Cross-view Domain Generalization via Geometric Consistency for LiDAR Semantic Segmentation
Authors: Jindong Zhao, Yuan Gao, Yang Xia, Sheng Nie, Jun Yue, Weiwei Sun, Shaobo Xia
Organizations: School of Aeronautic Engineering, Changsha University of Science and Technology, Hunan, China, 410004. · Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China, 100094. · School of Automation, Central South University, Changsha 410083, China · University of British Columbia.
Domain-generalized LiDAR semantic segmentation (LSS) seeks to train models on source-domain point clouds that generalize reliably to multiple unseen target domains, which is essential for real-world LiDAR applications. However, existing approaches assume similar acquisition views (e.g., vehicle-mounted) and struggle in cross-view scenarios, where observations differ substantially due to viewpoint-dependent structural incompleteness and non-uniform point density. Accordingly, we formulate cross-view domain generalization for LiDAR semantic segmentation and propose a novel framework, termed CVGC (Cross-View Geometric Consistency). Specifically, we introduce a cross-view geometric augmentation module that models viewpoint-induced variations in visibility and sampling density, generating multiple cross-view observations of the same scene. Subsequently, a geometric consistency module enforces consistent semantic and occupancy predictions across geometrically augmented point clouds of the same scene. Extensive experiments on six public LiDAR datasets establish the first systematic evaluation of cross-view domain generalization for LiDAR semantic segmentation, demonstrating that CVGC consistently outperforms state-of-the-art methods when generalizing from a single source domain to multiple target domains with heterogeneous acquisition viewpoints. The source code will be publicly available at https://github.com/KintomZi/CVGC-DG
Figures & tables
Figure 1: Challenges in cross-view domain generalization. (a) Conventional DG assumes similar sensing viewpoints across domains, whereas (b) Cross-view DG involves drastically different acquisition geometries, leading to severe density and visibility shifts. We address this challenge by generating view-dependent geometric variants and enforcing consistency across them.
Figure 2: Overview of the CVGC framework . The framework consists of two main modules: (i) Cross-view Geometric Augmentation (CGA), which generates a view-dependent variant Pα from the source point cloud Ps ; and (ii) Geometric Consistency Regularization (GCR), which enforces structural and semantic consistency across variants. A shared backbone predicts point-wise semantics for both views, with semantic consistency and voxel occupancy supervision jointly regularizing the learned representations, using only source-domain data.
Figure 3: Illustration of the CGA. (a) Viewpoint-agnostic density resampling, which adjusts point cloud scene density via tangent plane-based densification and voxel-based sparsification. (b) Viewpoint-dependent visibility simulation, which constructs occluded scenes based on a spherical projection process.
Figure 4: Schematic of the occupancy perception head. Point-wise features are aggregated into voxel representations via voxelization and KNN-based interpolation, and processed by sparse convolutional layers to predict voxel occupancy, providing unified geometric supervision across different viewpoints.
Figure 5: Benchmark for cross-view domain generalization. The six datasets are partitioned into two groups following a one-source, two-target protocol. (a) First-Group Datasets: H3D (UAV) → Paris-Lille-3D (MLS) and ISPRS Vaihingen (ALS). (b) Second-Group Experiments: STPLS3D (synthetic UAV) → Toronto-3D (MLS) and DALES (ALS).
Figure 6: Qualitative results for Hessigheim-3D → Paris-Lille-3D. Results of different methods are visualized on the MLS target domain, where colors indicate semantic categories.
Source
Target
Method
Per-class IoU (%)
mIoU
Ground
Building
Natural
Vehicle
U.Furniture
Hessigheim-3D
Paris-Lille-3D
Source-only
91.98
83.83
82.55
50.65
21.30
66.06
CoSMix [ 30 ]
95.29
87.05
80.04
64.71
31.93
71.80
PolarMix [ 28 ]
94.20
82.75
62.13
29.90
6.97
55.19
DGLSS [ 10 ]
92.33
84.89
81.12
42.58
20.23
64.23
UniMix [ 11 ]
93.44
69.99
62.12
44.06
25.04
58.93
Table I: Quantitative comparison on Hessigheim-3D (Source) to Paris-Lille-3D and ISPRS Vaihingen (Targets) cross-view benchmarks.
Figure 7: Qualitative results for Hessigheim-3D → ISPRS Vaihingen. Results of different methods are visualized on the ALS target domain, where colors indicate semantic categories.
Figure 8: Qualitative results for STPLS3D → Toronto-3D. Results of different methods are visualized on the MLS target domain, where colors indicate semantic categories.
Figure 9: Qualitative results for STPLS3D → DALES. Results of different methods are visualized on the ALS target domain, where colors indicate semantic categories.
Source
Target
Method
Per-class IoU (%)
mIoU
Ground
Building
Natural
Vehicle
Pole
Fence
STPLS3D
Toronto-3D
Source-only
96.51
57.83
84.51
9.44
35.72
2.70
47.79
CoSMix [ 30 ]
89.73
17.96
32.43
6.80
15.34
0.93
27.20
PolarMix [ 28 ]
89.45
45.08
62.58
13.09
28.34
3.68
40.37
DGLSS [ 10 ]
96.13
60.15
81.63
12.18
35.90
3.41
48.23
UniMix [ 11 ]
95.85
41.87
85.19
32.05
31.74
3.08
48.30
Table II: Quantitative comparison on STPLS3D (Source) to Toronto-3D and DALES (Targets) cross-view benchmarks.
Source
Target
Module
mIoU
CGA
GCR
Hessigheim-3D
Paris-Lille-3D
✗
✗
66.06
✓
✗
67.04
✓
✓
72.87
ISPRS Vaihingen
✗
✗
31.20
✓
✗
53.17
Table III: Ablation study on Hessigheim-3D as source, with Paris-Lille-3D and ISPRS Vaihingen as targets.
Source
Target
Module
mIoU
CGA
GCR
STPLS3D
Toronto-3D
✗
✗
47.79
✓
✗
50.42
✓
✓
51.28
DALES
✗
✗
58.57
✓
✗
61.91
Table IV: Ablation study on STPLS3D as source, with Toronto-3D and DALES as targets.
College of Computer Science and Artificial Intelligence, Fudan University, Shanghai, China · School of Computing, Department of Computer Science, National University of Singapore, Singapore · College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, China +5