=====BIG File Specification=====

====Main header====
Char [4] 'BIGB' \\
Char [4] Version \\
Int [4] Bank address \\
Int [4] unknown \\

====Bank Index====
Int [4] Number of Banks \\
Char [x] NULL terminted string \\
Int [4] Bank ID \\
===Bank===
Int [4] Number of Entries in Bank \\
Int [4] Index Start \\
Int [4] Index Size \\
Int [4] block size \\

==== FileIndex ====
=== Header ===
Int [4] NumberFileTypes \\
Int [4] FileType \\
Int [4] NumberFiles \\

=== Index ===
Int [4] Magic Number \\
Int [4] File ID \\
Int [4] File Type \\
Int [4] File Size \\
Int [4] File Start \\
--[dev info]-- \\
Int [4] File Type \\
Int [4] StringLength; \\
Int [StringLength] SymbolName \\
Int [4] File CRC \\
Int [4] Number of Source Files \\
Int [4] StringLength; \\
Int [StringLength] Source File Name \\
--[/dev info]-- \\
Int [4] SubHeaderSize \\
Int [SubHeaderSize] SubHeader \\
=== Texture sub-header: ===
Int [2] Width; // Texture size...// \\
Int [2] Height; \\
Int [2] Depth; // ...and depth for vol. textures// \\
Int [2] FrameWidth; // Actual image size (may be smaller)// \\
Int [2] FrameHeight; \\
Int [2] FrameCount; \\
Int [2] DXT Compression; \\
Int [2] Unkown; \\
Int [1] Transparency; // Number of alpha channels// \\
Int [1] MipMaps; // Number of MipMaps// \\
Int [2] Unkown; \\
Int [4] TopMipmapSize; \\
Int [4] TopMipmapCompressedSize; \\
Int [2] Unkown; // DXT compression again?// \\
Int [4] Unkown; \\

The first mipmap of each texture is compressed using lzo1x and the rest are uncompressed. \\
=== Mesh Sub-header: ===
Dword Physics_Mesh; \\
Float [10]; //matches first 40 bytes of bbm. possibly origin// \\
Dword Number_LOD's; \\
Dword [Number_LOD's] Size_compressed_LOD; \\
Dword padding; \\
Dword Number_Textures_Assigned; // 1 per surface within model// \\
Dword [Number_Textures_Assigned] Texture_ID; //Texture ID as used in the textures.big// \\