What is the CPY file format?
The .cpy file is a Character Studio copy track file used by Autodesk 3ds Max. It stores biped animation data - postures, gestures, or full motion tracks - copied via the Copy/Paste rollout in the Character Studio Motion panel. This allows animators to capture a pose or motion sequence from one biped rig and paste it onto another, either within the same scene or across different projects.
Character Studio was originally a plug-in for 3ds Max before being integrated directly into the software starting with 3ds Max 4 (released in 2000). The .cpy format is a proprietary binary file specific to Autodesk's biped animation system and is not interchangeable with general animation formats such as .bip (the biped motion file) or .fbx.
.cpy files can hold three types of data: a posture (single static pose), a gesture (short motion clip), or track data spanning a full animation range. They are created and consumed exclusively within 3ds Max via the Motion panel → Copy/Paste rollout. No third-party tools support the format, and no official binary specification has been published. A .cpy file saved in a newer version of 3ds Max may not load correctly in significantly older versions.
Security & safety
RISK: LOWBinary data file with no executable code or macro capability. Safe to receive from colleagues.
Format details
in a nutshell- COBOL Copybook - Industry-standard plain-text (.cpy) file defining COBOL record layouts; widely used in mainframe and enterprise data integration (SAP, MuleSoft, etc.) - completely unrelated to 3D.
- eCopy Desktop scanned document - Proprietary scanned-document format from eCopy (Nuance/Kofax); the db_name in the source database is incorrect for this extension's dominant use.
Programs that open CPY files
Windows1 app
Autodesk 3ds Max
Paid Open Motion panel → Biped rollout → Copy/Paste rollout → click Paste Posture / Paste Track and point to the CPY file. Technical details
deep spec| File encoding | Binary (proprietary Autodesk format) |
| Byte order | Little-endian (consistent with 3ds Max native file formats) |
| Platform | Windows only (3ds Max is a Windows-only application) |
| Created by | 3ds Max Motion panel → Copy/Paste rollout → Save Posture / Save Track buttons |
| Stored data types | Posture (single static pose), Gesture (short motion clip), or Track (full animation range) |
| Rig compatibility | Specific to Character Studio Biped system; not compatible with CAT rigs or Bone-based rigs |
| Companion formats | `.bip` (biped motion sequence), `.fig` (biped figure file) |
| Version compatibility | Files from newer 3ds Max versions may not load in significantly older versions; no cross-version guarantee |
| Interoperability | Not directly convertible to standard animation formats such as `.fbx` or BVH |
| Typical file size | 1 KB - 50 KB |
| MIME type | application/octet-stream (no dedicated MIME registered) |
| Magic bytes | None publicly documented |
| Compression / encryption | Unknown; likely none or minimal |
| Released | late 1990s (Character Studio for 3ds Max) |
| Latest version | 3ds Max 2026 |
| Specification | knowledge.autodesk.com |
CPY conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about CPY files.
