Claude Opus 5.5 builds a GPU-accelerated path tracer in one hour

A Reddit user used Anthropic's Claude Opus 5.5 model to generate a real-time hardware-accelerated path tracer from scratch in about one hour. A path tracer is a 3D renderer that simulates light propagation by tracing many rays and calculating how they interact with surfaces.

The program can write C++ and CUDA code and uses NVIDIA OptiX 9.1 to directly call modern GPU RT cores and Tensor cores. The user submitted just one initial prompt asking for a ray tracing demo accelerated by NVIDIA CUDA RTX and Blackwell kernels, using two RTX 5090 GPUs.

The renderer uses a dual-GPU frame-split multi-adapter pipeline that dynamically distributes image rows based on real-time load, reaching 34 FPS and processing 267 million ray samples per second. The algorithm combines Shader Execution Reordering, Next-Event Estimation and Multiple Importance Sampling to handle lighting distribution and soft shadows.