Although 3D Gaussian Splatting (3DGS) supports real-time rendering, training relies on offline geometry, long-horizon densification, and memory-intensive differentiation. We cast post-capture static-scene training as resource-constrained finite-horizon optimization, where terminal quality depends jointly on the initial representation and reference-consistent gradient execution. To the best of our knowledge, PocketGS is the first publicly documented pipeline to complete geometry construction, Gaussian initialization, and 3DGS optimization on a commodity smartphone. Its I, G warm start combines refined poses, a filtered dense prior, and surface-aligned anisotropic Gaussians. Its T operator replays compositing interactions and scatters gradients to canonical parameters, matching a numerical reference at the reported precision. Controlled 500-step experiments on LLFF, Mip-NeRF 360, and MobileScan show high-quality reconstruction at the device horizon. Across MobileScan, every scene remains below 3 GB peak memory and post-capture processing averages 255.2 s, enabling an on-device capture-to-render workflow. Separate 30k experiments characterize native-schedule behavior.
Figures & tables
Figure 2: Overview of the PocketGS framework. PocketGS tackles on-device 3DGS training through three coupled operators: ( G ) Geometry Prior Construction combines information-gated frame selection, GPU-native Schur-complement BA, and single-reference MVS to construct a dense geometric prior. ( I ) Prior-Conditioned Parameterization seeds anisotropic Gaussians by estimating local surface statistics (normals ni and scales) to front-load structure discovery via disc-like covariance seeding. ( T ) Hardware-Aligned Splatting implements a mobile-native differentiable renderer using unrolled alpha-compositing ( S=id,Cin,α ) and index-mapped gradient scattering for reference-consistent gradient execution at the reported precision within the mobile memory bounds of the canonical parameter buffer ( μ,Σ,c,α ) during end-to-end training.
Method
LLFF
Mip-NeRF 360
MobileScan
PSNR ↑
SSIM ↑
LPIPS ↓
Time(s)
Count
PSNR ↑
SSIM ↑
LPIPS ↓
Time(s)
Count
PSNR ↑
SSIM ↑
LPIPS ↓
Time(s)
Count
3DGS-SFM-WK
23.28
0.789
0.226
116.3
18k
21.05
0.649
0.377
398.7
46k
22.64
0.781
0.319
123.8
23k
3DGS-MVS-WK
21.04
0.730
0.262
320.3
41k
18.26
0.586
0.429
975.6
76k
22.23
0.834
0.226
547.5
165k
Mobile-GS
23.26
0.790
0.227
133.1
18k
21.06
0.650
0.377
405.2
46k
22.61
0.782
0.321
145.1
23k
DashGaussian
23.30
0.790
0.224
115.9
18k
21.54
0.672
0.351
399.9
46k
22.66
0.783
0.317
122.5
23k
Taming-3DGS
23.27
0.788
0.228
117.6
18k
21.09
0.651
0.375
402.6
46k
22.62
0.780
0.322
125.1
23k
Table 1: Reconstruction at a controlled 500-step horizon. Dataset-level averages on LLFF, Mip-NeRF 360, and MobileScan with densification and pruning disabled for every variant. The experiment measures terminal quality at K=500 from each method’s preprocessing and initialization pipeline, before adaptive density control. Completed native-schedule behavior is evaluated separately. Time reports per-system post-capture processing latency on the stated hardware. Higher is better for PSNR/SSIM, and lower is better for LPIPS. Red , orange , and yellow denote the best, second-best, and third-best results.
Figure 3: MobileScan reconstruction after 500 optimization steps. PocketGS better preserves textures and thin structures; generic MVS remains biased toward textured regions, leaving low-texture and specular areas under-sampled at initialization.
Method
Step
PSNR ↑
SSIM ↑
LPIPS ↓
3DGS-SFM-WK
30k
25.84
0.847
0.122
15k
25.71
0.845
0.127
7k
25.38
0.832
0.146
3k
24.44
0.800
0.181
1k
22.83
0.719
0.287
PocketGS
500
22.25
0.702
0.302
Table 2: Early convergence on Mip-NeRF 360. PocketGS’s controlled 500-step endpoint versus the 1k–30k native-schedule checkpoints of 3DGS-SFM-WK; complete native trajectories are reported in the supplement.
Method
On-device Train
FPS ↑
MobileNeRF ( Chen et al. 2023 )
×
31.40
MetaSapiens ( Lin et al. 2025 )
×
49.24
Mobile-GS ( Du et al. 2026 )
×
62.56
PocketGS (Ours)
✓
52.32
Table 3: Smartphone rendering. Baselines are rendering-only references under their reported setups; PocketGS is measured on the tested smartphone and trains fully on-device.
Variant
PSNR ↑
SSIM ↑
LPIPS ↓
Time ↓ (s)
PocketGS (Full)
23.67
0.791
0.225
255.2
w/o Global BA
23.54
0.760
0.227
251.8
w/o MVS
21.15
0.667
0.400
127.1
w/o Init. I
22.49
0.778
0.249
317.0
Table 4: MobileScan ablation. Averages over 16 scenes under the matched 500-step protocol; the w/o MVS runtime reflects its smaller initial primitive count.