This paper presents a unified surface reconstruction and rendering framework for LiDAR-visual systems, integrating Neural Radiance Fields (NeRF) and Neural Distance Fields (NDF) to recover both appearance and structural information from posed images and point clouds. We address the structural visible gap between NeRF and NDF by utilizing a visible-aware occupancy map to classify space into the free, occupied, visible unknown, and background regions. This classification facilitates the recovery of a complete appearance and structure of the scene. We unify the training of the NDF and NeRF using a spatial-varying scale SDF-to-density transformation for levels of detail for both structure and appearance. The proposed method leverages the learned NDF for structure-aware NeRF training by an adaptive sphere tracing sampling strategy for accurate structure rendering. In return, NeRF further refines structural in recovering missing or fuzzy structures in the NDF. Extensive experiments demonstrate the superior quality and versatility of the proposed method across various scenarios. To benefit the community, the codes will be released at \url{https://github.com/hku-mars/M2Mapping}.
Spinning LiDAR data are prevalent for 3D vision tasks. Since LiDAR data is presented in the form of point clouds, expensive 3D operations are usually required. This paper revisits spinning LiDAR scan formation and presents a cylindrical range image representation with a ray-wise projection/unprojection model. It is built upon raw scans and supports lossless conversion from 2D to 3D, allowing fast 2D operations, including 2D index-based neighbor search and downsampling. We then propose, to the best of our knowledge, the first multi-scale registration and dense signed distance function (SDF) rec…
LetsGo: Large-Scale Garage Modeling and Rendering via LiDAR-Assisted Gaussian Primitives
ShanghaiTech University（上海科技大学）；Shanghai Advanced Research Institute, Chinese Academy of Sciences（上海先进研究所，中国科学院）；University of Chinese Academy of Sciences（中国科学院大学）；NeuDim Digital Technology (Shanghai) Co.,Ltd.（NeuDim数字技术（上海）有限公司）；DGene Digital Technology Co., Ltd.（DGene数字技术有限公司）
PRED: Pre-training via Semantic Rendering on LiDAR Point Clouds
Center for Data Science, Peking University（北京大学数据科学中心）；National Key Laboratory of General Artificial Intelligence, School of Intelligence（通用人工智能全国重点实验室）；Pazhou Lab（琶洲实验室）
Harbin Institute of Technology (Shenzhen)（哈尔滨工业大学（深圳））；The University of Hong Kong（香港大学）；Hong Kong University of Science and Technology（香港科技大学）；DJI Co.（大疆创新科技有限公司）
Modeling scene geometry using implicit neural representation has revealed its advantages in accuracy, flexibility, and low memory usage. Previous approaches have demonstrated impressive results using color or depth images but still have difficulty handling poor light conditions and large-scale scenes. Methods taking global point cloud as input require accurate registration and ground truth coordinate labels, which limits their application scenarios. In this paper, we propose a new method that uses sparse LiDAR point clouds and rough odometry to reconstruct fine-grained implicit occupancy field…
The Oxford Spires Dataset: Benchmarking Large-Scale LiDAR-Visual Localisation, Reconstruction and Radiance Field Methods
Oxford Robotics Inst., Dept. of Eng. Science, Univ. of Oxford, UK（牛津大学机器人研究所、工程科学系）；Group of Automation, Robotics and Computer Vision (AUROVA), University of Alicante, Spain（自动化、机器人与计算机视觉小组（AUROVA）、阿尔基兰特大学）
University of Technology, Sydney（悉尼科技大学）；University of Calgary（卡尔加里大学）；Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences（中国科学院遥感与数字地球研究所）；University of Chinese Academy of Sciences（中国科学院大学）；College of Civil Engineering, Nanjing Forestry University（南京林业大学土木工程学院）
Airborne LiDAR (Light Detection and Ranging) data is widely applied in building reconstruction, with studies reporting success in typical buildings. However, the reconstruction of curved buildings remains an open research problem. To this end, we propose a new framework for curved building reconstruction via assembling and deforming geometric primitives. The input LiDAR point cloud are first converted into contours where individual buildings are identified. After recognizing geometric units (primitives) from building contours, we get initial models by matching basic geometric primitives to the…
We present a fully automatic approach for reconstructing compact 3D building models from large-scale airborne point clouds. A major challenge of urban reconstruction from airborne LiDAR point clouds lies in that the vertical walls are typically missing. Based on the observation that urban buildings typically consist of planar roofs connected with vertical walls to the ground, we propose an approach to infer the vertical walls directly from the data. With the planar segments of both roofs and walls, we hypothesize the faces of the building surface, and the final model is obtained by using an ex…
SuperiorGAT: Graph Attention Networks for Sparse LiDAR Point Cloud Reconstruction in Autonomous Systems
Electrical and Computer Engineering, Portland State University（电气与计算机工程系，波特兰州立大学）；Computational Data Science and Engineering Department, North Carolina A&T State University（计算数据科学与工程系，北卡罗来纳A&T州立大学）；Electrical and Computer Engineering Department, SUNY Oswego（电气与计算机工程系，SUNY奥威戈）
University of California, Berkeley（加州大学伯克利分校）；Didi Chuxing（滴滴出行）；University of California, San Diego（加州大学圣迭戈分校）；Facebook Inc（Facebook公司）；Tsinghua University（清华大学）
Due to its robust and precise distance measurements, LiDAR plays an important role in scene understanding for autonomous driving. Training deep neural networks (DNNs) on LiDAR data requires large-scale point-wise annotations, which are time-consuming and expensive to obtain. Instead, simulation-to-real domain adaptation (SRDA) trains a DNN using unlimited synthetic data with automatically generated labels and transfers the learned model to real scenarios. Existing SRDA methods for LiDAR point cloud segmentation mainly employ a multi-stage pipeline and focus on feature-level alignment. They req…
Shanghai Jiao Tong University（上海交通大学）；College of Intelligence Science and Technology, NUDT（国防科技大学智能科学与技术学院）
Simultaneously odometry and mapping using LiDAR data is an important task for mobile systems to achieve full autonomy in large-scale environments. However, most existing LiDAR-based methods prioritize tracking quality over reconstruction quality. Although the recently developed neural radiance fields (NeRF) have shown promising advances in implicit reconstruction for indoor environments, the problem of simultaneous odometry and mapping for large-scale scenarios using incremental LiDAR data remains unexplored. To bridge this gap, in this paper, we propose a novel NeRF-based LiDAR odometry and m…
FlexDrive: Toward Trajectory Flexibility in Driving Scene Reconstruction and Rendering
Multimedia Laboratory, The Chinese University of Hong Kong（香港中文大学多媒体实验室）；Centre for Perceptual and Interactive Intelligence, Hong Kong（香港感知与交互智能中心）；Institute of Automation, Chinese Academy of Sciences（中国科学院自动化研究所）；Beihang University（北京航空航天大学）
Reconstruction of the soft tissues in robotic surgery from endoscopic stereo videos is important for many applications such as intra-operative navigation and image-guided robotic surgery automation. Previous works on this task mainly rely on SLAM-based approaches, which struggle to handle complex surgical scenes. Inspired by recent progress in neural rendering, we present a novel framework for deformable tissue reconstruction from binocular captures in robotic surgery under the single-viewpoint setting. Our framework adopts dynamic neural radiance fields to represent deformable surgical scenes…
GSDF: 3DGS Meets SDF for Improved Rendering and Reconstruction
Shanghai Artificial Intelligence Laboratory（上海人工智能实验室）；The Chinese University of Hong Kong（香港中文大学）；University of Science and Technology of China（中国科学技术大学）；Cornell University（康奈尔大学）
The University of Hong Kong（香港大学）；Max Planck Institute for Informatics（马克斯·普朗克信息学研究所）；Texas A&M University（德州农工大学）
We present a novel neural surface reconstruction method, called NeuS, for reconstructing objects and scenes with high fidelity from 2D image inputs. Existing neural surface reconstruction approaches, such as DVR and IDR, require foreground mask as supervision, easily get trapped in local minima, and therefore struggle with the reconstruction of objects with severe self-occlusion or thin structures. Meanwhile, recent neural methods for novel view synthesis, such as NeRF and its variants, use volume rendering to produce a neural scene representation with robustness of optimization, even for high…
