| --- |
| license: mit |
| tags: |
| - robotics |
| - pointcloud |
| - droid |
| - 3d-object-detection |
| --- |
| |
| # DROID 3D Bounding-Box Pipeline — Visualization Data |
|
|
| Per-frame fused 3-camera pointclouds backing the web viewer at |
| <https://silicon23.github.io/droid_pipeline_visualization/>. |
|
|
| Each episode comes from the DROID v1.0.1 dataset and completed the full |
| detection pipeline (FoundationStereo depth -> optimized extrinsics -> SAM3 |
| masks -> SAM3D box -> FoundationPose video tracking). Point positions are in |
| the **Franka base (world) frame**, metres, Z up. |
|
|
| ## Layout |
|
|
| ``` |
| clouds/{episode_id}/cloud_{preset}.bin concatenated per-frame gzip blocks |
| clouds/{episode_id}/index_{preset}.json byte offsets + per-frame metadata |
| ``` |
|
|
| Presets trade file size against density: |
|
|
| | preset | pixel stride | voxel | typical | |
| |---|---|---|---| |
| | `low` | 4 | 15 mm | ~230 KB/frame | |
| | `medium` | 4 | 10 mm | ~380 KB/frame | |
| | `high` | 2 | 6 mm | ~1.25 MB/frame | |
|
|
| ## Block format |
|
|
| Blocks are listed in `index_{preset}.json` as `{t, o, c, n}` — source frame |
| index, byte offset, compressed length, point count. Fetch one with an HTTP |
| `Range` request and gunzip it. The inflated block is: |
|
|
| | offset | type | meaning | |
| |---|---|---| |
| | 0 | `float32[3]` | `lo` — quantization lower corner (world, m) | |
| | 12 | `float32[3]` | `hi` — quantization upper corner | |
| | 24 | `int16[n*3]` | XYZ, linearly mapped `lo..hi` -> `-32768..32767` | |
| | 24 + 6n | `uint8[n*3]` | RGB | |
|
|
| Dequantize with `xyz = lo + (q + 32768) / 65535 * (hi - lo)`. |
|
|
| `index_{preset}.json` also carries `frames[]` with the per-frame |
| FoundationPose `status`, `consensus_size`, and the 8-corner `bbox_world`. |
|
|
| ## Reading a frame in Python |
|
|
| ```python |
| import gzip, json, numpy as np, requests |
| |
| BASE = "https://huggingface.co/datasets/Silicon23/droid_pipeline_visualization/resolve/main" |
| eid, preset, frame = "shard01010_ep008", "medium", 40 |
| |
| ix = requests.get(f"{BASE}/clouds/{eid}/index_{preset}.json").json() |
| b = ix["blocks"][frame] |
| raw = requests.get(f"{BASE}/clouds/{eid}/{ix['bin']}", |
| headers={"Range": f"bytes={b['o']}-{b['o']+b['c']-1}"}).content |
| buf = gzip.decompress(raw) |
| |
| lo = np.frombuffer(buf, np.float32, 3, 0) |
| hi = np.frombuffer(buf, np.float32, 3, 12) |
| n = b["n"] |
| q = np.frombuffer(buf, np.int16, n * 3, 24).reshape(n, 3).astype(np.float32) |
| rgb = np.frombuffer(buf, np.uint8, n * 3, 24 + n * 6).reshape(n, 3) |
| xyz = lo + (q + 32768) / 65535 * (hi - lo) |
| ``` |
|
|
| ## Notes |
|
|
| - Depth is cropped at 2.5 m to keep the robot workspace and drop far-wall clutter. |
| - Wrist-camera pose is per-frame from `trajectory.h5` (Euler XYZ, camera-to-world |
| directly). Episodes flagged `wrist_sensor_flipped` use the right lens composed |
| with a 180 deg rotation about Z. |
| - Only the **left** eye of each side-by-side stereo recording is used. |
|
|
