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 | 16,805 | 21,073 | x1.25 |
| training time (optimisation) | 19 min | 71 min | |
| held-out frames (within 0.3 s of a training frame) | 13 (10) | 13 (10) | |
| LPIPS on the fish (lower = closer to the photo) | 0.1393 | 0.1250 | -0.0143 |
| PSNR full crop (dB) | 28.71 | 28.93 | +0.22 |
| PSNR on the fish mask (dB) | 26.08 | 26.55 | +0.46 |
| sharpness ratio render / photo, grain-robust (1 = as sharp as the photo) | 0.172 | 0.171 | x1.00 |
| sharpness ratio, raw | 0.082 | 0.083 | x1.02 |
| sharp match (photo detail reproduced in place) | 0.114 | 0.136 | +0.023 |
| IoU with the SAM mask | 0.890 | 0.887 | -0.003 |
Verdict: better. LPIPS -0.0143, grain-robust sharpness x1.00 (not 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: Balistidae 98%, Scaridae 2%, Monacanthidae 0% · agreement across crops 98% · 64 crops · bioclip-2.5 (hf-hub:imageomics/bioclip-2.5-vith14, open_clip, zero-shot)

| window | 58:00 – 68:00 |
| visits | 7: 58:37-58:39, 58:43-58:47, 59:02-59:07, 60:01-60:03, 60:34-60:42, 61:03-61:06, 63:12-63:21 |
| frames (10 fps) detected / kept | 354 / 304 |
| valid poses (10 fps) | 270 |
| frames with background plate | 349 |
| median size | 149.0 px |
| 30 fps frames / valid poses | 717 / 604 |
| method | 4D GS, fins + bending + tail (30 fps) |
| model shown | v2 (gs_v2, quality experiment rollout) |
| iterations | 12000 |
| gaussians | 21073 |
| training time | 71 min |
| trainer validation PSNR full / masked | 30.5 / 24.0 dB |
| trainer validation IoU vs SAM mask | 0.902 |
| near-fish band PSNR (fins) | 31.9 dB |
| production status | done |
| visual note (curation) | dark triggerfish with orange tail: orange-lined triggerfish, Balistapus undulatus (first guessed Zebrasoma xanthurum; parrotfish tracklet t5522 removed) |






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