首先，百度查到OnBecameVisible和OnBecameInvisible方法，但是该方法在物体被遮挡情况下不适用。

然后就考虑结合遮挡剔除，但是烘焙了多次，不太理想。

找到了InstantOC插件，发现里面用射线检测实现，先说一下该方法的缺点，update随机射线，消耗高，而且必须要有collider才能检测。

相机的检测代码：

namespace LastZero
{
    public class CameraDetection: MonoBehaviour {

        public LayerMask layerMsk;
        public int samples;
        public int hideDelay;
        public float viewDistance;

        private RaycastHit hit;
        private Ray ray;
        private DetectionTarget target;

        private void Awake()
        {
            hit = new RaycastHit();
            GetComponent<Camera>().farClipPlane = viewDistance;
        }

        private void Update()
        {
            for (int k = 0; k <= samples; k++)
            {
                ray = GetComponent<Camera>().ScreenPointToRay(new Vector3(Random.Range(0, Screen.width), Random.Range(0, Screen.height), 0f));
                if (Physics.Raycast(ray, out hit, viewDistance, layerMsk.value))
                {
                    if (target = hit.transform.GetComponent<DetectionTarget>())
                    {
                        target.SetShow(hideDelay);
                    }
                }
            }
        }
    }
}

物体自我处理逻辑：

namespace LastZero
{
    public class DetectionTarget: MonoBehaviour {

        private Renderer[] renders;
        private bool isShow;
        private float hideDelay;

        private void Awake()
        {
            renders = GetComponentsInChildren<Renderer>();
        }

        private void Update()
        {
            if (isShow)
            {
                hideDelay--;
                if (hideDelay < 0)
                {
                    SetHide();
                }
            }
            else
            {
                SetEnable(false);
            }
        }

        public void SetShow(int delay)
        {
            hideDelay = delay;           
            isShow = true;
            SetEnable(true);
        }

        private void SetHide()
        {
            isShow = false;
        }

        private void SetEnable(bool b)
        {
            for (int i = 0; i < renders.Length; i++)
            {
                renders[i].enabled = b;
            }
        }

        private void OnBecameVisible()
        {
            Debug.Log("OnBecameVisible");
        }

        private void OnBecameInvisible()
        {
            Debug.Log("OnBecameInvisible");
        }
    }
}