Unity 昼夜交替

将脚本挂载在Directional Light上，并将Directional Light的Rotation属性按照下图设置。

太阳环绕一周设定为24分钟。

可以选择初始时间为系统时间 / 随机时间 /预设时间。

最下面是游戏世界的时间。

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

public class SunMove : MonoBehaviour
{
    
    public float OrbitMinute = 24;      //太阳转一周，所需的时间设为24分钟
    private float AnglePerSec = 0;

    //Real Time
    [Range(0, 1440)]
    public float sec = 0;
    private float min = 0;

    public DefaultTime defaultTime = DefaultTime.SystemTime;
    public enum DefaultTime
    {
        SystemTime,
        Random,
        Preset,
    }

    public float PresetTime = 7;

    [Header("Only Read")]
    //Game Time
    public float GameHour = 0;
    public float GameMin = 0;

    void Start()
    {
        AnglePerSec = 360 / OrbitMinute / 60;
        if (defaultTime == DefaultTime.SystemTime)
            gameObject.transform.rotation = Quaternion.Euler(SunAngle(System.DateTime.Now.Hour), -90, 0);
        else if (defaultTime == DefaultTime.Random)
            SetTime(Random.Range(0, 24));
        else if (defaultTime == DefaultTime.Preset)
            SetTime(PresetTime);
    }

    void Update()
    {
        sec += Time.deltaTime;
        min = sec / 60;
        GameHour = (int) min % OrbitMinute;
        GameMin = (int) sec % 60;

        gameObject.transform.rotation = Quaternion.Euler(SunAngle(GameHour, GameMin), -90, 0);
    }

    float SunAngle(float hour)
    {       
        return 360 / OrbitMinute * hour - 90;     
    }

    float SunAngle(float hour,float minute)
    {
        return 360 / OrbitMinute * hour - 90 + AnglePerSec * minute;
    }

    void SetTime(float hour)
    {
        sec = hour * 60;
    }
}