Open-vocabulary panoptic reconstruction is essential for advanced robotics perception and simulation. However, existing methods based on 3D Gaussian Splatting (3DGS) often struggle to simultaneously achieve geometric accuracy, coherent panoptic understanding, and real-time inference frequency in large-scale scenes. In this paper, we propose a comprehensive framework that integrates geometric reinforcement, end-to-end panoptic learning, and efficient rendering. First, to ensure physical realism in large-scale environments, we leverage LiDAR data to construct plane-constrained multimodal Gaussian Mixture Models (GMMs) and employ 2D Gaussian surfels as the map representation, enabling high-precision surface alignment and continuous geometric supervision. Building upon this, to overcome the error accumulation and cumbersome cross-frame association inherent in traditional multi-stage panoptic segmentation pipelines, we design a query-guided end-to-end learning architecture. By utilizing a local cross-attention mechanism within the view frustum, the system lifts 2D mask features directly into 3D space, achieving globally consistent panoptic understanding. Finally, addressing the computational bottlenecks caused by high-dimensional semantic features, we introduce Precise Tile Intersection and a Top-K Hard Selection strategy to optimize the rendering pipeline. Experimental results demonstrate that our system achieves superior geometric and panoptic reconstruction quality in large-scale scenes while maintaining an inference rate exceeding 40 FPS, meeting the real-time requirements of robotic control loops.
Figures & tables
Figure 1: Ψ -Map provides a high-performance bridge from multi-modal sensor inputs to robotic applications. By fusing LiDAR-RGB-D data with Vision-Language Foundation Models, our framework achieves real-time, 3D-consistent panoptic reconstruction. This representation serves as a powerful engine for high-fidelity scene editing and virtual asset generation, ultimately empowering complex downstream skills such as generative 3D object completion and robust robotic navigation in wild environments.
Figure 2: Overview of the Ψ -Map Framework. The Input consists of multi-view RGB-D frames. During Geometric Reinforcement, the point cloud is modeled as a plane-constrained SOGMM to provide continuous structural supervision for the 2D Gaussian Surfels. In the Panoptic Learning stage, 2D mask features are lifted into 3D via a query-guided end-to-end architecture, where instance tokens are refined through local cross-attention within the view frustum to ensure global identity consistency. For Inference, our highly optimized rendering pipeline employs Precise Tile Intersection and Top- K Hard Selection. By leveraging the geometric sparsity and surface-aligned nature of 2DGS, Ψ -Map significantly reduces the computational overhead of high-dimensional feature accumulation, enabling real-time, high-fidelity multi-modal rendering.
Figure 3: The instance branch utilizes a cross-attention mechanism between 3D Gaussian-modulated query tokens and SOGMM-reinforced 2DGS scene fields.
Figure 4: Comparison of the quality of semantic segmentation and panoptic segmentation of different methods on ScanNet V2 and ScanNet++.
Method
Acc. ↓
Comp. ↓
C-L1 ↓
Recall ↑
Prec. ↑
F1 ↑
2DGS [ 15 ]
13.98
18.60
16.28
71.65
80.85
75.82
Gaussian Surfels [ 31 ]
14.25
35.95
25.10
70.47
48.33
57.29
PGSR [ 16 ]
13.52
19.63
16.58
72.66
73.67
73.08
RaDe-GS [ 32 ]
13.28
17.13
15.22
73.42
78.59
75.88
LIV-GaussMap [ 33 ]
14.17
15.48
14.80
72.54
80.33
76.18
GOF [ 34 ]
14.27
15.37
14.83
70.55
80.20
75.04
Table 1: Geometric quality comparison on self-collected datasets.
Figure 5: Qualitative rendering results on the Replica dataset, demonstrating Ψ -Map’s ability to produce high-fidelity geometry, semantic, and panoptic maps.
Method
ScanNet-V2
ScanNet++
PQ ↑
SQ ↑
RQ ↑
mIoU ↑
mAcc ↑
mCov ↑
mW-Cov ↑
PQ ↑
SQ ↑
RQ ↑
mIoU ↑
mAcc ↑
mCov ↑
mW-Cov ↑
NeRF-based Lifting Methods
Panoptic Lifting [ 36 ]
57.86
61.96
85.31
67.91
78.59
45.88
59.93
71.14
77.48
88.14
81.34
89.67
56.17
68.51
Contrastive Lift [ 37 ]
37.35
41.91
57.60
64.77
75.80
13.21
23.26
47.58
57.23
65.81
81.09
89.30
27.39
36.51
PVLFF [ 38 ]
30.11
51.71
44.43
55.41
63.96
45.75
48.41
52.24
66.86
65.56
62.53
70.31
67.95
75.47
PanopticRecon [ 39 ]
63.70
64.81
81.17
68.62
80.87
66.58
77.84
68.29
77.01
85.05
77.75
87.08
51.34
62.79
Table 2: Quantitative comparison of panoptic segmentation performance on ScanNet-V2 and ScanNet++ datasets.
Config
Time (ms) ↓
FPS ↑
RN-Total ↓
RN / Tile ↓
PQ ↑
Baseline
46
22
6.1M
1230
74.75
w/ Precise Tile
40
25
3.9M
800
74.73
w/ Top- K
27
37
1.2M
610
74.17
Full Method
22
45
1.2M
580
74.12
Table 3: Study on Precise Tile Intersection and Top- K Hard Selection.
Base Model
PQ ↑
SQ ↑
RQ ↑
mIoU ↑
mAcc ↑
mCov ↑
mW-Cov ↑
3DGS [ 41 ]
73.83
74.08
99.33
75.08
83.68
72.20
76.43
2DGS [ 15 ]
73.30
73.45
99.93
73.75
82.58
71.28
75.98
Ours
74.75
74.75
100.0
74.95
83.70
73.18
79.63
Table 4: Ablation study on different geometric representations on ScanNet-V2.
Method
CD-S ↓
F-Score-S ↑
CD-O ↓
F-Score-O ↑
IoU-B ↑
Col-O ↓
Col-S ↓
AdaPoinTr
0.018
0.841
0.062
0.532
0.597
0.329
0.023
InstPIFu
0.128
0.493
0.089
0.470
0.207
0.510
0.159
Gen3DSR
0.070
0.655
0.103
0.430
0.398
0.291
0.093
Ours
0.016
0.903
0.036
0.710
0.666
0.203
0.015
Table 5: Quantitative comparisons on Scan2CAD dataset
Figure 6: Quantitative comparisons on Scan2CAD dataset.
Figure 7: Comparison of navigation performance before and after fine-tuning with 3D-consistent labels.
Scene
SR-Before
SR-After
Laboratory Room
20%
100%
Private House
25%
50%
Table 6: Impact of fine-tuning with 3D-consistent labels on navigation success rate (SR).
Open-vocabulary panoptic reconstruction is crucial for advanced robotics and simulation. However, existing 3D reconstruction methods, such as NeRF or Gaussian Splatting variants, often struggle to achieve the real-time inference frequency required by robotic control loops. Existing methods incur prohibitive latency when processing the high-dimensional features required for robust open-vocabulary segmentation. We propose Fast-SegSim, a novel, simple, and end-to-end framework built upon 2D Gaussian Splatting, designed to realize real-time, high-fidelity, and 3D-consistent open-vocabulary segmentation reconstruction. Our core contribution is a highly optimized rendering pipeline that specifically addresses the computational bottleneck of high-channel segmentation feature accumulation. We introduce two key optimizations: Precise Tile Intersection to reduce rasterization redundancy, and a novel Top-K Hard Selection strategy. This strategy leverages the geometric sparsity inherent in the 2D Gaussian representation to greatly simplify feature accumulation and alleviate bandwidth limitations, achieving render rates exceeding 40 FPS. Fast-SegSim provides critical value in robotic applications: it serves both as a high-frequency sensor input for simulation platforms like Gazebo, and its 3D-consistent outputs provide essential multi-view 'ground truth' labels for fine-tuning downstream perception tasks. We demonstrate this utility by using the generated labels to fine-tune the perception module in object goal navigation, successfully doubling the navigation success rate. Our superior rendering speed and practical utility underscore Fast-SegSim's potential to bridge the sim-to-real gap.
Xuan Yu, Yuxuan Xie, Shichao Zhai +3
Department of Control Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, P. R. China
We present Genie Sim PanoRecon, a feed-forward Gaussian-splatting pipeline that delivers high-fidelity, low-cost 3D scenes for robotic manipulation simulation. The panorama input is decomposed into six non-overlapping cube-map faces, processed in parallel, and seamlessly reassembled. To guarantee geometric consistency across views, we devise a depth-aware fusion strategy coupled with a training-free depth-injection module that steers the monocular feed-forward network to generate coherent 3D Gaussians. The whole system reconstructs photo-realistic scenes in seconds and has been integrated into Genie Sim - a LLM-driven simulation platform for embodied synthetic data generation and evaluation - to provide scalable backgrounds for manipulation tasks. For code details, please refer to: https://github.com/AgibotTech/genie_sim/tree/main/source/geniesim_world.
Open-vocabulary scene understanding with online panoptic mapping is essential for embodied applications to perceive and interact with environments. However, existing methods are predominantly offline or lack instance-level understanding, limiting their applicability to real-world robotic tasks. In this paper, we propose OnlinePG, a novel and effective system that integrates geometric reconstruction and open-vocabulary perception using 3D Gaussian Splatting in an online setting. Technically, to achieve online panoptic mapping, we employ an efficient local-to-global paradigm with a sliding window. To build local consistency map, we construct a 3D segment clustering graph that jointly leverages geometric and semantic cues, fusing inconsistent segments within sliding window into complete instances. Subsequently, to update the global map, we construct explicit grids with spatial attributes for the local 3D Gaussian map and fuse them into the global map via robust bidirectional bipartite 3D Gaussian instance matching. Finally, we utilize the fused VLM features inside the 3D spatial attribute grids to achieve open-vocabulary scene understanding. Extensive experiments on widely used datasets demonstrate that our method achieves better performance among online approaches, while maintaining real-time efficiency.
Hongjia Zhai, Qi Zhang, Xiaokun Pan +5
State Key Lab of CAD & CG, Zhejiang University · VIVO BlueImage Lab · HKUST