Unity3D摄像机，键盘控制前后左右上下移动，鼠标控制旋转、放缩

Unity3D中运行场景时，实现摄像机的前、后、左、右、上、下，以及鼠标滚轮的放缩，鼠标右键的旋转操作。亲测有效，可供参考。
按键功能介绍：W——前；S——后；A——左；D——右；Q——下降；E——上升；鼠标右键——旋转；鼠标滚轮——放缩。
Tourcamera脚本需要挂在摄像机组件上。
在摄像机组件中还需要添加“Physics Raycaster”组件。

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

public class Tourcamera : MonoBehaviour
{
    
    public Transform tourCamera;
    #region 相机移动参数
    public float moveSpeed = 1.0f;
    public float rotateSpeed = 90.0f;
    public float shiftRate = 2.0f;// 按住Shift加速
    public float minDistance = 0.5f;// 相机离不可穿过的表面的最小距离（小于等于0时可穿透任何表面）
    #endregion

    #region 运动速度和其每个方向的速度分量
    private Vector3 direction = Vector3.zero;
    private Vector3 speedForward;
    private Vector3 speedBack;
    private Vector3 speedLeft;
    private Vector3 speedRight;
    private Vector3 speedUp;
    private Vector3 speedDown;
    #endregion
    void Start()
    {
    
        if (tourCamera == null) tourCamera = gameObject.transform;
        // 防止相机边缘穿透
        //if (tourCamera.GetComponent<Camera>().nearClipPlane > minDistance / 3)
        //{
    
        // tourCamera.GetComponent<Camera>().nearClipPlane /= 3;
        //}
    }
    void Update()
    {
    
        GetDirection();
        // 检测是否离不可穿透表面过近
        RaycastHit hit;
        while (Physics.Raycast(tourCamera.position, direction, out hit, minDistance))
        {
    
            // 消去垂直于不可穿透表面的运动速度分量
            float angel = Vector3.Angle(direction, hit.normal);
            float magnitude = Vector3.Magnitude(direction) * Mathf.Cos(Mathf.Deg2Rad * (180 - angel));
            direction += hit.normal * magnitude;
        }
        tourCamera.Translate(direction * moveSpeed * Time.deltaTime, Space.World);
    }
    private void GetDirection()
    {
    
        #region 加速移动
        if (Input.GetKeyDown(KeyCode.LeftShift)) moveSpeed *= shiftRate;
        if (Input.GetKeyUp(KeyCode.LeftShift)) moveSpeed /= shiftRate;
        #endregion

        #region 键盘移动
        // 复位
        speedForward = Vector3.zero;
        speedBack = Vector3.zero;
        speedLeft = Vector3.zero;
        speedRight = Vector3.zero;
        speedUp = Vector3.zero;
        speedDown = Vector3.zero;
        // 获取按键输入
        if (Input.GetKey(KeyCode.UpArrow) || Input.GetKey(KeyCode.W)) speedForward = tourCamera.forward;
        if (Input.GetKey(KeyCode.DownArrow) || Input.GetKey(KeyCode.S)) speedBack = -tourCamera.forward;
        if (Input.GetKey(KeyCode.LeftArrow) || Input.GetKey(KeyCode.A)) speedLeft = -tourCamera.right;
        if (Input.GetKey(KeyCode.RightArrow) || Input.GetKey(KeyCode.D)) speedRight = tourCamera.right;
        if (Input.GetKey(KeyCode.E)) speedUp = Vector3.up;
        if (Input.GetKey(KeyCode.Q)) speedDown = Vector3.down;
        direction = speedForward + speedBack + speedLeft + speedRight + speedUp + speedDown;
        #endregion

        #region 鼠标旋转
        if (Input.GetMouseButton(1))
        {
    
            // 转相机朝向
            tourCamera.RotateAround(tourCamera.position, Vector3.up, Input.GetAxis("Mouse X") * rotateSpeed * Time.deltaTime);
            tourCamera.RotateAround(tourCamera.position, tourCamera.right, -Input.GetAxis("Mouse Y") * rotateSpeed * Time.deltaTime);
            // 转运动速度方向
            direction = V3RotateAround(direction, Vector3.up, Input.GetAxis("Mouse X") * rotateSpeed * Time.deltaTime);
            direction = V3RotateAround(direction, tourCamera.right, -Input.GetAxis("Mouse Y") * rotateSpeed * Time.deltaTime);
        }
        #endregion

        #region 鼠标滚轮效果
        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;
        }
        #endregion
    }

    public Vector3 V3RotateAround(Vector3 source, Vector3 axis, float angle)
    {
    
        Quaternion q = Quaternion.AngleAxis(angle, axis);// 旋转系数
        return q * source;// 返回目标点
    }
}