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Contents: GRAFs page - All - 0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z - Edit

Format Type: Archive
Extensions: uasset
Platforms: Texture Files
Endian Order: Little Endian

Format Specifications

Unreal Engine 4 uasset file DETAILS OF THE IMPORT DIRECTORY... The ParentDirectoryNameID is the name The first few entries in the Import directory is ClassID = "Class" and NameID = the main data type (eg "Texture2D", "Material") The last entry is ClassID = "Package" and NameID = the main package name (eg "/Script/Engine") FILE HEADER uint32 {4} - Unreal Header (193,131,42,158) uint32 {4} - Version (6) (XOR with 255) byte {16} - null uint32 {4} - File Directory Offset? uint32 {4} - Unknown (5) uint32 {4} - Package Name (None) uint32 {4} - null byte {1} - Unknown (128) uint32 {4} - Number of Names uint32 {4} - Name Directory Offset uint64 {8} - null uint32 {4} - Number Of Exports uint32 {4} - Exports Directory Offset uint32 {4} - Number Of Imports uint32 {4} - Import Directory Offset byte {20} - null byte {16} - GUID Hash uint32 {4} - Unknown (1) uint32 {4} - Unknown (1/2) uint32 {4} - Unknown (Number of Names - again?) byte {36} - null uint32 {4} - Unknown uint32 {4} - null uint32 {4} - Padding Offset uint32 {4} - File Length [+4] (not always - sometimes an unknown length/offset) byte {12} - null uint32 {4} - Unknown (-1) uint32 {4} - Files Data Offset NAMES DIRECTORY for each name uint32 {4} - Name Length (including null) byte {X} - Name byte {1} - null Name Terminator uint32 {4} - Flags IMPORT DIRECTORY for each import (28 bytes per entry) uint64 {8} - Parent Directory Name ID uint64 {8} - Class ID (ID to "Package", "Class", etc) uint32 {4} - Parent Import Object ID (-1 for no parent) (XOR with 255) uint32 {4} - Name ID uint32 {4} - Unknown ID EXPORTS DIRECTORY for each export (100 bytes per entry) byte {100} - Unknown PADDING uint32 {4} - null FILE DATA for each file ??? for each property (continue until NameID == "None") uint64 {8} - Name ID if (NameID != None){ uint64 {8} - Class ID uint64 {8} - Length Property if (classID == StructProperty){ uint64 {8} - Class ID uint64 {8} - null uint64 {8} - null if (classID == IntPoint){ byte {1} - null uint32 {4} - Point X uint32 {4} - Point Y } else if (classID == Guid){ byte {1} - null byte {16} - GUID } else if (classID == ColorMaterialInput){ byte {1} - null byte {X} - Color Material Input Data (the length of X = LengthProperty from above) } else if (classID == ScalarMaterialInput){ byte {1} - null byte {X} - Scalar Material Input Data (the length of X = LengthProperty from above) } else if (classID == TextureStreamingData){ byte {1} - null uint64 {8} - null uint64 {8} - null } else if (classID == MaterialTextureInfo){ byte {1} - null Now keep reading properties until a "None" is reached - all these properties form the MaterialTextureInfo class } else if (classID == FontCharacter){ byte {1} - null uint32 {4} - Unknown uint32 {4} - Unknown uint32 {4} - Unknown uint64 {8} - Unknown } else if (classID == FontImportOptionsData){ byte {1} - null Now keep reading properties until a "None" is reached - all these properties form the FontImportOptionsData class These fields come after the property reading above uint64 {8} - Class ID (points to None) uint32 {4} - null uint32 {4} - Extra Data Length [*4] byte {X} - Extra Data } else { use the structure of one of the other properties (eg BoolProperty, ByteProperty, etc) } } else if (classID == BoolProperty){ uint16 {2} - Boolean Value (0/1) } else if (classID == FloatProperty){ byte {1} - null uint32 {4} - Float Value } else if (classID == NameProperty){ byte {1} - null uint32 {4} - Name ID uint32 {4} - Unknown } else if (classID == IntProperty){ byte {1} - null uint32 {4} - Integer Value } else if (classID == StrProperty){ byte {1} - null uint32 {4} - String Length (including null terminator) byte {X} - String byte {1} - null String Terminator } else if (classID == ObjectProperty){ uint32 {4} - Property } else if (classID == ByteProperty){ byte {X} - Bytes (the length of X = LengthProperty from above) byte {1} - null byte {X} - Bytes (the length of X = LengthProperty from above) } else if (classID == ArrayProperty){ uint64 {8} - Class ID byte {1} - null NOTE: LengthProperty from above gives the length of the next 4-byte field and the full contents of the array "for" loop uint32 {4} - Number of Values in the Array if (classID == StructProperty){ first comes the normal 4-field handler uint64 {8} - Name ID uint64 {8} - Class ID uint64 {8} - Length Property then comes the normal StructProperty handler uint64 {8} - Class ID <-- this is the Class for each item in the array uint64 {8} - null uint64 {8} - null } for each value in the array { use the structure of one of the other properties (eg BoolProperty, ByteProperty, etc) Either use the ClassID from the ArrayProperty definition, or if that is a StructProperty, use the ClassID in the StructProperty handler (details above) } if (classID == StructProperty && numberOfValuesInArray > 1){ byte {1} - null } } } uint32 {4} - null uint16 {2} - Flags (1/3) uint16 {2} - Flags (1/0) uint32 {4} - Unknown (1) uint64 {8} - Type ID (points to "PF_DXT5", "PF_B8G8R8A8", etc for a Texture2D Image) if (typeID == PF_DXT5 || PF_DXT3 || PF_DXT1){ uint32 {4} - Offset to Largest Mipmap [+8] uint32 {4} - Original Image Width uint32 {4} - Original Image Height uint32 {4} - Unknown (1) uint32 {4} - Type Name Length (including null) (8) byte {7} - Type Name (PF_DXT5/3/1) byte {1} - null Type Name Terminator uint32 {4} - null uint32 {4} - Mipmap Count for each large mipmap (where width/height >= 128), starting with largest mipmap and decreasing each time by /2 uint32 {4} - Entry Indicator (1) uint32 {4} - Flags (1025) uint32 {4} - Length of Mipmap Data uint32 {4} - Length of Mipmap Data uint64 {8} - Relative Offset to this mipmap (relative to the start of the largest mipmap data) uint32 {4} - This Mipmap Width uint32 {4} - This Mipmap Height for each Small Mipmap... uint32 {4} - Entry Indicator (1) uint32 {4} - Flags (72) uint32 {4} - Length of Mipmap Data uint32 {4} - Length of Mipmap Data uint64 {8} - Offset to start of Mipmap Data byte {X} - DXT5/3/1 Pixel Data uint32 {4} - This Mipmap Width uint32 {4} - This Mipmap Height uint32 {4} - Mipmap Count uint32 {4} - null for each large mipmap (where width/height >= 128), starting with largest mipmap and decreasing each time by /2 byte {X} - DXT5/3/1 Pixel Data } else if (typeID == PF_B8G8R8A8){ uint32 {4} - Offset to Largest Mipmap [+8] uint32 {4} - Original Image Width uint32 {4} - Original Image Height uint32 {4} - Unknown (1) uint32 {4} - Type Name Length (including null) (12) byte {11} - Type Name (PF_B8G8R8A8) byte {1} - null Type Name Terminator uint32 {4} - null uint32 {4} - Mipmap Count for each large mipmap (where width/height >= 128), starting with largest mipmap and decreasing each time by /2 uint32 {4} - Entry Indicator (1) uint32 {4} - Flags (1025) uint32 {4} - Length of Mipmap Data uint32 {4} - Length of Mipmap Data uint64 {8} - Relative Offset to this mipmap (relative to the start of the largest mipmap data) uint32 {4} - This Mipmap Width uint32 {4} - This Mipmap Height for each Small Mipmap... uint32 {4} - Entry Indicator (1) uint32 {4} - Flags (72) uint32 {4} - Length of Mipmap Data uint32 {4} - Length of Mipmap Data uint64 {8} - Offset to start of Mipmap Data byte {X} - BGRA Pixel Data uint32 {4} - This Mipmap Width uint32 {4} - This Mipmap Height uint32 {4} - Mipmap Count uint32 {4} - null for each large mipmap (where width/height >= 128), starting with largest mipmap and decreasing each time by /2 byte {X} - BGRA Pixel Data } else if (typeID == PF_BC5){ uint32 {4} - Offset to Largest Mipmap [+8] uint32 {4} - Original Image Width uint32 {4} - Original Image Height uint32 {4} - Unknown (1) uint32 {4} - Type Name Length (including null) (7) byte {6} - Type Name (PF_BC5) byte {1} - null Type Name Terminator uint32 {4} - Unknown (1) uint32 {4} - Mipmap Count for each large mipmap (where width/height >= 128), starting with largest mipmap and decreasing each time by /2 uint32 {4} - Entry Indicator (1) uint32 {4} - Flags (1025) uint32 {4} - Length of Mipmap Data uint32 {4} - Length of Mipmap Data uint64 {8} - Relative Offset to this mipmap (relative to the start of the largest mipmap data) uint32 {4} - This Mipmap Width uint32 {4} - This Mipmap Height for each small mipmap (where width/height < 128), decreasing each time by /2.. uint32 {4} - Entry Indicator (1) uint32 {4} - Flags (72) uint32 {4} - Length of Mipmap Data uint32 {4} - Length of Mipmap Data uint64 {8} - Offset to start of Mipmap Data byte {X} - BC5 Pixel Data uint32 {4} - This Mipmap Width uint32 {4} - This Mipmap Height uint32 {4} - Mipmap Count uint32 {4} - null for each large mipmap (where width/height >= 128), starting with largest mipmap and decreasing each time by /2 byte {X} - BC5 Pixel Data } else if (typeID == PF_G8){ uint32 {4} - Length of Image Data? uint32 {4} - Image Width uint32 {4} - Image Height uint32 {4} - Unknown (1) uint32 {4} - Type Name Length (including null) (6) byte {5} - Type Name (PF_G8) byte {1} - null Type Name Terminator uint32 {4} - null uint32 {4} - Mipmap Count (1) uint32 {4} - Unknown (1) uint32 {4} - Flags? (72) uint32 {4} - Length of Mipmap Data uint32 {4} - Length of Mipmap Data uint64 {8} - Offset to start of Mipmap Data (absolute offset) byte {X} - Greyscale Pixel Data uint32 {4} - Image Width uint32 {4} - ImageHeight uint64 {8} - Unknown (28) } else { NOT A TEXTURE IMAGE (or an unknown Texture format) byte {X} - File Data } FILE FOOTER uint32 {4} - Unreal Header (193,131,42,158)