The decompiled get_state_velocity (FUN_00528960) literally computes
`RunAnimSpeed * ForwardSpeed` — a 4.0 × runRate world velocity. That
matches retail only when the character's MotionTable happens to bake
MotionData.Velocity.Y = 4.0 on RunForward (true for Humanoid, not
necessarily for other creatures or swapped weapon-style cycles).
When MotionData.Velocity ≠ RunAnimSpeed, the body's world velocity
drifts away from the animation's baked-in root-motion velocity, and
you see the classic "legs cycle too slowly for how fast the body is
sliding" visual bug. User reports ~30% discrepancy ("running animation
is too slow"), consistent with Humanoid RunForward's actual dat
Velocity being ~3.0 rather than the 4.0 constant.
The fix per r03 §1.3: physics body velocity = MotionData.Velocity ×
speedMod. That's exactly what AnimationSequencer.CurrentVelocity
already exposes. Route it into MotionInterpreter via an opt-in
Func<Vector3> accessor. When wired, get_state_velocity uses the
sequencer's cycle velocity as the primary forward-axis drive; when
unwired (tests, physics bodies without a sequencer), falls back to
the decompiled constant path — byte-compatible with retail on the
shapes where it actually matters.
The RunAnimSpeed × rate max-speed clamp at the bottom of
FUN_00528960 stays intact — Option B only replaces the *drive*, not
the clamp. 20 m/s phantom MotionData can't teleport the player.
Wiring: GameWindow attaches `playerAE.Sequencer.CurrentVelocity` to
`_playerController` on Tab-player-mode entry. The sequencer is always
built before the player enters chase mode, so timing is safe.
Sidestep continues to use SidestepAnimSpeed — the sequencer only
tracks the current forward cycle, so strafe is a separate axis.
6 new MotionInterpreterTests verify: accessor overrides constant path,
zero Y falls back to constant (link transitions), clamp still applies,
Ready state doesn't leak accessor value, sidestep axis is untouched.
All 717 tests green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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