Decompositional scene reconstruction aims to reconstruct high-quality objects and background, yet existing methods still struggle with the level of quality under heavy occlusions. While generative priors offer a potential solution, 2D image-based priors often suffer from multi-view inconsistency due to a lack of 3D awareness. Conversely, 3D-native priors provide stronger structural inductive biases but frequently lead to spatial drift and misalignment within complex scenes. To address these issues, we propose DecomVoxel, formulating object completion as a guided in-situ denoising optimization that bridges 3D-native priors with neural scene reconstruction. Our framework introduces a reformulated epsilon-based distillation loss to ensure stable latent refinement, alongside adaptive spatial guidance that utilizes occupied and vacant anchors with temporal annealing to suppress generative hallucinations and mitigate spatial drift. Experiments on Replica and ScanNet++ show that DecomVoxel significantly outperforms state-of-the-art methods while faithfully preserving the original spatial layout, structural fidelity, and style-consistent texture. Our method pushes the boundary of decompositional reconstruction by delivering high-quality textured meshes with clean topology, geometry, and appearance, providing a robust solution for the decompositional reconstruction of complex real-world scenes. Code is available at https://github.com/DecomVoxel/DecomVoxel.
Figures & tables
Figure 1 . We propose DecomVoxel , a framework that integrates guided 3D-native priors to enhance decompositional scene reconstruction. By formulating object completion as guided in-situ optimization, our method achieves high-quality topology, geometry, and appearance for both individual objects and backgrounds while faithfully preserving the original spatial layout.
Figure 2 . Overview of DecomVoxel . Our framework bridges 3D generative priors with neural reconstruction through a guided in-situ denoising optimization. We segment objects from the initial scene and then sequentially optimize their geometry and appearance under adaptive spatial guidance. This process recovers missing structures and consistent textures while preserving the original scene layout, producing high-fidelity topology, geometry, and appearance.
Figure 3 . Visualization of intermediate results. The left panel illustrates our spatial anchors: the occupied anchor ΩO (purple) preserves verified structures, while the vacant anchor ΩV (red) suppresses hallucinations in prohibited zones. The green regions denote the free space for structural synthesis. The right panel displays the progressive geometric completion over iterations. Guided by these deterministic anchors, the generative process restores missing regions while maintaining the original scene layout.
Figure 4 . Qualitative comparison. Our method reconstructs complete geometry and consistent appearance while faithfully preserving the original scene layout, whereas baselines exhibit substantial drift in position, rotation, and scale.
Dataset
Method
Reconstruction
Rendering
CD ↓
F-score ↑
NC ↑
PSNR ↑
SSIM ↑
LPIPS ↓
Replica
SimRecon
17.55
40.61
63.25
18.04
0.858
0.152
ReconViaGen
15.49
51.02
68.09
18.58
0.861
0.147
CUPID
16.29
43.95
64.80
16.70
0.809
0.180
SAM3D
10.59
45.46
66.33
18.89
0.847
0.143
MV-SAM3D
12.87
40.46
64.19
18.83
0.848
0.142
Table 1. Quantitative comparison. Our method consistently outperforms state-of-the-art baselines across both reconstruction and rendering metrics. Top-3 results are highlighted as the first , second and third .
Method
Obj Geo. ↑
Obj App. ↑
Layout ↑
SimRecon
2.12±1.30
1.86±1.25
2.01±1.12
SAM3D
2.37±1.40
2.21±1.41
2.26±1.22
MV-SAM3D
2.66±1.59
2.52±1.60
2.68±1.01
ShapeR
2.19±1.36
-
2.95±1.20
Ours
3.81±1.25
3.78±1.33
4.08±0.95
Table 2 . User Study. Based on 44 expert questionnaires, we assess the scores (rated 1–5) of object completeness and consistency in geometry and appearance, along with spatial-layout fidelity relative to the original scene. Our method significantly outperforms all baselines across all metrics, particularly in preserving global structural alignment.
GP
G-SG
AP
A-SG
Reconstruction
Rendering
CD ↓
F-score ↑
NC ↑
PSNR ↑
SSIM ↑
LPIPS ↓
×
×
×
×
19.48
71.21
45.94
19.81
0.881
0.133
✓
×
×
×
6.52
66.34
72.81
20.03
0.860
0.129
✓
✓
×
×
3.91
78.16
78.99
21.32
0.874
0.117
✓
✓
✓
×
4.04
77.48
78.72
20.55
0.866
0.122
✓
✓
✓
✓
3.95
77.87
78.85
24.21
0.907
0.114
Table 3. Ablation study. Geometry (GP) and appearance (AP) priors improve the reconstruction and rendering quality, while adaptive spatial guidance (G-SG and A-SG) further enhances the consistency.
Figure 5 . Comparison of different optimization strategies. Our epsilon-based denoising loss (a), linear noise schedule (b), re-distributed pruning strategy (c), and cosine-power preservation loss weight schedule (d) consistently achieve the most stable convergence.
Method
Runtime ↓
Peak Memory ↓
Avg. Memory ↓
SimRecon
0.18
17.659
13.446
SAM3D
0.13
32.797
22.997
MV-SAM3D
3.13
68.157
51.580
ShapeR
0.37
11.255
5.691
ReconViaGen
0.18
14.911
7.348
CUPID
0.14
13.778
7.123
Table 4. Runtime (hours) and GPU memory (GB) on Replica.
Figure 6 . Comprehensive Reconstruction Results. Our method demonstrates robust, high-quality scene decompositional reconstruction performance on complex real-world captures.
Figure 7 . More Qualitative Comparison. Our method consistently outperforms other methods across different datasets.
Appendix figures & tables1 asset
Supplementary material from the paper’s appendix.
Appendix
Metric
Definition
cd ( cd )
2Accuracy+Completeness
Accuracy
p∈P\mboxmean(p∗∈P∗\mboxmin∣∣p−p∗∣∣1)
Completeness
p∗∈P∗\mboxmean(p∈P\mboxmin∣∣p−p∗∣∣1)
F-score
Precision+Recall2×Precision×Recall
Precision
p∈P\mboxmean(p∗∈P∗\mboxmin∣∣p−p∗∣∣1<0.05)
Recall
p∗∈P∗\mboxmean(p∈P\mboxmin∣∣p−p∗∣∣1<0.05)
Appendix
Table 6 . Evaluation metrics. We list the metrics used to evaluate reconstruction quality and their definitions. P and P∗ are the point clouds sampled from the predicted and ground-truth meshes. np is the normal vector at point p .
Department of Computer Science, the University of Hong Kong · Department of Computer Science, City University of Hong Kong · Faculty of Humanities and Arts, Macau University of Science and Technology +2