物体跟随鼠标移动

/*
这是一个第一人称移动脚本
*/
using UnityEngine;
using System.Collections;
using System;

public class Player : MonoBehaviour {
    //位置记录
    public Transform m_transform;
   
    //角色控制器组件
    CharacterController m_ch;
    //角色移动速度
    public float m_movSpeed = 3.0f;
    //重力
    float m_gravity = 2.0f;
    //生命值
    public int m_life = 5;

    //摄像机位置控制
    public Transform m_camTransform;
    //摄像机旋转角度
    Vector3 m_camRot;
    //摄像机高度
    public float m_camHeight = 1.4f;

    void Start()
    {
        m_transform = this.transform;
        //获取角色控制器
        m_ch = this.GetComponent<CharacterController>();

        //初始化摄像机
        //获取摄像机
        m_camTransform = Camera.main.transform;
        //设置摄像机初始位置
        Vector3 pos = m_transform.position;
        pos.y += m_camHeight;
        m_camTransform.position = pos;
        //摄像机的旋转方向与主 角方向一样
        m_camTransform.rotation = m_transform.rotation;
        m_camRot = m_camTransform.eulerAngles;
        //锁定鼠标
        Screen.lockCursor = true;
    }
    void Update()
    {
        if (m_life <= 0)
            return;
        Control();
        }

     void Control()
    {
        //三个值控制移动
        float ym = 0, xm = 0, zm = 0;
        //重力运动
        ym -= Time.deltaTime * m_gravity;
        //控制移动
        //向前移动
        if (Input.GetKey(KeyCode.W))
        { zm += Time.deltaTime * m_movSpeed; }
        //向后
        else if (Input.GetKey(KeyCode.S))
        { zm -= Time.deltaTime * m_movSpeed; }

        //向左
        if (Input.GetKey(KeyCode.A))
        { xm -= Time.deltaTime * m_movSpeed; }
        else if (Input.GetKey(KeyCode.D))
        { xm += Time.deltaTime * m_movSpeed; }
        //使用CharacterControl的Move函数进行移动，它会自动检测碰撞
        m_ch.Move(m_transform.TransformDirection(new Vector3(xm, ym, zm)));


        //获取鼠标移动距离
        float rh = Input.GetAxis("Mouse X");
        float rv = Input.GetAxis("Mouse Y");

        //旋转摄像机
        m_camRot.x -= rv;
        m_camRot.y += rh;
        m_camTransform.eulerAngles = m_camRot;

        //主角面向方向与摄像机一致
        Vector3 camrot = m_camTransform.eulerAngles;
        camrot.x = 0;
        camrot.z = 0;
        m_transform.eulerAngles = camrot;

        //使摄像机位置与主角一样
        Vector3 pos = m_transform.position;
        pos.y += m_camHeight;
        m_camTransform.position = pos;
    }
}