---
title: "Workshop Outcomes: Tile Derivation Contract (Q-101)"
description: "Final outcomes of the tile-derivation-contract workshop — resolution of Q-101 via D-239, the coarse→fine tile refinement chain, morphology family, anti-squaring warp, and district-temperature climate primitive."
type: workshop
status: complete
workshop: tile-derivation-contract
created: 2026-06-07
decision_refs: [D-239]
resolves: [Q-101]
participants: [Tyre, Gestalt, Troblum, Miri, Qatux]
---

# Workshop Outcomes: Tile Derivation Contract (Q-101)

**Result:** Q-101 resolved → **[[D-239]]** filed (architecture domain, confirmed, 2026-06-07).

The keystone "what's in a tile" question — how a coarse Layer-1 cell + seed becomes
coherent ~1 m voxel geometry across ~3 scale jumps — is now contracted. This was the one
unbuilt layer of the Phase-4 cascade (L0–L4 already exist).

## What was decided (D-239 in brief)

1. **Three-carrier refinement chain.** `RegionProfile` (~1 km) → `ChunkContext` (64 m) →
   `VoxelColumn` (1 m). Each a pure deterministic function of `(seed, atlas, body-params,
   position)` per D-227. Each scale boundary is its own derivation.

2. **No authoring at the derivation layers, ever.** Zero per-body override hooks. All
   gating params (`RIVER_THRESHOLD` → derived per-body-class, not the global `200`;
   `tectonic_class`; `GlaciationGrade`; `precipitation_class`) derive from body params.
   Lore bodies (Kallast, Velen, Cygni B) are honoured by *setting params* and serve as
   validation cases — fix params, never patch the derivation.

3. **District temperature is the climate primitive.** A scalar °C per 2×2 km district,
   **nullable** (no atmosphere → null → no climate branch; airless surface ice is geology).
   Derived from sun (luminosity + insolation), planet (latitude + elevation lapse +
   orbital/axial phase = season, day-phase = diurnal), atmosphere (greenhouse → base,
   heat-retention → diurnal-swing amplitude). **Moisture** is a separate primitive.
   Everything climatic — precipitation, vegetation/treeline, glaciation, the seasonal/clock
   state (Q-105) — derives from temperature (+ moisture). Formalises D-210's temperature proxy.

4. **Scattered, transient freeze/snow model.** Ice/snow is a *band with coherent spatial
   scatter*, not a hard `temp<0` contour: freshwater (lakes/rivers) **+5 → −10 °C** district
   mean (the +5 is night-frost reaching the coldest tiles); sea ice its own lower/wider band
   (≈ −2 onset, pack-ice pattern); snow (land) the same, **gated on moisture**. **Transient**
   in the marginal band — forms in the cold phase (night/season), melts in the warm phase →
   time-of-day passability shifts. Forward contract to Q-105.

5. **Anti-"squaring" warp.** A stateless, hash-based position-keyed domain-warp; **f64
   sub-metre precision through to the final voxel coordinate, then truncate to the integer
   voxel address** (a cast, IEEE-754-deterministic). ±8 m range makes FMA ULP variance
   harmless. Position math, not a structural decision — D-010 integer discipline preserved.

6. **8 morphology families** via a gated decision tree over integer `RegionProfile` inputs:
   LavaField · FjordWall · CliffCoast · BraidedDelta · DuneStrand · IncisedGorge ·
   MeanderReach · AlluvialPlain (fallback). Hard gates: fjord ≥ GlaciationGrade 2; LavaField
   = Volcanic; lithology bounds slope/form.

7. **Frozen 17-zone `MorphologyZone` vocabulary.** Freeze point = the Rust enum; changes need
   a D-record amendment (classifier *tuning* stays free). Four zones (tidal flat, estuarine,
   alpine, wetland) are derived sub-classifications, not generator families.

8. **Seams — prevent incompatible, allow valid (never patch).** Decision-tree gate ordering
   + a build-time compatibility-matrix invariant blocks incompatible adjacencies (e.g.
   MeanderReach↔Volcanic). Valid geomorphic seams (cliff↔fjord, lithology faults) are kept
   **sharp** (real geology is sharp), made organic by the warp — no feathering.

9. **Believability laws + game-feel constraints** are binding (drainage monotonicity,
   lithology→landform, glaciation→form, climate→vegetation; ≥1 tactical point/chunk, cover ≠
   concealment, chokepoint widths, real seasonal passability via `ElevationDelta`↔Q-105).

## Process notes

- **2-round lean format** (independent positions → lead-interviewed synthesis), not the full
  5-round workshop. Round-1 positions: `tyre-round1.md`, `gestalt-round1.md`,
  `troblum-round1.md`, `miri-round1.md`.
- The four core calls (seams, body-params-fully-derived, vocabulary lock, warp precision)
  were made by the human via AskUserQuestion. The climate model (temperature primitive,
  separate moisture, the three-sibling scattered freeze, day/night swing, transient ice/snow)
  was a human-driven design pivot during synthesis.
- An **adversarial verification pass** (the same four perspectives) caught ~10 issues, all
  folded into the final D-239: the "continuous→continuous" seam argument was false (boolean
  gates are discontinuities) → rewritten to gate-ordering + matrix; warp determinism gaps
  (FMA / statelessness / truncate-not-compare); "Block-or-higher" → "Region-or-higher";
  D-209 tier → D-203; missing LavaField tectonic gate; seasonal regained mechanical teeth;
  the 17-zones-vs-8-families gap closed; believability laws inlined; "frozen" given a real
  enforcement mechanism.

## Open siblings (left for later, contract does not preclude them)

- **Q-102** — cohesion matrix: effectively *is* the D-239 warp; can be closed against it or
  folded in when the material-scatter layer is built.
- **Q-103** — tile-mutator op schema: open, needed at the save system (Phase 5+).
- **Q-105** — region seasonal/clock state: D-239's temperature(time) + `ElevationDelta`
  calibration is the forward contract to it.

## Process friction captured

- **Team mode is broken in clide** — see `docs/briefings/clide-team-mode-friction.md`.
  Teammates ran in-process (no pane), the Team Chat view stayed inert, no `clide team` verb.
  The workshop ran as background Agent subagents instead. Hand-off material for the clide team.
- The `miri` agent type is **read-only** (no Write/Bash) — the lead transcribed
  `miri-round1.md` to disk.