diff --git a/AssetStudio/AssetStudio.csproj b/AssetStudio/AssetStudio.csproj
index 4ba2be2..6c4d56c 100644
--- a/AssetStudio/AssetStudio.csproj
+++ b/AssetStudio/AssetStudio.csproj
@@ -171,10 +171,16 @@
     <Compile Include="Classes\MonoScript.cs" />
     <Compile Include="Classes\NamedObject.cs" />
     <Compile Include="Classes\Object.cs" />
+    <Compile Include="StudioClasses\PPtr.cs" />
     <Compile Include="Classes\Renderer.cs" />
     <Compile Include="Classes\Texture.cs" />
     <Compile Include="StudioClasses\AudioClipConverter.cs" />
+    <Compile Include="StudioClasses\CommonString.cs" />
+    <Compile Include="StudioClasses\FileIdentifier.cs" />
     <Compile Include="StudioClasses\GameObjectTreeNode.cs" />
+    <Compile Include="StudioClasses\LocalSerializedObjectIdentifier.cs" />
+    <Compile Include="StudioClasses\ObjectInfo.cs" />
+    <Compile Include="StudioClasses\SerializedFileHeader.cs" />
     <Compile Include="StudioClasses\SevenZipHelper.cs">
       <SubType>Code</SubType>
     </Compile>
@@ -189,7 +195,7 @@
     <Compile Include="StudioClasses\BinaryWriterExtensions.cs" />
     <Compile Include="StudioClasses\BuildTarget.cs" />
     <Compile Include="StudioClasses\ClassIDReference.cs" />
-    <Compile Include="StudioClasses\TypeTree.cs" />
+    <Compile Include="StudioClasses\TypeTreeNode.cs" />
     <Compile Include="StudioClasses\TypeTreeHelper.cs" />
     <Compile Include="StudioClasses\ResourcesHelper.cs" />
     <Compile Include="Classes\AssetBundle.cs" />
@@ -226,7 +232,6 @@
     <Compile Include="Classes\Material.cs" />
     <Compile Include="Classes\Mesh.cs" />
     <Compile Include="Classes\GameObject.cs" />
-    <Compile Include="StudioClasses\PPtrHelpers.cs" />
     <Compile Include="Classes\MonoBehaviour.cs" />
     <Compile Include="Classes\PlayerSettings.cs" />
     <Compile Include="Classes\RectTransform.cs" />
diff --git a/AssetStudio/AssetStudioForm.cs b/AssetStudio/AssetStudioForm.cs
index b3f99d3..91ffd65 100644
--- a/AssetStudio/AssetStudioForm.cs
+++ b/AssetStudio/AssetStudioForm.cs
@@ -1783,7 +1783,7 @@ namespace AssetStudio
                 resourceFileReader.Value.Dispose();
             }
             resourceFileReaders.Clear();
-            sharedFileIndex.Clear();
+            assetsFileIndexCache.Clear();
             productName = "";
 
             sceneTreeView.Nodes.Clear();
diff --git a/AssetStudio/StudioClasses/AssetsFile.cs b/AssetStudio/StudioClasses/AssetsFile.cs
index 1014dca..6c8d546 100644
--- a/AssetStudio/StudioClasses/AssetsFile.cs
+++ b/AssetStudio/StudioClasses/AssetsFile.cs
@@ -2,163 +2,37 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Text;
 using System.Text.RegularExpressions;
-using System.Windows.Forms;
 
 namespace AssetStudio
 {
-    public class SerializedFileHeader
-    {
-        public uint m_MetadataSize;
-        public uint m_FileSize;
-        public uint m_Version;
-        public uint m_DataOffset;
-        public byte m_Endianess;
-        public byte[] m_Reserved;
-    }
-
     public class AssetsFile
     {
         public EndianBinaryReader reader;
-        public SerializedFileHeader header;
-        private EndianType m_FileEndianess;
-        public string unityVersion = "2.5.0f5";
-        public BuildTarget m_TargetPlatform = BuildTarget.UnknownPlatform;
-        private bool serializedTypeTrees;
-        public SortedDictionary<int, List<TypeTree>> m_Type = new SortedDictionary<int, List<TypeTree>>();
-        private List<int[]> classIDs = new List<int[]>();//use for 5.5.0
-
         public string filePath;
         public string parentPath;
         public string fileName;
         public string upperFileName;
         public int[] version = { 0, 0, 0, 0 };
         public string[] buildType;
-        public string platformStr = "";
-
+        public string platformStr;
+        public bool valid;
         public Dictionary<long, AssetPreloadData> preloadTable = new Dictionary<long, AssetPreloadData>();
         public Dictionary<long, GameObject> GameObjectList = new Dictionary<long, GameObject>();
         public Dictionary<long, Transform> TransformList = new Dictionary<long, Transform>();
-
         public List<AssetPreloadData> exportableAssets = new List<AssetPreloadData>();
-        public List<SharedAssets> sharedAssetsList = new List<SharedAssets> { new SharedAssets() };
 
-        public bool valid;
-
-        #region cmmon string
-        private static Dictionary<int, string> baseStrings = new Dictionary<int, string>
-        {
-            {0, "AABB"},
-            {5, "AnimationClip"},
-            {19, "AnimationCurve"},
-            {34, "AnimationState"},
-            {49, "Array"},
-            {55, "Base"},
-            {60, "BitField"},
-            {69, "bitset"},
-            {76, "bool"},
-            {81, "char"},
-            {86, "ColorRGBA"},
-            {96, "Component"},
-            {106, "data"},
-            {111, "deque"},
-            {117, "double"},
-            {124, "dynamic_array"},
-            {138, "FastPropertyName"},
-            {155, "first"},
-            {161, "float"},
-            {167, "Font"},
-            {172, "GameObject"},
-            {183, "Generic Mono"},
-            {196, "GradientNEW"},
-            {208, "GUID"},
-            {213, "GUIStyle"},
-            {222, "int"},
-            {226, "list"},
-            {231, "long long"},
-            {241, "map"},
-            {245, "Matrix4x4f"},
-            {256, "MdFour"},
-            {263, "MonoBehaviour"},
-            {277, "MonoScript"},
-            {288, "m_ByteSize"},
-            {299, "m_Curve"},
-            {307, "m_EditorClassIdentifier"},
-            {331, "m_EditorHideFlags"},
-            {349, "m_Enabled"},
-            {359, "m_ExtensionPtr"},
-            {374, "m_GameObject"},
-            {387, "m_Index"},
-            {395, "m_IsArray"},
-            {405, "m_IsStatic"},
-            {416, "m_MetaFlag"},
-            {427, "m_Name"},
-            {434, "m_ObjectHideFlags"},
-            {452, "m_PrefabInternal"},
-            {469, "m_PrefabParentObject"},
-            {490, "m_Script"},
-            {499, "m_StaticEditorFlags"},
-            {519, "m_Type"},
-            {526, "m_Version"},
-            {536, "Object"},
-            {543, "pair"},
-            {548, "PPtr<Component>"},
-            {564, "PPtr<GameObject>"},
-            {581, "PPtr<Material>"},
-            {596, "PPtr<MonoBehaviour>"},
-            {616, "PPtr<MonoScript>"},
-            {633, "PPtr<Object>"},
-            {646, "PPtr<Prefab>"},
-            {659, "PPtr<Sprite>"},
-            {672, "PPtr<TextAsset>"},
-            {688, "PPtr<Texture>"},
-            {702, "PPtr<Texture2D>"},
-            {718, "PPtr<Transform>"},
-            {734, "Prefab"},
-            {741, "Quaternionf"},
-            {753, "Rectf"},
-            {759, "RectInt"},
-            {767, "RectOffset"},
-            {778, "second"},
-            {785, "set"},
-            {789, "short"},
-            {795, "size"},
-            {800, "SInt16"},
-            {807, "SInt32"},
-            {814, "SInt64"},
-            {821, "SInt8"},
-            {827, "staticvector"},
-            {840, "string"},
-            {847, "TextAsset"},
-            {857, "TextMesh"},
-            {866, "Texture"},
-            {874, "Texture2D"},
-            {884, "Transform"},
-            {894, "TypelessData"},
-            {907, "UInt16"},
-            {914, "UInt32"},
-            {921, "UInt64"},
-            {928, "UInt8"},
-            {934, "unsigned int"},
-            {947, "unsigned long long"},
-            {966, "unsigned short"},
-            {981, "vector"},
-            {988, "Vector2f"},
-            {997, "Vector3f"},
-            {1006, "Vector4f"},
-            {1015, "m_ScriptingClassIdentifier"},
-            {1042, "Gradient"},
-            {1051, "Type*"}
-        };
-        #endregion
-
-        public class SharedAssets
-        {
-            public int Index = -2; //-2 - Prepare, -1 - Missing
-            public string aName = "";
-            public string fileName = "";
-        }
+        //class SerializedFile
+        public SerializedFileHeader header;
+        private EndianType m_FileEndianess;
+        public string unityVersion = "2.5.0f5";
+        public BuildTarget m_TargetPlatform = BuildTarget.UnknownPlatform;
+        private bool m_EnableTypeTree;
+        public SortedDictionary<int, List<TypeTreeNode>> m_Type = new SortedDictionary<int, List<TypeTreeNode>>();
+        private List<int[]> classIDs = new List<int[]>();
+        public Dictionary<long, ObjectInfo> m_Objects;
+        private List<LocalSerializedObjectIdentifier> m_ScriptTypes;
+        public List<FileIdentifier> m_Externals;
 
         public AssetsFile(string fullName, EndianBinaryReader reader)
         {
@@ -205,19 +79,19 @@ namespace AssetStudio
                     }
                 }
                 platformStr = m_TargetPlatform.ToString();
-                if (header.m_Version >= 14)
+                if (header.m_Version >= 13)
                 {
-                    serializedTypeTrees = reader.ReadBoolean();
+                    m_EnableTypeTree = reader.ReadBoolean();
                 }
 
-                // Read	types
+                //Read types
                 int typeCount = reader.ReadInt32();
                 for (int i = 0; i < typeCount; i++)
                 {
-                    if (header.m_Version < 14)
+                    if (header.m_Version < 13)
                     {
                         int classID = reader.ReadInt32();
-                        var typeTreeList = new List<TypeTree>();
+                        var typeTreeList = new List<TypeTreeNode>();
                         ReadTypeTree(typeTreeList, 0);
                         m_Type.Add(classID, typeTreeList);
                     }
@@ -232,7 +106,7 @@ namespace AssetStudio
                     var bigIDEnabled = reader.ReadInt32();
                 }
 
-                // Read Objects
+                //Read Objects
                 int objectCount = reader.ReadInt32();
 
                 string assetIDfmt = "D" + objectCount.ToString().Length; //format for unique ID
@@ -262,12 +136,9 @@ namespace AssetStudio
                         asset.Type2 = reader.ReadUInt16();
                         reader.Position += 2;
                     }
-                    if (header.m_Version == 15)
+                    if (header.m_Version == 15 || header.m_Version == 16)
                     {
-                        byte unknownByte = reader.ReadByte();
-                        //this is a single byte, not an int32
-                        //the next entry is aligned after this
-                        //but not the last!
+                        var stripped = reader.ReadByte();
                     }
 
                     if (Enum.IsDefined(typeof(ClassIDReference), asset.Type2))
@@ -301,28 +172,36 @@ namespace AssetStudio
                     #endregion
                 }
 
-                if (header.m_Version >= 14)
+                if (header.m_Version >= 11)
                 {
-                    //this looks like a list of assets that need to be preloaded in memory before anytihng else
-                    int someCount = reader.ReadInt32();
-                    for (int i = 0; i < someCount; i++)
+                    int scriptCount = reader.ReadInt32();
+                    m_ScriptTypes = new List<LocalSerializedObjectIdentifier>(scriptCount);
+                    for (int i = 0; i < scriptCount; i++)
                     {
-                        int num1 = reader.ReadInt32();
-                        reader.AlignStream(4);
-                        long m_PathID = reader.ReadInt64();
+                        var m_ScriptType = new LocalSerializedObjectIdentifier();
+                        m_ScriptType.localSerializedFileIndex = reader.ReadInt32();
+                        m_ScriptType.localIdentifierInFile = header.m_Version < 14 ? reader.ReadInt32() : reader.ReadInt64();
+                        m_ScriptTypes.Add(m_ScriptType);
                     }
                 }
 
-                sharedAssetsList[0].fileName = fileName; //reference itself because sharedFileIDs start from 1
-                int sharedFileCount = reader.ReadInt32();
-                for (int i = 0; i < sharedFileCount; i++)
+                int externalsCount = reader.ReadInt32();
+                m_Externals = new List<FileIdentifier>(externalsCount);
+                for (int i = 0; i < externalsCount; i++)
                 {
-                    var shared = new SharedAssets();
-                    shared.aName = reader.ReadStringToNull();
-                    reader.Position += 20;
-                    var sharedFilePath = reader.ReadStringToNull(); //relative path
-                    shared.fileName = Path.GetFileName(sharedFilePath);
-                    sharedAssetsList.Add(shared);
+                    var m_External = new FileIdentifier();
+                    if (header.m_Version >= 6)
+                    {
+                        var tempEmpty = reader.ReadStringToNull();
+                    }
+                    if (header.m_Version >= 5)
+                    {
+                        m_External.guid = new Guid(reader.ReadBytes(16));
+                        m_External.type = reader.ReadInt32();
+                    }
+                    m_External.pathName = reader.ReadStringToNull();
+                    m_External.fileName = Path.GetFileName(m_External.pathName);
+                    m_Externals.Add(m_External);
                 }
 
                 buildType = Regex.Replace(unityVersion, @"\d", "").Split(new[] { "." }, StringSplitOptions.RemoveEmptyEntries);
@@ -343,11 +222,11 @@ namespace AssetStudio
             }
         }
 
-        private void ReadTypeTree(List<TypeTree> typeTreeList, int depth)
+        private void ReadTypeTree(List<TypeTreeNode> typeTreeList, int depth)
         {
-            var typeTree = new TypeTree();
+            var typeTree = new TypeTreeNode();
             typeTreeList.Add(typeTree);
-            typeTree.m_Depth = depth;
+            typeTree.m_Level = depth;
             typeTree.m_Type = reader.ReadStringToNull();
             typeTree.m_Name = reader.ReadStringToNull();
             typeTree.m_ByteSize = reader.ReadInt32();
@@ -402,7 +281,7 @@ namespace AssetStudio
             }
             reader.Position += 16;
 
-            if (serializedTypeTrees)
+            if (m_EnableTypeTree)
             {
                 int varCount = reader.ReadInt32();
                 int stringSize = reader.ReadInt32();
@@ -410,14 +289,14 @@ namespace AssetStudio
                 reader.Position += varCount * 24;
                 using (var stringReader = new BinaryReader(new MemoryStream(reader.ReadBytes(stringSize))))
                 {
-                    var typeTreeList = new List<TypeTree>();
+                    var typeTreeList = new List<TypeTreeNode>();
                     reader.Position -= varCount * 24 + stringSize;
                     for (int i = 0; i < varCount; i++)
                     {
-                        var typeTree = new TypeTree();
+                        var typeTree = new TypeTreeNode();
                         typeTreeList.Add(typeTree);
                         typeTree.m_Version = reader.ReadUInt16();
-                        typeTree.m_Depth = reader.ReadByte();
+                        typeTree.m_Level = reader.ReadByte();
                         typeTree.m_IsArray = reader.ReadBoolean() ? 1 : 0;
 
                         ushort varTypeIndex = reader.ReadUInt16();
@@ -429,7 +308,7 @@ namespace AssetStudio
                         }
                         else //varType is an index in an internal strig array
                         {
-                            typeTree.m_Type = baseStrings.ContainsKey(varTypeIndex) ? baseStrings[varTypeIndex] : varTypeIndex.ToString();
+                            typeTree.m_Type = CommonString.StringBuffer.ContainsKey(varTypeIndex) ? CommonString.StringBuffer[varTypeIndex] : varTypeIndex.ToString();
                         }
 
                         ushort varNameIndex = reader.ReadUInt16();
@@ -441,7 +320,7 @@ namespace AssetStudio
                         }
                         else
                         {
-                            typeTree.m_Name = baseStrings.ContainsKey(varNameIndex) ? baseStrings[varNameIndex] : varNameIndex.ToString();
+                            typeTree.m_Name = CommonString.StringBuffer.ContainsKey(varNameIndex) ? CommonString.StringBuffer[varNameIndex] : varNameIndex.ToString();
                         }
 
                         typeTree.m_ByteSize = reader.ReadInt32();
@@ -453,5 +332,16 @@ namespace AssetStudio
                 }
             }
         }
+
+        public PPtr ReadPPtr()
+        {
+            var result = new PPtr
+            {
+                m_FileID = reader.ReadInt32(),
+                m_PathID = header.m_Version < 14 ? reader.ReadInt32() : reader.ReadInt64(),
+                assetsFile = this
+            };
+            return result;
+        }
     }
 }
diff --git a/AssetStudio/StudioClasses/CommonString.cs b/AssetStudio/StudioClasses/CommonString.cs
new file mode 100644
index 0000000..feefe6d
--- /dev/null
+++ b/AssetStudio/StudioClasses/CommonString.cs
@@ -0,0 +1,119 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace AssetStudio
+{
+    public static class CommonString
+    {
+        public static readonly Dictionary<int, string> StringBuffer = new Dictionary<int, string>
+        {
+            {0, "AABB"},
+            {5, "AnimationClip"},
+            {19, "AnimationCurve"},
+            {34, "AnimationState"},
+            {49, "Array"},
+            {55, "Base"},
+            {60, "BitField"},
+            {69, "bitset"},
+            {76, "bool"},
+            {81, "char"},
+            {86, "ColorRGBA"},
+            {96, "Component"},
+            {106, "data"},
+            {111, "deque"},
+            {117, "double"},
+            {124, "dynamic_array"},
+            {138, "FastPropertyName"},
+            {155, "first"},
+            {161, "float"},
+            {167, "Font"},
+            {172, "GameObject"},
+            {183, "Generic Mono"},
+            {196, "GradientNEW"},
+            {208, "GUID"},
+            {213, "GUIStyle"},
+            {222, "int"},
+            {226, "list"},
+            {231, "long long"},
+            {241, "map"},
+            {245, "Matrix4x4f"},
+            {256, "MdFour"},
+            {263, "MonoBehaviour"},
+            {277, "MonoScript"},
+            {288, "m_ByteSize"},
+            {299, "m_Curve"},
+            {307, "m_EditorClassIdentifier"},
+            {331, "m_EditorHideFlags"},
+            {349, "m_Enabled"},
+            {359, "m_ExtensionPtr"},
+            {374, "m_GameObject"},
+            {387, "m_Index"},
+            {395, "m_IsArray"},
+            {405, "m_IsStatic"},
+            {416, "m_MetaFlag"},
+            {427, "m_Name"},
+            {434, "m_ObjectHideFlags"},
+            {452, "m_PrefabInternal"},
+            {469, "m_PrefabParentObject"},
+            {490, "m_Script"},
+            {499, "m_StaticEditorFlags"},
+            {519, "m_Type"},
+            {526, "m_Version"},
+            {536, "Object"},
+            {543, "pair"},
+            {548, "PPtr<Component>"},
+            {564, "PPtr<GameObject>"},
+            {581, "PPtr<Material>"},
+            {596, "PPtr<MonoBehaviour>"},
+            {616, "PPtr<MonoScript>"},
+            {633, "PPtr<Object>"},
+            {646, "PPtr<Prefab>"},
+            {659, "PPtr<Sprite>"},
+            {672, "PPtr<TextAsset>"},
+            {688, "PPtr<Texture>"},
+            {702, "PPtr<Texture2D>"},
+            {718, "PPtr<Transform>"},
+            {734, "Prefab"},
+            {741, "Quaternionf"},
+            {753, "Rectf"},
+            {759, "RectInt"},
+            {767, "RectOffset"},
+            {778, "second"},
+            {785, "set"},
+            {789, "short"},
+            {795, "size"},
+            {800, "SInt16"},
+            {807, "SInt32"},
+            {814, "SInt64"},
+            {821, "SInt8"},
+            {827, "staticvector"},
+            {840, "string"},
+            {847, "TextAsset"},
+            {857, "TextMesh"},
+            {866, "Texture"},
+            {874, "Texture2D"},
+            {884, "Transform"},
+            {894, "TypelessData"},
+            {907, "UInt16"},
+            {914, "UInt32"},
+            {921, "UInt64"},
+            {928, "UInt8"},
+            {934, "unsigned int"},
+            {947, "unsigned long long"},
+            {966, "unsigned short"},
+            {981, "vector"},
+            {988, "Vector2f"},
+            {997, "Vector3f"},
+            {1006, "Vector4f"},
+            {1015, "m_ScriptingClassIdentifier"},
+            {1042, "Gradient"},
+            {1051, "Type*"},
+            {1057, "int2_storage"},
+            {1070, "int3_storage"},
+            {1083, "BoundsInt"},
+            {1092, "m_CorrespondingSourceObject"}
+        };
+    }
+}
diff --git a/AssetStudio/StudioClasses/FBXExporter.cs b/AssetStudio/StudioClasses/FBXExporter.cs
index 2ce1ffe..62277df 100644
--- a/AssetStudio/StudioClasses/FBXExporter.cs
+++ b/AssetStudio/StudioClasses/FBXExporter.cs
@@ -61,12 +61,12 @@ namespace AssetStudio
                 {
                     GameObjects.Add(m_GameObject);
 
-                    if (assetsfileList.TryGetPD(m_GameObject.m_MeshFilter, out var MeshFilterPD))
+                    if (m_GameObject.m_MeshFilter != null && m_GameObject.m_MeshFilter.TryGetPD(out var MeshFilterPD))
                     {
                         //MeshFilters are not unique!
                         //MeshFilters.Add(MeshFilterPD);
                         MeshFilter m_MeshFilter = new MeshFilter(MeshFilterPD);
-                        if (assetsfileList.TryGetPD(m_MeshFilter.m_Mesh, out var MeshPD))
+                        if (m_MeshFilter.m_Mesh.TryGetPD(out var MeshPD))
                         {
                             Meshes.Add(MeshPD);
 
@@ -78,13 +78,13 @@ namespace AssetStudio
                     }
 
                     #region get Renderer
-                    if (assetsfileList.TryGetPD(m_GameObject.m_MeshRenderer, out var RendererPD))
+                    if (m_GameObject.m_MeshRenderer != null && m_GameObject.m_MeshRenderer.TryGetPD(out var RendererPD))
                     {
                         MeshRenderer m_Renderer = new MeshRenderer(RendererPD);
 
                         foreach (var MaterialPPtr in m_Renderer.m_Materials)
                         {
-                            if (assetsfileList.TryGetPD(MaterialPPtr, out var MaterialPD))
+                            if (MaterialPPtr.TryGetPD(out var MaterialPD))
                             {
                                 Materials.Add(MaterialPD);
                                 cb2.AppendFormat("\n\n\t;Material::, Model::{0}", m_GameObject.m_Name);
@@ -96,7 +96,7 @@ namespace AssetStudio
                     #endregion
 
                     #region get SkinnedMeshRenderer
-                    if (assetsfileList.TryGetPD(m_GameObject.m_SkinnedMeshRenderer, out var SkinnedMeshPD))
+                    if (m_GameObject.m_SkinnedMeshRenderer != null && m_GameObject.m_SkinnedMeshRenderer.TryGetPD(out var SkinnedMeshPD))
                     {
                         Skins.Add(SkinnedMeshPD);
 
@@ -104,7 +104,7 @@ namespace AssetStudio
 
                         foreach (var MaterialPPtr in m_SkinnedMeshRenderer.m_Materials)
                         {
-                            if (assetsfileList.TryGetPD(MaterialPPtr, out var MaterialPD))
+                            if (MaterialPPtr.TryGetPD(out var MaterialPD))
                             {
                                 Materials.Add(MaterialPD);
                                 cb2.AppendFormat("\n\n\t;Material::, Model::{0}", m_GameObject.m_Name);
@@ -119,9 +119,9 @@ namespace AssetStudio
                             //collect skeleton dummies to make sure they are exported
                             foreach (var bonePPtr in m_SkinnedMeshRenderer.m_Bones)
                             {
-                                if (assetsfileList.TryGetTransform(bonePPtr, out var b_Transform))
+                                if (bonePPtr.TryGetTransform(out var b_Transform))
                                 {
-                                    if (assetsfileList.TryGetGameObject(b_Transform.m_GameObject, out var m_Bone))
+                                    if (b_Transform.m_GameObject.TryGetGameObject(out var m_Bone))
                                     {
                                         LimbNodes.Add(m_Bone);
                                         //also collect the root bone
@@ -136,9 +136,9 @@ namespace AssetStudio
                                     #region collect children because m_SkinnedMeshRenderer.m_Bones doesn't contain terminations
                                     foreach (var ChildPPtr in b_Transform.m_Children)
                                     {
-                                        if (assetsfileList.TryGetTransform(ChildPPtr, out var ChildTR))
+                                        if (ChildPPtr.TryGetTransform(out var ChildTR))
                                         {
-                                            if (assetsfileList.TryGetGameObject(ChildTR.m_GameObject, out var m_Child))
+                                            if (ChildTR.m_GameObject.TryGetGameObject(out var m_Child))
                                             {
                                                 //check that the Model doesn't contain a Mesh, although this won't ensure it's part of the skeleton
                                                 if (m_Child.m_MeshFilter == null && m_Child.m_SkinnedMeshRenderer == null)
@@ -225,7 +225,7 @@ namespace AssetStudio
                     foreach (var m_TexEnv in m_Material.m_TexEnvs)
                     {
                         #region get Porsche material from json
-                        if (!assetsfileList.TryGetPD(m_TexEnv.m_Texture, out var TexturePD) && jsonMats != null)
+                        if (!m_TexEnv.m_Texture.TryGetPD(out var TexturePD) && jsonMats != null)
                         {
                             if (jsonMats.TryGetValue(m_Material.m_Name, out var matProp))
                             {
@@ -430,7 +430,7 @@ namespace AssetStudio
                     ob.Append("\n\t\t\tP: \"ScalingMax\", \"Vector3D\", \"Vector\", \"\",0,0,0");
                     ob.Append("\n\t\t\tP: \"DefaultAttributeIndex\", \"int\", \"Integer\", \"\",0");
 
-                    if (assetsfileList.TryGetTransform(m_GameObject.m_Transform, out var m_Transform))
+                    if (m_GameObject.m_Transform.TryGetTransform(out var m_Transform))
                     {
                         float[] m_EulerRotation = QuatToEuler(new[] { m_Transform.m_LocalRotation[0], -m_Transform.m_LocalRotation[1], -m_Transform.m_LocalRotation[2], m_Transform.m_LocalRotation[3] });
 
@@ -485,7 +485,7 @@ namespace AssetStudio
                 foreach (var SkinnedMeshPD in Skins)
                 {
                     SkinnedMeshRenderer m_SkinnedMeshRenderer = new SkinnedMeshRenderer(SkinnedMeshPD);
-                    if (assetsfileList.TryGetGameObject(m_SkinnedMeshRenderer.m_GameObject, out var m_GameObject) && assetsfileList.TryGetPD(m_SkinnedMeshRenderer.m_Mesh, out var MeshPD))
+                    if (m_SkinnedMeshRenderer.m_GameObject.TryGetGameObject(out var m_GameObject) && m_SkinnedMeshRenderer.m_Mesh.TryGetPD(out var MeshPD))
                     {
                         //generate unique Geometry ID for instanced mesh objects
                         //instanced skinned geometry is possible in FBX, but all instances are linked to the same skeleton nodes
@@ -537,9 +537,9 @@ namespace AssetStudio
 
                                 for (int b = 0; b < m_SkinnedMeshRenderer.m_Bones.Length; b++)
                                 {
-                                    if (assetsfileList.TryGetTransform(m_SkinnedMeshRenderer.m_Bones[b], out var m_Transform))
+                                    if (m_SkinnedMeshRenderer.m_Bones[b].TryGetTransform(out var m_Transform))
                                     {
-                                        if (assetsfileList.TryGetGameObject(m_Transform.m_GameObject, out var m_Bone))
+                                        if (m_Transform.m_GameObject.TryGetGameObject(out var m_Bone))
                                         {
                                             int influences = 0, ibSplit = 0, wbSplit = 0;
                                             StringBuilder ib = new StringBuilder();//indices (vertex)
diff --git a/AssetStudio/StudioClasses/FileIdentifier.cs b/AssetStudio/StudioClasses/FileIdentifier.cs
new file mode 100644
index 0000000..8a76e77
--- /dev/null
+++ b/AssetStudio/StudioClasses/FileIdentifier.cs
@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace AssetStudio
+{
+    public class FileIdentifier
+    {
+        public Guid guid;
+        public int type; //enum { kNonAssetType = 0, kDeprecatedCachedAssetType = 1, kSerializedAssetType = 2, kMetaAssetType = 3 };
+        public string pathName;
+
+        //custom
+        public string fileName;
+    }
+}
diff --git a/AssetStudio/StudioClasses/Importer.cs b/AssetStudio/StudioClasses/Importer.cs
index 8aa5f52..2a10e83 100644
--- a/AssetStudio/StudioClasses/Importer.cs
+++ b/AssetStudio/StudioClasses/Importer.cs
@@ -64,7 +64,7 @@ namespace AssetStudio
                     #endregion
 
                     int value = 0;
-                    foreach (var sharedFile in assetsFile.sharedAssetsList)
+                    foreach (var sharedFile in assetsFile.m_Externals)
                     {
                         var sharedFilePath = Path.GetDirectoryName(fullName) + "\\" + sharedFile.fileName;
                         var sharedFileName = sharedFile.fileName;
diff --git a/AssetStudio/StudioClasses/LocalSerializedObjectIdentifier.cs b/AssetStudio/StudioClasses/LocalSerializedObjectIdentifier.cs
new file mode 100644
index 0000000..24f4553
--- /dev/null
+++ b/AssetStudio/StudioClasses/LocalSerializedObjectIdentifier.cs
@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace AssetStudio
+{
+    public class LocalSerializedObjectIdentifier
+    {
+        public int localSerializedFileIndex;
+        public long localIdentifierInFile;
+    }
+}
diff --git a/AssetStudio/StudioClasses/ModelConverter.cs b/AssetStudio/StudioClasses/ModelConverter.cs
index 09d401f..70afac8 100644
--- a/AssetStudio/StudioClasses/ModelConverter.cs
+++ b/AssetStudio/StudioClasses/ModelConverter.cs
@@ -25,7 +25,7 @@ namespace AssetStudio
 
         public ModelConverter(GameObject m_GameObject)
         {
-            if (assetsfileList.TryGetPD(m_GameObject.m_Animator, out var m_Animator))
+            if (m_GameObject.m_Animator != null && m_GameObject.m_Animator.TryGetPD(out var m_Animator))
             {
                 var animator = new Animator(m_Animator);
                 InitWithAnimator(animator);
@@ -38,7 +38,7 @@ namespace AssetStudio
 
         public ModelConverter(GameObject m_GameObject, List<AssetPreloadData> animationList)
         {
-            if (assetsfileList.TryGetPD(m_GameObject.m_Animator, out var m_Animator))
+            if (m_GameObject.m_Animator != null && m_GameObject.m_Animator.TryGetPD(out var m_Animator))
             {
                 var animator = new Animator(m_Animator);
                 InitWithAnimator(animator);
@@ -71,16 +71,16 @@ namespace AssetStudio
 
         private void InitWithAnimator(Animator m_Animator)
         {
-            if (assetsfileList.TryGetPD(m_Animator.m_Avatar, out var m_Avatar))
+            if (m_Animator.m_Avatar.TryGetPD(out var m_Avatar))
                 avatar = new Avatar(m_Avatar);
 
-            assetsfileList.TryGetGameObject(m_Animator.m_GameObject, out var m_GameObject);
+            m_Animator.m_GameObject.TryGetGameObject(out var m_GameObject);
             InitWithGameObject(m_GameObject, m_Animator.m_HasTransformHierarchy);
         }
 
         private void InitWithGameObject(GameObject m_GameObject, bool hasTransformHierarchy = true)
         {
-            assetsfileList.TryGetTransform(m_GameObject.m_Transform, out var m_Transform);
+            m_GameObject.m_Transform.TryGetTransform(out var m_Transform);
             var rootTransform = m_Transform;
             if (!hasTransformHierarchy)
             {
@@ -91,7 +91,7 @@ namespace AssetStudio
             else
             {
                 var frameList = new List<ImportedFrame>();
-                while (assetsfileList.TryGetTransform(rootTransform.m_Father, out var m_Father))
+                while (rootTransform.m_Father.TryGetTransform(out var m_Father))
                 {
                     frameList.Add(ConvertFrame(m_Father));
                     rootTransform = m_Father;
@@ -120,10 +120,10 @@ namespace AssetStudio
 
         private void ConvertMeshRenderer(Transform m_Transform)
         {
-            assetsfileList.TryGetGameObject(m_Transform.m_GameObject, out var m_GameObject);
+            m_Transform.m_GameObject.TryGetGameObject(out var m_GameObject);
             foreach (var m_Component in m_GameObject.m_Components)
             {
-                if (assetsfileList.TryGetPD(m_Component, out var assetPreloadData))
+                if (m_Component.TryGetPD(out var assetPreloadData))
                 {
                     switch (assetPreloadData.Type)
                     {
@@ -144,7 +144,7 @@ namespace AssetStudio
                                 var m_Animation = new Animation(assetPreloadData);
                                 foreach (var animation in m_Animation.m_Animations)
                                 {
-                                    if (assetsfileList.TryGetPD(animation, out var animationClip))
+                                    if (animation.TryGetPD(out var animationClip))
                                     {
                                         animationClipHashSet.Add(animationClip);
                                     }
@@ -156,24 +156,24 @@ namespace AssetStudio
             }
             foreach (var pptr in m_Transform.m_Children)
             {
-                if (assetsfileList.TryGetTransform(pptr, out var child))
+                if (pptr.TryGetTransform(out var child))
                     ConvertMeshRenderer(child);
             }
         }
 
         private void CollectAnimationClip(Animator m_Animator)
         {
-            if (assetsfileList.TryGetPD(m_Animator.m_Controller, out var assetPreloadData))
+            if (m_Animator.m_Controller.TryGetPD(out var assetPreloadData))
             {
                 if (assetPreloadData.Type == ClassIDReference.AnimatorOverrideController)
                 {
                     var m_AnimatorOverrideController = new AnimatorOverrideController(assetPreloadData);
-                    if (assetsfileList.TryGetPD(m_AnimatorOverrideController.m_Controller, out assetPreloadData))
+                    if (m_AnimatorOverrideController.m_Controller.TryGetPD(out assetPreloadData))
                     {
                         var m_AnimatorController = new AnimatorController(assetPreloadData);
                         foreach (var m_AnimationClip in m_AnimatorController.m_AnimationClips)
                         {
-                            if (assetsfileList.TryGetPD(m_AnimationClip, out assetPreloadData))
+                            if (m_AnimationClip.TryGetPD(out assetPreloadData))
                             {
                                 animationClipHashSet.Add(assetPreloadData);
                             }
@@ -192,7 +192,7 @@ namespace AssetStudio
                     var m_AnimatorController = new AnimatorController(assetPreloadData);
                     foreach (var m_AnimationClip in m_AnimatorController.m_AnimationClips)
                     {
-                        if (assetsfileList.TryGetPD(m_AnimationClip, out assetPreloadData))
+                        if (m_AnimationClip.TryGetPD(out assetPreloadData))
                         {
                             animationClipHashSet.Add(assetPreloadData);
                         }
@@ -204,7 +204,7 @@ namespace AssetStudio
         private ImportedFrame ConvertFrame(Transform trans)
         {
             var frame = new ImportedFrame();
-            assetsfileList.TryGetGameObject(trans.m_GameObject, out var m_GameObject);
+            trans.m_GameObject.TryGetGameObject(out var m_GameObject);
             frame.Name = m_GameObject.m_Name;
             frame.InitChildren(trans.m_Children.Count);
             var m_EulerRotation = QuatToEuler(new[] { trans.m_LocalRotation[0], -trans.m_LocalRotation[1], -trans.m_LocalRotation[2], trans.m_LocalRotation[3] });
@@ -242,7 +242,7 @@ namespace AssetStudio
             }
             foreach (var pptr in trans.m_Children)
             {
-                if (assetsfileList.TryGetTransform(pptr, out var child))
+                if (pptr.TryGetTransform(out var child))
                     ConvertFrames(child, frame);
             }
         }
@@ -253,8 +253,8 @@ namespace AssetStudio
             if (mesh == null)
                 return;
             var iMesh = new ImportedMesh();
-            assetsfileList.TryGetGameObject(meshR.m_GameObject, out var m_GameObject2);
-            assetsfileList.TryGetTransform(m_GameObject2.m_Transform, out var meshTransform);
+            meshR.m_GameObject.TryGetGameObject(out var m_GameObject2);
+            m_GameObject2.m_Transform.TryGetTransform(out var meshTransform);
             iMesh.Name = GetTransformPath(meshTransform);
             iMesh.SubmeshList = new List<ImportedSubmesh>();
             var subHashSet = new HashSet<int>();
@@ -293,7 +293,7 @@ namespace AssetStudio
                 Material mat = null;
                 if (i - firstSubMesh < meshR.m_Materials.Length)
                 {
-                    if (assetsfileList.TryGetPD(meshR.m_Materials[i - firstSubMesh], out var MaterialPD))
+                    if (meshR.m_Materials[i - firstSubMesh].TryGetPD(out var MaterialPD))
                     {
                         mat = new Material(MaterialPD);
                     }
@@ -388,9 +388,9 @@ namespace AssetStudio
                 for (int i = 0; i < sMesh.m_Bones.Length; i++)
                 {
                     var bone = new ImportedBone();
-                    if (assetsfileList.TryGetTransform(sMesh.m_Bones[i], out var m_Transform))
+                    if (sMesh.m_Bones[i].TryGetTransform(out var m_Transform))
                     {
-                        if (assetsfileList.TryGetGameObject(m_Transform.m_GameObject, out var m_GameObject))
+                        if (m_Transform.m_GameObject.TryGetGameObject(out var m_GameObject))
                         {
                             bone.Name = m_GameObject.m_Name;
                         }
@@ -536,7 +536,7 @@ namespace AssetStudio
             //TODO
             if (combine)
             {
-                assetsfileList.TryGetGameObject(meshR.m_GameObject, out var m_GameObject);
+                meshR.m_GameObject.TryGetGameObject(out var m_GameObject);
                 foreach (var root in FrameList)
                 {
                     var frame = ImportedHelpers.FindFrame(m_GameObject.m_Name, root);
@@ -569,22 +569,22 @@ namespace AssetStudio
         {
             if (meshR is SkinnedMeshRenderer sMesh)
             {
-                if (assetsfileList.TryGetPD(sMesh.m_Mesh, out var MeshPD))
+                if (sMesh.m_Mesh.TryGetPD(out var MeshPD))
                 {
                     return new Mesh(MeshPD);
                 }
             }
             else
             {
-                assetsfileList.TryGetGameObject(meshR.m_GameObject, out var m_GameObject);
+                meshR.m_GameObject.TryGetGameObject(out var m_GameObject);
                 foreach (var m_Component in m_GameObject.m_Components)
                 {
-                    if (assetsfileList.TryGetPD(m_Component, out var assetPreloadData))
+                    if (m_Component.TryGetPD(out var assetPreloadData))
                     {
                         if (assetPreloadData.Type == ClassIDReference.MeshFilter)
                         {
                             var m_MeshFilter = new MeshFilter(assetPreloadData);
-                            if (assetsfileList.TryGetPD(m_MeshFilter.m_Mesh, out var MeshPD))
+                            if (m_MeshFilter.m_Mesh.TryGetPD(out var MeshPD))
                             {
                                 return new Mesh(MeshPD);
                             }
@@ -599,7 +599,7 @@ namespace AssetStudio
 
         private string GetTransformPath(Transform meshTransform)
         {
-            assetsfileList.TryGetGameObject(meshTransform.m_GameObject, out var m_GameObject);
+            meshTransform.m_GameObject.TryGetGameObject(out var m_GameObject);
             var curFrame = ImportedHelpers.FindFrame(m_GameObject.m_Name, FrameList[0]);
             var path = curFrame.Name;
             while (curFrame.Parent != null)
@@ -667,7 +667,7 @@ namespace AssetStudio
                 foreach (var texEnv in mat.m_TexEnvs)
                 {
                     Texture2D tex2D = null;
-                    if (assetsfileList.TryGetPD(texEnv.m_Texture, out var TexturePD) && TexturePD.Type == ClassIDReference.Texture2D)//TODO other Texture
+                    if (texEnv.m_Texture.TryGetPD(out var TexturePD) && TexturePD.Type == ClassIDReference.Texture2D)//TODO other Texture
                     {
                         tex2D = new Texture2D(TexturePD, true);
                     }
@@ -986,7 +986,7 @@ namespace AssetStudio
             }
             foreach (var pptr in m_Transform.m_Children)
             {
-                if (assetsfileList.TryGetTransform(pptr, out var child))
+                if (pptr.TryGetTransform(out var child))
                     CreateBonePathHash(child);
             }
         }
diff --git a/AssetStudio/StudioClasses/ObjectInfo.cs b/AssetStudio/StudioClasses/ObjectInfo.cs
new file mode 100644
index 0000000..f5c7986
--- /dev/null
+++ b/AssetStudio/StudioClasses/ObjectInfo.cs
@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace AssetStudio
+{
+    public class ObjectInfo
+    {
+        public uint byteStart;
+        public uint byteSize;
+        public int typeID;
+        public int classID;
+        public ushort isDestroyed;
+    }
+}
diff --git a/AssetStudio/StudioClasses/PPtr.cs b/AssetStudio/StudioClasses/PPtr.cs
new file mode 100644
index 0000000..e67feb3
--- /dev/null
+++ b/AssetStudio/StudioClasses/PPtr.cs
@@ -0,0 +1,88 @@
+using static AssetStudio.Studio;
+
+namespace AssetStudio
+{
+    public class PPtr
+    {
+        public int m_FileID;
+        public long m_PathID;
+
+        //custom
+        public AssetsFile assetsFile;
+        public int index = -2; //-2 - Prepare, -1 - Missing
+
+        private bool TryGet(out AssetsFile result)
+        {
+            result = null;
+            if (m_FileID == 0)
+            {
+                result = assetsFile;
+                return true;
+            }
+
+            if (m_FileID > 0)
+            {
+                if (index == -2)
+                {
+                    var m_External = assetsFile.m_Externals[m_FileID - 1];
+                    var name = m_External.fileName.ToUpper();
+                    if (!assetsFileIndexCache.TryGetValue(name, out index))
+                    {
+                        index = assetsfileList.FindIndex(x => x.upperFileName == name);
+                        assetsFileIndexCache.Add(name, index);
+                    }
+                }
+
+                if (index >= 0)
+                {
+                    result = assetsfileList[index];
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
+        public bool TryGetPD(out AssetPreloadData result)
+        {
+            result = null;
+            if (TryGet(out var sourceFile))
+            {
+                if (sourceFile.preloadTable.TryGetValue(m_PathID, out result))
+                {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
+        public bool TryGetTransform(out Transform m_Transform)
+        {
+            if (TryGet(out var sourceFile))
+            {
+                if (sourceFile.TransformList.TryGetValue(m_PathID, out m_Transform))
+                {
+                    return true;
+                }
+            }
+
+            m_Transform = null;
+            return false;
+        }
+
+        public bool TryGetGameObject(out GameObject m_GameObject)
+        {
+            if (TryGet(out var sourceFile))
+            {
+                if (sourceFile.GameObjectList.TryGetValue(m_PathID, out m_GameObject))
+                {
+                    return true;
+                }
+            }
+
+            m_GameObject = null;
+            return false;
+        }
+    }
+}
diff --git a/AssetStudio/StudioClasses/PPtrHelpers.cs b/AssetStudio/StudioClasses/PPtrHelpers.cs
deleted file mode 100644
index 1af76fa..0000000
--- a/AssetStudio/StudioClasses/PPtrHelpers.cs
+++ /dev/null
@@ -1,90 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using static AssetStudio.Studio;
-
-namespace AssetStudio
-{
-    public class PPtr
-    {
-        //m_FileID 0 means current file
-        public int m_FileID;
-        //m_PathID acts more like a hash in some games
-        public long m_PathID;
-    }
-
-    public static class PPtrHelpers
-    {
-        public static PPtr ReadPPtr(this AssetsFile sourceFile)
-        {
-            var result = new PPtr();
-            var reader = sourceFile.reader;
-
-            int FileID = reader.ReadInt32();
-            if (FileID >= 0 && FileID < sourceFile.sharedAssetsList.Count)
-            {
-                var sharedFile = sourceFile.sharedAssetsList[FileID];
-                var index = sharedFile.Index;
-                if (index == -2)
-                {
-                    var name = sharedFile.fileName.ToUpper();
-                    if (!sharedFileIndex.TryGetValue(name, out index))
-                    {
-                        index = assetsfileList.FindIndex(aFile => aFile.upperFileName == name);
-                        sharedFileIndex.Add(name, index);
-                    }
-                    sharedFile.Index = index;
-                }
-                result.m_FileID = index;
-            }
-
-            result.m_PathID = sourceFile.header.m_Version < 14 ? reader.ReadInt32() : reader.ReadInt64();
-
-            return result;
-        }
-
-        public static bool TryGetPD(this List<AssetsFile> assetsfileList, PPtr m_elm, out AssetPreloadData result)
-        {
-            result = null;
-
-            if (m_elm != null && m_elm.m_FileID >= 0 && m_elm.m_FileID < assetsfileList.Count)
-            {
-                AssetsFile sourceFile = assetsfileList[m_elm.m_FileID];
-
-                //TryGetValue should be safe because m_PathID is 0 when initialized and PathID values range from 1
-                if (sourceFile.preloadTable.TryGetValue(m_elm.m_PathID, out result)) { return true; }
-            }
-
-            return false;
-        }
-
-        public static bool TryGetTransform(this List<AssetsFile> assetsfileList, PPtr m_elm, out Transform m_Transform)
-        {
-            m_Transform = null;
-
-            if (m_elm != null && m_elm.m_FileID >= 0 && m_elm.m_FileID < assetsfileList.Count)
-            {
-                AssetsFile sourceFile = assetsfileList[m_elm.m_FileID];
-
-                if (sourceFile.TransformList.TryGetValue(m_elm.m_PathID, out m_Transform)) { return true; }
-            }
-
-            return false;
-        }
-
-        public static bool TryGetGameObject(this List<AssetsFile> assetsfileList, PPtr m_elm, out GameObject m_GameObject)
-        {
-            m_GameObject = null;
-
-            if (m_elm != null && m_elm.m_FileID >= 0 && m_elm.m_FileID < assetsfileList.Count)
-            {
-                AssetsFile sourceFile = assetsfileList[m_elm.m_FileID];
-
-                if (sourceFile.GameObjectList.TryGetValue(m_elm.m_PathID, out m_GameObject)) { return true; }
-            }
-
-            return false;
-        }
-    }
-}
diff --git a/AssetStudio/StudioClasses/SerializedFileHeader.cs b/AssetStudio/StudioClasses/SerializedFileHeader.cs
new file mode 100644
index 0000000..438dbcb
--- /dev/null
+++ b/AssetStudio/StudioClasses/SerializedFileHeader.cs
@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace AssetStudio
+{
+    public class SerializedFileHeader
+    {
+        public uint m_MetadataSize;
+        public uint m_FileSize;
+        public uint m_Version;
+        public uint m_DataOffset;
+        public byte m_Endianess;
+        public byte[] m_Reserved;
+    }
+}
diff --git a/AssetStudio/StudioClasses/SpriteHelper.cs b/AssetStudio/StudioClasses/SpriteHelper.cs
index 045e544..f632304 100644
--- a/AssetStudio/StudioClasses/SpriteHelper.cs
+++ b/AssetStudio/StudioClasses/SpriteHelper.cs
@@ -5,7 +5,6 @@ using System.Drawing.Drawing2D;
 using System.Drawing.Imaging;
 using System.Linq;
 using System.Text;
-using static AssetStudio.Studio;
 
 namespace AssetStudio
 {
@@ -13,12 +12,12 @@ namespace AssetStudio
     {
         public static Bitmap GetImageFromSprite(Sprite m_Sprite)
         {
-            if (assetsfileList.TryGetPD(m_Sprite.m_SpriteAtlas, out var assetPreloadData))
+            if (m_Sprite.m_SpriteAtlas.TryGetPD(out var assetPreloadData))
             {
                 var m_SpriteAtlas = new SpriteAtlas(assetPreloadData);
                 var index = m_SpriteAtlas.guids.FindIndex(x => x == m_Sprite.first);
 
-                if (index >= 0 && assetsfileList.TryGetPD(m_SpriteAtlas.textures[index], out assetPreloadData))
+                if (index >= 0 && m_SpriteAtlas.textures[index].TryGetPD(out assetPreloadData))
                 {
                     try
                     {
@@ -36,7 +35,7 @@ namespace AssetStudio
             }
             else
             {
-                if (assetsfileList.TryGetPD(m_Sprite.texture, out assetPreloadData))
+                if (m_Sprite.texture.TryGetPD(out assetPreloadData))
                 {
                     return CutImage(assetPreloadData, m_Sprite.textureRect);
                 }
diff --git a/AssetStudio/StudioClasses/Studio.cs b/AssetStudio/StudioClasses/Studio.cs
index db6057f..db8cb4f 100644
--- a/AssetStudio/StudioClasses/Studio.cs
+++ b/AssetStudio/StudioClasses/Studio.cs
@@ -15,7 +15,7 @@ namespace AssetStudio
     internal static class Studio
     {
         public static List<AssetsFile> assetsfileList = new List<AssetsFile>(); //loaded files
-        public static Dictionary<string, int> sharedFileIndex = new Dictionary<string, int>(); //to improve the loading speed
+        public static Dictionary<string, int> assetsFileIndexCache = new Dictionary<string, int>();
         public static Dictionary<string, EndianBinaryReader> resourceFileReaders = new Dictionary<string, EndianBinaryReader>(); //use for read res files
         public static List<AssetPreloadData> exportableAssets = new List<AssetPreloadData>(); //used to hold all assets while the ListView is filtered
         private static HashSet<string> assetsNameHash = new HashSet<string>(); //avoid the same name asset
@@ -251,7 +251,7 @@ namespace AssetStudio
                             case ClassIDReference.MonoBehaviour:
                                 {
                                     var m_MonoBehaviour = new MonoBehaviour(asset);
-                                    if (m_MonoBehaviour.m_Name == "" && assetsfileList.TryGetPD(m_MonoBehaviour.m_Script, out var script))
+                                    if (m_MonoBehaviour.m_Name == "" && m_MonoBehaviour.m_Script.TryGetPD(out var script))
                                     {
                                         var m_Script = new MonoScript(script);
                                         asset.Text = m_Script.m_ClassName;
@@ -337,67 +337,63 @@ namespace AssetStudio
                         {
                             foreach (var m_Component in m_GameObject.m_Components)
                             {
-                                if (m_Component.m_FileID >= 0 && m_Component.m_FileID < assetsfileList.Count)
+                                if (m_Component.TryGetPD(out var asset))
                                 {
-                                    var sourceFile = assetsfileList[m_Component.m_FileID];
-                                    if (sourceFile.preloadTable.TryGetValue(m_Component.m_PathID, out var asset))
+                                    switch (asset.Type)
                                     {
-                                        switch (asset.Type)
-                                        {
-                                            case ClassIDReference.Transform:
+                                        case ClassIDReference.Transform:
+                                            {
+                                                m_GameObject.m_Transform = m_Component;
+                                                break;
+                                            }
+                                        case ClassIDReference.MeshRenderer:
+                                            {
+                                                m_GameObject.m_MeshRenderer = m_Component;
+                                                break;
+                                            }
+                                        case ClassIDReference.MeshFilter:
+                                            {
+                                                m_GameObject.m_MeshFilter = m_Component;
+                                                if (m_Component.TryGetPD(out var assetPreloadData))
                                                 {
-                                                    m_GameObject.m_Transform = m_Component;
-                                                    break;
-                                                }
-                                            case ClassIDReference.MeshRenderer:
-                                                {
-                                                    m_GameObject.m_MeshRenderer = m_Component;
-                                                    break;
-                                                }
-                                            case ClassIDReference.MeshFilter:
-                                                {
-                                                    m_GameObject.m_MeshFilter = m_Component;
-                                                    if (assetsfileList.TryGetPD(m_Component, out var assetPreloadData))
+                                                    var m_MeshFilter = new MeshFilter(assetPreloadData);
+                                                    if (m_MeshFilter.m_Mesh.TryGetPD(out assetPreloadData))
                                                     {
-                                                        var m_MeshFilter = new MeshFilter(assetPreloadData);
-                                                        if (assetsfileList.TryGetPD(m_MeshFilter.m_Mesh, out assetPreloadData))
-                                                        {
-                                                            assetPreloadData.gameObject = m_GameObject;
-                                                        }
+                                                        assetPreloadData.gameObject = m_GameObject;
                                                     }
-                                                    break;
                                                 }
-                                            case ClassIDReference.SkinnedMeshRenderer:
+                                                break;
+                                            }
+                                        case ClassIDReference.SkinnedMeshRenderer:
+                                            {
+                                                m_GameObject.m_SkinnedMeshRenderer = m_Component;
+                                                if (m_Component.TryGetPD(out var assetPreloadData))
                                                 {
-                                                    m_GameObject.m_SkinnedMeshRenderer = m_Component;
-                                                    if (assetsfileList.TryGetPD(m_Component, out var assetPreloadData))
+                                                    var m_SkinnedMeshRenderer = new SkinnedMeshRenderer(assetPreloadData);
+                                                    if (m_SkinnedMeshRenderer.m_Mesh.TryGetPD(out assetPreloadData))
                                                     {
-                                                        var m_SkinnedMeshRenderer = new SkinnedMeshRenderer(assetPreloadData);
-                                                        if (assetsfileList.TryGetPD(m_SkinnedMeshRenderer.m_Mesh, out assetPreloadData))
-                                                        {
-                                                            assetPreloadData.gameObject = m_GameObject;
-                                                        }
+                                                        assetPreloadData.gameObject = m_GameObject;
                                                     }
-                                                    break;
                                                 }
-                                            case ClassIDReference.Animator:
-                                                {
-                                                    m_GameObject.m_Animator = m_Component;
-                                                    asset.Text = m_GameObject.preloadData.Text;
-                                                    break;
-                                                }
-                                        }
+                                                break;
+                                            }
+                                        case ClassIDReference.Animator:
+                                            {
+                                                m_GameObject.m_Animator = m_Component;
+                                                asset.Text = m_GameObject.preloadData.Text;
+                                                break;
+                                            }
                                     }
                                 }
                             }
 
                             var parentNode = fileNode;
 
-                            if (assetsfileList.TryGetTransform(m_GameObject.m_Transform, out var m_Transform))
+                            if (m_GameObject.m_Transform != null && m_GameObject.m_Transform.TryGetTransform(out var m_Transform))
                             {
-                                if (assetsfileList.TryGetTransform(m_Transform.m_Father, out var m_Father))
+                                if (m_Transform.m_Father.TryGetTransform(out var m_Father))
                                 {
-                                    if (assetsfileList.TryGetGameObject(m_Father.m_GameObject, out var parentGameObject))
+                                    if (m_Father.m_GameObject.TryGetGameObject(out var parentGameObject))
                                     {
                                         if (!treeNodeDictionary.TryGetValue(parentGameObject, out parentNode))
                                         {
@@ -811,7 +807,7 @@ namespace AssetStudio
             sb.AppendLine($"\tint m_FileID = {m_MonoBehaviour.m_Script.m_FileID}");
             sb.AppendLine($"\tint64 m_PathID = {m_MonoBehaviour.m_Script.m_PathID}");
             sb.AppendLine($"string m_Name = \"{m_MonoBehaviour.m_Name}\"");
-            if (assetsfileList.TryGetPD(m_MonoBehaviour.m_Script, out var script))
+            if (m_MonoBehaviour.m_Script.TryGetPD(out var script))
             {
                 var m_Script = new MonoScript(script);
                 if (!LoadedModuleDic.TryGetValue(m_Script.m_AssemblyName, out var module))
diff --git a/AssetStudio/StudioClasses/TypeItem.cs b/AssetStudio/StudioClasses/TypeItem.cs
index c10a0c6..bd2806a 100644
--- a/AssetStudio/StudioClasses/TypeItem.cs
+++ b/AssetStudio/StudioClasses/TypeItem.cs
@@ -8,9 +8,9 @@ namespace AssetStudio
 {
     public class TypeItem : ListViewItem
     {
-        public List<TypeTree> typeTreeList;
+        public List<TypeTreeNode> typeTreeList;
 
-        public TypeItem(int classID, List<TypeTree> typeTreeList)
+        public TypeItem(int classID, List<TypeTreeNode> typeTreeList)
         {
             this.typeTreeList = typeTreeList;
             Text = typeTreeList[0].m_Type + " " + typeTreeList[0].m_Name;
@@ -22,7 +22,7 @@ namespace AssetStudio
             var sb = new StringBuilder();
             foreach (var i in typeTreeList)
             {
-                sb.AppendFormat("{0}{1} {2} {3} {4}\r\n", new string('\t', i.m_Depth), i.m_Type, i.m_Name, i.m_ByteSize, (i.m_MetaFlag & 0x4000) != 0);
+                sb.AppendFormat("{0}{1} {2} {3} {4}\r\n", new string('\t', i.m_Level), i.m_Type, i.m_Name, i.m_ByteSize, (i.m_MetaFlag & 0x4000) != 0);
             }
             return sb.ToString();
         }
diff --git a/AssetStudio/StudioClasses/TypeTreeHelper.cs b/AssetStudio/StudioClasses/TypeTreeHelper.cs
index 16fa516..3e9f53f 100644
--- a/AssetStudio/StudioClasses/TypeTreeHelper.cs
+++ b/AssetStudio/StudioClasses/TypeTreeHelper.cs
@@ -9,7 +9,7 @@ namespace AssetStudio
 {
     public static class TypeTreeHelper
     {
-        public static void ReadTypeString(StringBuilder sb, List<TypeTree> members, EndianBinaryReader reader)
+        public static void ReadTypeString(StringBuilder sb, List<TypeTreeNode> members, EndianBinaryReader reader)
         {
             for (int i = 0; i < members.Count; i++)
             {
@@ -17,10 +17,10 @@ namespace AssetStudio
             }
         }
 
-        private static void ReadStringValue(StringBuilder sb, List<TypeTree> members, EndianBinaryReader reader, ref int i)
+        private static void ReadStringValue(StringBuilder sb, List<TypeTreeNode> members, EndianBinaryReader reader, ref int i)
         {
             var member = members[i];
-            var level = member.m_Depth;
+            var level = member.m_Level;
             var varTypeStr = member.m_Type;
             var varNameStr = member.m_Name;
             object value = null;
@@ -106,7 +106,7 @@ namespace AssetStudio
                         var map = GetMembers(members, level, i);
                         i += map.Count - 1;
                         map.RemoveRange(0, 4);
-                        var first = GetMembers(map, map[0].m_Depth, 0);
+                        var first = GetMembers(map, map[0].m_Level, 0);
                         map.RemoveRange(0, first.Count);
                         var second = map;
                         for (int j = 0; j < size; j++)
@@ -154,7 +154,7 @@ namespace AssetStudio
                 reader.AlignStream(4);
         }
 
-        public static ExpandoObject ReadDynamicType(List<TypeTree> members, EndianBinaryReader reader)
+        public static ExpandoObject ReadDynamicType(List<TypeTreeNode> members, EndianBinaryReader reader)
         {
             var obj = new ExpandoObject();
             var objdic = (IDictionary<string, object>)obj;
@@ -167,10 +167,10 @@ namespace AssetStudio
             return obj;
         }
 
-        private static object ReadValue(List<TypeTree> members, EndianBinaryReader reader, ref int i)
+        private static object ReadValue(List<TypeTreeNode> members, EndianBinaryReader reader, ref int i)
         {
             var member = members[i];
-            var level = member.m_Depth;
+            var level = member.m_Level;
             var varTypeStr = member.m_Type;
             object value;
             var align = (member.m_MetaFlag & 0x4000) != 0;
@@ -246,7 +246,7 @@ namespace AssetStudio
                         var map = GetMembers(members, level, i);
                         i += map.Count - 1;
                         map.RemoveRange(0, 4);
-                        var first = GetMembers(map, map[0].m_Depth, 0);
+                        var first = GetMembers(map, map[0].m_Level, 0);
                         map.RemoveRange(0, first.Count);
                         var second = map;
                         for (int j = 0; j < size; j++)
@@ -291,14 +291,14 @@ namespace AssetStudio
             return value;
         }
 
-        private static List<TypeTree> GetMembers(List<TypeTree> members, int level, int index)
+        private static List<TypeTreeNode> GetMembers(List<TypeTreeNode> members, int level, int index)
         {
-            var member2 = new List<TypeTree>();
+            var member2 = new List<TypeTreeNode>();
             member2.Add(members[0]);
             for (int i = index + 1; i < members.Count; i++)
             {
                 var member = members[i];
-                var level2 = member.m_Depth;
+                var level2 = member.m_Level;
                 if (level2 <= level)
                 {
                     return member2;
@@ -308,7 +308,7 @@ namespace AssetStudio
             return member2;
         }
 
-        public static byte[] WriteDynamicType(ExpandoObject obj, List<TypeTree> members)
+        public static byte[] WriteDynamicType(ExpandoObject obj, List<TypeTreeNode> members)
         {
             var stream = new MemoryStream();
             var write = new BinaryWriter(stream);
@@ -322,10 +322,10 @@ namespace AssetStudio
             return stream.ToArray();
         }
 
-        private static void WriteValue(object value, List<TypeTree> members, BinaryWriter write, ref int i)
+        private static void WriteValue(object value, List<TypeTreeNode> members, BinaryWriter write, ref int i)
         {
             var member = members[i];
-            var level = member.m_Depth;
+            var level = member.m_Level;
             var varTypeStr = member.m_Type;
             var align = (member.m_MetaFlag & 0x4000) != 0;
             switch (varTypeStr)
@@ -401,7 +401,7 @@ namespace AssetStudio
                         var map = GetMembers(members, level, i);
                         i += map.Count - 1;
                         map.RemoveRange(0, 4);
-                        var first = GetMembers(map, map[0].m_Depth, 0);
+                        var first = GetMembers(map, map[0].m_Level, 0);
                         map.RemoveRange(0, first.Count);
                         var second = map;
                         for (int j = 0; j < size; j++)
diff --git a/AssetStudio/StudioClasses/TypeTree.cs b/AssetStudio/StudioClasses/TypeTreeNode.cs
similarity index 85%
rename from AssetStudio/StudioClasses/TypeTree.cs
rename to AssetStudio/StudioClasses/TypeTreeNode.cs
index 62c853b..644cfe4 100644
--- a/AssetStudio/StudioClasses/TypeTree.cs
+++ b/AssetStudio/StudioClasses/TypeTreeNode.cs
@@ -5,7 +5,7 @@ using System.Text;
 
 namespace AssetStudio
 {
-    public class TypeTree
+    public class TypeTreeNode
     {
         public string m_Type;
         public string m_Name;
@@ -14,6 +14,6 @@ namespace AssetStudio
         public int m_IsArray;
         public int m_Version;
         public int m_MetaFlag;
-        public int m_Depth;
+        public int m_Level;
     }
 }