gltforge

Spec-compliant, extension-first glTF 2.0 for Rust

gltforge is a glTF 2.0 toolkit built around a single principle: extensions are first-class citizens, not afterthoughts. Every intermediate stage of parsing, validation, and processing is owned by the caller — nothing is hidden.

• Extension-first — typed extension registration, import and export treated equally
• Open by design — every intermediate representation is public and caller-owned
• Cross-platform — native dylib (Windows, macOS, Linux, iOS, Android), WASM, PyO3 (Blender)
• Spec-compliant — extensionsRequired enforced as hard errors, not warnings

Workspace

Usage

[dependencies]

gltforge = "0.0.3"

use std::path::Path;
use gltforge::parser;
use gltforge::schema::Gltf;

// Parse a .gltf file
let json = std::fs::read_to_string("model.gltf")?;
let gltf: Gltf = parser::parse(&json)?;

// Load external binary buffers
let buffers = parser::load_buffers(&gltf, Path::new("."))?;

// Resolve an accessor to raw bytes
let accessors = gltf.accessors.as_deref().unwrap_or(&[]);
let buffer_views = gltf.buffer_views.as_deref().unwrap_or(&[]);
let bytes = parser::resolve_accessor(&accessors[0], buffer_views, &buffers)?;

CLI

cargo install gltforge-cli


gltforge inspect model.gltf

gltforge inspect model.gltf --mesh

glTF 2.0
scenes:      1
nodes:       1
meshes:      1
accessors:   2
buffer views:2
buffers:     1

mesh 0: Triangle
  primitive 0  [TRIANGLES]
    indices:  accessor 0   SCALAR  UNSIGNED_SHORT  3
    POSITION  accessor 1   VEC3    FLOAT           3

Unity

gltforge-unity compiles to a native plugin (gltforge_unity.dll) and exposes a P/Invoke API. Drop the DLL into Assets/Plugins/x86_64/ and import meshes at runtime:

var handle = GltforgeNative.gltforge_load_mesh(path, nodeIndex);

uint posLen;
float[] pos = new float[posLen];
Marshal.Copy(GltforgeNative.gltforge_mesh_positions(handle, out posLen), pos, 0, (int)posLen);

uint submeshCount = GltforgeNative.gltforge_mesh_submesh_count(handle);
// ... SetTriangles per submesh

GltforgeNative.gltforge_mesh_release(handle);

Coordinates are converted from glTF's right-handed system to Unity's left-handed system (X negated, winding reversed). Index format (UInt16/UInt32) is selected automatically based on vertex count.

Roadmap

• glTF 2.0 schema types
• JSON parser + buffer loading
• Accessor resolution
• CLI inspector
• Unity P/Invoke bindings (positions, indices, submeshes, names)
• Node transforms (translation, rotation, scale)
• Normals, UVs, tangents
• Scene graph traversal
• GLB binary chunk handling
• Extension registry + typed dispatch
• KHR_draco_mesh_compression
• EXT_meshopt_compression
• PyO3 / Blender addon
• WASM bindings

License

MIT — see LICENSE