Build a real-time WebGPU ocean renderer from scratch

GitHub user Noniv gave Claude Code, running Opus 5.5, a one-line brief: the most realistic water it could produce in WebGPU, with a free-flying camera, and no engine or rendering library. The architecture and the implementation were left to the agent. To check its own output, it rendered screenshots in headless Chrome and handed them to separate critic subagents for review, so the code writer was not also the judge. Noniv stepped in with feedback along the way, mostly about how the clouds looked.

The result is an open-source renderer with a six-cascade FFT wave simulation, a quadtree surface mesh reaching 160 km, whitecaps that drift and streak, a physically based sunset sky with two cloud layers, bloom and tone mapping. The author measured 6 to 8 ms of GPU time per frame at 2560 by 1440 on an RTX 5070 Ti. The volumetric clouds were dropped for flat layers after feedback, and their edge aliasing was fixed later. Open issues listed: far water reads too dark, no shoreline or objects, clouds are not volumetric.

It needs a recent Chrome with WebGPU and a capable GPU; laptops may fall back to the integrated GPU. The README says little about how long the build took or how many sessions it ran. The critic-subagent loop on rendered screenshots is the part worth copying for any visual work.