While neural rendering methods such as 3D Gaussian Splatting achieve remarkable visual fidelity, traditional polygonal meshes remain the backbone of established graphics pipelines. Triangle splatting bridges this gap by optimizing triangle primitives as differentiable splats, producing representations that are closer to mesh-based workflows. Central to these methods is the kernel function that softens triangle boundaries to propagate gradients to vertex positions. Existing triangle splatting methods make inconsistent choices of kernel functions, and analysis of these kernels' optimization behavior has been limited to unstructured triangle soups for novel-view synthesis. In this work, we consider triangle splatting as a generic tool for photometric optimization, comparing kernel properties through two complementary tasks: mesh optimization for shape reconstruction and triangle soup optimization for novel-view synthesis. Along with the analysis, we introduce an elastic kernel function that features bilateral gradient support across the boundary and an adaptive boundary value, which are shown to be essential for robust optimization. Under isolated comparison, our elastic kernel outperforms existing kernels on shape reconstruction and in the majority of novel-view synthesis benchmarks, demonstrating the importance of kernel design in the effectiveness and versatility of triangle splatting.
Figures & tables
Figure 2: A triangle with a softened boundary.
Kernel
Support
G(1)
Exterior grad.
Main limitation
Triangle Splatting [ 8 ]
inside
0
no
dead zones
2DTS [ 26 ]
bilateral
fixed
yes
boundary bias
Ours
bilateral
adaptive
yes
–
Table 1: Kernel design axes. Existing triangle kernels cover either interior-only support or bilateral support with fixed boundary weight. Our kernel keeps bilateral gradients while making the boundary value adaptive through σ .
Figure 3: Comparison of kernel functions. (a) Single-sided kernel [ 8 ] : non-zero only inside the triangle ( x≤1 ), providing no exterior gradient and shrinking when softened. (b) Bilateral kernel [ 26 ] : extends beyond the triangle boundary, but the boundary weight at x=1 is fixed, creating edge artifacts when sharpened and visual expansion when softened. (c) Our elastic kernel: the boundary weight G(1)=exp(−σ) is flexible with respect to σ , enabling wide gradient support while maintaining a stable visual size.
Figure 4: Edge artifacts for connected triangles. Transparent seams are unavoidable for soft kernels with high σ . However, only our elastic kernel produces seamless rendering with low σ (hard boundary) thanks to its flexible value on the boundary.
λσ
PSNR ↑
SSIM ↑
LPIPS ↓
CD( ×10−3 ) ↓
Nvdiffrast-F [ 14 ]
-
35.99
0.983
0.031
1.775
Nvdiffrast-V [ 14 ]
-
40.95
0.995
0.008
0.469
Triangle Splatting [ 8 ]
10−3
37.15
0.983
0.040
2.989
2DTS [ 26 ]
10−3
38.43
0.987
0.038
0.926
Ours
10−3
40.67
0.991
0.023
0.717
Triangle Splatting [ 8 ]
10−4
29.06
0.958
0.068
5.369
Table 2: Quantitative results of shape reconstruction on the FAMOUS dataset [ 27 ] . Our elastic kernel consistently outperforms splatting-based baselines under both λσ settings, approaching the accuracy of Nvdiffrast-V, which additionally relies on triangle connectivity to interpolate vertex colors.
Figure 5: Convergence speed comparison for mesh optimization. We compare our elastic kernel against the single-sided (TS) and bilateral (2DTS) kernels on shapes from the FAMOUS dataset, averaged over all objects reported in the paper.
Figure 6: Qualitative mesh reconstruction on the FAMOUS dataset [ 27 ] . Our elastic kernel recovers sharper surfaces and finer geometric details than Triangle Splatting [ 8 ] and 2DTS [ 26 ] .
Figure 7: Qualitative results of novel-view synthesis on the Mip-NeRF 360 [ 1 ] and Tanks&Temples [ 13 ] datasets. Our kernel function results in better visual details and fewer floaters and artifacts.
Mip-NeRF 360
Tanks&Temples
Deep Blending
PSNR ↑
SSIM ↑
LPIPS ↓
PSNR ↑
SSIM ↑
LPIPS ↓
PSNR ↑
SSIM ↑
LPIPS ↓
3DGS [ 11 ]
27.58
0.813
0.220
23.83
0.853
0.169
29.79
0.910
0.238
2DGS [ 9 ]
26.82
0.794
0.260
23.19
0.833
0.212
29.53
0.900
0.256
TS [ 8 ]
27.02
0.804
0.200
23.10
0.855
0.144
29.02
0.891
0.242
2DTS [ 26 ]
27.16
0.808
0.194
23.00
0.851
0.143
29.20
0.895
0.229
Ours
27.33
0.813
0.189
23.08
0.858
0.134
29.27
0.898
0.224
Table 3: Quantitative results of novel-view synthesis on Mip-NeRF 360 [ 1 ] , Tanks&Temples [ 13 ] , and Deep Blending [ 6 ] . Our method is the most competitive among all triangle-based methods.
Figure 8: Sharp and opaque rendering of optimized triangle soups on the Garden, Bicycle, and Kitchen scenes from Mip-NeRF 360 [ 1 ] .
cull small tri.
Mip-NeRF 360
Tanks&Temples
Deep Blending
PSNR ↑
SSIM ↑
LPIPS ↓
PSNR ↑
SSIM ↑
LPIPS ↓
PSNR ↑
SSIM ↑
LPIPS ↓
✓
27.33
0.813
0.189
23.08
0.858
0.134
29.27
0.898
0.224
27.32
0.813
0.190
23.12
0.859
0.133
29.28
0.900
0.224
Table 4: Ablation study on small triangle filtering . Not culling small triangles has negligible effect on novel-view synthesis performance.
Scale
λe
λn
λlap
0.1×
0.891
0.648
0.694
1×
0.607
0.607
0.607
10×
2.097
0.666
1.935
Table 5: Regularization sensitivity on a FAMOUS subset. Values are Chamfer Distance ( ×10−3 ) ↓ after changing one regularization weight at a time.
training time ↓
# triangles
FPS ↑
rendering time ↓
Triangle Splatting
58.54 min
3.71M
61.9
4.3 ms
2DTS
64.23 min
3.58M
58.4
4.8 ms
Ours
68.19 min
3.72M
57.5
4.7 ms
Table 6: Efficiency comparison on Mip-NeRF 360. Rendering time is measured per 1 million triangles.
Nvdiffrast-F
Nvdiffrast-V
TS
2DTS
Ours
TS
2DTS
Ours
λσ
-
-
10−3
10−3
10−3
10−4
10−4
10−4
armadillo
0.14
0.061
1.649
0.084
0.079
7.789
0.079
0.077
boot
1.515
0.082
0.601
0.631
0.192
2.373
0.174
0.129
brucewick
3.463
2.146
11.177
2.393
2.613
7.474
2.381
2.453
bunny_hr
0.782
0.047
2.362
0.15
0.066
4.548
0.072
0.064
cat-low-resolution
0.571
0.05
0.713
0.436
0.059
1.123
0.121
0.056
Table 7: CD( ×10−3 ) ↓ on FAMOUS [ 27 ] .
bicycle
bonsai
counter
flowers
garden
kitchen
room
stump
treehill
3DGS
25.15
32.48
29.18
21.41
27.37
31.56
31.90
26.69
22.50
2DGS
24.61
31.38
28.15
20.81
26.66
30.28
30.83
26.19
22.44
TS
24.54
32.13
28.90
20.47
27.00
31.42
31.10
26.00
21.61
2DTS
24.70
32.63
28.99
20.56
27.19
31.50
31.44
25.91
21.54
Ours
24.92
32.79
29.24
20.79
27.42
31.41
31.77
26.10
21.53
Table 8: PSNR ↑ on Mip-NeRF 360 [ 1 ] .
bicycle
bonsai
counter
flowers
garden
kitchen
room
stump
treehill
3DGS
0.748
0.948
0.916
0.588
0.857
0.933
0.928
0.768
0.635
2DGS
0.713
0.936
0.900
0.554
0.834
0.921
0.915
0.753
0.619
TS
0.738
0.949
0.914
0.585
0.849
0.932
0.930
0.744
0.593
2DTS
0.743
0.952
0.917
0.590
0.852
0.933
0.933
0.751
0.603
Ours
0.754
0.954
0.920
0.597
0.858
0.935
0.936
0.758
0.608
Table 9: SSIM ↑ on Mip-NeRF 360 [ 1 ] .
bicycle
bonsai
counter
flowers
garden
kitchen
room
stump
treehill
3DGS
0.241
0.180
0.182
0.359
0.122
0.116
0.195
0.243
0.346
2DGS
0.306
0.204
0.214
0.404
0.163
0.138
0.222
0.290
0.398
TS
0.224
0.143
0.157
0.316
0.122
0.107
0.163
0.242
0.322
2DTS
0.220
0.137
0.150
0.307
0.117
0.106
0.161
0.235
0.317
Ours
0.208
0.138
0.148
0.299
0.111
0.105
0.160
0.226
0.311
Table 10: LPIPS ↓ on Mip-NeRF 360 [ 1 ] .
Train
Truck
Drjohnson
Playroom
PSNR ↑
SSIM ↑
LPIPS ↓
PSNR ↑
SSIM ↑
LPIPS ↓
PSNR ↑
SSIM ↑
LPIPS ↓
PSNR ↑
SSIM ↑
LPIPS ↓
3DGS
22.21
0.82
0.195
25.44
0.89
0.142
29.49
0.91
0.236
30.08
0.91
0.240
2DGS
21.26
0.79
0.250
25.12
0.87
0.173
28.90
0.90
0.257
30.15
0.91
0.260
TS
21.22
0.82
0.182
24.99
0.89
0.105
28.87
0.89
0.250
29.18
0.89
0.234
2DTS
21.24
0.82
0.180
24.77
0.88
0.106
28.81
0.89
0.240
29.58
0.90
0.217
Ours
21.47
0.83
0.162
24.68
0.89
0.105
28.91
0.90
0.235
29.64
0.90
0.214
Table 11: Per-scene results of novel-view synthesis on Tanks&Temples [ 13 ] and Deep Blending [ 6 ] .