Saved in:
Bibliographic Details
Main Authors: Qu, Kevin, Qi, Haozhe, Dusmanu, Mihai, Rad, Mahdi, Wang, Rui, Pollefeys, Marc
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2603.18002
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917351898742784
author Qu, Kevin
Qi, Haozhe
Dusmanu, Mihai
Rad, Mahdi
Wang, Rui
Pollefeys, Marc
author_facet Qu, Kevin
Qi, Haozhe
Dusmanu, Mihai
Rad, Mahdi
Wang, Rui
Pollefeys, Marc
contents Multimodal Large Language Models (MLLMs) have made impressive progress in connecting vision and language, but they still struggle with spatial understanding and viewpoint-aware reasoning. Recent efforts aim to augment the input representations with geometric cues rather than explicitly teaching models to reason in 3D space. We introduce Loc3R-VLM, a framework that equips 2D Vision-Language Models with advanced 3D understanding capabilities from monocular video input. Inspired by human spatial cognition, Loc3R-VLM relies on two joint objectives: global layout reconstruction to build a holistic representation of the scene structure, and explicit situation modeling to anchor egocentric perspective. These objectives provide direct spatial supervision that grounds both perception and language in a 3D context. To ensure geometric consistency and metric-scale alignment, we leverage lightweight camera pose priors extracted from a pre-trained 3D foundation model. Loc3R-VLM achieves state-of-the-art performance in language-based localization and outperforms existing 2D- and video-based approaches on situated and general 3D question-answering benchmarks, demonstrating that our spatial supervision framework enables strong 3D understanding. Project page: https://kevinqu7.github.io/loc3r-vlm
format Preprint
id arxiv_https___arxiv_org_abs_2603_18002
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Loc3R-VLM: Language-based Localization and 3D Reasoning with Vision-Language Models
Qu, Kevin
Qi, Haozhe
Dusmanu, Mihai
Rad, Mahdi
Wang, Rui
Pollefeys, Marc
Computer Vision and Pattern Recognition
Artificial Intelligence
Computation and Language
Multimodal Large Language Models (MLLMs) have made impressive progress in connecting vision and language, but they still struggle with spatial understanding and viewpoint-aware reasoning. Recent efforts aim to augment the input representations with geometric cues rather than explicitly teaching models to reason in 3D space. We introduce Loc3R-VLM, a framework that equips 2D Vision-Language Models with advanced 3D understanding capabilities from monocular video input. Inspired by human spatial cognition, Loc3R-VLM relies on two joint objectives: global layout reconstruction to build a holistic representation of the scene structure, and explicit situation modeling to anchor egocentric perspective. These objectives provide direct spatial supervision that grounds both perception and language in a 3D context. To ensure geometric consistency and metric-scale alignment, we leverage lightweight camera pose priors extracted from a pre-trained 3D foundation model. Loc3R-VLM achieves state-of-the-art performance in language-based localization and outperforms existing 2D- and video-based approaches on situated and general 3D question-answering benchmarks, demonstrating that our spatial supervision framework enables strong 3D understanding. Project page: https://kevinqu7.github.io/loc3r-vlm
title Loc3R-VLM: Language-based Localization and 3D Reasoning with Vision-Language Models
topic Computer Vision and Pattern Recognition
Artificial Intelligence
Computation and Language
url https://arxiv.org/abs/2603.18002