User-observed regressions on commit 186a584:
1. "Monster keeps running in different directions when it should be
attacking" — chase oscillates around the player at melee range
instead of stopping. Root cause: arrival check used MinDistance
only (retail's algorithm), but ACE puts the melee threshold in
DistanceToObject (default 0.6) and leaves MinDistance at 0. So
our check was never satisfied; body kept re-targeting around the
player as each MoveTo refresh moved the destination.
Fix: arrival = dist <= max(MinDistance, DistanceToObject) + epsilon.
Honors retail when retail sets MinDistance > 0; falls through to
ACE's DistanceToObject when MinDistance is 0. Confirmed by
independent research (named retail decomp, ACE wire writers,
holtburger client) that DistanceToObject is the documented chase
threshold in ACE; retail's MinDistance is only meaningful when
server config overrides the default 0.
2. "Monster disappears, then runs in place" — entity left our
streaming view, server stopped emitting MoveTo, last destination
stayed cached. When entity re-entered view, body still steered
toward the stale point, eventually arrived (V=0), animation kept
playing → "running on the spot."
Fix: 1.5 s stale-destination timeout. ACE re-emits MoveTo at
~1 Hz during active chase; if no fresh packet for 1.5 s, the
entity has either left view, transitioned off MoveTo without us
seeing the cancel UM, or had its move cancelled server-side.
Clear destination + zero velocity so the next interpreted-motion
UM (or fresh MoveTo) drives the body cleanly.
Also confirmed (via dispatched research subagent against ACE writer
side, named retail MovementManager::PerformMovement, and holtburger):
the wire's "Origin" field IS the destination, not the start position.
My driver's interpretation was correct; the symptoms were arrival
threshold + staleness, not a misread of the wire.
Tests: 1412 → 1414 (ACE-melee arrival, retail-MinDistance arrival).
Origin-stale lag during active chase remains — server's Origin is
the target's position at packet-emit time, ~1 s behind the player.
For type 6 MoveToObject, the retail-faithful fix is target-guid
live resolution per HandleUpdateTarget @ 0x0052a7d0; deferred per
the pseudocode doc's "out of scope" list. For type 7 there's no
fix without target-velocity prediction.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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