关键代码：LightmapSettings.lightmaps = lightmapDatas;

LightmapData中操作三张图：lightmapColor,lightmapDir,以及一张ShadowMap

这里只操作前两张：

using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

public class LightingSwitchBtn : MonoBehaviour
{
    public bool IsTurnOn = false;

    // / 光照信息
    LightmapData[] lightmapDatas;

    /// 暗的时候的贴图
    public Texture2D[] lightmapDark;
    public Texture2D[] lightmapDarkDir;

    /// 亮的时候的贴图
    public Texture2D[] lightmapLight;
    public Texture2D[] lightmapLightDir;

    void Awake()
    {
    }
    public void OnPointerClick()
    {
        Debug.Log("1111");
        SwichState();
    }
    public void SwichState()
    {
        Debug.Log("2222");
        bool ClickState = !IsTurnOn;
        if (ClickState)
        {
            SetLightMap(lightmapLight, lightmapLightDir);
        }
        else
        {
            SetLightMap(lightmapDark, lightmapDarkDir);
        }
        IsTurnOn = ClickState;
    }

    public void SetLightMap(Texture2D[] lightmapTex, Texture2D[] lightmapDir)
    {
        if (lightmapTex == null)
        {
            return;
        }
        lightmapDatas = new LightmapData[lightmapTex.Length];
        for (int i = 0; i < lightmapTex.Length; i++)
        {
            LightmapData lmd = new LightmapData();
            lmd.lightmapColor = lightmapTex[i];
            lmd.lightmapDir = lightmapDir[i];
            lightmapDatas[i] = lmd;
        }
        LightmapSettings.lightmaps = lightmapDatas;
    }

}