I have here documented the "VRM" file format Valve was working on back when TF2 was subtitled "Brotherhood of Arms". My documentation can be found in the valve-vrm-docs.md file in this repo.
I have tested the included Python script on the only VRM I know to exist, which is in the 2023 Gigaleak with the path hl2/models/Weapons/V_physcannon/Older/TESTreference.vRM.
External info on the format:
- VRM on VDC (I have added my documentation to this article AFTER having documented it in this repo)
- An article about VRM on ValveArchive