README.md

---
pretty_name: RevoTac OXT — Ten Simulated Tactile Manipulation Episodes
language:
- en
tags:
- robotics
- tactile
- simulation
- zarr
- open-x-tactile
size_categories:
- n<1K
---

# RevoTac OXT

Ten scripted **simulated** tactile manipulation episodes, one per task, from RevoBench / RevoSim. Contributing institutions: **HKUST(GZ), BrainCo, Georgia Tech**. Contact: Lixin Xu, davidxulixin@gmail.com.

Project: https://braincotech.github.io/RevoSim-web/  
Code: https://github.com/BrainCoTech/RevoBench  
Format and contribution requirements: **[Open-X-Tactile](https://open-x-tactile.github.io/)** and [OXT-QC](https://github.com/nolann030628/OXT-QC).

This release follows section 4.1 of the OXT submission guide: the single dataset directory `RevoTac-OXT/` contains all ten `<task>.zarr.zip` archives. No task archive or unpacked Zarr is stored at the repository root. Uploading this repository does not mean that OXT organizers have accepted the dataset.

## File layout

```text
BrainCoTech/RevoTac-OXT
├── RevoTac-OXT/
│   ├── cup_hang.zarr.zip
│   ├── hammer.zarr.zip
│   ├── insert_peg.zarr.zip
│   ├── insert_pipette.zarr.zip
│   ├── kitchen.zarr.zip
│   ├── plug_charger.zarr.zip
│   ├── pour_can.zarr.zip
│   ├── power_drill.zarr.zip
│   ├── rotate_knob.zarr.zip
│   └── tray_carry.zarr.zip
├── README.md
├── metadata.json
├── manifest.json
├── citation.bib
└── qc/
```

The repository, dataset directory and current `metadata.name` all use `RevoTac-OXT`. Earlier audit reports retain the historical source identifier `RevoBenchSimTactile10NoIdle`. The directory update only changes repository paths and descriptive metadata; the ten archive SHA-256 hashes and all Zarr values are unchanged.

## Contents

Version 0.1.0 contains **10 episodes, 32,272 frames at 60 Hz**. The unpacked Zarr files total **62,347,719,867 bytes (62.348 GB)**. Exact archive sizes, SHA-256 hashes and source file counts are in `manifest.json`.

| Task | Frames | Archive |
| --- | ---: | --- |
| cup_hang | 4178 | `RevoTac-OXT/cup_hang.zarr.zip` |
| hammer | 1856 | `RevoTac-OXT/hammer.zarr.zip` |
| insert_peg | 3406 | `RevoTac-OXT/insert_peg.zarr.zip` |
| insert_pipette | 2937 | `RevoTac-OXT/insert_pipette.zarr.zip` |
| kitchen | 5655 | `RevoTac-OXT/kitchen.zarr.zip` |
| plug_charger | 2671 | `RevoTac-OXT/plug_charger.zarr.zip` |
| pour_can | 4653 | `RevoTac-OXT/pour_can.zarr.zip` |
| power_drill | 2866 | `RevoTac-OXT/power_drill.zarr.zip` |
| rotate_knob | 2459 | `RevoTac-OXT/rotate_knob.zarr.zip` |
| tray_carry | 1591 | `RevoTac-OXT/tray_carry.zarr.zip` |

Each ZIP contains one `<task>.zarr/` directory, including `data`, auxiliary observations and `edit_provenance`. Extract all entries; do not discard auxiliary or edit-provenance arrays. ZIP64 is used. ZIP storage preserves the already-compressed Zarr chunk bytes.

## Download and open

```python
from huggingface_hub import hf_hub_download
from pathlib import Path
import hashlib
import json
import zipfile
import zarr

repo = "BrainCoTech/RevoTac-OXT"
manifest = json.loads(Path(hf_hub_download(repo, "manifest.json", repo_type="dataset")).read_text())
entry = next(x for x in manifest["archives"] if x["task"] == "cup_hang")
archive = Path(hf_hub_download(repo, entry["path"], repo_type="dataset"))
digest = hashlib.sha256()
with archive.open("rb") as stream:
    for block in iter(lambda: stream.read(16 * 1024 * 1024), b""):
        digest.update(block)
assert digest.hexdigest() == entry["sha256"]
with zipfile.ZipFile(archive) as packed:
    packed.extractall("data")
episode = zarr.open_group("data/cup_hang.zarr", mode="r")
print(episode.tree())
```

## Signals and editing

The bimanual robot has 56 joint coordinates. The dataset includes measured joints and commands, four scene RGB cameras, canonical ego/wrist poses, five optical tactile pads per hand, numeric indentation depth in **meters**, marker displacement, pad-contact wrenches, and 285 pressure taxels per hand. Stiffness and damping are omitted from this OXT view.

Pressure is a **nonnegative normalized response**, not Pa or N. DIP optical pads and palm/MCP/PIP pressure regions have different spatial coverage. The sensor facade is target-specific. Simulated Taxim RGB marker warping is not implemented; these are not real sensor recordings.

Long stationary holds were removed offline, reducing 34,528 original frames to 32,272. Modalities share the same retained source-frame indices. Native retained values, sensor resolution and chunk codecs are preserved; timestamps were reindexed at 60 Hz. Original capture frame indices/times are retained in `edit_provenance`. No interpolation or physics rerun was performed. These ten development demonstrations are not a statistical task-success benchmark.

## Quality checks and known limitations

See `qc/` for the review records. The official metadata check passed all ten dataset structures; its historical report still notes the then-missing download URL and FTP-1 `code_trigger`. This release fills `metadata.json.url`; `code_trigger` remains unassigned. The release metadata check was rerun after adding the URL: all ten dataset structures passed, with only `code_trigger` still missing (see `qc/release_metadata_check/`).

The official external VLM stage was attempted without dry-run but could not produce scores because no API key was available. Its reports are preserved with `missing_api_key` and null scores. A separate Codex multimodal agent review examined sampled scene/both-hand tactile evidence plus all-frame numerical checks. This does not constitute organizer approval or a completed external VLM API check. Published JSON reports replace internal source-directory prefixes with descriptive placeholders; the original private audit reports remain unchanged.

- **pour_can:** right pinky force reaches 416.2466 N at retained/original frame 600, an isolated peak much larger than neighboring values. The value is preserved and flagged for contact-model review.
- **plug_charger:** the left thumb DIP records contact in only eight frames. Source validation supports successful insertion and post-release stability, but does not establish continuous three-fingertip contact.
- **rotate_knob:** peak angle is about 34.16 degrees; the knob returns near zero after release. This is not a demonstration of maintaining a 35-degree final angle.
- Active-hand pressure is zero throughout eight tasks. Optical and pressure regions differ; these pressure channels should not be described as rich contact observations.
- 4D recordings use a full-duration 10 Hz inspection view with 320x240 RGB and documented nominal intrinsics/display adaptations. No scene depth was available, so point clouds were disabled. All 32,272 native pose frames were checked numerically against previously validated FK sources. The recording is sampled coordinate-review evidence, not a full native-rate task video or pixel-accurate calibration certificate.

The kitchen task targets one potato piece and two meat pieces; carrots remaining in the pan are distractors. The drill task requires alignment above the board, not actual drilling. The pipette task ends with the grasp maintained.

## Citation

See `citation.bib` for the citation supplied on the project website. No paper identifier is inferred. A separate dataset license has not been specified in this release.