glytch/fktry/lanes/LANE-RENDER.md

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.

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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.

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NOTES (append-only log, newest at bottom)

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