Quickstart

This guide walks you through a complete workflow: loading videos, annotating poses, grouping across views, triangulating 3D, and exporting.

1. Launch LUC3D

You can use LUC3D in two ways:

• Hosted (easiest): Go to https://talmolab.github.io/luc3d/ — no installation required.

• Local session (recommended): Run a local server for better performance with large files:

  cd lucid
  python3 -m http.server 8080
  

  Then open http://localhost:8080 in Chrome.

2. Load a Session

Go to File → Load Session Folder (or press Ctrl+O) and select a folder containing your multi-camera videos and calibration file.

Your session folder should have per-camera subdirectories:

my_recording/
├── calibration.toml
├── back/
│   └── video.mp4
├── side/
│   └── video.mp4
└── top/
    └── video.mp4

LUC3D automatically matches camera subdirectory names to the camera names in the calibration file.

3. Annotate a Pose

1. Navigate to a frame using the timeline or arrow keys
2. Press N to create a new instance
3. Drag keypoint nodes to position them on the animal/person
4. Repeat for each camera view where the subject is visible

4. Group Across Views

1. Click an unlinked instance in one camera view — this starts a group (assignment mode)
2. Click the instance in each other camera view that represents the same individual
3. Press Shift+G (or Enter) to create the group

The instances are now linked as an InstanceGroup — they represent the same skeleton seen from different angles.

Or let the tracker do it

Instead of grouping by hand, run Track Frame (Shift+T) or Track All (Ctrl+Shift+T) to group instances across views and assign identities automatically. See Tracking.

5. Triangulate

Press T to triangulate the current frame. LUC3D computes 3D positions using DLT and shows:

• Reprojected instances (dashed outlines) on each camera view
• Reprojection error in the Instances tab
• 3D skeleton in the 3D viewport (press \ to open)

6. Export

Go to File and choose your export format:

• Export Labels (JSON) — All 2D annotations, LUC3D's native format
• Export SLEAP File Per Session / By Cam — SLEAP-compatible .slp files (see Exporting Data)
• Export 3D Points (H5) — Triangulated 3D keypoints in HDF5
• Export 3D Video — Render the 3D viewport to an MP4

That's it! See the User Guide and Tutorials for detailed walkthroughs.