Unity相机跟随小结

public class FollowCamera : MonoBehaviour
{
    internal enum UpdateMode
    {
        Update,
        FixedUpdate
    }

    [SerializeField] UpdateMode updateMode=UpdateMode.Update;
    [SerializeField]Transform cam;
    [SerializeField]Transform player;
    [SerializeField]Vector3 offsetPos;
    [SerializeField] float speed;
    [SerializeField] float rSpeed;
    Vector3 pos;
    [SerializeField] Vector3 angel;//对目标的局部旋转
    Quaternion rotation;

    private void Awake()
    {
        player = GameObject.FindGameObjectWithTag("Player").transform;
    }

    // Update is called once per frame
    void Update()
    {
        if (updateMode != UpdateMode.Update) return;
        SetCameraPosLerp(UpdateMode.Update);
    }

    private void FixedUpdate()
    {
        if (updateMode != UpdateMode.FixedUpdate) return;
        SetCameraPosLerp(UpdateMode.FixedUpdate);
    }

    //获取目标位置
    Vector3 GetTargetPos(Transform target)
    {
        Vector3 p = target.TransformPoint(offsetPos);
        return p;
    }

    //获取目标旋转
    Quaternion GetTargetRotation(Transform target)
    {
        Quaternion r= Quaternion.Euler(angel);
        r = target.rotation * r;//跟随目标旋转的方式就是让目标旋转和局部旋转相乘
        return r;
    }

    //更新相机的旋转和位置
    void SetCameraPosLerp(UpdateMode mode)
    {
        if (!player) return;
        float deltaTime = 0;
        switch (mode)
        {
            case UpdateMode.Update:
                deltaTime = Time.deltaTime;
                break;
            case UpdateMode.FixedUpdate:
                deltaTime = Time.fixedDeltaTime;
                break;
        }
        transform.position = Vector3.Lerp(transform.position, GetTargetPos(player), deltaTime * speed);
        transform.rotation = Quaternion.Lerp(transform.rotation, GetTargetRotation(player), deltaTime * rSpeed);
    }

    //In Editor
    public void SetCameraPos()
    {
        if (!player) return;
        transform.position= GetTargetPos(player);
        transform.rotation = GetTargetRotation(player);
    }

    private void OnDrawGizmos()
    {
        if (!player) return;
        Gizmos.color = Color.red;
        Vector3 p = GetTargetPos(player);
        Gizmos.DrawWireSphere(p, 0.5f);
        Gizmos.DrawLine(p, player.position);
    }
}