ImMesh: An Immediate LiDAR Localization and Meshing Framework

In this paper, we propose a novel LiDAR(-inertial) odometry and mapping framework to achieve the goal of si- multaneous localization and meshing in real-time. This pro- posed framework termed ImMesh comprises four tightly-coupled modules: receiver, localization, meshing, and broadcaster. The localization module first utilizes the preprocessed sensor data from the receiver, estimates the sensor pose online by register- ing LiDAR scans to maps, and dynamically grows the map. Then, our meshing module takes the registered LiDAR scan for incrementally reconstructing the triangle mesh on the fly. Finally, the real-time odometry, map, and mesh are published via our broadcaster. The primary contribution of this work is the meshing module, which represents a scene by an efficient voxel structure, performs fast finding of voxels observed by new scans, and incrementally reconstructs triangle facets in each voxel. This voxel-wise meshing operation is delicately designed Manuscript received February 5, 2023; revised July 23, 2023; accepted September 18, 2023. This work is supported by the University Grants Committee of Hong Kong General Research Fund (project number 17206421) and DJI Donation. (Corresponding author: Fu Zhang.) ̊These two authors contribute equally to this work. J. Lin, C. Yuan, Y. Cai and F. Zhang are with the Depart- ment of Mechanical Engineering, The University of Hong Kong, Hong Kong SAR, China. tjiarong.lin, ycj1, yixicai, haotianl, renyf, zyycici, fuzhangu@connect.hku.hk X. Hong are with the School of System Design and Intelligent Manufac- turing, Southern University of Science and Technology, Shenzhen, People’s Republic of China. thongxpu@sustech.edu.cn for the purpose of efficiency; it first performs a dimension reduction by projecting 3D points to a 2D local plane contained in the voxel, and then executes the meshing operation with pull, commit and push steps for incremental reconstruction of triangle facets. To the best of our knowledge, this is the first work in literature that can reconstruct online the triangle mesh of large-scale scenes, just relying on a standard CPU without GPU acceleration. To share our findings and make contributions to the community, we make our code publicly available on our GitHub: github.com/hku-mars/ImMesh.