themartiano/luz — reverse-engineered prompt

Build me a standalone C++20 path tracing renderer from scratch with no third party libraries. I want it to render realistic scenes on the CPU with global illumination, multithreading, and BVH acceleration so it is actually usable, not just a toy demo.

It should load simple custom scene files, support common shapes like spheres, planes, rectangles, cubes, triangles, volumes, and OBJ meshes, and have practical materials and lights. Please include quality features like adaptive sampling, denoising, depth of field, antialiasing, environment maps, tone mapping, bloom, and atmospheric scattering for fog and light shafts.

Make it easy to run from the command line so I can choose the scene, resolution, samples, threads, output file, and toggle things like denoising or adaptive sampling. I would also like a few bundled example scenes, tests, and a basic benchmark mode so I can compare performance changes. If possible, add a simple Blender export workflow that converts a blend scene into the custom scene format. It should build cleanly on Mac, Linux, and Windows. Look up current docs online if you need to.