这个是转自侑虎的文章
下图中的动画文件不包含Scale曲线，所以这次优化中只压缩了浮点数精度。
我分别对比了动画文件优化前和优化后的大小。
FileSize
FileInfo.Length取得的文件大小
可以在操作系统的文件系统中看到
MemorySize
Profiler.GetRuntimeMemorySize取得的内存大小
可以在Profiler中通过采样看到
分别在真机和Editor下进行了采样
BlobSize
反射取得的AnimationClipStats.size二进制大小
显示在AnimationClip的Inspector的面板上
红色框内即是BlobSize，在我的理解，FileSize是指文件在硬盘中占的大小，BlobSize是从文件反序列化出来的对象的二进制大小。Editor下的MemorySize不仅有序列化后的内存大小，还维护了一份原文件的内存。就像我们在Editor下加载一张Texture内存是双份一样，而真机下就约等于BlobSize。真机下的MemorySize和Inspector里的BlobSize非常接近，BlobSize可以认为是真机上的内存大小，这个大小更有参考意义。
同时，我也对去除Scale曲线的方法进行了实验。下图这个动画文件原来Inspector中Scale的值为4，即有Scale曲线，原始文件BlobSize为10.2KB，去除Scale曲线后，Blob Size变为7.4KB，所以BlobSize减小了27%。
Curve减少导致内存减小
从上面的实验可以看出来，只裁剪动画文件的压缩精度，没有引起Curve减少。BlobSize是不会有任何变化的，因为每个浮点数固定占32bit。而文件大小、AB大小、Editor下的内存大小，压缩精度后不管有没有引起Curve的变化，都会变小。
裁剪动画文件的精度，意味着点的位置发生了变化，所以Constant Curve和Dense Curve的数量也有可能发生变化。由于是裁剪精度所以动画的点更稀疏了，而连续相同的点更多了。所以Dense Curve是减少了，Constant Curve是增多了，总的内存是减小了。
Constant Curve只需要最左边的点就可以描述一个曲线段。
只裁剪精度使BlobSize减小的实例
裁剪精度前，大小为2.2kb，ScaleCurve为0， ConstantCurve为4(57.1%)，Stream(使用Optimal模式这部分数据将储存为Dense)为3(42.9%)。
裁剪精度后，大小为2.1kb，ConstantCurve为7(100%)，Stream为0(0%)。裁剪完精度后导致ConstantCurve增加了3，Stream(Optimal模式下即为Dense)减少了3，BlobSize减小了0.1kb。
因此，可以看出，通过精度优化降低内存的方式，其实质是将曲线上过于接近的数值（例如相差数值出现在小数点4位以后）直接变为一致，从而使部分曲线变为constant曲线来降低内存消耗。
总结
隔壁项目组对他们项目中所有的动画文件都进行了优化。其中文件大小从820MB->225MB, ab大小从72MB->64MB, 内存大小从50MB->40MB。总的来说动画文件的scale越多优化越明显。
取BlobSize代码
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工具代码
最后附上工具的代码和简要使用说明，选中想要优化的文件夹或文件，右键Animation->裁剪浮点数去除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曲线 foreach (EditorCurveBinding theCurveBinding in AnimationUtility.GetCurveBindings(_clip)) { string name = theCurveBinding.propertyName.ToLower (); if (name.Contains ("scale")) { AnimationUtility.SetEditorCurve (_clip, theCurveBinding, null); Debug.LogFormat ("关闭{0}的scale curve", _clip.name); } } } } void _OptmizeAnimationFloat_X (uint x) { if (_clip != null && x > 0) { //浮点数精度压缩到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}位浮点", 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/裁剪浮点数去除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("优化AnimationClip", _AnimOpt.path, (float)_Index / (float)_AnimOptList.Count); _AnimOpt.Optimize_Scale_Float3(); _Index++; if (isCancel || _Index >= _AnimOptList.Count) { EditorUtility.ClearProgressBar(); Debug.Log(string.Format("--优化完成-- 错误数量: {0} 总数量: {1}/{2} 错误信息↓:\n{3}\n----------输出完毕----------", _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; } }}
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