# Handoff: speed research moves to abyss (Debian 13, i9-12900HK)

Written 2026-10-19 by the Windows orchestrator (Claude) for the Claude instance on abyss.

## Where things stand
- Branch `assembler/world`. Rounds S3–S13 committed. Each round's report is `Standalone/Research/WorldAssemblerM3/Round*/REPORT.md`.
  Latest committed: S13 `87b0e5d` (Round17, a tile-cost breakdown, diagnostics only).
- **S14 (Round18) is running on the Windows PC.** Its targets:
  - LOD0 marching cubes costs 243 ns/sample: find out what's inside it;
  - fix LOD4's column-cache misses (8,224 vs about 1,700);
  - add shared column pages only if they're still worth it.

  The Windows side finishes, reviews, commits and pushes it. Pull before you touch Core files.
- **Current in-game numbers** (owner plan, BuildHost actor, 25 cm SurfaceWorld, owner's 5800X3D):
  - full set about 4.9 s (S7: 17.4 s);
  - walkable ring about 0.51 s;
  - LOD0 about 1.09 s;
  - 40 m/s ring 75/75;
  - about 29 worker-seconds over 8 TaskGraph background workers.
- **Open levers, in rough order:**
  1. the S14 findings;
  2. a frequency-aware far detail cutoff. A global octave drop failed, and the 2 cm LOD-agreement gate rejects any far
     simplification, so a screen-space gate would need the owner's OK;
  3. visibility-aware scheduling in caves;
  4. RMC batching;
  5. per-strate voxel size;
  6. a disk terrain cache.

  The disk cache is approved as a FEATURE (multiplayer-compatible, compression tested), not as a speed fix.

## Owner rules (non-negotiable)
- **Writable scope:** the VoxelForge repo only. On abyss, ask the owner before installing system packages, UE or
  toolchains.
- Never push `main`. Pushing `assembler/world` (and feature branches) is allowed.
- **Byte-identical output vs earlier rounds is NEVER a gate.** The gates are:
  - determinism of the current build across worker counts;
  - no quality regression;
  - bump the recipe version when output changes.
- **Speed is judged on the cold path** (nothing cached): walking, flying and 40 m/s running must be smooth on a
  first visit.
- Changes go in the shared layer and must benefit every generator family.
- Luna (Codex `gpt-6-luna`, effort max) implements; Claude orchestrates. Claude doesn't write code itself. Sol costs
  20× and is used only for short read-only design asks, with the owner's OK.
- **Briefs:**
  - investigation rounds are open QUESTIONS answered with measurements, not directives;
  - give the goal, invariants and evidence bar, not the method;
  - be kind: credit what the last round got right.
- Every brief says "Do not commit, push or stash". Claude reviews against the code and captures, then commits
  specific files (never files over 300 KB, never raw PNGs).
- **Owner explanations:**
  - plain language, headline first;
  - say what he'll SEE or feel in game;
  - say what's measured vs inferred.
- Plugin hard rules are in `CLAUDE.md`, plus `CODEMAP.md` and `ARCHITECTURE.md` (§8.10 protected invariants).

## Codex launch (Linux)
```
codex exec -m gpt-6-luna -c model_reasoning_effort="max" -c sandbox_mode="workspace-write" -c tools.web_search=true - < brief.md > out.log 2>&1
```
- Launch it as a tracked background task, so you're notified when it ends.
- **On "Selected model is at capacity":** wait 120 s, then resume with
  `codex exec resume <session id> -m gpt-6-luna ... -` and a short "continue where you left off" on stdin.
- Watch for runaway processes (more than 40 min) and rounds longer than 6 h.

## First round on abyss: Linux baseline (proposed)
1. **Build.** Get the Core library (`Standalone/Core`) and its headless benchmark/audit/hash tools building with Clang
   on Linux. The Windows standalone uses MSVC plus a D3D11 viewer, so the viewer stays Windows-only.
2. **Baseline.** Record the laptop baseline on its performance cores (plugged in, fixed power profile):
   - per-LOD tile cost (S13 counters);
   - standalone full clipmap;
   - W1/W8/W12 hashes.
3. **Determinism.** Compare the hashes against Windows (Round17/Round16 list them). A Linux/Windows mismatch is a real
   multiplayer finding: dedicated servers usually run Linux.
4. **Later, only if the owner agrees and provides UE 5.7 Linux plus his assets:** headless BuildHost (`-nullrhi`)
   tests on Linux.

**Not transferable:** cache-size effects (24 MB vs 96 MB L3), thread/slot tuning, smoothness, captures. Those must be
confirmed on the owner's Windows PC before they're claimed to him.