README.md

---
license: other
pretty_name: Multi-Drive World Model Data
tags:
- world-model
- driving
- video-games
viewer: false
---

# Multi-Drive World Model Data

Action-conditioned driving gameplay from multiple racing games, grouped by visual **theme**, for
training a single multi-game world model. 1,073,248 frames across 155 clips.

| theme | source games | clips | frames |
|---|---|---|---|
| cartoon | supertuxkart | 118 | 589,560 |
| realistic | forza-horizon, need-for-speed | 27 | 340,722 |
| arcade | asphalt-9 | 10 | 142,966 |

- **Frames:** 384x216 RGB JPEG.
- **`metadata.jsonl`:** one line per clip — `{clip, theme, game, n_frames, path}`.

## Why tar files (and why the dataset viewer is off)

The `.tar` files are **not a WebDataset**. Each tar holds ordered directories, one per contiguous
gameplay run:

```
<run>/frames/frame_000000.jpg
<run>/frames/frame_000001.jpg
...
<run>/actions.jsonl          # one JSON line per frame, same order as the frames
```

Three reasons for this layout:

1. **A world model trains on contiguous sequences, not independent samples.** The unit of training
   is a window of N consecutive frames plus the actions taken across them. WebDataset's flat
   `key.jpg` / `key.json` pairing has no way to express "these frames are consecutive and ordered",
   and the viewer would shuffle them — which is meaningless for video.
2. **File count.** Stored as loose files this would be millions of objects in one repo, which makes
   listing, cloning and LFS painful. Tars keep it to a few hundred objects.
3. **Sequential reads.** Training reads neighbouring frames together; a tar keeps them adjacent
   rather than scattered across a bucket.

Because the layout is deliberately not WebDataset, HF's auto-detection cannot parse it and the
dataset viewer is disabled (`viewer: false`). Load the tars directly with the snippets below.

## Loading

```python
import json, tarfile, glob, os
from huggingface_hub import hf_hub_download

REPO = "codelion/multi-drive-model-data"

# the index: one line per run -> pick what you want without downloading everything
meta = [json.loads(l) for l in
        open(hf_hub_download(REPO, "metadata.jsonl", repo_type="dataset")) if l.strip()]
print(len(meta), "runs")

# fetch and unpack one tar
tar = hf_hub_download(REPO, meta[0]["path"] if "path" in meta[0]
                      else f"data/{meta[0]['shard']}.tar", repo_type="dataset")
with tarfile.open(tar) as tf:
    tf.extractall("work")
```

Each tar unpacks to a single `<clip>/` directory.

## Building training sequences

Frames and action records are index-aligned, so a training window is just a slice:

```python
import numpy as np
from PIL import Image

def load_run(run_dir):
    frames = sorted(glob.glob(os.path.join(run_dir, "frames", "*.jpg")))
    recs = [json.loads(l) for l in open(os.path.join(run_dir, "actions.jsonl")) if l.strip()]
    n = min(len(frames), len(recs))                 # always slice to the shorter of the two
    actions = np.array([r["actions"] for r in recs[:n]], np.float32)   # [n, 7]
    return frames[:n], actions

def windows(frames, actions, seq_len=16, stride=8):
    """contiguous (frames, actions) windows — the unit a world model trains on"""
    for s in range(0, len(frames) - seq_len + 1, stride):
        imgs = np.stack([np.asarray(Image.open(f).convert("RGB"), np.float32) / 255.0
                         for f in frames[s:s + seq_len]])       # [seq,H,W,3]
        yield imgs, actions[s:s + seq_len]                      # [seq,7]
```

Themes are the conditioning label used by the model (game names stay in the metadata).

## Actions (7-dim)

| idx | field | type | notes |
|---|---|---|---|
| 0-4 | `accel, brake, left, right, drift` | binary | key presses = the player's *intent* |
| 5 | `speed` | float [-1,1] | measured forward expansion, **negative when reversing** |
| 6 | `turn_rate` | float [-1,1] | measured horizontal flow |

Indices 0-4 are what the player pressed; 5-6 measure what the world actually did (optical flow).
Both are included deliberately: key presses alone are a weak conditioning signal here, because
`accel` is held in 73-88% of frames — a near-constant bit carries almost no information, and a
model trained on it alone ignores the throttle entirely.

Normalisation: `speed /= 1.266`, `turn_rate /= 1.559` (p95 of |value|), then clipped to [-1,1].
Note `turn_rate` is a *measurement*, so it lags the key press by ~6 frames (~0.4 s) — the car's
visual response to steering, not the input event.


## Curation

1. Gameplay-only filtering of commercial-game screen recordings: a CLIP content classifier removes
   menus, car-select, results/reward screens, loading, and non-game content (browsers, streams)
   present in the source captures; near-static frames are dropped by a motion floor. ~45% of the
   raw recordings were not gameplay.
2. Ego-motion measured per frame with optical flow and appended to the action vector.