Unity LightMapSwitcher

LightMapSwitcher.cs

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

#if UNITY_EDITOR
using UnityEditor;
#endif

[Serializable]
public class LightMapGroup
{
	public string sourceFolder;
	public LightProbeGroup[] lightProbeGroups;
	public Light[] lights;
	public List<Texture2D> directionTextures, lightTextures, shadowMaskTextures;

	internal LightmapData[] data;
	internal bool isInit;

	private Texture2D LoadAssetTexture(string file)
	{
		string assetPath = Path.Combine("Assets", sourceFolder);
		assetPath = Path.Combine(assetPath, Path.GetFileName(file));
		var texture = AssetDatabase.LoadAssetAtPath<Texture2D>(assetPath);
		if (texture == null)
		{
			Debug.LogError("Unable to load texture: " + assetPath);
			return null;
		}

		return texture;
	}

	public void GatherFiles()
	{
		if (string.IsNullOrEmpty(sourceFolder))
		{
			isInit = true;
			return;
		}

		// format source path
		string sourceFolderFormated = sourceFolder.Replace('/', '\\');
		string sourceFolderFull = Path.Combine(Application.dataPath, sourceFolderFormated);
		#if UNITY_EDITOR_WIN || UNITY_STANDALONE_WIN
		sourceFolderFull = sourceFolderFull.Replace('/', '\\');
		#else
		sourceFolderFull = sourceFolderFull.Replace('\\', '/');
		#endif

		// validate source path
		if (!Directory.Exists(sourceFolderFull))
		{
			Debug.LogError("LightMapGroup source folder does not exist: " + sourceFolderFull);
			return;
		}

		// gather textures
		directionTextures = new List<Texture2D>();
		lightTextures = new List<Texture2D>();
		shadowMaskTextures = new List<Texture2D>();
		foreach (string file in Directory.GetFiles(sourceFolderFull))
		{
			if (file.EndsWith("_dir.png"))
			{
				var texture = LoadAssetTexture(file);
				if (texture != null) directionTextures.Add(texture);
				else return;
			}
			else if (file.EndsWith("_light.exr"))
			{
				var texture = LoadAssetTexture(file);
				if (texture != null) lightTextures.Add(texture);
				else return;
			}
			else if (file.EndsWith("_shadowmask.png"))
			{
				var texture = LoadAssetTexture(file);
				if (texture != null) shadowMaskTextures.Add(texture);
				else return;
			}
		}

		// create data object
		CreateDataObject();

		isInit = true;
	}

	public void CreateDataObject()
	{
		data = new LightmapData[directionTextures.Count];
		for (int i = 0; i != data.Length; ++i)
		{
			data[i] = new LightmapData();
			data[i].lightmapDir = directionTextures[i];
			if (i < lightTextures.Count) data[i].lightmapColor = lightTextures[i];
			if (i < shadowMaskTextures.Count) data[i].shadowMask = shadowMaskTextures[i];
		}
	}

	public void Disable()
	{
		if (lightProbeGroups != null)
		{
			foreach (var group in lightProbeGroups) group.enabled = false;
		}

		if (lights != null)
		{
			foreach (var light in lights) light.enabled = false;
		}
	}

	public void Enable()
	{
		LightmapSettings.lightmaps = data;

		if (lightProbeGroups != null)
		{
			foreach (var group in lightProbeGroups) group.enabled = true;
		}

		if (lights != null)
		{
			foreach (var light in lights) light.enabled = true;
		}
	}
}

public class LightMapSwitcher : MonoBehaviour
{
	public static LightMapSwitcher singleton;
	public int defaultGroup;

	public LightMapGroup[] lightMapGroups;

	public LightMapSwitcher()
	{
		singleton = this;
	}

	[InitializeOnLoadMethod]
	private static void PostBuild()
	{
		foreach (var group in singleton.lightMapGroups) group.CreateDataObject();
		singleton.ApplyDefaultGroup();
	}

	[ContextMenu("LightMap: Gather Files")]
	private void GatherFiles()
	{
		foreach (var group in lightMapGroups) group.GatherFiles();
		Apply(defaultGroup);
	}

	[ContextMenu("LightMap: Apply Default Group")]
	private void ApplyDefaultGroup()
	{
		Apply(defaultGroup);
	}

	public void Apply(int groupIndex)
	{
		if (lightMapGroups == null || groupIndex > lightMapGroups.Length-1) return;

		foreach (var group in lightMapGroups) group.Disable();
		lightMapGroups[groupIndex].Enable();
	}
}