Unity微端场景加载（三）动态加载光照贴图

上文中我们已经提供了方法将一个场景用微端的方式进行加载，其实主要是对场景模型进行加载，一般地形需要保留在level中，理论上其他所有资源都可以分割出去然后进行动态加载，我们在制作场景时免不了要对场景进行烘焙，这样模型上就带了光照贴图，但是在unity5.0中，prefab并不会保存模型的光照贴图，这样如果你将模型分割出去再进行动态加载，那么他重新显示出来的模型并不带贴图效果，这个问题在unity4.6之前是不需要考虑的，但官方出于其他考虑将这一功能给去掉了，导致给我们的微端场景加载带来了困难。

为了解决这一问题我们想了很多方法，查看了很多资料，最后从unity3d开发人员那里得到了一个比较满意的处理结果，以下就是福利了，你只需将以下脚本挂到你需要加载的prefab模型上即可

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

public class PrefabLightmapData : MonoBehaviour
{
    [System.Serializable]
    struct RendererInfo
    {
        public Renderer renderer;
        public int lightmapIndex;
        public Vector4 lightmapOffsetScale;
    }

    [SerializeField]
    RendererInfo[] m_RendererInfo;
    [SerializeField]
    Texture2D[] m_Lightmaps;

    void Awake()
    {
        if (m_RendererInfo == null || m_RendererInfo.Length == 0)
            return;

        var lightmaps = LightmapSettings.lightmaps;
        var combinedLightmaps = new LightmapData[lightmaps.Length + m_Lightmaps.Length];

        lightmaps.CopyTo(combinedLightmaps, 0);
        for (int i = 0; i < m_Lightmaps.Length; i++)
        {
            combinedLightmaps[i + lightmaps.Length] = new LightmapData();
            combinedLightmaps[i + lightmaps.Length].lightmapFar = m_Lightmaps[i];
        }

        ApplyRendererInfo(m_RendererInfo, lightmaps.Length);
        LightmapSettings.lightmaps = combinedLightmaps;
    }


    static void ApplyRendererInfo(RendererInfo[] infos, int lightmapOffsetIndex)
    {
        for (int i = 0; i < infos.Length; i++)
        {
            var info = infos[i];
            info.renderer.lightmapIndex = info.lightmapIndex + lightmapOffsetIndex;
            info.renderer.lightmapScaleOffset = info.lightmapOffsetScale;
        }
    }

#if UNITY_EDITOR
    [UnityEditor.MenuItem("Assets/Bake Prefab Lightmaps")]
    static void GenerateLightmapInfo()
    {
        if (UnityEditor.Lightmapping.giWorkflowMode != UnityEditor.Lightmapping.GIWorkflowMode.OnDemand)
        {
            Debug.LogError("ExtractLightmapData requires that you have baked you lightmaps and Auto mode is disabled.");
            return;
        }
        //UnityEditor.Lightmapping.Bake();

        PrefabLightmapData[] prefabs = FindObjectsOfType();

        foreach (var instance in prefabs)
        {
            var gameObject = instance.gameObject;
            var rendererInfos = new List();
            var lightmaps = new List();

            GenerateLightmapInfo(gameObject, rendererInfos, lightmaps);

            instance.m_RendererInfo = rendererInfos.ToArray();
            instance.m_Lightmaps = lightmaps.ToArray();

            var targetPrefab = UnityEditor.PrefabUtility.GetPrefabParent(gameObject) as GameObject;
            if (targetPrefab != null)
            {
                //UnityEditor.Prefab
                UnityEditor.PrefabUtility.ReplacePrefab(gameObject, targetPrefab);
            }
        }
    }

    static void GenerateLightmapInfo(GameObject root, List rendererInfos, List lightmaps)
    {
        var renderers = root.GetComponentsInChildren();
        foreach (MeshRenderer renderer in renderers)
        {
            if (renderer.lightmapIndex != -1)
            {
                RendererInfo info = new RendererInfo();
                info.renderer = renderer;
                info.lightmapOffsetScale = renderer.lightmapScaleOffset;

                Texture2D lightmap = LightmapSettings.lightmaps[renderer.lightmapIndex].lightmapFar;

                info.lightmapIndex = lightmaps.IndexOf(lightmap);
                if (info.lightmapIndex == -1)
                {
                    info.lightmapIndex = lightmaps.Count;
                    lightmaps.Add(lightmap);
                }

                rendererInfos.Add(info);
            }
        }
    }
#endif

}

这个代码是从unity3d开发人员给的Demo中取出了，所以我也不会敝扫自珍，拿出来分享了，只需要对代码稍作分析应该就懂了，我在此就不在多做解释了。