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EXP-046Result

Reflective car capture in a quarter of the time

23.86dB

average PSNR on 30 photographs the model never saw

Silver van on a street: the real photograph against the splatting render from the same camera (Our render)Silver van on a street: the real photograph against the splatting render from the same camera (Held-out photo)
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Held-out photoOur render

We trained our own Gaussian splatting recipe on a published vehicle scene and scored it on held-out photographs. It edges past our reproduction of RT-Splatting (23.57 dB) while training in 36 minutes instead of 2 hours 41 minutes on one RTX 4070.

What we tried

  • A published 208-photo vehicle scene, with 30 photographs held back for scoring only.
  • gsplat with MCMC densification and a 1.5 million Gaussian cap, trained for 30,000 steps.
  • The same scene and split as our earlier RT-Splatting reproduction, so the numbers compare directly.

What we measured

MeasureRT-Splatting, our reproductionOur recipeNote
Average PSNR, 30 held-out photos23.57 dB23.86 dB
Training time, one RTX 40702 h 41 m36 m
Glass-region PSNR31.72 dB30.72 dBstill behind
Test view shown above—24.47 dBthe median of the 30, not the best

What went wrong

  • Our first reflection-aware run scored 22.92 dB, worse than the plain baseline. Degree-3 spherical harmonics let the ordinary colour absorb the reflections, so the reflection branch had nothing left to learn.
  • A second reflection run with degree-0 colour, which forces view-dependent light through the reflection branch, did worse again: 22.37 dB overall and 28.81 dB on glass.
  • A background GPU job silently stalled for 101 minutes. Past 12 GB of VRAM this card does not crash; it slows to roughly 0.1 % speed, so every run now checks memory before it starts.

What happens next

  • Work out why an explicit reflection branch keeps losing to plain view-dependent colour on this scene before trying a third variant.
  • Close the 1.0 dB glass gap, then apply the recipe to customer car captures.

Built with

  • gsplat 1.5.3 Apache-2.0
  • PyTorch 2.4 BSD-3