Argus: Leveraging Multiview Images for Improved 3-D Scene Understanding With Large Language Models.

Advancements in foundation models have made it possible to conduct applications in various downstream tasks. Especially, the new era has witnessed a remarkable capability to extend large language models (LLMs) for tackling tasks of 3-D scene understanding. Current methods rely heavily on 3-D point clouds, but the 3-D point cloud reconstruction of an indoor scene often results in information loss. Some textureless planes or repetitive patterns are prone to omission and manifest as voids within the reconstructed 3-D point clouds. Besides, objects with complex structures tend to introduce distortion of details caused by misalignments between the captured images and the dense reconstructed point clouds. The 2-D multiview images present visual consistency with 3-D point clouds and provide more detailed representations of scene components, which can naturally compensate for these deficiencies. Based on these insights, we propose Argus, a novel 3-D multimodal framework that leverages multiview images for enhanced 3-D scene understanding with LLMs. In general, Argus can be treated as a 3-D large multimodal foundation model (3D-LMM) since it takes various modalities as input (text instructions, 2-D multiview images, and 3-D point clouds) and expands the capability of LLMs to tackle 3-D tasks. Argus involves fusing and integrating multiview images and camera poses into view-as-scene features, which interact with the 3-D features to create comprehensive and detailed 3-D-aware scene embeddings. Our approach compensates for the information loss while reconstructing 3-D point clouds and helps LLMs better understand the 3-D world. Extensive experiments demonstrate that our method outperforms existing 3D-LMMs in various downstream tasks.