Voronoi tessellations have recently emerged as an adaptive, space-partitioning discretization for shape and appearance reconstruction from multi-view images. However, the irregular cells they produce make the repeated reconstruction of the tessellation during optimization costly. We therefore explore adaptive centroidal Voronoi tessellations (CVTs), which extend standard CVTs with non-uniform cell sizes while preserving the regular, well-shaped cells that make them efficient to compute. In CVTSplat, cell size is modulated by the evolving signed distance field, concentrating sites near the zero level set while keeping cells nearly centroidal. This regularity lets us specialize the whole pipeline, with GPU algorithms for nearest-neighbor queries and approximate Voronoi construction, and a rasterizer tailored to small, nearly isotropic cells. Our Voronoi construction is 5 to 10 times faster than general-purpose alternatives in this regime. On DTU and BlendedMVS, CVTSplat reaches geometric accuracy competitive with the best Gaussian-splatting surface methods while training in about 2.5 minutes on a single GPU.
Figures & tables
Figure 1. We represent the scene with Voronoi cells carrying trainable signed-distance and view-dependent appearance attributes, and directly rasterize them for differentiable volume rendering (middle). Our adaptive CVT combines regular cells with increased spatial resolution near the zero level set, concentrating representation capacity where it is most needed (bottom right). Top left: signed-distance values mapped to hue; bottom right: randomized cell colors illustrate the adaptive refinement near the surface.
Figure 2. Overview of our approach during optimization. Top row: Construction of the tessellation. (a) The sites are processed to obtain a list of their 32 nearest neighbors, (b) before building the Voronoi diagram as an adjacency graph. (c) The center of mass of each cell is then computed to regularize the distribution of the sites via the CVT loss. (d) The Voronoi diagram is optionally converted to a Delaunay triangulation to extract the zero-level set with marching tetrahedra. Bottom row: Differentiable volume rendering from posed images. (e) The sites’ attributes (learnable SDF and features) are smoothed with a Gaussian kernel. (f) The gradient of the SDF is also computed to produce normal vectors, which define a piecewise linear SDF over the cells. Then, for all viewpoints in the mini-batch, (g) a per-site color is computed based on the camera’s position, (h) before rasterizing the scene and comparing against the ground-truth image.
Figure 3. Left: The volume and centroid of the cell are computed by casting rays from the site’s location. Right: Our biased CVT loss maintains the sites slightly closer to the implicit surface than the centroids xˉ , resulting in stretched cells along the SDF gradient.
Figure 4. Voronoi cell in 2D. The bisector plane Pk is inactive since it does not participate in defining the cell Ci . Any neighboring point beyond the security radius, defined as twice the cell radius, is guaranteed to not participate.
Figure 5. The 2D inequalities enclose the feasibility region, which corresponds to a facet of the polyhedron wrapping the cell. Each line is the intersection of the reference plane Pr with another bisector plane Pj .
Figure 6. The adjacency matrix of the site i encodes which of its neighbors are adjacent to each other.
Figure 7. The light probes, parametrized with spherical harmonics, are interpolated to produce view-dependent features Fa,v and Fa,w , based on the local view direction v and reflected vector w .
Figure 8. The color is constant but the density varies inside the cells. They are sorted by distance to the camera for pop-free rasterization.
Figure 9. The pixel tiles are split into chunks of 32 consecutive cells. All chunks are rasterized in parallel but the ones marked in red have been skipped by detecting occlusions dynamically. The final result (top left) is the α -blending of all the chunks in front-to-back order, evaluated in a subsequent pass.
Method
Mean
Dog
Bear
Clock
Durian
Man
Sculpture
Stone
Jade
NeuS2 ( Wang et al., 2023 )
2.93
2.78
2.71
2.63
4.23
2.25
2.50
1.91
4.43
Voxurf ( Wu et al., 2023 )
2.64
2.28
2.20
1.88
2.98
2.11
1.75
3.96
3.99
ProbeSDF ( Toussaint et al., 2025 )
2.21
2.24
2.03
1.69
3.26
1.81
1.61
1.36
3.71
PGSR ( Chen et al., 2024 )
1.56
1.21
1.20
N/A
2.15
1.39
1.81
1.58
N/A
GGGS ( Zhang et al., 2026b )
0.88
0.55
0.37
0.71
0.93
0.85
0.99
0.40
2.28
CVTSplat
1.13
0.91
0.49
0.97
1.44
0.91
1.21
0.60
2.53
Table 1. Chamfer distance on BlendedMVS with 4M sites.
Method
24
37
40
55
63
65
69
83
97
105
106
110
114
118
122
Mean
Runtime
GPU
Implicit
VolSDF ( Yariv et al., 2021 )
1.14
1.26
0.81
0.49
1.25
0.70
0.72
1.29
1.18
0.70
0.66
1.08
0.42
0.61
0.55
0.86
>12 h
RTX 2080 Ti
NeuS ( Wang et al., 2021 )
1.00
1.37
0.93
0.43
1.10
0.65
0.57
1.48
1.09
0.83
0.52
1.20
0.35
0.49
0.54
0.84
8 h
RTX 2080 Ti
Neuralangelo ( Li et al., 2023 )
0.37
0.72
0.35
0.35
0.87
0.54
0.53
1.29
0.97
0.73
0.47
0.74
0.32
0.41
0.43
0.61
>128h
V100
NeuS2 ( Wang et al., 2023 )
0.56
0.76
0.49
0.37
0.92
0.71
0.76
1.22
1.08
0.63
0.59
0.89
0.40
0.48
0.55
0.70
5 min
RTX 3090
Voxurf ( Wu et al., 2023 )
0.91
0.73
0.45
0.34
0.99
0.66
0.83
1.36
1.31
0.78
0.53
1.12
0.37
0.53
0.51
0.76
15 min
A100
ProbeSDF ( Toussaint et al., 2025 )
0.65
0.74
0.34
0.34
1.02
0.71
0.62
1.34
0.94
0.70
0.53
0.96
0.36
0.45
0.47
0.68
2.5 min
RTX 3090
Table 2. Chamfer distance on the DTU benchmark in millimeters. Lower is better. Best, second-best, and third-best results are highlighted.
Figure 10. Qualitative comparison on DTU against GGGS ( Zhang et al., 2026b ) and PGSR ( Chen et al., 2024 ) . The ground truth meshes were obtained by applying Poisson reconstruction ( Kazhdan and Hoppe, 2013 ) on the ground truth point clouds. Our approach recovers finer details, especially visible on scans 24, 106 and 122.
Figure 11. Qualitative comparison on BlendedMVS against GGGS ( Zhang et al., 2026b ) and PGSR ( Chen et al., 2024 ) . Errors are mesured relative to the unit bounding box enclosing the objects. Our approach produces smoother geometry than GGGS (see close-ups on man and clock, heatmaps on jade), although some concavities are better reconstructed with GGGS (clock, jade, dog). PGSR fails on two examples and is less accurate overall.
Method (#Sites, #Optim. steps)
24
37
40
55
63
65
69
83
97
105
106
110
114
118
122
Mean
Time (s)
1M Sites, 10K
0.38
0.54
0.30
0.30
0.82
0.50
0.47
1.02
0.75
0.53
0.33
0.66
0.30
0.34
0.34
0.50
87
2M Sites, 10K
0.36
0.51
0.30
0.30
0.82
0.48
0.47
1.00
0.74
0.51
0.33
0.65
0.30
0.33
0.33
0.50
110
4M Sites, 5K
0.36
0.58
0.30
0.30
0.75
0.46
0.46
0.97
0.74
0.50
0.39
0.75
0.29
0.32
0.31
0.50
79
4M Sites, 7.5K
0.35
0.50
0.30
0.30
0.75
0.46
0.46
0.97
0.74
0.49
0.39
0.65
0.29
0.32
0.31
0.48
115
Basic Rasterizer (4M Sites, 10K)
0.35
0.49
0.30
0.29
0.76
0.45
0.46
0.97
0.76
0.49
0.41
0.58
0.29
0.32
0.31
0.48
280
Chunked Rasterizer (4M Sites, 10K)
0.35
0.49
0.30
0.29
0.76
0.45
0.46
0.97
0.75
0.49
0.38
0.58
0.29
0.32
0.31
0.48
147
Table 3. Training speed analysis on DTU.
Figure 12. Test with fewer sites or fewer optimization steps. Top: Using fewer sites produces a predictable loss of geometric details with faster optimization. Bottom: Our model converges after 10K training steps, with marginal improvement beyond 7.5K steps.
Method
24
37
40
55
63
65
69
83
97
105
106
110
114
118
122
Mean
No Linear Radiance
0.35
0.49
0.30
0.29
0.79
1.78
0.44
0.99
0.84
0.50
0.32
0.59
0.29
0.32
0.31
0.57
No ZNCC
0.40
0.57
0.33
0.31
0.80
0.52
0.52
1.05
0.83
0.54
0.38
1.07
0.29
0.35
0.32
0.55
No Depth Smoothing
0.44
0.50
0.46
0.29
0.75
0.45
0.46
0.97
0.75
0.50
0.50
0.70
0.29
0.36
0.31
0.52
Biased CVT ( a=0.05 )
0.36
0.51
0.34
0.30
0.81
0.50
0.48
1.02
0.77
0.52
0.34
0.80
0.30
0.34
0.34
0.52
No Ref. Probes
0.35
0.56
0.30
0.29
0.76
0.45
0.50
0.97
0.82
0.49
0.38
0.81
0.30
0.32
0.31
0.51
No Envmap
0.35
0.52
0.29
0.29
0.80
0.44
0.44
1.12
0.76
0.53
0.39
0.64
0.28
0.31
0.30
0.50
Table 4. Ablation study on DTU.
Figure 13. We remove one loss on each example to ablate our model. Bottom: The multi-view (ZNCC), depth and normal losses as well as the reflection probes are important for geometric accuracy. Top: Training with a linear radiance avoids a failure case on scan 65. Not replacing the planar ZNCC with a nonplanar variant in the last phase of training suppresses fine details (scan 106). The envmap alleviates silhouette artifacts from inaccurate masks (scan 83).
CVTSplat with/without warmup
RestrictedVoronoi ( Basselin et al., 2021 )
CuPy-KNN ( Igelbrink, )
Torch-kdtree ( Grandits, )
Sklearn ( Pedregosa et al., 2011 )
TrueKNN ( Nagarajan et al., 2023 )
Build Tree
1.3
<1
17.3
6742*
1925*
-
Query Tree
13.7 / 46.8
97.9
720
1026
25630*
-
Total
15.0 / 48.1
97.9
737
7768
27556
28543
Table 5. KNN timings (ms) on our DTU point clouds with 4M points. The * symbol denotes CPU operations.
CVTSplat (Ours)
MeshlessVoronoi ( Ray et al., 2018 )
RestrictedVoronoi ( Basselin et al., 2021 )
Paragram ( Taveira et al., 2026a )
gDel3D ( Cao et al., 2014 )
RadFoam ( Govindarajan et al., 2025 )
KNN
15.0
126.6
97.9
-
-
-
Adjacency
11.9
44.5
40.5
275.5
617.4
18995
Centroids
3.0
-
-
-
Total
29.9
171.0
138.4
275.5
617.4
18995
Table 6. Voronoi diagram construction timings (ms) on our trained DTU point clouds (4M points).
Figure 14. Timings for Voronoi diagram construction, evaluated on DTU checkpoints saved every 500 optimization steps. Reported numbers include KNN and centroids computations if applicable.
Adjacency → Del.
Marching Tet.
Total
All cells
11.5 ms
4.0 ms
15.5 ms
Zero-crossing only
4.5 ms
0.6 ms
5.1 ms
Table 7. Mesh extraction timings on DTU.
Appendix figures & tables12 assets
Supplementary material from the paper’s appendix.
Appendix
Training phases. 10,000 iterations: 400 initialization, 9200 main training, and 400 cleanup. No sites are added during initialization or cleanup.
Point population. 200k initial sites up to 4M sites. Densification every 10 iterations.
Data and optimization. 4 image levels of detail, batch size: 4 images per batch using gradient accumulation, learning rate [0.025, 0.001] .
Structure updates. KNN every 10 iterations, Voronoi diagram construction frequency [1, 2, 5] .
Table 8. Optimization schedule. Array values are linearly interpolated throughout training.
Dataset
Non-manifold edges
Boundary edges
Triangles
DTU
2.7
2.3
6.4M
BlendedMVS
2.4
1.4
6.7M
Appendix
Table 9. Average mesh extraction defects by dataset.
Figure 15. Relative error curves when computing cell volume, centroid and bounding sphere radius using a varying number of ray samples. The volume and centroid error curves are nearly overlapped in the plot.
Figure 16. Histograms pooled over all 23 DTU and BlendedMVS scenes (92 million sites). The blue one queries KNN at each site while the red one queries at the cell centroid computed at the previous update. Left : Number of Voronoi neighbors per site. The mean is ≈14.2 , corresponding to 14 bisector planes contributing to each cell on average. Middle and Right : zero-based index of the last detected Voronoi neighbor in the KNN list, with linear and logarithmic frequency scales respectively. For ≈60% of sites, all Voronoi neighbors lie among the first 16 nearest neighbors. The frequency decreases roughly exponentially beyond index 15, with ≈0.1% of cells not finding their last Voronoi neighbor within the 32-KNN list with the base strategy. Using shifted ball queries reduces the frequency of incomplete cells by a factor of 170 in comparison ( ≈600 cells in total out of 92M).
Figure 17. Cell-radius statistics averaged over all scenes. Left : the distribution of cell radius r against SDF d . The cyan curve fits the median radius in each distance bin, showing approximately linear growth with ∣d∣ . Its similar branches on either side of zero indicate comparable cell size inside and outside the surface at equal distance. Middle : the distribution of log2(r) . The red curve fits a power-law tail over 2−8≤r≤2−4 , containing 26.2% of sites. Within this range, each doubling of r corresponds to approximately 3.9× fewer sites per histogram bin ( h(r)/h(2r)≈3.9 ). Right : The number of cells decreases very quickly away from the implicit surface.
Figure 18. Adaptive discretization of a known SDF. Top : 2D slice with random colors and superimposed extracted mesh. Bottom : 2D slice with SDF mapped to hue. We fit the SDF using N=105 sites and vary the parameter a in the CVT loss. The mesh approximates the zero level set more accurately for a>0 . The proportion of cells e with missing bisector planes increases sharply for a>0.1 when using 32 Euclidean nearest neighbors. Missing bisector planes can cause cells to clearly overlap for larger values of a (see a=0.2 , center of the horseshoe in the top panel).
Dataset
Image size
Cell radius (px)
Render time (ms)
FPS
DTU
1600×1200
1.55±0.31
3.63±0.29
277±21
BlendedMVS
768×576
1.21±0.15
2.40±0.21
419±36
Appendix
Table 10. Average projected cell radius and rendering speed (mean ± standard deviation across scenes).
Figure 19. Qualitative comparison of renderings on DTU. Our approach can represent high-frequency texture patterns (scan 24, house roof) but misses some specularities compared to GGGS and PGSR.
Figure 20. Qualitative comparison of renderings on BlendedMVS. PGSR failed to converge on the clock scene.
Department of Electrical and Computer Engineering (ECE), Sungkykwan University (SKKU), Suwon 16419, South Korea · Department of Display Convergence Engineering (DCE), SKKU, Suwon 16419, South Korea · AiM Future, Seoul 06804, South Korea +1
East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China · Shanghai Open University, 288 Guoshun Road, 200433, Shanghai, China · Shanghai Xiaoyuan Innovation Center, 599 Xingmei Road, 200237, Shanghai, China