--- title: "Asset Brief — Rural Walls" description: "Building-exterior wall models/textures for rural/vernacular settlement types — D-235 wall axis" type: design status: active ticket: "" decision_refs: [D-235, D-244, D-257] author: "Araminta" created: 2026-07-25 updated: 2026-07-25 --- # Asset Brief — Rural Walls One page. Gates its child story — the story does not enter `in_progress` without this brief attached. --- ## 1. Scope Building-exterior **wall** surfaces for rural/vernacular/frontier settlement types — the D-235 `WallMaterial` axis tags a rural-type template's `allow` filter selects (`stone_wall`, `timber_wall`, `rammed_earth_wall`, `stucco_wall`, `brick_wall` — the "vernacular/agrarian" register). No prior art exists for this class beyond the T-961 epic text mention (2026-06-12 audit matrix) — unlike `station-walls.md`'s sibling, this is a clean-slate brief. Out of scope: station/urban walls (`concrete_wall`, `steel_frame`, `glass_curtain_wall`, `composite_panel` — sibling brief), barns (a rural building *type*, not a wall-axis token — deferred, see `deferred.md`), doors, floors. ## 2. Visual Reference `palette.md` §3.1 rows for `stone_wall`, `timber_wall`, `rammed_earth_wall`, `stucco_wall`, `brick_wall` — every one of these tags is explicitly warm-hued (warm grey-tan, warm mid-brown, ochre-to-umber banding, warm off-white sand, warm terracotta-to-ochre) and the table is explicit that `stone_wall` is D-235's flagship "gets it wrong if literal" case — **never render it cool grey**. This is the register where the "functional warmth" mood target (`palette.md` §4) reads most directly — rural walls are the class most likely to be mistaken for a generic cool-grey default if a generation pass isn't told otherwise. `generic_wall` (§3.5) is the shared fallback terminal with `station-walls.md` — one placeholder texture serves both siblings until specific tags ship. ## 3. Naming Texture: `_.png` per `conventions.md` §3 — e.g. `stone_wall_basecolor.png`, `stone_wall_normal.png`, `timber_wall_basecolor.png`, `rammed_earth_wall_basecolor.png`. If a standalone wall-segment model is produced (rural walls are more likely to need a discrete model than station walls, given rammed-earth's strong horizontal banding reads better as geometry+texture than texture-only), it follows §1's `_ .glb` (e.g. `wall_structural_timber.glb`) with the same `props`-category placement as its station sibling. No tint mask — material register (not player-favorite color) drives these hues. ## 4. Generation Path Standard path: `/image-gen` → `/glb-gen` (Trellis) → Blender postprocess → `client/assets/models/props/` + `manifest.json`, OR the texture-only path (`/image-gen` concept, no Trellis step) landing in `textures.md` — same choice as `station-walls.md` §4, decided per-tag based on whether the material's character (rammed-earth banding, stone coursing) needs real geometry or reads fine as a flat PBR map. Concept prompts for this class should explicitly state the target hue family from §2 (warm, not cool-grey) since Gemini's default "concrete/stone" association skews cool without that steer. ## 5. Acceptance 3 starter assets enter `models.md`/`textures.md` + `manifest.json` at `planned`: (1) `stone_wall` texture — the flagship warm-hue worked example, highest risk of a cool-grey miss without explicit review; (2) `timber_wall` texture; (3) `rammed_earth_wall` texture (the banding signature makes it a good early test of whether the texture-only path is sufficient or a modeled relief is needed). `generic_wall` is shared with `station-walls.md` — do not duplicate it in this class's count; **milestone-0 IF Q-119 resolves yes** (not resolved here). --- ## Cross-References - `docs/assets/visual/conventions.md` §1, §3 — model naming, D-235-keyed texture naming - `docs/assets/visual/palette.md` §3.1, §4 — wall material register, "functional warmth" mood target - `docs/assets/visual/models.md`, `docs/assets/visual/textures.md` — target catalogs - `client/assets/models/manifest.json` - `docs/assets/briefs/station-walls.md` — sibling brief, shares `generic_wall` fallback