generate_path() fills the foundation2 stub with the deterministic v1 rules:
top-N events by confidence (ties -> earlier, then shot chronologically);
per event, the registered camera whose pose track is nearest the event
time; keyframes at t_event - lead_s (clamped >= 0) and t_event + duration;
nearest-beat snapping when beats.json exists (missing/corrupt file -> no
snapping); FOV = 2*atan(h/(2*fy)) like scene3d.snapTo. Every pose goes
through the frozen geometry.colmap_to_threejs and the camPath quaternion
is emitted in Three.js [x,y,z,w] order (pitfall #1 — locked by test).
Degradation: no events / no registered poses -> valid empty camPath with a
note; the response always round-trips through camPath.fromJSON.
frontend/src/director.js wires the pre-wired hidden 🎬 button: POST
/api/director, camPath.fromJSON(response), auto-play via the existing
#btn-path flow; empty path or fetch failure surfaces on the button and
recovers — never a crash.
Acceptance (test_director.py, 14 tests): structure-locked against the
frozen camPath shape (exact key sets, unit quats, monotone times);
top-3 grid == [1,4,8,11,14] incl. shared-keyframe dedupe; conversion
matches colmap_to_threejs + mat_to_quat exactly; snapping puts every key
on the beat grid; unregistered poses excluded; API route + CLI dispatch
real output. Suite 148 passed; frontend build clean.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
