acdream/docs
Erik ddb5a96799 feat(#184): Slice 2b — unify the remote player/NPC fork (players collide faithfully)
Collapse the two-path fork in RemotePhysicsUpdater.Tick: the former Path A
(grounded PLAYER remotes advanced by the interp catch-up with ResolveWithTransition
deliberately OMITTED, per the now-retired issue-#40 premise) is gone. Every remote --
player and NPC -- now runs the SAME per-tick catch-up + sweep + shadow-follows-resolved.
Retail's UpdateObjectInternal (0x005156b0) has no player/remote fork; this is the
faithful shape. Player remotes now get terrain-Z snap (no slope staircase), wall
collision, and MONSTER collision -- previously (Path A) they skipped ALL collision.

RETAIL PvP (adversarial review caught this): two non-PK players WALK THROUGH each
other in AC (you can stand inside another non-PK player) -- they do NOT de-overlap.
The remote-player mover now carries IsPlayer|EdgeSlide (mirroring the LOCAL player at
PlayerMovementController), so CollisionExemption's PvP block exempts a non-PK pair,
exactly as retail sets IsPlayer on every object's own transition (OBJECTINFO::init
0x0050cf30) and FindObjCollisions (pc:276812) exempts it. The first 2b draft passed
bare EdgeSlide and de-overlapped players (MORE solid than retail); the 3-lens review
flagged it. PK/PKLite/Impenetrable are not plumbed onto the remote mover yet -- the
same M1.5 gap the local player carries (TS-23, extended).

#40 proven dead in code (before the gate): PlayerVsMonster_DeOverlapsAndAbsorbsTheStallBlip
drives the real ComputeOffset -> InterpolationManager catch-up (incl. the fail_count
blip-to-tail) for a player mover converging on a monster and asserts de-overlap +
maxSpike<0.30 -- the sweep absorbs the stall-blip. ConvergingPlayers_WalkThroughEachOther
proves the PvP exemption (non-PK players pass through). Path B already ran the
#40-feared config stably; #40 (May 2026) predates the CSphere/#137/#170/#171 rebuild.

Placement (HIGH, review finding 3): the player UP routing gains the SAME placement-snap
backstop Slice 1 gave NPCs (AP-87). Without it a UM-first player (RemoteMotion seeded
to the spawn pos, then a first UP in a different cell) would sweep from a stale cell ->
garbage -> the digest's invisible/misplaced-player bug. The 4 m bodyToTarget guard +
!willBeDrTicked + dist>96 snap; near placed corrections still enqueue for smooth
catch-up. Also seed Body.Position=worldPos at UP-handler RemoteMotion creation
(mirrors the UM handler :5176) for the UP-first case.

Coupled shadow edits (research finding 9): RETIRED the players-only raw-worldPos shadow
sync -- now that players run the sweep + shadow-follows-resolved, the raw sync would
re-snap a packed player's shadow into overlap each UP. Player shadows follow the
RESOLVED body via the DR-tick loop + a new player UP-branch-tail SyncRemoteShadowToBody.

Surviving player/NPC split (AP-88): the omega -- grounded PLAYERS keep the
ObservedOmega-or-seqOmega world-frame (Concatenate) fallback ("rectangle when running
circles"); NPCs + airborne keep ObservedOmega-only body-frame (Multiply). They commute
for an upright body + yaw omega, so the fork is faithful.

Register: TS-23 extended (remote-player mover PK gap); AP-86 updated (raw sync retired
for players too, Where column fixed); AP-88 added (omega fork + eval-order note).

Tests: Core 2623 / App 741 green, 0 warnings. 3-lens adversarial review + per-finding
verification (10 agents); all 6 confirmed findings addressed (2 substantive: PvP mover
flags + player placement-snap; 4 doc/cosmetic).

VISUAL GATE (acceptance test) owed by the user -- NOTE the corrected expectation:
  (a) a player remote on a hill -- no slope staircase;
  (b) two packed player remotes -- they WALK THROUGH each other (retail PvP), NOT
      de-overlap (this corrects the design's original "players de-overlap" gate);
  (c) a player remote cannot stand inside a MONSTER (new: player-vs-monster collision);
  (d) remote walk/run/jump/land/turn UNCHANGED.

Handoff: docs/research/2026-07-07-184-slice2-unify-extract-handoff.md.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-08 00:45:44 +02:00
..
architecture feat(#184): Slice 2b — unify the remote player/NPC fork (players collide faithfully) 2026-07-08 00:45:44 +02:00
audit docs: update audit — Sprint 1 items verified (sequence counters + scenery LCG) 2026-04-13 13:51:39 +02:00
plans docs(pipeline): PARK Track MP - FPS-swing win banked, ECS+remainder deferred 2026-07-06 00:57:04 +02:00
research docs(#184): Slice 2 handoff — extract RemotePhysicsUpdater (2a) + unify the player/NPC fork (2b) 2026-07-07 23:31:01 +02:00
superpowers docs: remote-creature de-overlap — design spec + fresh-session handoff 2026-07-07 20:29:06 +02:00
bugs.md docs: update bugs.md — close BUG-002/003/004, add BUG-005/006/007 2026-04-14 12:17:31 +02:00
ISSUES.md docs(#184): Slice 2 handoff — extract RemotePhysicsUpdater (2a) + unify the player/NPC fork (2b) 2026-07-07 23:31:01 +02:00