SwiftGLTF

A project that enables using glTF files in Swift.

Features

• Decodes glTF and GLB files and makes them available as MDLAsset in Swift
• High-performance glTF rendering with Metal

Planned Features

• glTF animation support
• glTF extension support
• Customizable rendering pipeline
• 3D model editing and exporting features
• VRM format support
  And more.

Usage

Platform

• iOS 15.0+
• macOS 13.0+

Installation

Swift Package Manager

dependencies: [
    .package(url: "https://github.com/nhiroyasu/SwiftGLTF.git", branch: "main")
]

Sample Code

UIKit

import SwiftGLTF

let gltfUrl = // URL to your glTF or GLB file
let gltfView = GLTFView(frame: view.frame, url: gltfUrl)
view.addSubview(gltfView)

SwiftUI

import SwiftGLTF

var body: some View {
    @State private var gltfUrl = // URL to your glTF or GLB file
    GLTFMetalView(url: gltfUrl)
}

Supported glTF Features

• Unsupported features are planned to be added in future updates.

File Formats

Format	Supported
glTF Binary (.glb)	✅
glTF JSON (.gltf)	✅

Buffer Formats

Format	Supported
External .bin file	✅
Embedded (data URI in .gltf)	✅

Image Formats

Format	Supported
PNG	✅
JPEG	✅
KTX2	❌

Mesh Compression

Extension	Supported
KHR_draco_mesh_compression	❌

PBR Materials (metallic-roughness)

Property	Supported
baseColorFactor	✅
baseColorTexture	✅
metallicFactor	✅
roughnessFactor	✅
metallicRoughnessTexture	✅

Additional Material Properties

Property	Supported
normalTexture	✅
occlusionTexture	✅
emissiveTexture	✅
emissiveFactor	✅
alphaMode	✅
alphaCutoff	✅
doubleSided	❌

Vertex Attributes

Attribute	Supported
POSITION	✅
NORMAL	✅
TANGENT	✅
TEXCOORD_0	✅
TEXCOORD_1	✅
COLOR_0	✅
JOINTS_0	❌
WEIGHTS_0	❌

Node Hierarchy and Transforms

Feature	Supported
Node hierarchy	✅
matrix (4x4 transform matrix)	✅
translation / rotation / scale (TRS)	✅

Animation

Channel	Supported
translation	❌
rotation	❌
scale	❌
morph target weights	❌

Scenes

Feature	Supported
Multiple scenes	❌

Cameras

Feature	Supported
Camera	❌

Build

Sample Project

• You can build the sample project by opening SwiftGLTFSample.xcodeproj.

Project Structure

SwiftGLTFRenderer

• A library for rendering glTF files using Metal.

SwiftGLTFParser

• A library that parses glTF and converts it into MDLAsset for use in Swift.

SwiftGLTF

• Provides GLTFView and GLTFMetalView components to display glTF files in UIKit and SwiftUI views.

SwiftGLTFCore

• A library that defines the core data structures of glTF.

MikkTSpace

• Performs normal vector computation for glTF
• Based on mmikk/MikkTSpace