Autonomous headless spin harness (BT_AUTODRIVE+BT_FORCE_TURN) + probes that
finally measure what the eye sees, not the sim heading:
- BT_RENDHDG (L4VIDEO render loop): per-RENDERED-frame peer heading step
evenness -- avgStep/maxStep/max-avg ratio. Confirmed the residual spin
'hesitation' is UNEVEN rendered rotation (max/avg ~2.8x), correlated with the
byAngle resync-flood bursts (maxAng ~= pi), NOT a render-vs-sim rate stall
(render redraws a fresh heading every frame).
- BT_SPIN / BT_ANGSIGN: resync trigger breakdown (byAngle/byVel/byRest) + the
frame-level local/update/projected angular-Y that exposed the Abs() macro bug.
- gBTReplRenderYaw: peer heading published from the sim to the render probe.
- Normalize projectedOrigin.angularPosition after the peer-mirror advance
(adding a scaled ang-vel VECTOR to a quaternion denormalizes it) -- correct,
but NOT sufficient: the pi divergence is REAL, from the crude large-angle
quaternion projection over the sparse angular-record interval during a PURE
spin (linear dense-send doesn't fire when not translating; type-4 is the only
orientation carrier and resets the horizon, so dense type-4 -> half-rate).
Residual ROOT (scoped, not yet fixed): the reckoner (MOVER.cpp:457-466) projects
rotation by ADDING vector*t to the heading quaternion -- a small-angle approx the
original kept valid via dense records; our pure-spin case has 1.6s record gaps so
it diverges to ~180deg -> uneven render. Fix path = proper quaternion integration
in the reckoner, or refresh the angular origin without the type-4 horizon reset.
Both touch the shared engine dead-reckon -> aligning before the change.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
