Long-LRM: Long-sequence Large Reconstruction Model for Wide-coverage
  Gaussian Splats
Authors: name: Chen Ziwen, name: Hao Tan, name: Kai Zhang, name: Sai Bi, name: Fujun Luan, name: Yicong Hong, name: Li Fuxin, name: Zexiang Xu

We propose Long-LRM, a generalizable 3D Gaussian reconstruction model that is
capable of reconstructing a large scene from a long sequence of input images.
Specifically, our model can process 32 source images at 960x540 resolution
within only 1.3 seconds on a single A100 80G GPU. Our architecture features a
mixture of the recent Mamba2 blocks and the classical transformer blocks which
allowed many more tokens to be processed than prior work, enhanced by efficient
token merging and Gaussian pruning steps that balance between quality and
efficiency. Unlike previous feed-forward models that are limited to processing
1~4 input images and can only reconstruct a small portion of a large scene,
Long-LRM reconstructs the entire scene in a single feed-forward step. On
large-scale scene datasets such as DL3DV-140 and Tanks and Temples, our method
achieves performance comparable to optimization-based approaches while being
two orders of magnitude more efficient. Project page:
https://arthurhero.github.io/projects/llrm