Show HN: Turn a text prompt into an interactive world, with just one A100

Demo Link: https://www.youtube.com/watch?v=rMBfE1ugpPw Twitter Post: https://x.com/_mattqlf/status/2020679489798255080?s=20

Hi, I'm Matthew, a freshman from CMU, and I built Ephemeral in 24 hours for TartanHacks 2026.

In short, Ephemeral takes a text prompt, generates an image with Nano Banana and uses a 1.3B parameter action-conditioned DiT to generate the next frames in realtime based on user actions (e.g. WASD).

Some other features - Reverse engineered Suno Client to generate music based off text prompt. - Multiple users can interact with a "world" at the same time simply by scanning a QR code from their phone. They can then perform actions and see how their worlds evolve in parallel with everyone elses. GPU infrastructure powered by Modal. - Claude auto generates captions for the world