Left: a real backhand (31-shot session, visual lock swing1 = BH) reduced to its tracked skeleton; every camera pixel, including the person and room, is removed. Right: a watch-shaped part designed live through Andrii Shylenko's kernelCAD connector. Press play: the CAD tumbles from measured Apple Watch orientation for this swing, frame by frame.
MediaPipe Pose Landmarker tracked all 35 frames from the real phone clip, then drew only joints and bones on a clean field. The frame is tightly cropped around the full swing; no person or room pixels remain. The Apple Watch measurements drive the CAD at right; they are not decorative animation or inferred from this skeleton.
Geometry authored via kernelCAD MCP (evaluate_script / get_model_mesh).
Source: watch_mount.kcad.ts. Mesh export packed into
mesh_data.js.
Orientation: 107 frames from USB
/run/media/blueaz/F1E0-14F6/tennis_31shot_session/watch.db,
not invented keyframes.
The window is anchored on the clip itself, not on a stroke-table row: the
phone clip was located inside the session master by frame match, the
master's clock pinned to session time by aligning ball-strike audio onsets
to the watch's own |ω| peaks, and the window centred on the
peak that falls inside this clip.
Press play — this rotation is the real measured orientation of the Apple Watch for this backhand window, frame by frame.
~45 × 38 × 10.7 mm watch-class case with crown, side button, optical
back, and band stubs — authored in kernelCAD (watch_mount.kcad.ts).
The camera-angle slider only orbits your viewpoint; it does not move the part.
Orientation comes from AW quat_wxyz on session
watch_20260104_185001, ±0.85 s around this backhand's peak
|ω| of 14.9 rad/s, sampled at ~63 Hz.
Axis caveat: facing may be off by a fixed frame rotation; the tumbling is real measured orientation, not decorative spin.
Serve / Zepp handle mount — different sensor, different firmware, different form factor.
Forehand / Apple Watch mount — same wrist sensor and same watch geometry, different stroke and a different measured window.
This page is backhand-only and wrist-AW.