情况
最近场景越来越大,大概800M的场景加载时间可能长达40秒左右,所以需要测试看看发生了什么。
测试环境
测试环境Win10,21thI5-12600KF,32GRam , Nvidia GF RTX2060 32G
Scene1大小:741M
加载代码
首先放上部分的加载场景的代码:
public float sceneprog;public AsyncOperation sceneAsync;async public Task LoadScene(string path){sceneprog = 0f;await Task.Delay(10);StreamAssetVer sav = GameJsonMain.inst.Get(path);if (sav == null){Debug.LogWarning("不存在的场景:" + path);return ;}if (!sav.isab){Debug.LogWarning("场景isab必须对勾:" + path);return;}float loadtime = Time.realtimeSinceStartup;float computloadtime;float ratetime = 0.9f;//Application.backgroundLoadingPriority = ThreadPriority.Low;Debug.Log("LoadScene - begin ..."+ Application.backgroundLoadingPriority);
#if UNITY_EDITOR && TESTRESstring[] dirs = UnityEditor.AssetDatabase.GetAssetPathsFromAssetBundle(path);//Object[] listobj = new Object[dirs.Length];if(dirs.Length == 0)Debug.LogWarning("找不到这个资源:" + path);for (int i = 0; i < dirs.Length; i++){string assetPathAndName = dirs[i];LoadSceneParameters ls;ls = new LoadSceneParameters();ls.loadSceneMode = LoadSceneMode.Additive;sceneAsync = EditorSceneManager.LoadSceneAsyncInPlayMode(assetPathAndName,ls); // .LoadSceneInPlayMode(assetPathAndName, ls);sceneAsync.allowSceneActivation = false;while (sceneAsync.progress < 0.9f){sceneprog = sceneAsync.progress;await Task.Delay(100);Debug.Log("load - " + sceneprog);}//sceneAsync.allowSceneActivation = true;//listobj[i] = null;}sceneprog = 1f;//Debug.Log("load1 - " + sceneprog);computloadtime = Time.realtimeSinceStartup - loadtime;Debug.Log("LoadScene unity- load file time : " + computloadtime);return ;
#endifTask<UnityWebRequest> task;if (sav.include){task = streamingAssetsLoader(sav);}else{task = AssetsLoader(sav);}await task;UnityWebRequest www = task.Result;if (www.result != UnityWebRequest.Result.Success){www.Dispose();return ;}computloadtime = Time.realtimeSinceStartup - loadtime;Debug.Log("LoadScene - load file time : " + computloadtime);//这个LoadFromFileAsync函数的路径不需要file://AssetBundleCreateRequest abRequest;
#if UNITY_EDITORabRequest = AssetBundle.LoadFromFileAsync(sav.savepath.Replace(filelink, ""));
#elseif(Application.platform == RuntimePlatform.Android){abRequest = AssetBundle.LoadFromFileAsync(sav.savepath);}else{abRequest = AssetBundle.LoadFromFileAsync(sav.savepath.Replace(filelink, ""));}
#endifabRequest.allowSceneActivation = false;while (!abRequest.isDone){sceneprog = abRequest.progress;await Task.Delay(100);//Debug.Log("ab:"+ sceneprog);}abRequest.allowSceneActivation = true;AssetBundle ab = abRequest.assetBundle;computloadtime = Time.realtimeSinceStartup - loadtime;Debug.Log("LoadScene - load AssetBundle time :" + computloadtime);//Debug.Log("ab1:ok," + sav.path +" - "+ sav.url);sceneAsync = SceneManager.LoadSceneAsync(sav.path, LoadSceneMode.Additive);sceneAsync.allowSceneActivation = false;while (sceneAsync.progress < 0.9f){sceneprog = ratetime + sceneAsync.progress * (1- ratetime);await Task.Delay(100);//Debug.Log("load:" + sceneprog);}sceneprog = 1f;computloadtime = Time.realtimeSinceStartup - loadtime;Debug.Log("LoadScene - load LoadSceneAsync time :" + computloadtime);await Task.Delay(300);//sceneAsync.allowSceneActivation = true;//SceneManager.LoadScene(ab.GetAllScenePaths()[0]);//Object[] objs = ab. ab.LoadAllAssets();www.Dispose();ab.Unload(false);return ;}
大致代码分为2部分,在编辑器下#if UNITY_EDITOR && TESTRES 使用编辑器加载方式。
首先我们直接用编辑器通过UnityEditor.AssetDatabase.GetAssetPathsFromAssetBundle(path);方法来载入,大概需要5.5-7秒时间。为什么AB包需要那么久 ?
异步和同步加载测试
所有有了下面的AB包测试。
因为是AB包下载,所以关闭宏定义TESTRES ,我在想是不是使用了AssetBundle.LoadFromFileAsync来异步加载的,所以比较慢,所以把函数改为了AssetBundle.LoadFromFile,发现:
同步LoadFromFile方式:33秒
异步LoadFromFileAsync方式:38秒
时间都挺长的,发现有一个修改后台CPU级别的函数Application.backgroundLoadingPriority。
- ThreadPriority.Low - 2ms
- ThreadPriority.BelowNormal - 4ms
- ThreadPriority.Normal - 10ms
- ThreadPriority.High - 50ms
改为了High,发现测试的结果相差不大。
压缩方式的对比
把场景的AB包我又打包成了无压缩格式和LZ4格式。我们看看测试结论
默认我的场景是LZMA格式
LZMA : 38秒
无压缩: 4.8秒
LZ4 : 4.7秒
结论
LZ4的压缩方式解压速度非常快和无压缩相差不大,压缩后大小比无压缩强的多,这种不需要从公网下载资源的推荐LZ4。
知识点
LZMA通过UnityWebRequestAssetBundle加载的LZMA格式AB包将自动重新压缩为LZ4压缩,并缓存在本地文件系统上。而通过自己写的下载方案,则可以调用AssetBundle.RecompressAssetBundleAsync API重新压缩。
参考:
https://zhuanlan.zhihu.com/p/342694796
Gzip_vs_Bzip2_vs_LZMA_vs_XZ_vs_LZ4_vs_LZO
https://segmentfault.com/a/1190000019656656