One big prompt: Fable 5.1 Ultracode builds interactive neutron star merger sim
This_Cell_1829 · reddit · 2026-09-03
A Redditor gave Fable 5.1 Ultracode one big prompt to build an interactive neutron star merger simulation. The result includes multiple matter models, merger outcomes, ejecta, kilonova effects, controls, sound, and cameras, with a full settings UI.
The funny part: the model didn't know when to stop — near the end the author had to tell it to quit polishing and ship. The video shows the actual preview build.
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