zgltf

Zig library for the glTF 2.0 standard.

Goal: full Core glTF 2.0 feature coverage.

Example Project

NOTE: This example project was created with the help of Claude Code.

zgltf-vulkan glTF 2.0 viewer in Zig + Vulkan using this library. Demonstrates .gltf / .glb loading, PBR metallic-roughness, skinning, animations, and KHR extensions (materials_specular, sheen, iridescence, anisotropy, transmission, volume, lights_punctual).

Feature Checklist

Container Formats

• .gltf (JSON)
• .glb (binary container)
• External buffer / image files
• Embedded base64 data URIs

Asset

• version
• minVersion
• generator
• copyright

Scenes & Nodes

• Scenes
• Default scene
• Node hierarchy
• Node transforms — matrix
• Node transforms — TRS (translation / rotation / scale)

Buffers / Buffer Views / Accessors

• Buffers
• Buffer views (with byteStride)
• Accessors — all component types (BYTE, UNSIGNED_BYTE, SHORT, UNSIGNED_SHORT, UNSIGNED_INT, FLOAT)
• Accessors — all element types (SCALAR, VEC2, VEC3, VEC4, MAT2, MAT3, MAT4)
• Accessors — normalized
• Accessors — min / max
• Sparse accessors

Meshes

• Mesh primitives
• Attribute POSITION
• Attribute NORMAL
• Attribute TANGENT
• Attribute TEXCOORD_0 / TEXCOORD_1
• Attribute COLOR_0
• Attribute JOINTS_0
• Attribute WEIGHTS_0
• Indexed primitives
• Primitive mode POINTS
• Primitive mode LINES
• Primitive mode LINE_LOOP
• Primitive mode LINE_STRIP
• Primitive mode TRIANGLES
• Primitive mode TRIANGLE_STRIP
• Primitive mode TRIANGLE_FAN
• Morph targets
• Morph target weights

Materials (PBR Metallic-Roughness)

• baseColorFactor
• baseColorTexture
• metallicFactor / roughnessFactor
• metallicRoughnessTexture
• normalTexture (with scale)
• occlusionTexture (with strength)
• emissiveFactor
• emissiveTexture
• Alpha mode OPAQUE
• Alpha mode MASK (with alphaCutoff)
• Alpha mode BLEND
• doubleSided

Textures / Samplers / Images

• Textures
• Samplers — mag / min filter
• Samplers — wrap S / T
• Images — URI
• Images — buffer view + mimeType
• PNG decode (via pluggable ImageDecoder; reference backend in examples/image_stb)
• JPEG decode (via pluggable ImageDecoder; reference backend in examples/image_stb)

Cameras

• Perspective
• Orthographic

Skins & Animation

• Skins (joints, inverseBindMatrices)
• Animation channels
• Animation samplers
• Interpolation LINEAR
• Interpolation STEP
• Interpolation CUBICSPLINE
• Target path translation
• Target path rotation
• Target path scale
• Target path weights

Extensibility

• extensionsUsed
• extensionsRequired
• extensions passthrough
• extras passthrough
• Typed extension access via getTypedExtension(comptime T, ...)
• Optional zgltf_khr submodule with typed structs for all Khronos-ratified extensions: KHR_lights_punctual, KHR_materials_unlit/clearcoat/emissive_strength/ior/transmission/volume/specular/sheen/anisotropy/iridescence/dispersion/variants, KHR_texture_transform/basisu, KHR_draco_mesh_compression, KHR_mesh_quantization, KHR_xmp_json_ld, KHR_animation_pointer

Validation

• JSON schema conformance (required fields, non-empty arrays, camera-block match, min/max length)
• Reference resolution checks
• Accessor bounds checks