《Unity5实战-使用C#和Unity开发多平台游戏》第二章-构建一个让你置身3D空间的演示
鼠标观察/键盘控制移动飞行/行走/碰撞检测
Unity版本：2019.4.23f1c1

• 注意脚本名称和组件添加，不在文章中一一强调
• 场景模型都是在资源商店选择的免费下载（选择Sort by Price(Low to High)排序）搜索参考关键字：airplane、sky
• 整篇的实例代码是修改累加的，为了防止混乱我就全部贴上，不强调新增或删减部分

搭建：一架飞机模型（脚本挂载物体），天空盒（照明设置），摄像机Camera
原始画面：

跟随鼠标观察周围脚本

运行效果：

如果改为鼠标X则只能水平旋转（我这里是摄像机角度有些倾斜，不是飞机

using UnityEngine;
using System.Collections;

public class MouseLook : MonoBehaviour
{
    //观察周围
    public enum RotationAxes
    {
        MouseXAndY=0,
        MouseX=1,
        MouseY=2
    }
    public RotationAxes axes = RotationAxes.MouseXAndY;

    public float sensitivityHor = 9.0f;//旋转速度
    public float sensitivityVert = 9.0f;

    public float miniumVert = -45.0f;
    public float maximumVert = 45.0f;

    private float _rotationX = 0;
    
    void Start()
    {
        Rigidbody body = GetComponent<Rigidbody>();
        if (body != null)
            body.freezeRotation = true;
    }

    // Update is called once per frame
    void Update()
    {
        if (axes == RotationAxes.MouseX)//水平旋转
        {
            transform.Rotate(0, Input.GetAxis("Mouse X") * sensitivityHor, 0);//GetAxis()获取鼠标的输入
        }
        else if (axes == RotationAxes.MouseY)//垂直旋转
        {
            _rotationX -= Input.GetAxis("Mouse Y") * sensitivityVert;//基于鼠标增加垂直角度
            _rotationX = Mathf.Clamp(_rotationX, miniumVert, maximumVert);//将垂直角度限制在最小值和最大值之间

            float rotationY = transform.localEulerAngles.y;//保持Y的角度一样（也就是水平没有旋转）

            transform.localEulerAngles = new Vector3(_rotationX, rotationY, 0);//使用存储旋转值创建新的Vector
        }
        else//水平且垂直旋转
        {
            _rotationX -= Input.GetAxis("Mouse Y") * sensitivityVert;
            _rotationX = Mathf.Clamp(_rotationX, miniumVert, maximumVert);

            float delta = Input.GetAxis("Mouse X") * sensitivityHor;//旋转变化量
            float rotationY = transform.localEulerAngles.y + delta;//使用delta增加旋转角度

            transform.localEulerAngles = new Vector3(_rotationX, rotationY, 0);
        }
    }
}

第一人称控件

运行效果：键盘WSAD或上下左右，鼠标移动水平高度

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

public class FPS : MonoBehaviour
{
    public float speed = 3.0f;
    //观察周围
    public enum RotationAxes
    {
        MouseXAndY = 0,
        MouseX = 1,
        MouseY = 2
    }
    public RotationAxes axes = RotationAxes.MouseXAndY;

    public float sensitivityHor = 9.0f;//旋转速度
    public float sensitivityVert = 9.0f;

    public float miniumVert = -45.0f;
    public float maximumVert = 45.0f;

    private float _rotationX = 0;

    void Start()
    {
        Rigidbody body = GetComponent<Rigidbody>();
        if (body != null)
            body.freezeRotation = true;
    }

    // Update is called once per frame
    void Update()
    {
        if (axes == RotationAxes.MouseX)//水平旋转
        {
            transform.Translate(0, Input.GetAxis("Mouse X") * sensitivityHor, 0);//GetAxis()获取鼠标的输入
        }
        else if (axes == RotationAxes.MouseY)//垂直旋转
        {
            _rotationX -= Input.GetAxis("Mouse Y") * sensitivityVert;//基于鼠标增加垂直角度
            _rotationX = Mathf.Clamp(_rotationX, miniumVert, maximumVert);//将垂直角度限制在最小值和最大值之间

            float rotationY = transform.localEulerAngles.y;//保持Y的角度一样（也就是水平没有旋转）

            transform.localEulerAngles = new Vector3(_rotationX, rotationY, 0);//使用存储旋转值创建新的Vector
        }
        else//水平且垂直旋转
        {
            _rotationX -= Input.GetAxis("Mouse Y") * sensitivityVert;
            _rotationX = Mathf.Clamp(_rotationX, miniumVert, maximumVert);

            float delta = Input.GetAxis("Mouse X") * sensitivityHor;//旋转变化量
            float rotationY = transform.localEulerAngles.y + delta;//使用delta增加旋转角度

            transform.localEulerAngles = new Vector3(_rotationX, rotationY, 0);
        }
        float deltaX = Input.GetAxis("Horizontal") * speed;
        float deltaZ = Input.GetAxis("Vertical") * speed;
        transform.Translate(deltaX, 0, deltaZ);
    }
}

碰撞检测

问题：如果前面有一堵墙飞机往前会直接穿过去

运行效果：碰到墙壁无法穿过

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

public class FPS : MonoBehaviour
{
    public float speed = 3.0f;
    private CharacterController _charController;

    void Start()
    {
        _charController = GetComponent<CharacterController>();
    }

    // Update is called once per frame
    void Update()
    {

        float deltaX = Input.GetAxis ("Horizontal") * speed;
        float deltaZ = Input.GetAxis ("Vertical") * speed;
        Vector3 movement = new Vector3 (deltaX, 0, deltaZ);
        movement = Vector3.ClampMagnitude (movement, speed);

        movement *= Time.deltaTime;
        movement = transform.TransformDirection  (movement);
        _charController.Move (movement);
    }
}

重力添加

添加重力gravity就能改为陆地行走，在面板将重力改为0则飞行模式

using System.Collections;
using UnityEngine;

[RequireComponent(typeof(CharacterController))]
[AddComponentMenu("Control Script/FPS Input")]
public class FPS : MonoBehaviour
{
    public float speed = 6.0f;
    public float gravity = -9.8f;

    private CharacterController _charController;
    // Start is called before the first frame update
    void Start()
    {
        _charController = GetComponent<CharacterController>();
    }

    // Update is called once per frame
    void Update()
    {
        float deltaX = Input.GetAxis("Horizontal") * speed;
        float deltaZ = Input.GetAxis("Vertical") * speed;
        Vector3 movement = new Vector3(deltaX, 0, deltaZ);
        movement = Vector3.ClampMagnitude(movement, speed);

        movement.y = gravity;

        movement *= Time.deltaTime;
        movement = transform.TransformDirection(movement);
        _charController.Move(movement);
    }
}