rednoise 0.2.1

Python ctypes bindings for the RedNoise CPU software renderer, with the native library bundled.

RedNoise Python bindings

Python ctypes bindings for the RedNoise CPU software renderer. They call the stable C ABI declared in include/rednoise/rednoise.h. There is no compiled extension module: the bindings load the RedNoise shared library at runtime. The native library is built and bundled into the package, so a normal install is self-contained.

Install

pip install rednoise

Prebuilt wheels ship the native library, so on a supported platform this is all you need. Installing from an sdist compiles the native library on your machine via CMake, so you need a C++23-capable compiler (GCC 12+, Clang 15+, or MSVC 2022+) and CMake 3.24 or newer. The build uses the vendored glm in third_party/ and runs fully offline; it does not fetch SDL3 or any other optional dependency.

Under the hood, pip install drives scikit-build-core and CMake to build only the installable rednoise library (-DBUILD_LIB=ON, everything else off) and installs the resulting shared library into the importable rednoise/ package:

• Linux: librednoise.so
• macOS: librednoise.dylib
• Windows: rednoise.dll

Pillow is optional and only needed for Image.to_pillow() or saving non-PNG formats:

pip install "rednoise[pillow]"

Library discovery

The bundled library is found automatically. For development against a separately built library, the bindings locate it in this order:

1. The library bundled next to the package (what a wheel installs).
2. The REDNOISE_LIBRARY environment variable (an explicit path to the file).
3. The system search path (ctypes.util.find_library("rednoise")).
4. Common local build paths (build/, next to the package, and similar).

To override with a locally built library, set REDNOISE_LIBRARY:

# Linux
export REDNOISE_LIBRARY="$PWD/build/librednoise.so"

# macOS
export REDNOISE_LIBRARY="$PWD/build/librednoise.dylib"

# Windows (cmd)
set REDNOISE_LIBRARY=%CD%\build\rednoise.dll

Develop from a local checkout

Install the bindings straight from this directory:

pip install ./bindings/python

Add the Pillow extra with:

pip install "./bindings/python[pillow]"

You can still build the shared library by hand from the repository root and point REDNOISE_LIBRARY at it:

cmake -B build -S . -DBUILD_LIB=ON -DBUILD_APP=OFF
cmake --build build

Usage

import rednoise

print(rednoise.version())

with rednoise.Scene.load_obj("assets/cornell-box.obj") as scene:
    print("triangles:", scene.triangle_count)
    image = scene.render(mode="pathtraced", width=400, height=300, samples=64)
    image.save("cornell.png")

Scene.render accepts a render mode as a RenderMode enum, an integer, or a name string: "wireframe", "rasterised", "raytraced", or "pathtraced". The returned Image exposes .rgba (raw RGBA8 bytes), .size, .save(path), and .to_pillow() when Pillow is installed.

A complete runnable example lives in example.py. Run it from the repository root (after building the library and setting REDNOISE_LIBRARY):

python bindings/python/example.py