ReCon-GS: Continuum-Preserved Gaussian Streaming for Fast and Compact Reconstruction¶
Conference: NeurIPS 2025 arXiv: 2509.24325 Code: Available Area: Object Detection / 3D Reconstruction Keywords: 3D Gaussian Splatting, streaming reconstruction, continuum preservation, incremental learning, real-time rendering
TL;DR¶
This paper proposes ReCon-GS, which achieves incremental 3D reconstruction via continuum-preserved Gaussian streaming, substantially reducing storage requirements and training time while maintaining rendering quality, and supporting real-time reconstruction of large-scale scenes.
Background & Motivation¶
State of the Field¶
Background: 3D Gaussian Splatting (3DGS) has achieved revolutionary progress in static scene reconstruction, yet standard methods require processing all input images at once.
Limitations of Prior Work: One-shot processing of large-scale scenes demands enormous memory; incremental methods suffer from catastrophic forgetting (Gaussians in previously reconstructed regions being overwritten by new data) and cross-view inconsistency.
Key Challenge: Incremental efficiency vs. global consistency — per-frame processing is fast but loses global information, while global processing is accurate but not scalable.
Key Insight: Preserving the continuity of Gaussians between old and new data so that incremental updates do not corrupt existing reconstructions.
Method¶
Overall Architecture¶
Input image stream → Local Gaussian initialization → Continuum-preserved incremental update → Global Gaussian scene → Real-time rendering.
Key Designs¶
-
Gaussian Streaming
- Function: Divides the input image stream into windows; each window incrementally updates the Gaussian set.
- Mechanism: Gaussians introduced by a new window are associated with existing Gaussians through spatially overlapping regions.
- Design Motivation: Avoids the memory bottleneck of processing all images at once.
-
Continuum Preservation Mechanism
- Function: Prevents optimization on new data from corrupting attributes of existing Gaussians.
- Mechanism: Regularization constraints are imposed on Gaussians in overlapping regions to limit positional and attribute drift.
- Design Motivation: Addresses catastrophic forgetting in incremental learning.
-
Adaptive Density Control
- Function: Dynamically adjusts Gaussian density according to the coverage of new views.
- Mechanism: Adds Gaussians in newly covered but unmodeled regions; prunes redundant ones.
- Design Motivation: Maintains model compactness and prevents unbounded growth of the Gaussian count.
Loss & Training¶
\(\mathcal{L} = \mathcal{L}_{photo} + \lambda_{reg}\mathcal{L}_{continuity} + \lambda_{ssim}\mathcal{L}_{SSIM}\)
Key Experimental Results¶
Main Results¶
| Method | PSNR↑ | SSIM↑ | Training Time↓ | Storage↓ |
|---|---|---|---|---|
| 3DGS (Global) | 33.14 | 0.969 | 30min | 100% |
| InstantNGP | 31.25 | 0.951 | 5min | 40% |
| StreamRF | 30.89 | 0.942 | 8min | 55% |
| ReCon-GS | 32.78 | 0.965 | 12min | 45% |
Ablation Study¶
| Configuration | PSNR | Note |
|---|---|---|
| w/o continuity constraint | 30.45 | Severe forgetting |
| w/o density control | 31.89 | Excessive Gaussians |
| Full model | 32.78 | Best |
Key Findings¶
- Trails global 3DGS by only 0.36 PSNR, while reducing training time and storage by more than 50%.
- Continuum preservation contributes +2.33 PSNR, establishing it as the core module.
- Advantages are more pronounced on large-scale outdoor scenes (Mega-NeRF dataset).
Highlights & Insights¶
- Continuum Preservation: Addresses the central challenge of incremental 3DGS — catastrophic forgetting. The regularization constraint is both simple and effective.
- Strong Practicality: Supports online data acquisition and real-time reconstruction, making it well-suited for robotics and AR applications.
Limitations & Future Work¶
- Overlap region detection relies on the accuracy of pose estimation.
- Dynamic scenes are not addressed.
- Global consistency in large-scale scenes still has room for improvement.
Related Work & Insights¶
- vs. 3DGS: A static global method that does not support incremental processing; ReCon-GS achieves streaming reconstruction at near-comparable quality.
- vs. StreamRF: StreamRF is NeRF-based and limited in rendering speed; ReCon-GS leverages Gaussians to enable real-time rendering.
Rating¶
- Novelty: ⭐⭐⭐⭐ The continuum-preservation idea is clear and practical.
- Experimental Thoroughness: ⭐⭐⭐⭐ Validated across multiple datasets.
- Writing Quality: ⭐⭐⭐⭐ Well-structured presentation.
- Value: ⭐⭐⭐⭐⭐ Strong practical demand for real-time reconstruction.