# Data Format and Evaluation Conventions

Return to the [dataset card](README.md) or [download instructions](DOWNLOAD.md).

## File Layout

```text
OccStress/
  README.md
  DOWNLOAD.md
  FORMAT.md
  EXTERNAL_DATA.md
  DISTRIBUTION.md
  manifests/
  meta/
    OccStress-nuScenes/
    OccStress-Waymo/
    OccStress-CARLA/
  protocols/
    manual/<dataset>/
    upstream/<dataset>/<subtrack>/<source>/
    position_sweep/OccStress-nuScenes/<setting>/
  occ/
    manual/<dataset>/<family>/<severity-if-applicable>/
    upstream/<dataset>/<subtrack>/<source>/<condition>/
  events/
    manual/<dataset>/
```

`<dataset>` is one of `OccStress-nuScenes`, `OccStress-Waymo` or
`OccStress-CARLA`. Paths in protocols are relative to this shared root.
References beginning with `external/<dataset>/` resolve through
`OCCSTRESS_EXTERNAL_ROOT`; external assets are not bundled in this tree.

| Location | Contents |
| --- | --- |
| `meta/<dataset>/dataset.json` | Scene/frame/anchor counts, temporal window, grid and source metadata |
| `meta/<dataset>/` | Class mapping and dataset-specific pose/control metadata or dependency descriptions |
| `protocols/` | Anchor-aligned evaluation records and corruption/temporal settings |
| `occ/` | Canonical derived occupancy NPZ assets shared across temporal protocols |
| `events/` | Corruption event metadata where provided |
| `manifests/` | Inventories and validation coverage |

Upstream clean predictions are model outputs, not official clean GT.
Misalignment uses transformation metadata rather than a second full occupancy
copy. Do not duplicate assets for every temporal protocol.

## Temporal and Label Conventions

| Field | Convention |
| --- | --- |
| Canonical input window | Four historical states plus current: -2.0, -1.5, -1.0, -0.5, 0.0 seconds |
| Future targets | Six actual future states: +0.5, +1.0, +1.5, +2.0, +2.5, +3.0 seconds |
| Derived grid | 200 x 200 x 16 |
| Canonical labels | Occ3D 18-class space, including free space; actual class support is dataset-dependent |
| Anchor selection | Complete H4/current/F6 windows within a scene; identical anchors across its protocols |

GenieDrive uses the last four observed states and does not observe -2.0 seconds.
Record the actual model input window and control strategy in every comparison.
Do not replace the first future target with current-frame reconstruction.

The nuScenes position sweep includes ten hard settings, each with a clean
reference and five single-state injection positions. Compare the four jointly
observed positions across four- and five-state models; an unobserved earliest
state is not evidence of robustness.

Native Waymo `voxel_label` must be mapped using the supplied class map. Derived
`semantics` arrays are already canonical and must not be mapped again.
CARLA's native UniOcc arrays are left-handed; the evaluation view is
x-forward/y-left/z-up. The external preparation tool maps labels and flips grid
axis 1 exactly once while preserving the published right-handed controls.

For CARLA, command order is `[right, left, straight]`. At the sixth future
state, local y <= -2 m selects right and y >= 2 m selects left; otherwise
straight. Non-anchor tail frames retain future-validity masks and a straight
fallback. Every evaluated anchor has six valid future targets.
Traffic mirrors y consistently in occupancy, poses and trajectories, and swaps
the right/left command entries. Preserve these transformations when adapting
another model.

## Validation Scope

Report semantic mIoU and binary occupancy IoU per future horizon and identify
which horizons are averaged. Keep the metric convention, class support and
control policy explicit. Historical paper scores and the code release's
`occstress-present-gt-v1` convention can differ in absent-class handling and
must not be mixed without qualification.

Preparation checks cover protocol structure, anchor counts, relative-path
resolution, NPZ members, grid shapes, legal labels and finite values. CARLA
controls and traffic transforms have separate audits. The complete clean
dependency check covers 14,377 GT references for existence and nonzero size.
Loader equivalence and GPU compatibility checks are sampled, not exhaustive
reruns of every model/protocol combination.

Public coverage is recorded in `manifests/protocols.json`,
`manifests/validation_coverage.json` and the CARLA control/metadata audit files.
Internal job records and condition-level completion markers are not distributed.
Event JSON files omit machine-specific `source_path` and `output_path` provenance;
their numerical corruption metadata and occupancy contents are preserved.
Use `packages.json`, not preparation receipts, to check download availability.
Preparation status does not certify distribution permission or paper-score
reproduction.

## Sources

The source datasets are [Occ3D](https://github.com/Tsinghua-MARS-Lab/Occ3D),
[nuScenes](https://www.nuscenes.org/) and [Waymo](https://waymo.com/open/), plus
[UniOcc CARLA](https://huggingface.co/datasets/tasl-lab/uniocc/tree/e81775b36e376f591a1145ca054b72fd541a67eb)
(`Carla-2Hz-val`, three 120-frame scenes). Cite the corresponding datasets,
corruption operators and upstream models in addition to OccStress.

Access to these derived assets does not grant access to the source datasets or
override their terms. Obtain the required source registration and permissions
before use. This collection has source-dependent terms, not a blanket MIT
license; see [DISTRIBUTION.md](DISTRIBUTION.md).