gltf

A Go package for simple, efficient, and robust serialization/deserialization of glTF 2.0 (GL Transmission Format), a royalty-free specification for the efficient transmission and loading of 3D scenes and models by applications.

Features

• High parsing time and moderate memory consumption.
• glTF specification v2.0.0
  • ASCII glTF.
  • Binary glTF(GLB).
  • PBR material description.
• glTF validaton
  • Validate against schemas.
  • Validate coherence.
• Buffers
  • Parse BASE64 encoded embedded buffer data(DataURI).
  • Load .bin file.
• Read from io.Reader
  • Boilerplate for disk loading.
  • Custom callback handlers.
  • Automatic ASCII / glTF detection.
• Write to io.Writer
  • Boilerplate for disk saving.
  • Custom callback handlers.
  • ASCII / Binary
• Extensions
  • KHR_draco_mesh_compression
  • KHR_lights_punctual
  • KHR_materials_pbrSpecularGlossiness
  • KHR_materials_unlit
  • KHR_techniques_webgl
  • KHR_texture_transform

Perfomance

All the functionality is benchmarked and tested using the official glTF Samples in the utility package qmuntal/gltf-bench. The results show that the perfomance of this package is equivalent to fx-gltf, a reference perfomance-driven glTF implementation for C++, .

Examples

Read

doc, err := gltf.Open("./a.gltf")
if err != nil {
  panic(err)
}
fmt.Print(doc.Asset)

Write

doc := &gltf.Document{
  Scene: 0, 
  Asset: gltf.Asset{Generator: "qmuntal/gltf"}, 
  Scenes: []gltf.Scene{{Extras: 8.0, Extensions: gltf.Extensions{"a": "b"}, Name: "s_1"}}
}
 
if err := gltf.Save(doc, "./a.gltf", true); err != nil {
  panic(err)
}

Write complex

doc := &gltf.Document{
  Accessors: []gltf.Accessor{
    {BufferView: 0, ByteOffset: 0, ComponentType: gltf.UnsignedShort, Count: 36, Type: gltf.Scalar},
    {BufferView: 1, ByteOffset: 0, ComponentType: gltf.Float, Count: 24, Max: []float64{0.5, 0.5, 0.5}, Min: []float64{-0.5, -0.5, -0.5}, Type: gltf.Vec3},
    {BufferView: 2, ByteOffset: 0, ComponentType: gltf.Float, Count: 24, Type: gltf.Vec3},
    {BufferView: 3, ByteOffset: 0, ComponentType: gltf.Float, Count: 24, Type: gltf.Vec4},
    {BufferView: 4, ByteOffset: 0, ComponentType: gltf.Float, Count: 24, Type: gltf.Vec2},
  },
  Asset: gltf.Asset{Version: "2.0", Generator: "FBX2glTF"},
  BufferViews: []gltf.BufferView{
    {Buffer: 0, ByteLength: 72, ByteOffset: 0, Target: gltf.ElementArrayBuffer},
    {Buffer: 0, ByteLength: 288, ByteOffset: 72, Target: gltf.ArrayBuffer},
    {Buffer: 0, ByteLength: 288, ByteOffset: 360, Target: gltf.ArrayBuffer},
    {Buffer: 0, ByteLength: 384, ByteOffset: 648, Target: gltf.ArrayBuffer},
    {Buffer: 0, ByteLength: 192, ByteOffset: 1032, Target: gltf.ArrayBuffer},
  },
  Buffers: []gltf.Buffer{{ByteLength: 1224, Data: readFile("testdata/BoxVertexColors/glTF-Binary/BoxVertexColors.glb")[1628+20+8:]}},
  Materials: []gltf.Material{{Name: "Default", AlphaMode: gltf.Opaque, AlphaCutoff: 0.5, 
    PBRMetallicRoughness: &gltf.PBRMetallicRoughness{BaseColorFactor: [4]float64{0.8, 0.8, 0.8, 1}, MetallicFactor: 0.1, RoughnessFactor: 0.99}}
  },
  Meshes: []gltf.Mesh{{Name: "Cube", Primitives: []gltf.Primitive{{Indices: 0, Material: 0, Mode: gltf.Triangles, Attributes: map[string]uint32{"POSITION": 1, "COLOR_0": 3, "NORMAL": 2, "TEXCOORD_0": 4}}}}},
  Nodes: []gltf.Node{
    {Name: "RootNode", Mesh: -1, Camera: -1, Skin: -1, Children: []uint32{1, 2, 3}, Matrix: [16]float64{1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1}, Rotation: [4]float64{0, 0, 0, 1}, Scale: [3]float64{1, 1, 1}},
    {Name: "Mesh", Mesh: -1, Camera: -1, Skin: -1, Matrix: [16]float64{1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1}, Rotation: [4]float64{0, 0, 0, 1}, Scale: [3]float64{1, 1, 1}},
    {Name: "Cube", Mesh: 0, Camera: -1, Skin: -1, Matrix: [16]float64{1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1}, Rotation: [4]float64{0, 0, 0, 1}, Scale: [3]float64{1, 1, 1}},
    {Name: "Texture Group", Mesh: -1, Camera: -1, Skin: -1, Matrix: [16]float64{1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1}, Rotation: [4]float64{0, 0, 0, 1}, Scale: [3]float64{1, 1, 1}},
  },
  Samplers: []gltf.Sampler{{WrapS: gltf.Repeat, WrapT: gltf.Repeat}},
  Scene: 0,
  Scenes: []gltf.Scene{{Name: "Root Scene", Nodes: []uint32{0}}},
}
if err := gltf.Save(doc, "./a.gltf", true); err != nil {
  panic(err)
}