# Open items pickup prompt — 2026-05-21 session aftermath After the 2026-05-21 collision-fix session, six discrete items remain. This doc gives a fresh session the full landscape: how the items relate, what depends on what, what order makes sense. The pasteable session-start prompt is at the bottom of this doc. ## The landscape at a glance (updated 2026-05-20 — MILESTONE PROMOTION) **Status as of end of 2026-05-20 session:** the original 6-item landscape has been promoted to a milestone of its own — **M1.5 "Indoor world feels right"** — opened today. M2 ("Kill a drudge") is deferred until M1.5 lands. Today's session shipped a 5-fix M1.5 baseline (A4 + #89 + #90 workaround + #91 + #92) closing the user-visible "walls walk through at Holtburg inn" symptom; the proper root-cause fix (BSP push-back distance investigation + synthesis removal) is the actual M1.5 work. | # | Item | Domain | M1.5 phase | Status | |---|---|---|---|:---:| | A4 | Multi-cell BSP iteration — walls in adjacent cells too | Collision | (baseline, shipped) | ✅ CLOSED 2026-05-20 | | #89 | Sphere-overlap in CheckBuildingTransit | Collision | (baseline, shipped) | ✅ CLOSED 2026-05-20 | | #90 | CellId ping-pong at doorway threshold (workaround in place) | Collision — cell tracking | A6.P4 (workaround removal) | ⚠ WORKAROUND | | #91 | Indoor cell shadows in FindObjCollisions | Collision | (baseline, shipped) | ✅ CLOSED 2026-05-20 | | #92 | Server cell id at player-mode entry | Cell tracking | (baseline, shipped) | ✅ CLOSED 2026-05-20 | | #83 | Indoor multi-Z walking (cellars, 2nd floors) — UMBRELLA | Physics | A6.P1-P3 | OPEN (M1.5 primary) | | stairs | Stairs walk-through + stuck-in-falling | Physics | A6.P1-P3 (subsumed by #83) | OPEN | | 2nd-floor / cellar | Multi-Z navigation | Physics | A6.P1-P3 (subsumed by #83) | OPEN | | `TryFindIndoorWalkablePlane` | Per-frame CP synthesis (99.87% MISS) | Physics — synthesis removal | A6.P4 | OPEN (workaround) | | #88 | Indoor static objects vibrate | Physics — sub-step state | A6 (suspected family) | OPEN | | **#93** | Indoor lighting broken (UMBRELLA — new) | Lighting | A7.L1-L3 | OPEN (M1.5 primary) | | **#94** | Held items project spotlight on walls (new) | Lighting | A7.L1-L3 | OPEN | | #80 | Camera on 2nd floor goes dark | Lighting | A7.L1-L3 | OPEN | | #81 | Static building stabs don't react to atmospheric lighting | Lighting | A7.L1-L3 | OPEN | | A2 | PHSP inversion | Collision math | post-M1.5 (Low) | OPEN | ## Two domains, one critical-path chain The 6 items split cleanly: **Domain 1 — Collision (M2 critical path).** A4, stairs, A2, A3. These block "kill a drudge" because dungeons have drudges and dungeons have walls/stairs/floors that need to behave correctly. The dependency chain is: ``` A4 (multi-cell iteration) │ ┌──────────┴──────────┐ ▼ ▼ stairs (verify A3 (remove post-A4) synthesis, relies on A4 retention) ▲ │ A2 (PHSP fix — also useful standalone) ``` A4 is the biggest user-visible win and it unblocks A3. A2 is a small self-contained correctness fix that pairs naturally with A3. Stairs are likely an A4 side-effect. **Domain 2 — Rendering (M7 polish).** L-indoor + L-spotlight. These don't affect gameplay correctness — the world just looks wrong. Different code paths (lighting, not physics), different files, different domain knowledge. Best tackled in their own session, ideally after collision is solid so the visual artifacts are easier to isolate. ## Why this order 1. **A4 first.** Biggest user-visible improvement. Closes the "vestibule cells don't block walls" gap by querying every cell the sphere overlaps, not just the one cell the player's center is in. Retail oracle: `CTransition::check_other_cells` at `acclient_2013_pseudo_c.txt:272717-272798`. Existing `CellTransit.FindCellList` already enumerates the right cells; A4 wires that into `FindEnvCollisions`. Probably 1-2 days. 2. **Verify stairs after A4.** If A4 closes vestibule walls, it probably also closes stairs (same architectural gap — stairs span cells). If stairs still walk-through after A4, investigate per-cell physics-poly coverage for stair geometry as a separate sub-issue. 3. **A2.** One-line flip in `PolygonHitsSpherePrecise` ([BSPQuery.cs:117](src/AcDream.Core/Physics/BSPQuery.cs:117)) plus a unit test for the tangent boundary. Improves correctness across every BSP query (walls, step-up, step-down). Pairs cleanly with A3. 4. **A3.** Once A4 + A2 land, the architectural cleanup becomes safe. Delete `TryFindIndoorWalkablePlane` (TransitionTypes.cs:1294) and the synthesis call site. Retail's grounded path doesn't synthesize CP — it retains via Mechanisms A/B/C (already in our code at BSPQuery.cs:1615, TransitionTypes.cs:2618, TransitionTypes.cs:896). The 2026-05-20 session tried A3 prematurely (Bug A) and reverted because the doorway-exit case relied on multi-cell iteration that wasn't there. A4 closes that gap. 5. **Lighting (M7).** Separate session. Different domain. Defer until M2 ships. ## Per-item starter notes ### A4 — multi-cell BSP iteration **Read first:** - §"Phase A4" of `docs/research/2026-05-21-collision-fixes-shipped-handoff.md` - `acclient_2013_pseudo_c.txt:272717-272798` (`check_other_cells`) - [`src/AcDream.Core/Physics/TransitionTypes.cs:1407-1559`](src/AcDream.Core/Physics/TransitionTypes.cs:1407) (`FindEnvCollisions` — change site) - [`src/AcDream.Core/Physics/CellTransit.cs`](src/AcDream.Core/Physics/CellTransit.cs) (helpers already exist) **Approach:** - Extract a "cell_array" set from the player's current cell via the existing CellTransit BFS. - Iterate each cell, run `BSPQuery.FindCollisions` against each one. - Combine results: any cell returning Collided/Adjusted halts; any cell returning Slid is remembered; all OK = return OK. **Acceptance:** Walk into the Holtburg inn vestibule (cell `0xA9B40164`). Walls in cell `0xA9B40157` should now block when the player's sphere extends into them, even though the player's center is still in the vestibule. ### Stairs walk-through **Strategy:** verification-only, after A4. Launch with the same probe set, walk up the inn stairs, watch the `[indoor-bsp]` results. If stair hits fire correctly, done. If not, investigate the cell's physics-poly data — stairs may be packed as static objects rather than cell-structure polys. ### A2 — PHSP inversion fix **Bug:** [`BSPQuery.cs:117`](src/AcDream.Core/Physics/BSPQuery.cs:117) has `if (MathF.Abs(dist) > rad) return false;` — bails when sphere is FAR from plane. Retail's `polygon_hits_sphere_slow_but_sure` at `acclient_2013_pseudo_c.txt:322509-322517` does the opposite — bails when sphere is OVERLAPPING plane. **Fix:** flip the comparison. New unit test for the tangent boundary (sphere center at `radius` distance from plane → continue, not reject). **Caveat:** doesn't fix walkable synthesis on its own — `AdjustSphereToPlane` also rejects at the tangent boundary (strict `<` check on interp). The two together gate the synthesis. Fixing A2 alone changes which side of the boundary the rejection happens on but doesn't close the gap. Pair with A3 for the full benefit. **Read first:** - §"Phase A2" of `docs/research/2026-05-21-collision-fixes-shipped-handoff.md` - `docs/research/2026-05-21-walk-miss-capture-findings.md` (the smoking-gun analysis of the 2 cm boundary) ### A3 — synthesis removal **Bug:** retail's grounded path doesn't re-synthesize ContactPlane. It retains via three mechanisms (Path 4 land, LKCP proximity restore, post-OK step-down probe — all already in our code). Our `TryFindIndoorWalkablePlane` runs every frame and is unfaithful. **Fix:** delete `TryFindIndoorWalkablePlane` ([TransitionTypes.cs:1294](src/AcDream.Core/Physics/TransitionTypes.cs:1294)) and its call site. ~500 lines deleted. **Critical prerequisite:** A4 must ship first. The 2026-05-20 session tried A3 prematurely (Bug A) and reverted because doorway transitions caused free-fall — Mechanism C couldn't find a floor poly at the threshold because the indoor cell's BSP had no coverage past the doorway, and multi-cell iteration wasn't there to query the adjacent cell. **Read first:** - `docs/research/2026-05-20-indoor-walking-bug-a-handoff.md` (Bug A's premise + reversion) - §"Phase A3" of the 2026-05-21 handoff ### L-indoor — lighting broken inside **Symptom:** lights inside buildings don't illuminate correctly. **Likely areas:** - Cell-light association (which lights belong to which cell) - Light visibility culling (visible-cells set + light bounds) - Per-light projection matrix indoors **Domain:** rendering, not physics. Separate session. ### L-spotlight — items projecting spotlight on walls **Symptom:** held items (torches, etc.) project spotlight effects onto walls in unexpected directions. **Likely areas:** - Per-entity light direction transform - LightingHookSink owner-tracking **Domain:** rendering, not physics. Separate session. ## CLAUDE.md rules to remember 1. **Work-order autonomy.** You pick what to work on. Recommended order above but adjust if you find something blocking. 2. **No workarounds, retail-faithful.** Same rule that drove A1 through A1.7. If a fix starts to look like a band-aid, stop. 3. **Probe-first, design-second.** Already have rich probes (`[indoor-bsp]`, `[cell-transit]`, `[cell-cache]`, `[walk-miss]`, `[floor-polys]`, `[resolve-bldg]`). Capture before theorizing. 4. **Visual verification is the acceptance test.** Walk the building after each fix. 5. **Stop signals.** Three failed visual verifications in a session = write a handoff, don't push for a fourth. 6. **Don't enable `ACDREAM_PROBE_RESOLVE` for live play.** It lagged the client last session (400k+ lines at 30 Hz). 7. **Subagent policy: Sonnet for implementers, Opus only for load-bearing review.** 8. **Worktrees.** Use the `superpowers:using-git-worktrees` skill to create a fresh worktree branched from main before touching code. ## Launch command (light probes only) ```powershell $env:ACDREAM_DAT_DIR = "$env:USERPROFILE\Documents\Asheron's Call" $env:ACDREAM_LIVE = "1" $env:ACDREAM_TEST_HOST = "127.0.0.1" $env:ACDREAM_TEST_PORT = "9000" $env:ACDREAM_TEST_USER = "testaccount" $env:ACDREAM_TEST_PASS = "testpassword" $env:ACDREAM_DEVTOOLS = "1" $env:ACDREAM_PROBE_INDOOR_BSP = "1" $env:ACDREAM_PROBE_CELL = "1" $env:ACDREAM_PROBE_CELL_CACHE = "1" dotnet build -c Debug dotnet run --project src\AcDream.App\AcDream.App.csproj --no-build -c Debug 2>&1 | Tee-Object -FilePath "launch.log" ``` UTF-16LE → UTF-8 conversion for grep: ```powershell Get-Content launch.log -Encoding Unicode | Out-File launch.utf8.log -Encoding utf8 ``` --- ## The pasteable session-start prompt Open a new Claude Code session in the main acdream worktree (`C:\Users\erikn\source\repos\acdream`, branch `main` at SHA `f80b537` or later). Then paste: --- ``` Pick up the acdream open-items cleanup. After the 2026-05-21 session, 6 items remain across collision + rendering. 1. Read docs/research/2026-05-21-open-items-pickup-prompt.md FIRST. It maps the 6 items, their dependencies, and the recommended order (A4 → verify-stairs → A2 → A3 → lighting in a separate session). Each item has its own "Read first" anchor list inside. 2. Branch state: main is at f80b537 with all 2026-05-21 fixes landed (A1, A1.5, A1.6, A1.7 + probe spike + handoff docs). Build green, 1129-test baseline holds, four user-visible improvements visually verified. Local main is ahead of origin/main (origin at 7034be9); push only if explicitly asked. 3. **Set up isolation FIRST.** Use the superpowers:using-git-worktrees skill to create a fresh worktree from main. Don't work directly in the parent worktree. The 2026-05-21 session's worktree (claude/lucid-goldberg-1ba520) is identical to main and can be removed. 4. Recommended first phase: **A4 (multi-cell BSP iteration)**. It has the biggest user-visible payoff (closes vestibule-cell wall walk-through, likely closes stairs too) and unblocks A3 architectural cleanup. Retail oracle is at acclient_2013_pseudo_c.txt:272717-272798 (CTransition::check_other_cells). Existing CellTransit helpers (FindCellList, FindTransitCellsSphere, AddAllOutsideCells) already enumerate the right cells; A4's work is wiring them into Transition.FindEnvCollisions. 5. Use the superpowers:brainstorming skill before writing A4 code. A4 is a real architectural change (multi-day, 2 files modified + tests) and deserves its own spec + plan. Don't shortcut it. 6. CLAUDE.md rules: - No workarounds. Retail-faithful. - Probe-first, design-second. - Visual verification at Holtburg inn cell 0xA9B40164 vestibule is the A4 acceptance test (walls in adjacent cell 0xA9B40157 should block when the player straddles the boundary). - Don't enable ACDREAM_PROBE_RESOLVE for live play (lags the client). Use [indoor-bsp] + [cell-transit] + [cell-cache] only. - Three failed visual verifications = handoff, not a fourth attempt. 7. M2 ("kill a drudge") is the active milestone. A4 + stair verification + A2 + A3 are all on the M2 critical path because dungeons need walkable indoor space. Lighting is M7 polish; defer. 8. Launch command (light probes only): $env:ACDREAM_DAT_DIR = "$env:USERPROFILE\Documents\Asheron's Call" $env:ACDREAM_LIVE = "1" $env:ACDREAM_TEST_HOST = "127.0.0.1" $env:ACDREAM_TEST_PORT = "9000" $env:ACDREAM_TEST_USER = "testaccount" $env:ACDREAM_TEST_PASS = "testpassword" $env:ACDREAM_DEVTOOLS = "1" $env:ACDREAM_PROBE_INDOOR_BSP = "1" $env:ACDREAM_PROBE_CELL = "1" $env:ACDREAM_PROBE_CELL_CACHE = "1" dotnet build -c Debug dotnet run --project src\AcDream.App\AcDream.App.csproj --no-build -c Debug 2>&1 | Tee-Object -FilePath "launch.log" State the milestone + chosen phase in your first action. ```