GazeInputModule--VR凝视瞄准头控交互

VR最原始的人机交互方式-凝视瞄准头控操作，

通过屏幕中央的cursor瞄准点瞄准ui界面或物体，自动点击进入或手柄触摸板点击，实现的核心步骤：

// Cast a ray into the scene
    pointerData.Reset();
    pointerData.position = new Vector2(hotspot.x * Screen.width, hotspot.y * Screen.height);
    eventSystem.RaycastAll(pointerData, m_RaycastResultCache);

    m_RaycastResultCache = m_RaycastResultCache.OrderBy(o => o.distance).ToList();
    //If the Canvas and an Element are Z-Fighting, remove the Canvas from the runnings
    if ((m_RaycastResultCache.Count > 1) && (m_RaycastResultCache[0].gameObject.GetComponent<Canvas>()) && (Mathf.Abs(m_RaycastResultCache[0].distance - m_RaycastResultCache[1].distance)) < 0.1f)
    {
        m_RaycastResultCache.RemoveAt(0);
    }
    for(int i=m_RaycastResultCache.Count-1; i>=0; i--)
    {
        if(m_RaycastResultCache[i].gameObject.tag == "GazeReticleDisable")
        {
            m_RaycastResultCache.RemoveAt(i);
        }
    }

    pointerData.pointerCurrentRaycast = FindFirstRaycast(m_RaycastResultCache);  
    m_RaycastResultCache.Clear();

射线检测，按距离排序或剔除

// 凝视悬停点击
    if (go)
    {
        if (go == previousGazedObject)
        {
            if (Time.time - lastTime > DetTime)
            {
                lastTime = Time.time;

                // 触发点击事件
                GameObject handler = ExecuteEvents.GetEventHandler<IPointerClickHandler>(pointerData.pointerEnter);
                if (handler != null)
                {
                    ExecuteEvents.ExecuteHierarchy(handler, pointerData, ExecuteEvents.pointerClickHandler);
                }

                if(!IsOverGaze)
                {
                    IsOverGaze = true;

                    // 触发mousedown 并为拖动准备数据
                    HandleTrigger();
                }
             }
        }
        else
        {
            IsOverGaze = false;
            lastTime = Time.time;
            // 触发mouseup
            HandlePendingClick();
        }
    }
    else
    {
        // 触发mouseup
        HandlePendingClick();
    }

倒计时发出点击事件

void UpdateReticle(GameObject previousGazedObject) {
    GameObject gazeObject = GetCurrentGameObject(); // Get the gaze target

    if (gazeObject)
    {
        if(gazeObject.tag == "GazeDisable")
        {
            m_Reticle.Hide();
        }
        else
        {
            m_Reticle.Show();
        }
        if (m_Reticle)
            m_Reticle.SetPosition(GetIntersectionPosition(), GetIntersectionDistace());
        if(gazeObject == previousGazedObject)
        {
            GameObject handler = ExecuteEvents.GetEventHandler<IPointerDownHandler>(gazeObject);
            if (m_SelectionRadial && (handler != null || gazeObject.tag == "GazeReticleEnable"))
                m_SelectionRadial.HandleDown();
        }
        else
        {
            if (m_SelectionRadial)
                m_SelectionRadial.HandleUp();
        }
    }
    else
    {
        m_Reticle.Show();
        if (m_Reticle)
            m_Reticle.SetPosition();
        if (m_SelectionRadial)
            m_SelectionRadial.HandleUp();
    }
  }

cursor动画