Claude Opus 5 just auto-generated a 3D game from one text prompt
andrej karpathy used claude opus 5 to turn a 'lord of the rings' paragraph into a playable 3d browser scene for $10, proving models can now write complex code autonomously.
anthropic researcher andrej karpathy tested claude opus 5's capabilities by having it transform a 'lord of the rings' paragraph into a 3d browser scene, generating 5,500 lines of code over two hours with a budget of 1 million tokens ($10). the model used three.js for rendering and demonstrated autonomous object placement and animation, though it struggled to verify visual output because it could only interpret screenshots rather than video. karpathy compares this to previous 'pelican' and 'unicorn' tests, arguing that while these lack scientific rigor, they signal a shift toward on-demand, generative game development where users can inhabit custom worlds for near-zero cost.