Claude Opus 5.5 Ports Three.js 3D Scene to Vanilla WebGL
Developer Simon Willison used Claude Opus 5.5 in a standard chat session to port a Three.js 3D scene into dependency-free vanilla JavaScript and WebGL, with both versions rendering successfully. It is an anecdotal hands-on demo showing the model can rewrite 3D graphics code across libraries, but offers no quantitative benchmark or reproducible methodology.
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My comment on The Web Is More Than Enough, by Paul Ford — Hacker News.
OK, this comment convinced me to give that a shot.
Here's a thing I made in Three.js this morning - a Nudibranch themed Faberge Egg: https://static.simonwillison.net/static/2026/Hidden-Reef-Egg... (77KB)
I just asked Claude (Opus 5.5 Medium running in regular Claude Chat) to port that to Vanilla JS, in the same thread where it had built it, and got this: https://static.simonwillison.net/static/2026/Hidden-Reef-Egg... (98KB)
They aren't identical - you can see what Claude said about that in the transcript (I don't fully understand why it differed): https://claude.ai/share/e56d163e-2793-4677-aa11-191d5058b414
But yeah, it turns out Claude Opus 5.5 is perfectly capable of 3D modeling in Vanilla JS + WebGL without Three.js.
In eyeballing the code I find the Three.js slightly easier to understand myself, but I rarely look at the code for these 3D projects so that isn't a particularly big deal.
Tags: hacker-news, javascript, ai, generative-ai, llms, claude, three-js