這個(gè)是轉(zhuǎn)自侑虎的文章
下圖中的動(dòng)畫文件不包含Scale曲線，所以這次優(yōu)化中只壓縮了浮點(diǎn)數(shù)精度。
我分別對比了動(dòng)畫文件優(yōu)化前和優(yōu)化后的大小。
FileSize
FileInfo.Length取得的文件大小
可以在操作系統(tǒng)的文件系統(tǒng)中看到
MemorySize
Profiler.GetRuntimeMemorySize取得的內(nèi)存大小
可以在Profiler中通過采樣看到
分別在真機(jī)和Editor下進(jìn)行了采樣
BlobSize
反射取得的AnimationClipStats.size二進(jìn)制大小
顯示在AnimationClip的Inspector的面板上
紅色框內(nèi)即是BlobSize，在我的理解，F(xiàn)ileSize是指文件在硬盤中占的大小，BlobSize是從文件反序列化出來的對象的二進(jìn)制大小。Editor下的MemorySize不僅有序列化后的內(nèi)存大小，還維護(hù)了一份原文件的內(nèi)存。就像我們在Editor下加載一張Texture內(nèi)存是雙份一樣，而真機(jī)下就約等于BlobSize。真機(jī)下的MemorySize和Inspector里的BlobSize非常接近，BlobSize可以認(rèn)為是真機(jī)上的內(nèi)存大小，這個(gè)大小更有參考意義。
同時(shí)，我也對去除Scale曲線的方法進(jìn)行了實(shí)驗(yàn)。下圖這個(gè)動(dòng)畫文件原來Inspector中Scale的值為4，即有Scale曲線，原始文件BlobSize為10.2KB，去除Scale曲線后，Blob Size變?yōu)?.4KB，所以BlobSize減小了27%。
Curve減少導(dǎo)致內(nèi)存減小
從上面的實(shí)驗(yàn)可以看出來，只裁剪動(dòng)畫文件的壓縮精度，沒有引起Curve減少。BlobSize是不會(huì)有任何變化的，因?yàn)槊總€(gè)浮點(diǎn)數(shù)固定占32bit。而文件大小、AB大小、Editor下的內(nèi)存大小，壓縮精度后不管有沒有引起Curve的變化，都會(huì)變小。
裁剪動(dòng)畫文件的精度，意味著點(diǎn)的位置發(fā)生了變化，所以Constant Curve和Dense Curve的數(shù)量也有可能發(fā)生變化。由于是裁剪精度所以動(dòng)畫的點(diǎn)更稀疏了，而連續(xù)相同的點(diǎn)更多了。所以Dense Curve是減少了，Constant Curve是增多了，總的內(nèi)存是減小了。
Constant Curve只需要最左邊的點(diǎn)就可以描述一個(gè)曲線段。
只裁剪精度使BlobSize減小的實(shí)例
裁剪精度前，大小為2.2kb，ScaleCurve為0， ConstantCurve為4(57.1%)，Stream(使用Optimal模式這部分?jǐn)?shù)據(jù)將儲(chǔ)存為Dense)為3(42.9%)。
裁剪精度后，大小為2.1kb，ConstantCurve為7(100%)，Stream為0(0%)。裁剪完精度后導(dǎo)致ConstantCurve增加了3，Stream(Optimal模式下即為Dense)減少了3，BlobSize減小了0.1kb。
因此，可以看出，通過精度優(yōu)化降低內(nèi)存的方式，其實(shí)質(zhì)是將曲線上過于接近的數(shù)值（例如相差數(shù)值出現(xiàn)在小數(shù)點(diǎn)4位以后）直接變?yōu)橐恢?，從而使部分曲線變?yōu)閏onstant曲線來降低內(nèi)存消耗。
總結(jié)
隔壁項(xiàng)目組對他們項(xiàng)目中所有的動(dòng)畫文件都進(jìn)行了優(yōu)化。其中文件大小從820MB->225MB, ab大小從72MB->64MB, 內(nèi)存大小從50MB->40MB。總的來說動(dòng)畫文件的scale越多優(yōu)化越明顯。
取BlobSize代碼
AnimationClip aniClip = AssetDatabase.LoadAssetAtPath<AnimationClip> (path);var fileInfo = new System.IO.FileInfo(path);Debug.Log(fileInfo.Length);//FileSizeDebug.Log(Profiler.GetRuntimeMemorySize (aniClip));//MemorySizeAssembly asm = Assembly.GetAssembly(typeof(Editor));MethodInfo getAnimationClipStats = typeof(AnimationUtility).GetMethod("GetAnimationClipStats", BindingFlags.Static | BindingFlags.NonPublic);Type aniclipstats = asm.GetType("UnityEditor.AnimationClipStats");FieldInfo sizeInfo = aniclipstats.GetField ("size", BindingFlags.Public | BindingFlags.Instance);var stats = getAnimationClipStats.Invoke(null, new object[]{aniClip});Debug.Log(EditorUtility.FormatBytes((int)sizeInfo.GetValue(stats)));//BlobSize工具代碼
最后附上工具的代碼和簡要使用說明，選中想要優(yōu)化的文件夾或文件，右鍵Animation->裁剪浮點(diǎn)數(shù)去除Scale。
//****************************************************************************//// File: OptimizeAnimationClipTool.cs//// Copyright (c) SuiJiaBin//// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A// PARTICULAR PURPOSE.////****************************************************************************using System;using System.Collections.Generic;using UnityEngine;using System.Reflection;using UnityEditor;using System.IO;namespace EditorTool{ class AnimationOpt { static Dictionary<uint,string> _FLOAT_FORMAT; static MethodInfo getAnimationClipStats; static FieldInfo sizeInfo; static object[] _param = new object[1]; static AnimationOpt () { _FLOAT_FORMAT = new Dictionary<uint, string> (); for (uint i = 1; i < 6; i++) { _FLOAT_FORMAT.Add (i, "f" + i.ToString ()); } Assembly asm = Assembly.GetAssembly (typeof(Editor)); getAnimationClipStats = typeof(AnimationUtility).GetMethod ("GetAnimationClipStats", BindingFlags.Static | BindingFlags.NonPublic); Type aniclipstats = asm.GetType ("UnityEditor.AnimationClipStats"); sizeInfo = aniclipstats.GetField ("size", BindingFlags.Public | BindingFlags.Instance); } AnimationClip _clip; string _path; public string path { get{ return _path;} } public long originFileSize { get; private set; } public int originMemorySize { get; private set; } public int originInspectorSize { get; private set; } public long optFileSize { get; private set; } public int optMemorySize { get; private set; } public int optInspectorSize { get; private set; } public AnimationOpt (string path, AnimationClip clip) { _path = path; _clip = clip; _GetOriginSize (); } void _GetOriginSize () { originFileSize = _GetFileZie (); originMemorySize = _GetMemSize (); originInspectorSize = _GetInspectorSize (); } void _GetOptSize () { optFileSize = _GetFileZie (); optMemorySize = _GetMemSize (); optInspectorSize = _GetInspectorSize (); } long _GetFileZie () { FileInfo fi = new FileInfo (_path); return fi.Length; } int _GetMemSize () { return Profiler.GetRuntimeMemorySize (_clip); } int _GetInspectorSize () { _param [0] = _clip; var stats = getAnimationClipStats.Invoke (null, _param); return (int)sizeInfo.GetValue (stats); } void _OptmizeAnimationScaleCurve () { if (_clip != null) { //去除scale曲線 foreach (EditorCurveBinding theCurveBinding in AnimationUtility.GetCurveBindings(_clip)) { string name = theCurveBinding.propertyName.ToLower (); if (name.Contains ("scale")) { AnimationUtility.SetEditorCurve (_clip, theCurveBinding, null); Debug.LogFormat ("關(guān)閉{0}的scale curve", _clip.name); } } } } void _OptmizeAnimationFloat_X (uint x) { if (_clip != null && x > 0) { //浮點(diǎn)數(shù)精度壓縮到f3 AnimationClipCurveData[] curves = null; curves = AnimationUtility.GetAllCurves (_clip); Keyframe key; Keyframe[] keyFrames; string floatFormat; if (_FLOAT_FORMAT.TryGetValue (x, out floatFormat)) { if (curves != null && curves.Length > 0) { for (int ii = 0; ii < curves.Length; ++ii) { AnimationClipCurveData curveDate = curves [ii]; if (curveDate.curve == null || curveDate.curve.keys == null) { //Debug.LogWarning(string.Format("AnimationClipCurveData {0} don't have curve; Animation name {1} ", curveDate, animationPath)); continue; } keyFrames = curveDate.curve.keys; for (int i = 0; i < keyFrames.Length; i++) { key = keyFrames [i]; key.value = float.Parse (key.value.ToString (floatFormat)); key.inTangent = float.Parse (key.inTangent.ToString (floatFormat)); key.outTangent = float.Parse (key.outTangent.ToString (floatFormat)); keyFrames [i] = key; } curveDate.curve.keys = keyFrames; _clip.SetCurve (curveDate.path, curveDate.type, curveDate.propertyName, curveDate.curve); } } } else { Debug.LogErrorFormat ("目前不支持{0}位浮點(diǎn)", x); } } } public void Optimize (bool scaleOpt, uint floatSize) { if (scaleOpt) { _OptmizeAnimationScaleCurve (); } _OptmizeAnimationFloat_X (floatSize); _GetOptSize (); } public void Optimize_Scale_Float3 () { Optimize (true, 3); } public void LogOrigin () { _logSize (originFileSize, originMemorySize, originInspectorSize); } public void LogOpt () { _logSize (optFileSize, optMemorySize, optInspectorSize); } public void LogDelta () { } void _logSize (long fileSize, int memSize, int inspectorSize) { Debug.LogFormat ("{0} \nSize=[ {1} ]", _path, string.Format ("FSize={0} ; Mem->{1} ; inspector->{2}", EditorUtility.FormatBytes (fileSize), EditorUtility.FormatBytes (memSize), EditorUtility.FormatBytes (inspectorSize))); } } public class OptimizeAnimationClipTool { static List<AnimationOpt> _AnimOptList = new List<AnimationOpt> (); static List<string> _Errors = new List<string>(); static int _Index = 0; [MenuItem("Assets/Animation/裁剪浮點(diǎn)數(shù)去除Scale")] public static void Optimize() { _AnimOptList = FindAnims (); if (_AnimOptList.Count > 0) { _Index = 0; _Errors.Clear (); EditorApplication.update = ScanAnimationClip; } } private static void ScanAnimationClip() { AnimationOpt _AnimOpt = _AnimOptList[_Index]; bool isCancel = EditorUtility.DisplayCancelableProgressBar("優(yōu)化AnimationClip", _AnimOpt.path, (float)_Index / (float)_AnimOptList.Count); _AnimOpt.Optimize_Scale_Float3(); _Index++; if (isCancel || _Index >= _AnimOptList.Count) { EditorUtility.ClearProgressBar(); Debug.Log(string.Format("--優(yōu)化完成-- 錯(cuò)誤數(shù)量: {0} 總數(shù)量: {1}/{2} 錯(cuò)誤信息↓:\n{3}\n----------輸出完畢----------", _Errors.Count, _Index, _AnimOptList.Count, string.Join(string.Empty, _Errors.ToArray()))); Resources.UnloadUnusedAssets(); GC.Collect(); AssetDatabase.SaveAssets(); EditorApplication.update = null; _AnimOptList.Clear(); _cachedOpts.Clear (); _Index = 0; } } static Dictionary<string,AnimationOpt> _cachedOpts = new Dictionary<string, AnimationOpt> (); static AnimationOpt _GetNewAOpt (string path) { AnimationOpt opt = null; if (!_cachedOpts.ContainsKey(path)) { AnimationClip clip = AssetDatabase.LoadAssetAtPath<AnimationClip> (path); if (clip != null) { opt = new AnimationOpt (path, clip); _cachedOpts [path] = opt; } } return opt; } static List<AnimationOpt> FindAnims() { string[] guids = null; List<string> path = new List<string>(); List<AnimationOpt> assets = new List<AnimationOpt> (); UnityEngine.Object[] objs = Selection.GetFiltered(typeof(object), SelectionMode.Assets); if (objs.Length > 0) { for(int i = 0; i < objs.Length; i++) { if (objs [i].GetType () == typeof(AnimationClip)) { string p = AssetDatabase.GetAssetPath (objs [i]); AnimationOpt animopt = _GetNewAOpt (p); if (animopt != null) assets.Add (animopt); } else path.Add(AssetDatabase.GetAssetPath (objs [i])); } if(path.Count > 0) guids = AssetDatabase.FindAssets (string.Format ("t:{0}", typeof(AnimationClip).ToString().Replace("UnityEngine.", "")), path.ToArray()); else guids = new string[]{}; } for(int i = 0; i < guids.Length; i++) { string assetPath = AssetDatabase.GUIDToAssetPath (guids [i]); AnimationOpt animopt = _GetNewAOpt (assetPath); if (animopt != null) assets.Add (animopt); } return assets; } }}