aspireai.
PUBLIC EDITION

Mundo turns a few photos of a room into a world you can walk through, edit and simulate

AspireAI community · Hugging Face (Luo-Yihang, Chen Change Loy)
*A few photos became a room you can open a drawer in.* Mundo, by Yihang Luo and Chen Change Loy, rebuilds a place as an explicit 3D proxy of bounding boxes plus a code scene program, then runs it in MuJoCo so objects collide under gravity. A vision-language agent refines the boxes by rendering the proxy and comparing it against the input photos, and a video diffusion model renders the simulation back out as video. The payoff is real-to-sim robotics and controllable video: move a camera through the room, open a drawer, send a robot in to put a bag on the bed. The renderer was fine-tuned from MiniMax-H3's Ref2VA on about 40k paired videos. Caveat: it is slow. Reconstruction takes ten to twenty minutes, rendering runs at roughly 1.5 frames per second on eight A800 GPUs, small objects tend to float, and there is no long-horizon memory yet. https://huggingface.co/blog/Luo-Yihang/mundo-world-model
Read the story and explore more from the AspireAI community.
Discover more stories
Stay curious.
THE BIG PICTURE
A FRESH PERSPECTIVE
Research
One distance function matched sparse-autoencoder features across layers and compressed feature circuits into supernodes
Two sparse-autoencoder analyses have resisted scaling: matching semantically similar features across layers, and compressing large feature circuits into interpretable supernodes. This paper argues both are the same underlying problem, estimating semantic distances between SAE features that sit on different activation manifolds. Its representation treats each feature not as a single decoder vector but as an activation-weighted distribution over the hidden states expressing it, projects those distributions into a shared reference space, and compares them with Wasserstein distance. The representation is proved invariant to activation rescaling and stable under perturbation, and recovers true matches under finite-sample margin conditions. Empirically it outperformed decoder-vector and LLM-based baselines and captured subtle functional distinctions between related features, and it compressed large feature circuits into interpretable supernodes automatically. The limitation is that this is interpretability tooling: the paper demonstrates better feature matching and circuit compression, not that downstream interpretability claims become more accurate.
Swipe into something new
01 / 1729
The conversation continues
Explore Builds — projects by Kiran Adimatyam ↗
A fresh perspective changes everything.
ASPIREAI — STAY CURIOUS.