Awesome

A proof-of-concept of an extensible 3D asset interchange format

After almost two years, I have put into this everything I can.

This project is at a point where I'm pretty confident about the container-format and the core concept.

At this point a lot more people than just me would have to have a go at it, people with different use cases and experiences, to get this somewhere.

If you are looking to extend your 3D assets right now, I've started working on NNA - Node Name Abuse.
It is an extension system for any 3D format, primarily FBX.

Original Readme:

For Unity 2022.3 or higher.

! Do Not Use Productively !

STF - Scene Transfer Format

STF is an extensible interchange & authoring format for 3d assets.
It is a binary format consisting of a definition in JSON and a bunch of binary buffers.

Video Showcase (~1 Minute)

MTF - Material Transfer Format

MTF is a shader & game engine agnostic material system used by STF.

Video Showcase (~1 Minute)

AVA - Components For VR & V-Tubing Avatars

AVA is a proof-of-concept set of extensions for STF, which support VR & V-tubing avatar components.

How to Use

Create a Unity 2022.3 or higher Project.
Ensure you have the Newtonsoft JSON package imported in Unity. If you set up your Unity project with the VRC Creator Companion, it will be already imported. If not, install the official package in UPM.
Import the all-in-one .unitypackage from the latest release.
Play around!

Find an example model here!

Screenshot of an STF file's inspector in Unity. Screenshot of an STF model with its authoring components shown in the Unity inspector.

Why

I am in need of an open & extensible interchange format for 3d assets.

Unfortunately, such a format does not exist.

fbx is the next best thing, being the most widely supported and able to store the most of my models. However, it is proprietary, undocumented and not extensible. Some open source implementations are unfortunately faulty. Blender for example won't export animation curves, baking animations instead and making them useless for further editing. The paid Better FBX Importer & Exporter addon for Blender does the job.

glTF 2.0 was originally designed as a distribution format, intended to be easily loaded into GPU memory. Some projects are trying to use it as an authoring/interchange format. Apparently this is a matter of a somewhat active debate. After trying to work with glTF 2.0 in this manner and analyzing its spec I don't think it can work for interchange/authoring. Read in detail why here!

My core requirements for an open & extensible 3d interchange format are:

Extensions must be hot loadable and trivial to implement, enabling the rapid prototyping of extensions.
Between import and export, the file can not change (except for some metadata perhaps). If an extension is not supported, it and all of its dependencies must be preserved and re-exported, unless manually removed by the author.
Everything must be addressed by a unique ID. This makes third party addons for a base model more robust for example.
Materials must be arbitrary and shader agnostic.