# LANE-RENDER — three.js world renderer

You are an Opus 4.8 executor on the RENDER lane of FKTRY. Read `../MASTERPLAN.md` and
`../CONTRACTS.md` first; the world bible + visual style guide (§8) is
`../../docs/FKTRY_LORE.md` — §8 is YOUR section, follow it.

**Mission:** make the Bitstream visible. Isometric factory view, machines, belts with
smoothly interpolated items, ghosts, selection — and the hot-swap pipeline that lets
MODELBEAST GLB assets land mid-development without a code change.

**Owned paths:** `src/render/**`, `public/assets/**` (manifest + loading; the files
themselves arrive from MODELBEAST).
**Never touch:** contracts, main.ts, other lanes. Sim is truth: you render snapshots,
you never simulate. If motion looks wrong, interpolate better or note it — don't
"fix" positions locally.

**Standing rules (all rounds):**
- 60fps with 500 entities + 2,000 belt items on an M-series MacBook. Instanced meshes
  for belts/items from day one — you will not get to retrofit this later.
- Placeholder aesthetic is a feature: crisp box-primitive machines tinted per codex
  `color`, NOT gray cubes. Two-material rule even for placeholders: dark body + one
  emissive accent.
- Every entity mesh keys off `MachineDef.asset` / `ItemDef.id` through the registry —
  zero hard-coded ids.

---

## CURRENT ORDERS — Round 1 (goal: milestone M1 "FLOW")

Replace the stub in `src/render/index.ts`:

1. **Camera + controls.** Orthographic isometric-style view. Pan: middle-drag or WASD.
   Zoom: wheel (clamped ~8..40 world units). Window resize handled.
2. **Ground.** Tile grid over the 64×64 world; subtle Stream-Crust styling (dark
   `#0a0812` base, faint `#181425` lines) — see style guide §8. A soft vignette or
   fog so the world doesn't just end.
3. **Asset registry + hot-swap.** `registry.ts`: maps asset key → THREE.Object3D
   factory. Default: procedural placeholder (footprint-sized beveled box, body color
   from data, one emissive accent, tiny idle animation — e.g. quantizer jaw bob).
   On init, attempt `GLTFLoader` for `public/assets/models/<key>.glb`; if present it
   replaces the placeholder factory. Also poll or re-check on a 10s timer in dev so
   assets dropped in mid-session appear without reload (note what you implement).
4. **Entities.** Sync scene to `snap.entities` (add/remove/rotate). Belts get a flat
   directional piece with an animated arrow/chevron texture (shader or UV scroll).
5. **Belt items.** InstancedMesh per item type (colored octahedron/box placeholder),
   positioned from `BeltItem.t` + belt entity pos/dir, interpolated with `alpha` for
   butter-smooth motion at 30 tps sim.
6. **Picking + ghost.** `pickTile` via raycast to the ground plane. `setGhost` shows
   the selected machine's placeholder at the hovered tile, tinted cyan; red tint if
   tiles occupied (you can read occupancy from `snap.entities` footprints).
7. **Feedback dressing (cheap but load-bearing):** jammed machines get a small
   blinking amber light; brownout dims the whole scene ~30% and flickers lights
   (listen to snapshot.bandwidth.brownout).

**Definition of done:** dev server shows the factory; placing a line from the UI (or
console dispatch) shows machines + items gliding down belts smoothly; a GLB dropped
into `public/assets/models/quantizer.glb` replaces the placeholder. `npm run check`
clean. NOTES written.

---

## NOTES (append-only log, newest at bottom)

```
### Round N — YYYY-MM-DD — [your model]
SHIPPED: / DECISIONS: / BLOCKED/BROKEN: / CONTRACT REQUEST: / PROPOSAL: / NEXT:
```