public class xuanzhuan : MonoBehaviour {    //平移速度变量    public float MoveSpeed;// Use this for initialization    void Start () {
        }        // Update is called once per frame    void Update () {//键盘判断        if(Input.GetKey(KeyCode.A)){            transform.Translate(Vector3.left* MoveSpeed,Space.World);        }        if(Input.GetKey(KeyCode.D)){            transform.Translate(Vector3.right* MoveSpeed,Space.World);        }        if(Input.GetKey(KeyCode.W)){            transform.Translate(Vector3.up* MoveSpeed,Space.World);        }        if(Input.GetKey(KeyCode.S)){            transform.Translate(Vector3.down* MoveSpeed,Space.World);        }        //鼠标判断        if(Input.GetMouseButton(0)){            transform.Rotate(Vector3.down* MoveSpeed,Space.World);        }        //鼠标判断        if(Input.GetMouseButton(1)){            transform.Rotate(Vector3.up* MoveSpeed,Space.World);        }        //滚轮放大缩小        //Zoom out        if (Input.GetAxis("Mouse ScrollWheel") <0)        {            if(Camera.main.fieldOfView<=100)                Camera.main.fieldOfView +=2;            if(Camera.main.orthographicSize<=20)                Camera.main.orthographicSize +=0.5F;        }        //Zoom in        if (Input.GetAxis("Mouse ScrollWheel") > 0)        {            if(Camera.main.fieldOfView>2)                Camera.main.fieldOfView-=2;            if(Camera.main.orthographicSize>=1)                Camera.main.orthographicSize-=0.5F;        }            }}