What this tool does
Detects a single athlete in an ordinary video using on-device AI (BlazePose), builds a rotatable 3D skeleton estimate, and plots 3D joint angles over time. Everything runs in your browser; nothing is uploaded.
Important: this is an estimate
3D from a single camera is inferred depth, not measured. It is good for visualisation, gross movement assessment and relative joint angles, but it is not lab-grade 3D motion capture. Depth (toward/away from camera) is the weakest axis, and front/back or left/right confusion can occur, especially on rotations away from the camera.
Step by step
- Capture tab — load a video of one person, filmed roughly side-on or front-on.
- Set the analysis samples per second (this does not detect the original camera frame rate), then click Process clip. The model downloads once (a few seconds) and then every frame is analysed — a progress bar shows where it is.
- Switch to the 3D Analysis tab. Drag to rotate the skeleton, scroll to zoom, and play or scrub the timeline.
- In the side panel, choose a body part and component, then click + Add. Hide or remove traces individually.
- Export the angle time-series as CSV, or send it straight to the Figure builder.
Tips
- Best results: one person, well lit, filling a good portion of the frame, moving in the camera plane.
- Drag the trim handles after loading; only the selected range is sampled.
- Gaps in an angle trace mean low confidence on one of its joints that frame; they are left blank rather than guessed.
Full reference →