📊 Evaluations

🖼️ I. Qualitative Results (Generated Scene Graphs)

In vS-Graphs, the Building Components Recognition module extracts semantic entities such as walls and ground surfaces from each KeyFrame using a panoptic segmentation backbone that provides pixel-level labels and instance boundaries. A parallel Structural Elements Recognition thread then infers higher-level entities (rooms and floors) by grouping spatially consistent components into enclosed areas and aggregating them across building levels. This hierarchical reasoning enhances spatial understanding and enables geometry-aware optimization in vS-Graphs. Below, you can find some qualitative results of the generated scene graphs on different datasets, where bc and se refer to the building components and structural elements, respectively.

🏷️ AutoSense Dataset

🏷️ ICL Dataset

🏷️ OpenLoris Dataset

🏷️ TUM-RGBD Dataset


📈 II. Absolute Trajectory Error (ATE)

Below table shows the performance of vS-Graphs on different datasets and compared to the state-of-the-art methods. It is measured using ATE reported in meters. For evaluation, each system was evaluated over eight runs on dataset instances.


📍 III. Mapping Performance

Root Mean Square Error (RMSE) values for ORB-SLAM 3.0 and vS-Graphs across different sequences of the AutoSense dataset (over eight iterations). The results indicate that vS-Graphs generally achieve lower RMSE values, with around 10.15% fewer points (on average).

Method Sequence 1 2 3 4 5 6 7 8
vGraphs (link) SR01 0.2598 0.3102 0.2608 0.3454 0.3409 0.3122 0.2891 0.3246
SR02 0.2333 0.2165 0.2301 0.2494 0.2499 0.2414 0.2564 0.2853
SR03 0.2749 0.5544 0.2426 0.3509 0.2837 0.3801 0.2725 0.2920
MR01 4.3774 5.5194 6.2763 4.7143 6.8155 4.4640 4.8322 4.5823
MR02 1.1153 1.1836 0.9430 0.9017 0.9210 1.0799 0.9575 0.7648
MR03 1.2933 0.2978 0.3472 0.3137 1.1864 0.2894 0.4122 0.2721
ORB-SLAM 3.0 (link) SR01 0.2772 0.4435 0.3509 0.3964 0.2753 0.3006 0.3995 0.3602
SR02 0.3111 0.2781 0.2862 0.2668 0.3000 0.2955 0.2408 0.2787
SR03 0.3451 0.3380 0.3279 0.2931 0.3054 0.3728 0.3076 0.3435
MR01 5.1266 5.0866 5.6484 5.6531 4.7557 6.2066 5.2847 5.2242
MR02 1.1828 1.1521 0.9291 0.9648 0.9379 1.0269 1.2719 1.0016
MR03 0.2869 2.5426 1.5765 2.3271 2.0381 0.2725 0.6926 0.4120

Number of map points generated by ORB-SLAM 3.0 and vS-Graphs on the AutoSense dataset (over eight iterations). The measurements show that vS-Graphs produces fewer points than ORB-SLAM 3.0, while positively impacting the mapping accuracy.

Method Sequence 1 2 3 4 5 6 7 8
vGraphs (link) SR01 6759 6704 6744 6741 6875 6804 6780 6842
SR02 7304 7120 7420 7457 7421 7212 7382 7160
SR03 11764 11591 11937 12054 12156 11844 11471 11475
MR01 20607 20682 19692 20714 21042 20274 19433 20546
MR02 16838 16622 16479 16563 17065 17200 16905 17274
MR03 48364 46237 48250 47850 47149 49008 48442 45224
ORB-SLAM 3.0 (link) SR01 6931 7085 7057 6903 7012 6894 7063 7130
SR02 7639 7378 7548 7712 7540 7590 7363 7377
SR03 13140 12631 12818 12903 13021 13187 12613 12990
MR01 22564 22685 21916 22688 22552 22759 22701 22506
MR02 18816 18196 17899 18547 17722 18492 18117 17643
MR03 54797 55342 56531 55499 56056 55853 56187 54545

🖼️ IV. Scene Understanding Performance

The results are in the form of reconstructed maps enriched with building components, which are later used to infer the structural elements of the environment.


Detected / Real Precision Recall
Method Sequence BC SE BC SE BC SE
S-Graphs (link) MR01 11 / 14 4 / 4 0.92 1.00 0.92 1.00
MR02 12 / 13 4 / 4 1.00 1.00 0.92 1.00
MR03 20 / 22 6 / 6 0.90 1.00 0.95 1.00
Hydra (link) MR01 N/A 4 / 4 N/A 1.00 N/A 1.00
MR02 N/A 6 / 4 N/A 0.75 N/A 0.75
MR03 N/A 6 / 6 N/A 1.00 N/A 0.80
vGraphs (link) MR01 13 / 14 4 / 4 0.86 1.00 1.00 1.00
MR02 13 / 13 4 / 4 0.92 1.00 0.92 1.00
MR03 23 / 22 6 / 6 0.96 1.00 1.00 1.00


⏱️ V. Runtime Analysis

vS-Graphs achieves real-time performance with an average processing rate of 22 ± 3 FPS, exceeding the 20 FPS threshold for real-time operation.


🚀 Team

Core Team

Ali Tourani


Doctoral Researcher

SnT, University of Luxembourg

Saad Ejaz


Doctoral Researcher

SnT, University of Luxembourg

Miguel Fernandez-Cortizas

Postdoc Researcher

SnT, University of Luxembourg

Asier Bikandi-Noya

Doctoral Researcher

SnT, University of Luxembourg

Jose Luis Sanchez-Lopez

Research Scientist

SnT, University of Luxembourg

Holger Voos


Full Professor

SnT, University of Luxembourg

Former Team Members

Hriday Bavle

GAMMA AR

Luxembourg

External Collaborators

David Morilla-Cabello

Ph.D. Student

Universidad de Zaragoza, Spain

David Pérez Saura

Ph.D. Student

Universidad Politécnica de Madrid, Spain

📚 Citation

@article{vsgraphs,
title={vS-Graphs: Tightly Coupling Visual SLAM and 3D Scene Graphs Exploiting Hierarchical Scene Understanding},
author={A. Tourani, S. Ejaz, H. Bavle, M. Fernandez-Cortizas, D. Morilla-Cabello, J.L. Sanchez-Lopez, H. Voos},
year={2025},
url={https://arxiv.org/abs/2503.01783}
}
@article{tourani2024towards,
title={Towards Localizing Structural Elements: Merging Geometrical Detection with Semantic Verification in RGB-D Data},
author={A. Tourani, S. Ejaz, H. Bavle, J.L. Sanchez-Lopez, H. Voos},
year={2024},
url={https://arxiv.org/abs/2409.06625}
}

☎️ Contact Us

https://www.uni.lu/snt-en/research-groups/arg/
https://github.com/snt-arg
6, rue Coudenhove-Kalergi, L-1359 LUXEMBOURG
Block E, Automation and Robotics Group (ARG)