Root-causing the user-reported "monsters disappearing some time +
laggy/jittery locomotion" via systematic-debugging Phase 1: our
UpdateMotion parser kept only speed/runRate/flags from a movementType
6/7 packet and discarded Origin (destination), targetGuid, and the
distance/walkRunThreshold/desiredHeading half of MovementParameters.
The integrator consequently held Body.Velocity at zero during MoveTo
("incomplete state" stabilizer 882a07c), so the body froze with legs
animating until UpdatePosition snap-teleported it — sometimes outside
the visible window (disappearing) — and constant-velocity drift along
the old heading between snaps produced jitter on every UP correction.
The 882a07c stabilizer was deliberately conservative because the state
WAS incomplete. Completing the data plumbing makes its restriction
moot: with the full MoveTo payload captured, the body solver has every
field retail's MoveToManager::HandleMoveToPosition (0x00529d80) reads.
Why: server re-emits MoveTo packets ~1 Hz with refreshed Origin while
chasing — verified in the live log (guid 0x800003B5 seq 0x01FE→0x0204
all show different cell/xyz floats). Those are heading updates we'd
been throwing away. With the full payload retained, the per-tick driver
steers body orientation toward Origin (±20° snap tolerance, π/2 rad/s
turn rate above tolerance) and lets apply_current_movement fill in
Velocity from the existing RunForward cycle — no new motion path,
just the right heading.
Scope is the minimum viable subset: target re-tracking, sticky/StickTo,
fail-distance progress detector, and sphere-cylinder distance are
server-side concerns we don't need (server's emit cadence handles all
of them). MoveToObject_Internal target-guid resolution is also skipped
— Origin is refreshed each packet, so the effective target tracks the
real entity even without a guid lookup.
Cross-references:
- docs/research/named-retail/acclient_2013_pseudo_c.txt — MoveToManager
+ MovementParameters::UnPackNet (0x0052ac50) + apply_run_to_command
(0x00527be0). 18,366 named PDB symbols make this the primary oracle.
- references/ACE/Source/ACE.Server/Physics/Animation/MoveToManager.cs
— port aid; flagged divergences (WalkRunThreshold default, set_heading
snap, inRange one-shot) called out in the new pseudocode doc.
- docs/research/2026-04-28-remote-moveto-pseudocode.md — pseudocode +
ACE divergence flags + out-of-scope list per CLAUDE.md mandatory
workflow (decompile → cross-reference → pseudocode → port).
Tests: 1404 → 1412 (parser type-7 path retention + type-6 target guid
retention; driver arrival, in-tolerance snap, beyond-tolerance step,
behind-target shortest-path turn, arrival preserves orientation,
Origin→world landblock-grid arithmetic).
Pending visual sign-off — handoff stabilizer 882a07c was the last
commit the user tested.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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