UTF (Universal Tree Format)

Overview

Container file format used to store various assets in Freelancers. Little-endian byte order.

Freelancer uses UTF in these type of files:

• .utf (audio library, etc)
• .ale (particle effects library)
• .vms (rigid mesh buffer library)
• .3db (single-part rigid model)
• .cmp (compound rigid model)
• .dfm (compound deformable model)
• .sph (simple sphere model)
• .txm (texture library)
• .mat (material library)

Header

File begins with header block which is always 56 bytes.

Name	Type	Description
signature	uint32	Magic bytes, string reads as "UTF ".
version	uint32	Always 0x101.
treeOffset	uint32	Absolute byte offset to tree block.
treeSize	uint32	Tree byte size.
unusedEntryOffset	uint32	Usually is 0.
entrySize	uint32	Entry byte size is always 44. Freelancer will crash otherwise.
namesOffset	uint32	Absolute byte offset to dictionary block.
namesSizeAllocated	uint32	Dictionary byte size allocated.
namesSizeUsed	uint32	Dictionary used byte size. Must be equal or less than namesSizeAllocated.
dataOffset	uint32	Absolute byte offset to data block.
unusedOffset	uint32	Absolute byte offset to extra data (unused).
unusedSize	uint32	Extra data byte size (unused).
filetime	uint64	Windows 64-bit FILETIME.

• Header is usually followed by entries but not always, some files have dictionary before entries.
• Dictionary is a concatenated collection of ASCIIz strings (NUL-terminated ASCII strings).
• Dictionary reserves first string as empty (i.e. first byte in dictionary block is 0x0). Entries with zero length name are ignored.

Entry

Each entry in tree block is 44 bytes.

Name	Type	Description
nextOffset	uint32	Offset to next sibling in tree block.
nameOffset	uint32	Offset to entry name in dictionary block.
attributes	uint32	File system attributes.
sharingAttributes	uint32	File system sharing attributes (unused).
childOffset	uint32	Either offset to first child or to entry data.
dataSizeAllocated	uint32	Allocated data byte length.
dataSizeUsed	uint32	Actual used data byte length.
dataSizeUncompressed	uint32	Uncompressed data byte length (unused).
createTime	uint32	File creation timestamp.
accessTime	uint32	File last access timestamp.
modifyTime	uint32	File last modification timestamp.

• Tree root entry name should be "/", but other names are possible.
• For attributes see Win32 API dwFileAttributes. In short it should be either 0x80 for file or 0x10 for folder. It is not necessary, however, that all three bytes after the first here are zero, and, in fact, in some vanilla files, they are not.
• When entry is a folder the childOffset points to first child byte offset, relative to treeOffset in header, and dataSize* are all zeroes.
• When entry is a file the childOffset points to data block, relative to dataOffset in header, and dataSize* indicate file size.
• Timestamps are DOS file timestamp, see: https://blogs.msdn.microsoft.com/oldnewthing/20030905-02/?p=42653