过程##

这瞬移过程中最重要的是拿到目标位置的坐标，我们可以通过射线检测拿到位置.
在Steam VR插件给我们提供了封装好的类与方法，我们做出相应的改变得到我们需要的结果.

射线检测脚本

重写代码展示：
using UnityEngine;
using System.Collections;

//public struct PointerEventArgs
//{
//    public uint controllerIndex;
//    public uint flags;
//    public float distance;
//    public Transform target;
//}

//public delegate void PointerEventHandler(object sender, PointerEventArgs e);



public class Test_LaserPointer : MonoBehaviour
{
    public bool active = true;
    public Color color;
    public float thickness = 0.002f;
    public GameObject holder;
    public GameObject pointer;
    bool isActive = false;
    public bool addRigidBody = false;
    public Transform reference;
    public event PointerEventHandler PointerIn;
    public event PointerEventHandler PointerOut;

    public Vector3 HitPoint;//添加的量找到目标位置
    Transform previousContact = null;

    // Use this for initialization
    void Start ()
    {
        holder = new GameObject();
        holder.transform.parent = this.transform;
        holder.transform.localPosition = Vector3.zero;
        holder.transform.localRotation = Quaternion.identity;

        pointer = GameObject.CreatePrimitive(PrimitiveType.Cube);
        pointer.transform.parent = holder.transform;
        pointer.transform.localScale = new Vector3(thickness, thickness, 100f);
        pointer.transform.localPosition = new Vector3(0f, 0f, 50f);
        pointer.transform.localRotation = Quaternion.identity;
        BoxCollider collider = pointer.GetComponent<BoxCollider>();
        if (addRigidBody)
        {
            if (collider)
            {
                collider.isTrigger = true;
            }
            Rigidbody rigidBody = pointer.AddComponent<Rigidbody>();
            rigidBody.isKinematic = true;
        }
        else
        {
            if(collider)
            {
                Object.Destroy(collider);
            }
        }
        Material newMaterial = new Material(Shader.Find("Unlit/Color"));
        newMaterial.SetColor("_Color", color);
        pointer.GetComponent<MeshRenderer>().material = newMaterial;
    }

    public virtual void OnPointerIn(PointerEventArgs e)
    {
        if (PointerIn != null)
            PointerIn(this, e);
    }

    public virtual void OnPointerOut(PointerEventArgs e)
    {
        if (PointerOut != null)
            PointerOut(this, e);
    }


    // Update is called once per frame
    void Update ()
    {
        if (!isActive)
        {
            isActive = true;
            this.transform.GetChild(0).gameObject.SetActive(true);
        }

        float dist = 100f;

        SteamVR_TrackedController controller = GetComponent<SteamVR_TrackedController>();

        Ray raycast = new Ray(transform.position, transform.forward);
        RaycastHit hit;
        bool bHit = Physics.Raycast(raycast, out hit);

        if(previousContact && previousContact != hit.transform)
        {
            PointerEventArgs args = new PointerEventArgs();
            if (controller != null)
            {
                args.controllerIndex = controller.controllerIndex;
            }
            args.distance = 0f;
            args.flags = 0;
            args.target = previousContact;
            OnPointerOut(args);
            previousContact = null;
        }
        if(bHit && previousContact != hit.transform)
        {
            PointerEventArgs argsIn = new PointerEventArgs();
            if (controller != null)
            {
                argsIn.controllerIndex = controller.controllerIndex;
            }
            argsIn.distance = hit.distance;
            argsIn.flags = 0;
            argsIn.target = hit.transform;
            OnPointerIn(argsIn);
            previousContact = hit.transform;
        }
        if(!bHit)
        {
            previousContact = null;
        }
        if (bHit && hit.distance < 100f)
        {
            dist = hit.distance;
        }

        if (bHit)//添加的实现代码；
        {
            HitPoint = hit.point;
        }

        if (controller != null && controller.triggerPressed)
        {
            pointer.transform.localScale = new Vector3(thickness * 5f, thickness * 5f, dist);
        }
        else
        {
            pointer.transform.localScale = new Vector3(thickness, thickness, dist);
        }
        pointer.transform.localPosition = new Vector3(0f, 0f, dist/2f);
    }
}

SteamVR_TrackedController脚本

下面就是自己写代码实现瞬移过程：
代码展示及逻辑：
public class Test_Teleporter : MonoBehaviour {

    // 拿到手柄对象
    public GameObject LeftController;
    //修改后的射线检测脚本
    private Test_LaserPointer Pointer;
    // 右手柄的控制器
    private SteamVR_TrackedController LeftSt;
    // 事件调用函数
    ClickedEventHandler ce;
    // 当前的目标位置
    Transform currentTransform;
    // 碰撞事件
    PointerEventArgs arg;
    void Start()
    {
        Pointer = LeftController.GetComponent<Test_LaserPointer>();
        LeftSt = LeftController.GetComponent<SteamVR_TrackedController>();
        // 利用Laserpoint里面的事件函数来检测目标位置
        Pointer.PointerIn += LeftPointIn;
        //  利用Laserpoint里面的事件函数来检测目标位置
        Pointer.PointerOut += LeftPointOut;
        // 利用手柄控制器来检测我们的扳机事件
        LeftSt.TriggerClicked += TriggerClicked;
    }

    // 没有检测到碰撞信息
    void LeftPointOut(object sender, PointerEventArgs e)
    {   // 当前位置没有
        currentTransform = null;
    }
    // 检测到碰撞信息
    void LeftPointIn(object sender, PointerEventArgs e)
    {   // 设置目标位置为检测到的目标
        currentTransform = e.target;
    }
    // 扳机事件
    void TriggerClicked(object sender, ClickedEventArgs e)
    {
        // 如果检测到目标位置
        if (currentTransform != null)
        {    // 移动
            this.gameObject.transform.position = new Vector3(Pointer.HitPoint.x - LeftController.transform.localPosition.x, Pointer.HitPoint.y, Pointer.HitPoint.z - LeftController.transform.localPosition.z);
        }
    }
}

三、结果实现##

挂载脚本，实现结果