3D models are built from compact codes, but fine details need more detail than those codes can hold. Training bigger codes needs too much memory, and adding more codes at use time stops helping quickly.
The method splits a scene into small pieces and runs the same already trained compressor on each piece after rescaling its coordinates. The compressor spends the same amount of code on a smaller area, so each piece gets finer detail. Total code grows without retraining.
Reconstruction quality is close to much larger models that cannot fit on one graphics card, and the representation also powers a 3D generator. That matters because it gives high detail without expensive retraining.
