B4DL: A Benchmark for 4D LiDAR LLM in Spatio-Temporal Understanding

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Choi, Changho, Shin, Youngwoo, Han, Gyojin, Lee, Dong-Jae, Kim, Junmo
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909034431381504
author Choi, Changho
Shin, Youngwoo
Han, Gyojin
Lee, Dong-Jae
Kim, Junmo
author_facet Choi, Changho
Shin, Youngwoo
Han, Gyojin
Lee, Dong-Jae
Kim, Junmo
contents Understanding dynamic outdoor environments requires capturing complex object interactions and their evolution over time. LiDAR-based 4D point clouds provide precise spatial geometry and rich temporal cues, making them ideal for representing real-world scenes. However, despite their potential, 4D LiDAR remains underexplored in the context of Multimodal Large Language Models (MLLMs) due to the absence of high-quality, modality-specific annotations and the lack of MLLM architectures capable of processing its high-dimensional composition. To address these challenges, we introduce B4DL, a new benchmark specifically designed for training and evaluating MLLMs on 4D LiDAR understanding. In addition, we propose a scalable data generation pipeline and an MLLM model that, for the first time, directly processes raw 4D LiDAR by bridging it with language understanding. Combined with our dataset and benchmark, our model offers a unified solution for spatio-temporal reasoning in dynamic outdoor environments. We provide rendered 4D LiDAR videos, generated dataset, and inference outputs on diverse scenarios at: https://github.com/ccho4702/B4DL
format Preprint
id arxiv_https___arxiv_org_abs_2508_05269
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle B4DL: A Benchmark for 4D LiDAR LLM in Spatio-Temporal Understanding
Choi, Changho
Shin, Youngwoo
Han, Gyojin
Lee, Dong-Jae
Kim, Junmo
Computer Vision and Pattern Recognition
Understanding dynamic outdoor environments requires capturing complex object interactions and their evolution over time. LiDAR-based 4D point clouds provide precise spatial geometry and rich temporal cues, making them ideal for representing real-world scenes. However, despite their potential, 4D LiDAR remains underexplored in the context of Multimodal Large Language Models (MLLMs) due to the absence of high-quality, modality-specific annotations and the lack of MLLM architectures capable of processing its high-dimensional composition. To address these challenges, we introduce B4DL, a new benchmark specifically designed for training and evaluating MLLMs on 4D LiDAR understanding. In addition, we propose a scalable data generation pipeline and an MLLM model that, for the first time, directly processes raw 4D LiDAR by bridging it with language understanding. Combined with our dataset and benchmark, our model offers a unified solution for spatio-temporal reasoning in dynamic outdoor environments. We provide rendered 4D LiDAR videos, generated dataset, and inference outputs on diverse scenarios at: https://github.com/ccho4702/B4DL
title B4DL: A Benchmark for 4D LiDAR LLM in Spatio-Temporal Understanding
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2508.05269