Organizations: School of Mathematics, Hefei University of Technology, Hefei 230601, China · School of Software, Tsinghua University, Beijing 100084, China · School of Computer Science and Technology, University of Science and Technology of China, Hefei 230026, China
Mobile robots and IoT devices demand real-time localization and dense reconstruction under tight compute and energy budgets. While 3D Gaussian Splatting (3DGS) enables efficient dense SLAM, dynamic objects and occlusions still degrade tracking and mapping. Existing dynamic 3DGS-SLAM often relies on heavy optical flow and per-frame segmentation, which is costly for mobile deployment and brittle under challenging illumination. We present DAGS-SLAM, a dynamic-aware 3DGS-SLAM system that maintains a spatiotemporal motion probability (MP) state per Gaussian and triggers semantics on demand via an uncertainty-aware scheduler. DAGS-SLAM fuses lightweight YOLO instance priors with geometric cues to estimate and temporally update MP, propagates MP to the front-end for dynamic-aware correspondence selection, and suppresses dynamic artifacts in the back-end via MP-guided optimization. Experiments on public dynamic RGB-D benchmarks show improved reconstruction and robust tracking while sustaining real-time throughput on a commodity GPU, demonstrating a practical speed-accuracy tradeoff with reduced semantic invocations toward mobile deployment.
Figures & tables
Fig. 1: Typical failure cases of 3DGS-SLAM in dynamic scenes. Moving objects are often fused into the Gaussian map, leading to ghosting/blobs, smeared textures, and broken surfaces, which in turn degrades both tracking stability and static-scene reconstruction quality.
Fig. 2: System pipeline of DAGS-SLAM. A semantic thread maintains a temporally updated per-Gaussian MP state by fusing lightweight instance priors with geometric cues, and an uncertainty-aware scheduler triggers semantics on demand to reduce overhead. MP is propagated to the tracking thread for dynamic-aware correspondence filtering and to the mapping thread for MP-guided rendering optimization, producing clean static-scene reconstructions under dynamic interference.
Fig. 3: Illustration of the proposed labeling process, where yellow denotes dynamic outliers and green denotes static features.
Fig. 4: The uncertainty-aware semantic-on-demand scheduling mechanism. MP uncertainty and tracking/geometry inconsistency are fused into a trigger score to decide whether to refresh the instance prior. Segmentation is invoked only at trigger moments; otherwise the prior is reused and MP is updated temporally.
Fig. 5: Epipolar-verified static recovery and densification. We first obtain a coarse MP-based dynamic mask to localize ambiguous boundary regions, then use epipolar geometry to validate static correspondences and filter dynamic outliers. The verified static regions are restored and incorporated into the densification stage.
Fig. 6: MP-guided rendering and joint optimization. We convert per-Gaussian MP to a pixel-wise static confidence map to down-weight dynamic regions during rasterization. The objective combines MP-weighted photometric/depth losses, a static motion-consistency regularizer, and an MP-guided edge-warp term to improve alignment near motion boundaries under imperfect priors.
Sequence
ORB-SLAM3
Photo-SLAM
SplaTAM
DDN-SLAM
DG-SLAM
Ours
ATE
Std.
ATE
Std.
ATE
Std.
ATE
Std.
ATE
Std.
ATE
Std.
fr3/walking/xyz
0.3729
0.1966
0.3054
0.1482
0.4323
0.1381
0.0148
0.0096
0.0166
0.0088
0.0128
0.0080
fr3/walking/xyz_val
0.6821
0.5125
0.6147
0.3986
0.8849
0.8096
0.0112
0.0071
0.0215
0.0108
0.0131
0.0054
fr3/walking/static
0.1769
0.0968
0.1347
0.0118
0.3470
0.4326
0.0118
0.0060
0.0062
0.0101
0.0069
0.0032
fr3/walking/static_val
0.2784
0.0713
0.2634
0.0728
0.7368
0.4290
0.0138
0.0079
0.0208
0.0311
0.0109
0.0087
fr3/walking/rpy
0.6129
0.2696
0.5644
0.2789
—
0.0421
0.0266
0.0435
0.0209
0.0318
0.0292
TABLE I: Absolute trajectory error (ATE, RMSE) on TUM RGB-D dynamic sequences ( fr3/walking/* ).
Sequence
ORB-SLAM3
Photo-SLAM
SplaTAM
DDN-SLAM
DG-SLAM
Ours
ATE
Std.
ATE
Std.
ATE
Std.
ATE
Std.
ATE
Std.
ATE
Std.
crowd
0.4300
0.0210
0.5104
0.0113
1.8286
1.2384
0.0191
0.0110
0.0211
0.0180
0.0178
0.0090
crowd2
0.9160
0.5577
0.9332
0.5789
3.4560
1.8706
0.0226
0.0109
0.0322
0.0245
0.0231
0.0127
person_tracking
0.6121
0.3220
0.3293
0.4518
0.5290
0.1022
0.0431
0.0168
0.0458
0.0340
0.0420
0.0179
person_tracking2
0.6568
0.5564
0.3245
0.2681
0.6606
0.4266
0.0374
0.0128
0.0690
0.0388
0.0400
0.0219
synchronous
0.7670
1.2382
0.4562
0.5641
—
0.0300
0.0289
0.0491
0.0284
0.0280
0.0211
TABLE II: Absolute trajectory error (ATE, RMSE) on the BONN RGB-D dataset.
Fig. 7: Qualitative visualization of DAGS-SLAM on representative dynamic sequences.
Recent advances in 3D Gaussian Splatting (3DGS) have enabled significant progress in dense dynamic Simultaneous Localization And Mapping (SLAM). Prevailing methods typically discard predefined dynamic objects, ignoring that transiently static objects offer valuable geometric constraints for pose estimation. A recent work attempts to leverage this potential by employing per-pixel uncertainty maps to quantify the magnitude of motion. While this approach enables transiently static objects to enhance pose estimation, it erroneously integrates these objects into the static map, resulting in persistent artifacts. Moreover, its reliance on purely geometric information leads to ambiguous object boundaries in the uncertainty maps. To overcome these limitations, we present DL-SLAM, a monocular Gaussian Splatting SLAM system built upon a novel dual-level probabilistic framework. Our method computes dynamic probability maps by combining semantic and geometric information. These pixel-level probabilities are lifted to 3D and aggregated to derive an object-level dynamic probability for each instance. Object-level probability enables the categorical pruning of dynamic Gaussians, resulting in an artifact-free static map. The static map, in turn, provides a geometrically consistent guidance to refine the pixel-wise probabilities, enhancing their reliability. Experimental results demonstrate that DL-SLAM outperforms existing approaches, improving tracking accuracy by up to 13% while generating high-fidelity semantic maps.
Handling the dynamic environments is a significant research challenge in Visual Simultaneous Localization and Mapping (SLAM). Recent research combines 3D Gaussian Splatting (3DGS) with SLAM to achieve both robust camera pose estimation and photorealistic renderings. However, using SLAM to efficiently reconstruct both static and dynamic regions remains challenging. In this work, we propose an efficient framework for dynamic 3DGS SLAM guided by optical flow. Using the input depth and prior optical flow, we first propose a category-agnostic motion mask generation strategy by fitting a camera ego-motion model to decompose the optical flow. This module separates dynamic and static Gaussians and simultaneously provides flow-guided camera pose initialization. We boost the training speed of dynamic 3DGS by explicitly modeling their temporal centers at keyframes. These centers are propagated using 3D scene flow priors and are dynamically initialized with an adaptive insertion strategy. Alongside this, we model the temporal opacity and rotation using a Gaussian Mixture Model (GMM) to adaptively learn the complex dynamics. The empirical results demonstrate our state-of-the-art performance in tracking, dynamic reconstruction, and training efficiency.
Yunsong Wang, Gim Hee Lee
School of Computing, National University of Singapore
Visual SLAM algorithms achieve significant improvements through the exploration of 3D Gaussian Splatting (3DGS) representations, particularly in generating high-fidelity dense maps. However, they depend on a static environment assumption and experience significant performance degradation in dynamic environments. This paper presents GGD-SLAM, a framework that employs a generalizable motion model to address the challenges of localization and dense mapping in dynamic environments - without predefined semantic annotations or depth input. Specifically, the proposed system employs a First-In-First-Out (FIFO) queue to manage incoming frames, facilitating dynamic semantic feature extraction through a sequential attention mechanism. This is integrated with a dynamic feature enhancer to separate static and dynamic components. Additionally, to minimize dynamic distractors' impact on the static components, we devise a method to fill occluded areas via static information sampling and design a distractor-adaptive Structure Similarity Index Measure (SSIM) loss tailored for dynamic environments, significantly enhancing the system's resilience. Experiments conducted on real-world dynamic datasets demonstrate that the proposed system achieves state-of-the-art performance in camera pose estimation and dense reconstruction in dynamic scenes.
Yi Liu, Haoxuan Xu, Hongbo Duan +5
Shenzhen International Graduate School, Tsinghua University, Shenzhen, China. · Thrust of Robotics and Autonomous Systems, The Hong Kong University of Science and Technology (Guangzhou), Guangzhou, China. · the School of Cyber Science and Technology, Sun Yat-sen University, Shenzhen, China. +1