gs_final, 4000 iterations) with 12000 iterations and a gaussian cap of 100,000 — the only change of the quality experiment that passed its review. Other changes (frame selection, water and motion-blur models, white balance, lossless crops) did not. The two turntables play in sync (same orbit and timing).
| metric | v1 gs_final | v2 gs_v2 | change |
|---|---|---|---|
| iterations | 4000 | 12000 | |
| gaussians | 19,978 | 26,719 | x1.34 |
| training time (optimisation) | 18 min | 72 min | |
| held-out frames (within 0.3 s of a training frame) | 23 (5) | 23 (5) | |
| LPIPS on the fish (lower = closer to the photo) | 0.1163 | 0.1132 | -0.0031 |
| PSNR full crop (dB) | 25.79 | 25.85 | +0.06 |
| PSNR on the fish mask (dB) | 25.66 | 25.87 | +0.21 |
| sharpness ratio render / photo, grain-robust (1 = as sharp as the photo) | 0.378 | 0.395 | x1.04 |
| sharpness ratio, raw | 0.172 | 0.190 | x1.10 |
| sharp match (photo detail reproduced in place) | 0.126 | 0.116 | -0.011 |
| IoU with the SAM mask | 0.919 | 0.919 | +0.000 |
Verdict: same (within noise). LPIPS -0.0031, grain-robust sharpness x1.04 (sharper). Differences below 0.0034 LPIPS or x1.12 sharpness are within the run-to-run noise of training.
Held-out frames: fixed per fish (work/quality_exp/<fish>/heldout.json), evaluated identically for both models (test-time fit of pose, colour and bending with the gaussians frozen). Both models were trained on all frames of the same data set, so held-out frames near a training frame favour both equally; this is a like-for-like comparison of the two recipes, not a generalisation test.
Family: Serranidae 85%, Labridae 4%, Balistidae 4% · agreement across crops 86% · 64 crops · bioclip-2.5 (hf-hub:imageomics/bioclip-2.5-vith14, open_clip, zero-shot)

| window | 58:00 – 68:00 |
| visits | 6: 58:22-58:26, 58:52-59:00, 59:03-59:10, 64:10-64:18, 65:33-65:49, 66:51-66:53 |
| frames (10 fps) detected / kept | 405 / 395 |
| valid poses (10 fps) | 398 |
| frames with background plate | 333 |
| median size | 153.0 px |
| 30 fps frames / valid poses | 713 / 637 |
| method | 4D GS, fins + bending + tail (30 fps) |
| model shown | v2 (gs_v2, quality experiment rollout) |
| iterations | 12000 |
| gaussians | 26719 |
| training time | 72 min |
| trainer validation PSNR full / masked | 26.9 / 26.6 dB |
| trainer validation IoU vs SAM mask | 0.919 |
| near-fish band PSNR (fins) | 26.0 dB |
| production status | done |
| visual note (curation) | dark grey grouper/snapper-like |






point_cloud.ply (canonical 3D gaussians) · poses_refined.json · model.pt (incl. per-frame 4D params) · species.json · previous version v1: gs_final point_cloud.ply