acdream/docs/plans/2026-07-29-physics-parity-campaign.md

# Campaign P — Physics Retail-Feel Parity

**Filed:** 2026-07-29. **Directed by the user** as a pre-vendor-management
detour after the same-day physics/collision retail-fidelity audit. The
world-interaction program (Slice 5, vendor browsing) resumes when this
campaign closes.

**Execution model:** Claude drives autonomously slice-to-slice. Sonnet
subagents implement bounded chunks against this plan's specs; an Opus
review subagent gates every slice boundary. The only user stops are
(a) the final batched connected visual matrix, (b) a DO-NOT-RETRY
conflict, (c) anything destructive. All the CLAUDE.md workflow rules
apply: grep-named-first → pseudocode → port → conformance test; register
moves in the same commit; no workarounds.

---

## The parity goal (the autonomy contract)

**"Retail Movement Parity v1"** — the campaign is DONE when all of the
following are auditable-true:

1. **Zero physics-scope temporary stopgaps.** TS-1, TS-4, TS-5, TS-23,
   TS-46 retired by porting the retail mechanism. TS-24, TS-35, TS-40
   either retired or re-classified (IA/AD) with a recorded justification.
2. **No feel-affecting approximations left unargued.** AP-7 resolved by
   decoding retail's friction state gate; AP-10 restored to retail's
   0.1 m water sink-in; AP-25 replaced by the retail effective-skill
   chain (vitae/enchantment-aware); AP-71 (`check_entry_restrictions`)
   ported.
3. **Issue ledger:** #262, #165, #166, #116, #167, #72, #153 closed;
   the stale "pending visual gate" statuses on #172/#173/#174/#175/#41
   reconciled (folded into the final matrix below). Explicitly excluded:
   #235 (user-deferred 2026-07-27) and #256/#257 (lifecycle/memory, not
   physics feel — separate track).
4. **Verification:** each port carries decomp citations + conformance
   tests; `dotnet build` + full Release suite green at every slice
   commit; one batched connected visual matrix (below) passes at the
   end, run by the user.

Anything not in this list is out of scope for the campaign — file it,
don't chase it.

---

## Slices

### P1 — Stat-coupled movement (burden / stamina / vitae) — retires TS-5, AP-25, the burden gap

Today `PlayerWeenie.SetBurden` has zero callers, `CanJump` is always
true, `JumpStaminaCost` is 0, and pushed run/jump skill is
attributeBonus + init + ranks only. Retail modulates movement by
character state continuously.

**Retail anchors (named decomp, verified 2026-07-29):**
- `ACCWeenieObject::{CanJump 0x0058c400, JumpStaminaCost 0x0058c440, InqJumpVelocity 0x0058c520, InqRunRate 0x0058c560, InqMaxRunRate 0x0058c5a0}` — thin delegations to the qualities DB (pseudo-C ~406512).
- `CACQualities::{InqMaxRunRate 0x00591b20, CanJump 0x00591b50, JumpStaminaCost 0x00591b90, InqRunRate 0x00592800, InqJumpVelocity 0x00592980, InqLoad 0x0058f130}` (pseudo-C ~412901–413975, ~409756) — the real load/skill/vitae composition. `InqJumpVelocity` ends in `sqrt(GetJumpHeight(...) * 19.6)` (pc 413975).
- `MovementSystem::{GetRunRate 0x006b0950, GetJumpHeight 0x006b09b0, JumpStaminaCost 0x006b0a40}` (pseudo-C ~695958) — GetJumpHeight readable: `LoadMod(load) * (skill/(skill+1300) * 22.2 + 0.05) * power / scaling`, floor 0.35; JumpStaminaCost readable: `ceil(((power + 0.5) * load) * 8 + 2)` on the arg3==0 branch.
- `EncumbranceSystem::{EncumbranceCapacity 0x004fcc00, Load 0x004fcc40, LoadMod 0x004fcc70}` (pseudo-C ~256393).
- Cross-refs: ACE `MovementSystem`/`EncumbranceSystem` C# ports; holtburger if it models load.

**Work:**
1. Port the full chain into Core (`EncumbranceSystem` + `MovementSystem`
   statics; `PlayerWeenie` becomes the CACQualities-shaped composition).
   Where BN x87 mush blocks a branch (GetRunRate body), use Ghidra MCP
   or the ACE port as the tiebreaker and cite which.
2. Determine, from `CACQualities::InqRunRate`'s own body, exactly which
   skill level retail feeds (base vs enchantment/vitae-adjusted) and
   port THAT — scoped to the run/jump query path only, reading vitae +
   relevant skill enchantments from the M3 active-effect state. Do not
   build a general effective-skill engine.
3. Plumb the inputs from Runtime: burden (EncumbranceVal/capacity from
   PlayerDescription + property updates), current stamina (vitals),
   vitae. Extend `RuntimeMovementSkillState` (J4.4 seam) so updates flow
   mid-session, same as run/jump skill today.
4. Wire the existing `jump_is_allowed` stamina-refusal branch and the
   `ReportExhaustion` dual-dispatch gate (R3-W4 seam) to a real
   consumer, matching retail's refusal/weak-jump behavior.
5. Conformance tests: formula tables (golden values incl. 800-skill cap,
   load-mod knees at 100%/200%, stamina cost ceil), gating tests
   (no-stamina jump refusal), plumbing tests (burden/stamina/vitae
   changes move the produced rate). Register: delete TS-5 + AP-25 rows,
   note the retirement in the same commit.

### P2 — Response-layer edge family — retires TS-1, TS-4, AP-7; closes #166, #116

The collision *response* layer (what happens after a hit): ground
friction, cliff edges, downhill landings, near-perpendicular wall
slides. One oracle-driven pass; the physics digest's DO-NOT-RETRY table
binds every subagent here.

**Work (research doc FIRST, then port):**
1. **AP-7:** decode the state gate on retail's friction block
   (`calc_friction` region, pseudo-C ~276702-276705) that lets retail
   use threshold 0.25 without hammering normal locomotion (the reverted
   L.3c attempt). Ghidra MCP for the x87 branch if BN is garbled.
2. **TS-1:** port the `EdgeSlide → PrecipiceSlide / CliffSlide` chain
   (precipice context, steep-plane bookkeeping) replacing our
   stop-at-edge.
3. **#166:** port the landing "sled" (Sledding state set/clear sites;
   the sled friction constants already sit in `calc_friction`).
4. **TS-4:** replace the Path-6 steep-poly in-place-slide shortcut with
   retail's `SetCollide → Path-4 → ContactPlane` landing chain, and
   remove the two BSP-layer `SetSlidingNormal` writes (retail's only
   in-transition writer is `validate_transition`).
5. **#116:** the near-perpendicular lateral-slide loss + first-airborne-
   frame divergence, driven by the existing tick-22760 replay and D4
   pins.
6. Apparatus: extend the trajectory-replay tests; capture fixtures
   before changing behavior. Register: delete TS-1/TS-4/AP-7 rows.

### P3 — Remote-object residuals — retires TS-46, TS-23; closes #165; narrows/retires AD-25

1. **TS-46:** pass the Setup's verbatim sphere LIST into the transition
   (`CPhysicsObj::transition 0x00512dc0 → init_sphere`) instead of the
   two-scalar reconstruction, for local player and remotes; derive
   remote step-up/step-down from the Setup instead of the pinned 0.4 m.
   Captured-fixture replays must stay green or be re-baselined with
   evidence.
2. **AD-25:** align the remote post-resolve with the ported
   `handle_all_collisions` (grounded-bounce rule) as the player half
   already did in #182.
3. **#165:** remotes visibly penetrate walls before stopping — diagnose
   against the (now Setup-true) sweep; suspect list starts at the
   catch-up step length vs sweep sub-steps.
4. **TS-23:** parse PlayerKillerStatus from PlayerDescription/property
   updates and plumb PK/PKLite/Impenetrable onto local + remote player
   movers (`OBJECTINFO::init 0x0050cf30` state bits). Non-PK ACE
   behavior must be provably unchanged.

### P4 — World specials — retires AP-71, AP-10

1. **AP-71:** port the `CObjCell::check_entry_restrictions` gate at the
   head of `find_env_collisions` (pc:309576) — barred house cells block
   at the threshold client-side.
2. **AP-10:** restore retail's 0.1 m water sink-in; while there, verify
   the water-contact step behavior (`WATER_CONTACT_TS` consumers)
   against retail and file anything found.

### P5 — Deferred fidelity — closes #167, #153, #72

1. **#167:** decode the two unknown x87 ConstraintManager constants
   (Ghidra) and port leash arming.
2. **#153:** the far-teleport arrival onto an unstreamed landblock near
   a 192 m edge — apparatus first (the issue's own trigger table), then
   the streaming-gap hold shape ALREADY sketched there (freeze the
   per-tick resolve until the landblock loads — the async equivalent of
   retail's synchronous load; this is an AD row, not a workaround, and
   gets filed as one).
3. **#72:** close on the R6 evidence (DAT-authored omega ±1.5 rad/s is
   live; the cdb confirmation ask is obsolete).

### P6 — #262 login run-on-the-spot (live defect)

Probe-instrumented fresh-process login repros (`ACDREAM_PROBE_RESOLVE=1`
+ net probes) against local ACE; the issue's hypothesis list is the
script. Root cause, fix, regression test. No workarounds (no auto-recall,
no synthetic position kick). Runs serialized (owns the build tree +
client).

### P7 — Ledger + camera feel

1. Retire the stale TS-25 row (outbound stance ships via
   `RawState.CurrentStyle` since #219) and refresh TS-24/TS-35/TS-40
   classifications.
2. #115 camera-drag: investigation-only against `CameraManager`
   constants (AD-37's vector-nlerp vs retail quaternion-slerp is the
   prime suspect); fix if a concrete divergence falls out, otherwise
   re-classify with evidence.
3. Reconcile #172/#173/#174/#175/#41 statuses via the final matrix.

---

## Final batched connected visual matrix (the ONE user gate)

1. Burden >100%: run slows, jump shrinks; ~200%: barely moves/jumps.
2. Repeated jumps drain stamina; low stamina → weak/refused jump;
   exhaustion behavior matches retail.
3. Fresh vitae: movement penalty present.
4. Walk off a cliff/roof edge: slides over like retail, no dead stop.
5. Downhill jump landing: sled glide + bounce.
6. Shallow-angle wall graze: lateral slide preserved.
7. Packed crowd: spacing + shuffle-out unchanged (regression).
8. Two-client: remote stops at walls without visible penetration;
   remote ceiling-jump bounces down immediately (#173); Holtburg portal
   platform step-up (#172); door Use after jumping (#174); closed-door
   collision matches the visual door (#175); observed-player blips
   gone (#41).
9. Locked/barred house: blocked at the threshold.
10. Wading: slight retail sink-in.
11. ~20 fresh logins: no run-on-the-spot.
12. Regression sweep: walk/run/strafe/turn/jump/stairs/doors/water
    edges feel unchanged from the accepted R6 baseline.

## Risk notes

- P2 and P3 touch the frozen-adjacent transition internals — every
  subagent prompt must carry the digest's DO-NOT-RETRY table and the
  no-workarounds rule; 3 failed attempts on any item = stop and build
  apparatus, per [[feedback_apparatus_for_physics_bugs]].
- TS-46 changes the collision capsule of every mover; the captured
  replay fixtures pin behavior — re-baseline only with a recorded
  retail argument.
- P1's enchantment-aware skill read is the scope-creep risk; it is
  bounded to the run/jump query path by this plan.