raytracingiin

Raytracingiin is a cross-platform, open-source framework for ray tracing designed to be accessible to researchers and developers. It provides a modular pipeline for generating images by tracing rays through scenes, supporting both path tracing for global illumination and conventional ray tracing for reflections and shadows. The project emphasizes readability and portability, with a reference implementation in C++ and optional back ends for CUDA, Vulkan, and DirectX Raytracing (DXR).

Origins and development: The project began as an educational effort in the early 2020s by a collaboration of academics and enthusiasts to demonstrate how sampling strategies and acceleration structures affect image quality and performance. It is maintained by an open contributor community.

Architecture: Raytracingiin organizes rendering into scene representation, ray generation, intersection, shading, and post-processing. It uses a BVH for fast intersections and supports instancing, motion blur, area lights, and textures. A denoising pass reduces noise at low sample counts, using either learned models or traditional filters.

Algorithms and features: Supports stochastic sampling, next event estimation, multiple importance sampling, and both unidirectional and bidirectional path tracing. It includes a simple physically based BRDF model, transparent materials, and participating media. Renderers can switch between CPU and GPU backends.

Impact and reception: Used in teaching, research, and small-scale production. Its readable codebase and tests make it a common starting point for ray tracing concepts, particularly acceleration structures and denoising techniques.

See also: ray tracing, path tracing, BVH, denoising, real-time rendering.