unity 场景摄像机游览脚本

        该脚本适用于大场景浏览时摄像机位移的脚本，可以控制摄像机的移动范围，和俯仰角，避免出现旋转360度，镜头中出现倒着看的情况。

        该脚本的核心代码是通过update函数,获取相机每一帧的旋转角度和位置，然后再判断位置 和俯仰角， 如果超出界限，则将值归回每一帧初的旋转角度和位置，达到限制相机位移和角度。代码思路来源网友，自己将代码封装，供大家参考，其中有一个问题还没有解决，即判断倾斜，然后归正。

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class CamerraMove : MonoBehaviour
{

    //x轴 最大值、最小值

    [Header("X轴范围")]
    public float xMaxMove = 50;
    public float xMinMove = -385;
    //y轴 最大值、最小值
    [Header("Y轴范围")]
    public float yMaxMove = 58;
    public float yMinMove = 1;
    //z轴 最大值、最小值

    [Header("Z轴范围")]
    public float zMaxMove = 180;
    public float zMinMove = -157;

    [Header("俯仰角范围")]
    public float xMaxAngle;
    public float xMinAngle;

    [Header("灵敏度")]
    public float MoveSensitivity;
    public float AngleSensitivity;

    #region 基础定义
    Transform CammeraMain;
    //滑轮滚动基数
    float WheelMove = 0;
    //鼠标每帧移动基数
    float MouseMove_X = 0;
    float MouseMove_Y = 0;
    //相机自身X/Y轴方向
    Vector3 X_Aix = new Vector3(1, 0, 0);
    Vector3 Y_Aix = new Vector3(0, 1, 0);
    //相机x轴在水平面投影
    Vector3 HX_Aix = new Vector3(1, 0, 0);
    //世界坐标Y轴
    Vector3 WY_Aix = new Vector3(0, 1, 0);
   
    private Vector3 LPosition;//控制点
    private float LRotation_X;//俯仰角控制点
    #endregion

    // Use this for initialization
    void Start()
    {
        CammeraMain = transform;
    }

    // Update is called once per frame
    void Update()
    {
        //更新相机自身X/Y轴方向
        X_Aix = CammeraMain.right;
        Y_Aix = CammeraMain.up;          
        
        //获取每一帧物体的位置 和俯仰角
        LPosition = transform.position;
        LRotation_X = transform.localEulerAngles.x;


        #region 鼠标右击相机旋转
        if (Input.GetMouseButton(1))
        {
            if ((MouseMove_X = Input.GetAxis("Mouse X")) != 0)
            {
                HX_Aix.x = X_Aix.x;
                HX_Aix.z = X_Aix.z;
                CammeraMain.Rotate(WY_Aix, MouseMove_X* AngleSensitivity, Space.World);
            }

            if ((MouseMove_Y = Input.GetAxis("Mouse Y")) != 0)
            {
                CammeraMain.Rotate(X_Aix, -MouseMove_Y* AngleSensitivity, Space.World);
            }
        }
        #endregion

        #region 鼠标滑动滚轮移动
        //滑轮滚动 摄像机前后移动
        if ((WheelMove = Input.GetAxis("Mouse ScrollWheel")) != 0)
        {
            CammeraMain.Translate(0, 0, WheelMove* MoveSensitivity);
        }

        //摄像机在世界坐标下的水平移动
        if (Input.GetMouseButton(2))
        {
            CammeraMain.Translate(Vector3.right * MoveSensitivity * Time.deltaTime * -Input.GetAxis("Mouse X"));
            //纵向平移，若相机垂直地面则向前平移
            CammeraMain.Translate(Vector3.up * MoveSensitivity * Time.deltaTime * -Input.GetAxis("Mouse Y")); 
        }
        #endregion

        #region 控制摄像机位移
        if ((transform.position.x > xMaxMove || transform.position.x < xMinMove))
        {
            transform.position = new Vector3(LPosition.x, transform.position.y, transform.position.z);
        }
        //检查相机y轴
        if ((transform.position.y > yMaxMove || transform.position.y < yMinMove))
        {
            transform.position = new Vector3(transform.position.x, LPosition.y, transform.position.z);
        }
        //检查相机z轴
        if ((transform.position.z > zMaxMove || transform.position.z < zMinMove))
        {
            transform.position = new Vector3(transform.position.x, transform.position.y, LPosition.z);
        }
        #endregion

        #region 控制摄像机俯仰角
        if (CheckAngle(transform.localEulerAngles.x) > xMaxAngle || CheckAngle(transform.localEulerAngles.x) < xMinAngle) {  
            transform.localEulerAngles = new Vector3(LRotation_X, transform.localEulerAngles.y, transform.localEulerAngles.z);
        }
        #endregion
       
    }

    private float CheckAngle(float value)  // 将大于180度角进行以负数形式输出
    {
        float angle = value - 180;

        if (angle > 0)
        {
            return angle - 180;
        }
        if (value == 0)
        {
            return 0;
        }
        return angle + 180;
    }
}