Accurate Point Cloud Registration (PCR) is an important task in 3D data processing, involving the estimation of a rigid transformation between two point clouds. While deep-learning methods have addressed key limitations of traditional non-learning approaches, such as sensitivity to noise, outliers, occlusion, and initialization, they are developed and evaluated on clean, dense, synthetic datasets (limiting their generalizability to real-world industrial scenarios). This paper introduces R3PM-Net, a lightweight, global-aware, object-level point matching network designed to bridge this gap by prioritizing both generalizability and real-time efficiency. To support this transition, two datasets, Sioux-Cranfield and Sioux-Scans, are proposed. They provide an evaluation ground for registering imperfect photogrammetric and event-camera scans to digital CAD models, and have been made publicly available. Extensive experiments demonstrate that R3PM-Net achieves competitive accuracy with unmatched speed. On ModelNet40, it reaches a perfect fitness score of 1 and inlier RMSE of 0.029 cm in only 0.007s, approximately 7 times faster than the state-of-the-art method RegTR. This performance carries over to the Sioux-Cranfield dataset, maintaining a fitness of 1 and inlier RMSE of 0.030 cm with similarly low latency. Furthermore, on the highly challenging Sioux-Scans dataset, R3PM-Net successfully resolves edge cases in under 50 ms. These results confirm that R3PM-Net offers a robust, high-speed solution for critical industrial applications, where precision and real-time performance are indispensable. The code and datasets are available at https://github.com/YasiiKB/R3PM-Net.
Figures & tables
Figure 1: Qualitative results of R3PM-Net. As a real-time, feature-based deep learning method for point cloud registration, R3PM-Net improves generalizability and inference speed by expanding the network’s field-of-view.
Figure 2: Overview of the R3PM-Net Architecture. Built upon [ 34 ] , R3PM-Net employs an iterative Siamese framework for robust point cloud registration. The architecture includes four primary stages: (1) global-aware feature extraction employing shared MLPs to learn geometric similarities across a full receptive field; (2) correspondence estimation via a match matrix M computed from feature distances; (3) outlier rejection driven by a parameter prediction module (4) transformation estimation using a differentiable SVD module to solve for the optimal rigid alignment (R∗,t∗) . The estimated transformation is applied back to the source point cloud for iterative refinement.
Figure 3: Coarse-to-Fine Registration approach to handle noisy, sparse scans. Initially, X and Y are pre-processed via downsampling, normalization and alignment. Large misalignments are then resolved through coarse global registration performed by R3PM-Net, followed by a final high-precision local refinement with GICP.
Method
RRE [ ∘ ] ↓
RTE [cm] ↓
CD [cm] ↓
Fitness ↑
Inlier RMSE [cm] ↓
Time [s] ↓
RPMNet [ 34 ]
30.898 ± 0.322
0.002 ± 0.000
0.153 ± 0.001
0.998 ± 0.000
0.094 ± 0.001
0.021 ± 0.000
Predator [ 14 ]
7.262 ± 0.555
0.028 ± 0.002
0.045 ± 0.002
1.000 ± 0.000
0.026 ± 0.001
0.071 ± 0.001
GeoTransformer [ 18 ]
50.357 ± 1.238
0.215 ± 0.003
0.255 ± 0.005
0.921 ± 0.001
0.101 ± 0.002
0.065 ± 0.000
RegTR [ 35 ]
1.712 ± 0.061
0.007 ± 0.000
0.017 ± 0.000
1.000 ± 0.000
0.009 ± 0.000
0.045 ± 0.000
LoGDesc [ 22 ]
42.762 ± 1.254
0.158 ± 0.003
0.183 ± 0.004
0.978 ± 0.001
0.097 ± 0.002
0.075 ± 0.000
R3PM-Net (ours)
5.198 ± 0.067
0.010 ± 0.000
0.052 ± 0.000
1.000 ± 0.000
0.029 ± 0.000
0.007 ± 0.000
Table 1: Quantitative comparison on ModelNet40. Performance is reported in terms of RRE, RTE, Chamfer distance (CD), fitness (↑ higher is better), inlier RMSE, and inference time (↓ lower is better). R3PM-Net achieves the fastest inference while maintaining competitive accuracy. Best and second-best results are highlighted.
Method
RRE [ ∘ ] ↓
RTE [cm] ↓
CD [cm] ↓
Fitness ↑
Inlier RMSE [cm] ↓
Time [s] ↓
RPMNet [ 34 ]
32.217 ± 0.844
0.002 ± 0.000
0.160 ± 0.004
0.997 ± 0.002
0.098 ± 0.001
0.021 ± 0.000
Predator [ 14 ]
16.448 ± 1.548
0.044 ± 0.003
0.072 ± 0.002
1.000 ± 0.000
0.042 ± 0.001
0.071 ± 0.001
GeoTrans. [ 18 ]
45.582 ± 0.549
0.183 ± 0.005
0.297 ± 0.007
0.906 ± 0.004
0.111 ± 0.002
0.065 ± 0.000
RegTR [ 35 ]
1.311 ± 0.032
0.004 ± 0.000
0.023 ± 0.000
1.000 ± 0.000
0.012 ± 0.000
0.045 ± 0.000
LoGDesc [ 22 ]
121.224 ± 10.396
0.773 ± 0.060
0.692 ± 0.022
0.718 ± 0.010
0.224 ± 0.002
0.075 ± 0.000
R3PM-Net (ours)
5.451 ± 0.287
0.006 ± 0.001
0.054 ± 0.002
1.000 ± 0.000
0.030 ± 0.001
0.006 ± 0.000
Table 2: Quantitative comparison on Sioux-Cranfield dataset. R3PM-Net offers the best trade-off between real-time execution and competitive accuracy; it remains highly competitive, exceeding the performance of recent methods on most metrics while operating at an inference latency over 6.5× faster than RegTR. Best and Second-best results are highlighted.
Method
Lime
Cube
House
Teeth
Success
Time
CD
Fit.
RMSE
CD
Fit.
RMSE
CD
Fit.
RMSE
CD
Fit.
RMSE
Rate
(s)
RPMNet [ 34 ]
0.270
1.000
0.047
0.290
1.000
0.023
-
-
-
-
-
-
28.6%
0.042
Predator [ 14 ]
0.270
1.000
0.048
0.289
1.000
0.023
-
-
-
-
-
-
28.6%
0.038
GeoTrans. [ 18 ]
0.260
1.000
0.041
0.295
1.000
0.024
-
-
-
-
-
-
28.6%
0.042
RegTR [ 35 ]
0.270
1.000
0.047
0.292
1.000
0.023
-
-
-
-
-
-
28.6%
0.038
LoGDesc [ 22 ]
-
-
-
0.292
1.000
0.024
0.222
1.000
0.052
-
-
-
28.6%
0.043
Table 3: Registration performance for successful cases of Sioux-Scans dataset (visually verified). ’-’ indicates that the method did not solve the object case. Success Rate is the ratio of successful trials to the seven test objects. Runtime reflects the average time (in seconds) to attempt all seven cases. Please refer to the Supplementary material (section A.3 ) for the full table including all failed cases.
Figure 4: Qualitative registration results of R3PM-Net on real-world event-camera data. It successfully aligns the “teeth” and “cube” models in under 50 ms.
Model
Total Params. [M] ↓
Throughput [fps]
RPMNet
0.91
48
Predator
22.57
14
GeoTrans.
5.21
15
RegTR
11.49
22
LoGDesc
4.71
13
R3PM-Net (ours)
0.96
167
Table 4: Model complexity and throughput comparison. Throughput is the number of point cloud pairs registered per second. Despite comparable performance, R3PM-Net reduces total parameters by over 90% compared to RegTR.
Input Rep.
Norm.
Rad.
RRE ↓
RTE ↓
CD ↓
Fit. ↑
Time
PC Feat.1
✓
Fixed
31.86
0.00
0.16
1.00
0.021
PC Feat.2
–
Fixed
9.35
0.01
0.07
1.00
0.006
PC Feat.3
✓
Flex
13.65
0.01
0.08
0.99
0.006
PC Feat.4
–
Flex
12.90
0.01
0.08
0.99
0.006
Direct PC R3PM-Net
–
–
2.01
0.00
0.02
1.00
0.006
Table 5: Ablation study on input features. Hand-crafted local features are compared to R3PM-Net’s direct point cloud (PC) approach on the Sioux-Cranfield dataset. Bold indicates the best results.
Dataset
Method
RRE ↓
RTE ↓
CD ↓
Fit. ↑
Time
Model-Net40
R3PM-Net
5.198
0.010
0.052
0.029
0.007
R3PM-Net (FT)
1.963
0.003
0.025
0.014
0.007
Sioux-Cranfield
R3PM-Net
5.451
0.006
0.054
0.030
0.006
R3PM-Net (FT)
2.297
0.002
0.033
0.018
0.006
Table 6: Ablation study of cross-domain fine-tuning (FT). Fine-tuning on a subset of the proposed Sioux-Cranfield dataset improves performance across both dataset benchmarks. Bold indicates best results.
Method
FT Subset
Success Cases
Rate (%)
R3PM-Net
—
teeth, cube
28.6
R3PM-Net (FT)*
teeth, lime, cube, lego
teeth, lime, house
42.9
R3PM-Net (FT)
rd-peg, sep, shoe
teeth, lime, cube
42.9
Plate, eleph., house
cube
14.3
Plate, eleph., house, rd-peg
teeth, cube
28.6
rd-peg, sep, shoe, lego
teeth
14.3
Table 7: Ablation study on fine-tuning subsets of Sioux-Cranfield dataset evaluated on Sioux-Scans.* denotes the model studied in the effectiveness of fine-tuning experiment shown in Table 6 .
Figure 5: 3D Quality Control Setup developed by Sioux Technologies [ 24 ] . This setup leverages event-camera technology to provide fast, high-fidelity 3D scanning suitable for in-line real-time quality assurance for specialized products. It aims to deliver optimized process control in applications including 3D metal printing, integrated electronics in molded parts, and dental prosthetics.
Category
Source Type
Qty
Sioux (Reconstructed)
Photogram.
4
Sioux (Synthetic)
CAD Models
3
Cranfield [ 6 ]
Pristine
6
Total
—
13
Table 8: Composition of the Sioux-Cranfield Dataset. Sioux (Reconstructed) and Sioux (Synthetic) are also used in Sioux-Scans dataset to produce Target point clouds.
Figure 6: CAD models of the Sioux-Cranfield dataset. The first six belong to the Cranfield Assembly benchmark [ 6 ] and the rest are contributions of this paper (Sioux dataset).
Figure 7: Sioux-Scans point cloud data overview. Target (blue) and Source (yellow) point clouds for seven distinct objects.
Metric
Type
Pros
Cons
GT-Free
RRE
Geodesic dist.
Scale-invariant
Less intuitive, not always objective
✗
RTE
Euclidean dist.
Scale-invariant
Less intuitive, not always objective
✗
Chamfer Dist.
Euclidean dist.
Suitable for symmetric shapes
Scale-variant
✓
Fitness
Overlap ratio
Intuitive
Scale-variant
✓
Inlier RMSE
Euclidean dist.
Practical
Scale-variant, can be misleading with poor alignment
✓
Time
Seconds
Important for real-time use
Does not reflect accuracy
✓
Table 9: Summary of Evaluation Metrics: Types, strengths, limitations, and ground-truth (GT) requirements. Scale-invariant metrics do not depend on the point cloud size. GT-free metrics are suitable for real-world scenarios whereas GT-based metrics are used in simulations.
Method
Data
Teeth
Lime
Cube
Lego
Eleph.
House
Shoe
SR (%)
Time
RPMNet [ 34 ]
CD
.205
.270
.290
.218
.173
.264
.191
28.6
0.042s
Fit.
1.00
1.00
1.00
1.00
1.00
1.00
.968
RMSE
.059
.047
.023
.065
.064
.132
.106
Status
failed
success
success
failed
failed
failed
failed
Predator [ 14 ]
CD
.185
.270
.289
.210
.158
.284
.092
28.6
0.038s
Fit.
1.00
1.00
1.00
1.00
1.00
.992
1.00
Table 10: Complete performance comparison of baseline methods on real-life industrial data. Results are averaged over seven independent runs across seven test objects. A successful registration is defined as achieving accurate alignment, verified visually, in at least four out of seven trials.
School of Software, Xi’an Jiaotong University, No. 28 Xianning West Road, China · CEPRI, China Electric Power Research Institute No. 15 Xiaoying East Road, Qinghe, Haidian District, Beijing, China
Institute of Geodesy and Photogrammetry, Technische Universität Braunschweig, Germany · Institute of Geodesy · Department of Infrastructure Engineering, University of Melbourne, Australia. +1