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 | 18,825 | 33,531 | x1.78 |
| training time (optimisation) | 18 min | 76 min | |
| held-out frames (within 0.3 s of a training frame) | 28 (11) | 28 (11) | |
| LPIPS on the fish (lower = closer to the photo) | 0.1314 | 0.1272 | -0.0041 |
| PSNR full crop (dB) | 26.03 | 26.34 | +0.31 |
| PSNR on the fish mask (dB) | 21.08 | 21.65 | +0.57 |
| sharpness ratio render / photo, grain-robust (1 = as sharp as the photo) | 0.815 | 0.838 | x1.03 |
| sharpness ratio, raw | 0.695 | 0.755 | x1.09 |
| sharp match (photo detail reproduced in place) | 0.711 | 0.770 | +0.059 |
| IoU with the SAM mask | 0.881 | 0.877 | -0.004 |
Verdict: better. LPIPS -0.0041, grain-robust sharpness x1.03 (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: Pomacentridae 100%, Labridae 0%, Serranidae 0% · agreement across crops 100% · 64 crops · bioclip-2.5 (hf-hub:imageomics/bioclip-2.5-vith14, open_clip, zero-shot)

| window | 58:00 – 68:00 |
| visits | 16: 58:10-58:20, 59:02-59:07, 59:12-59:17, 59:22-59:30, 60:01-60:03, 61:02-61:10, 61:19-61:24, 61:57-62:03, 62:22-62:27, 63:28-63:29, 63:34-63:36, 63:54-63:56, 64:13-64:20, 64:25-64:31, 67:37-67:41, 67:45-67:50 |
| frames (10 fps) detected / kept | 684 / 666 |
| valid poses (10 fps) | 651 |
| frames with background plate | 539 |
| median size | 122.0 px |
| 30 fps frames / valid poses | 655 / 588 |
| method | 4D GS, fins + bending + tail (30 fps) |
| model shown | v2 (gs_v2, quality experiment rollout) |
| iterations | 12000 |
| gaussians | 33531 |
| training time | 76 min |
| trainer validation PSNR full / masked | 28.2 / 21.3 dB |
| trainer validation IoU vs SAM mask | 0.885 |
| near-fish band PSNR (fins) | 30.5 dB |
| production status | done |
| visual note (curation) | Chromis dimidiata likely |






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