鼠标控制unity视角

//鼠标控制视角脚本

using UnityEngine;
using System.Collections;

public class view_control : MonoBehaviour 
{
    float sensitivityMouse = 2f;
    float sensitivetyKeyBoard = -0.5f;
    float sensitivetyMouseWheel = 30f;

    public Camera mainCamera;

    void Update()
    {
        //滚轮实现镜头缩进和拉远
        if (Input.GetAxis("Mouse ScrollWheel") != 0)
        {
            mainCamera.fieldOfView = mainCamera.fieldOfView - Input.GetAxis("Mouse ScrollWheel") * sensitivetyMouseWheel;
        }
        //按着鼠标右键实现视角转动
        if (Input.GetMouseButton(1))
        {
            transform.Rotate(-Input.GetAxis("Mouse Y") * sensitivityMouse, Input.GetAxis("Mouse X") * sensitivityMouse, 0);
        }

        //左键平移
        if (Input.GetMouseButton(0))
        {
            transform.Translate(Input.GetAxis("Mouse X") * sensitivetyKeyBoard, 0, 0);
        }
        if (Input.GetMouseButton(0))
        {
            transform.Translate(0, Input.GetAxis("Mouse Y") * sensitivetyKeyBoard, 0);
        }
    }
}