metal-cpp-sample

Render pipeline sample in C++20, using Apple's Metal API. The program loads a glTF model and renders it with a perspective camera, depth testing, PBR-inspired lighting and procedural bump mapping.

glTF scene (--scene=gltf)	Minimal scene (--scene=minimal)

Features

• glTF: 2.0 via fastgltf (mesh, normals, material factors)
• Camera: perspective, framed from the model's bounding sphere
• Frames in flight: triple-buffered uniforms, semaphore paced
• Lighting: Lambert diffuse, Blinn-Phong specular, Fresnel and procedural environment reflection
• Bump mapping: procedural noise, surface gradient method, no UVs
• Rendering: depth buffer, 4x MSAA (switchable with --msaa)
• Animation: frame-delta turntable rotation with bounded tilt

Build and run

Requires Apple Clang (GCC / MSVC are not supported), Xcode w/ Metal toolchain, and CMake 3.26+. Tested on macOS 27.0, CMake 4.4.3 and Ninja.

git clone --recursive https://github.com/blakesimpson-dev/metal-cpp-sample.git
cd metal-cpp-sample
cmake -S . -B build -G Ninja
cmake --build build
./build/metal-cpp-sample [--scene=gltf|minimal] [--msaa=on|off]

Download

Alternatively, you may download the sample. Run the following on your machine after unzipping (Gatekeeper can be problematic):

xattr -dr com.apple.quarantine metal-cpp-sample-v1.0.0-macos-arm64

Layout

Path	Contents
src/app	Application and view delegates
src/renderer	Metal renderer, camera, math and Metal helpers
src/scenes	Scene interface, glTF loader, glTF and minimal scenes
src/shaders	Metal shaders, types shared with C++
src/platform	Executable path, metal-cpp ownership helpers
assets	glTF model (see Credits)
docs	README images
external	Dependencies

Dependencies

Dependency	Version	Licence
metal-cpp	macOS27_iOS27 release	Apache-2.0
metal-cpp-extensions	from Apple's LearnMetalCPP	Apache-2.0
fastgltf	v0.9.0	MIT
simdjson	v3.12.3	Apache-2.0

Credits

Model: "Exalted Orb" by justingulenchyn (CC-BY-4.0). The application code is my own (MIT, see LICENSE); an LLM was used for explanations, code review and tooling configuration.

References

• Apple: metal-cpp, "Learn Metal with C++" samples, Metal Best Practices (Triple Buffering, Buffer Bindings)
• glTF: fastgltf, glTF 2.0 specification
• LearnOpenGL: Camera, Basic Lighting, Advanced Lighting
• Bump mapping: Mikkelsen, "Bump Mapping Unparametrized Surfaces on the GPU", three.js bumpmap_pars_fragment, The Book of Shaders: Noise
• Triple Buffering
• Buffer Bindings
• C++: Google C++ Style Guide, learncpp.com