Campaign P Slice P2 step 3 (docs/research/2026-07-30-response-layer-edge-family-pseudocode.md
§1, §6 Step 5). The named retail decomp (CPhysicsObj::calc_friction,
pseudo-C:276694-276822, 0050ee70) independently re-confirms the 0.25f
threshold (derived twice, once per BN-rendered branch); the in-code claim
that "the decompile uses 0.0" traced to the older, unnamed FUN_0050f940
Ghidra chunk at a different address -- per CLAUDE.md the named decomp wins.
calc_friction now reads angle = dot(Velocity, GroundNormal); if (angle >=
0.25f) return; then unconditionally removes the normal-aligned velocity
component, then applies the existing (already-present but previously
unreachable) PhysicsState.Sledding-gated friction overrides. The BN-rendered
"two duplicated branches" around the state check is adopted as a single
linear function matching ACE's PhysicsObj.calc_friction shape -- the branch
split is most likely a BN decompiler artifact around one `if (state &
SLEDDING_PS)` block (ACE-derived, Ghidra-verify; low implementation risk
either way since ACE's reading is adopted regardless).
Why this doesn't repeat the reverted 2026-04-30 L.3c regression (naive 0.0
-> 0.25f bump dropped forward locomotion 3 -> 0.16 m/s): that test predates
the 2026-07-17 R6 "local player animation-owned grounded movement" landing.
PlayerMovementController (Runtime/Gameplay, out of this slice's scope) zeroes
Velocity.X/Y to exactly zero every tick before calc_friction runs whenever
animation root motion drives the walk, so friction has nothing horizontal
left to hammer on the production graphical local-player path. Pinned at the
PhysicsBody level (the only file this slice may touch) by
GroundedRootMotion_FrictionThreshold_DoesNotHammerLocomotionTests. The
headless/get_state_velocity path and remote/NPC movers still feed real
velocity into this function and remain the ones to watch if a similar
regression resurfaces there -- flagged in the retired AP-7 row for future
sessions working in Runtime/Gameplay.
Left an open, explicitly-flagged discrepancy: the raw decomp's Sledding
slope-flatness test computes cos(10 deg) (~0.984808) while ACE's port (and
acdream's prior dead code) compares GroundNormal.Z > 0.99999536f (~0.175 deg
from flat) -- physically different tests, neither confirmed this pass
(Ghidra MCP down). Kept 0.99999536f provisionally (least churn) and filed
AD-55 for just that constant rather than silently picking one.
Register: AP-7 retired with a corrected citation; AD-55 filed for the
cos(10 deg) question. Core.Tests: 3916 passed, 2 skipped (both pre-existing
and unrelated), 0 failed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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