| --- |
| license: other |
| tags: [4d-reconstruction, video-to-4d, sam-3d] |
| --- |
| |
| # ff4d-sam3d prepped training data (motion324 + syn4d) |
|
|
| > **STATUS: upload in progress (started 2026-09-07 ~00:20 CDT, ETA ~04:00 CDT).** |
| > Files appear a few GB at a time, stream by stream. `pointmaps` is the largest stream and lands |
| > last for each root. Check the file list for what is already complete; a `__NNN.tar` that is |
| > present is complete (each is committed only after a successful upload). |
| |
| Prepped training samples for ff4d-sam3d — video-to-4D on the SAM-3D Objects backbone. Each sample |
| is **one scene × object × motion**; views are augmentation and share the SS/SLat latents, differing |
| only in the layout target and the input conditioning. |
| |
| **Derived data.** These are artifacts (renders, pointmaps, encoded latents, layout targets) computed |
| from third-party sources — see *Sources* below. Use of this data is bounded by those sources' |
| licenses; cite them, not just this repo. |
| |
| ## Sources |
| |
| | root | derived from | samples | |
| | --- | --- | --- | |
| | `ff4d_sam3d_m324_scale4k` | [River-Chen/Motion324](https://huggingface.co/datasets/River-Chen/Motion324) train shards `part_0001`–`part_0004` | ~4,000 objects | |
| | `ff4d_sam3d_motion324` | Motion324 (earlier 500-object prep, 13-camera rig) | 500 objects | |
| | `ff4d_sam3d_syn4d_full_objscale` | syn4d corpus | 2,678 samples (geometry only, no SLat) | |
| |
| Objects in `scripts/prepare/m324_eval_holdout_shas.txt` are excluded — they are the evaluation |
| holdout and must not appear in training data. |
| |
| ## Streams |
| |
| ``` |
| layout_targets/<sha>.npz per-frame (R, t, s) + rotation-6d tokens |
| layout_targets_metric/<sha>.npz per-view metric layout |
| renders_cond_pm/<sha>/<view>/%04d.png full-frame RGBA conditioning renders |
| renders_cond_pm/<sha>/cameras.npz extrinsics / intrinsics / cam names |
| pointmaps/<sha>/<view>/%04d.npy 512x512x3 float16, NaN off-object |
| ss_latents_video_canon/sam3d_ss_enc_16l8/<sha>.npz mean (F,8,16,16,16) + per-frame center, scale |
| slat_latents_video_canon/sam3d_slat_enc_8l8/<sha>.npz sparse coords (N,4) + feats (N,8) |
| ``` |
| |
| Files are named by sha and disjoint across shards, so merging two shards is a plain copy. |
| |
| ## Recipe |
| |
| `scripts/prepare/prep_motion324.sh`, 8 frames, steps `rigid cond canon slat pointmap` (no `align`), |
| encoders `sam3d_ss_enc_16l8` / `sam3d_slat_enc_8l8`, `checkpoints/hf`. Objects from `part_0001`– |
| `part_0002` were prepped with 4 yaws (`0 90 180 270`); later objects with a single yaw (`270`), since |
| views share the latents and only multiply the conditioning streams. |
| |
| ## Packaging |
| |
| Streams are uploaded as tars (`<root>__<stream>__NNN.tar`) because the untarred roots are 100k+ |
| small files. Extract with `tar xf <file> -C data/<root>/<stream>/`. |
| |
