# dit_block_tower_norm_fix

Diffusion policy checkpoint for the **build_block_tower** task (with DAgger rounds 1.0.0–1.4.0), trained with per-timestep (H,D) RAMEN action normalization and corrected action chunk semantics (slot 0 = current action).

## Checkpoint

| Step  | train_loss | Status | Hash |
|-------|-----------|--------|------|
| 29000 | 0.0047    | partial (29k/50k) | `8843965c8dcf0fc68b71784fe0875b7e43eb25aa4e05b59bf796b2280b50ea96` |

Training was interrupted by walltime (1 day limit) at step ~29588/50000. Loss was still decreasing healthily — this checkpoint will be resumed.

## Config

- dataset: `villekuosmanen/build_block_tower` + DAgger rounds 1.0.0–1.4.0
- batch_size: 80 per GPU (320 global, 4x GPUs)
- optimizer_lr: 3e-4
- lr_scheduler: cosine (warmup 500 steps, min_lr_scale 0.1)
- horizon: 32, n_action_steps: 32
- noise_scheduler: DDIM, 100 train timesteps, 20 inference steps
- observation_encoder: CLIP ViT-B/16 (vision + text)
- action normalization: RAMEN with per-timestep stats (H=32, D=17)

## Files

```
checkpoints/29000/params/model.safetensors   # model weights
checkpoints/29000/params/config.json         # model config
assets/ramen_stats.json                      # action normalization stats
TRAINING_LOG.md                              # sanitized training log
```

## Verify integrity

```bash
cd checkpoints/29000/params
find config.json model.safetensors -type f | sort | xargs sha256sum | sha256sum
# expected: 8843965c8dcf0fc68b71784fe0875b7e43eb25aa4e05b59bf796b2280b50ea96
```

Note: `ramen_stats.json` is in `assets/`, not in the params directory. The hash above covers only the params files. To reproduce the full hash including ramen_stats, download all three files into one directory and run the same command over all three.

## W\&B

- [Training dashboard](https://wandb.ai/pravsels/dit_block_tower_norm_fix/runs/ksuxe451)

## Source

- repo: [pravsels/multitask_dit_policy](https://github.com/pravsels/multitask_dit_policy) (branch `stage1-multimodal-abstraction`)