Docs: DR-025 world redo (natural-frontier biomes) + session log; CLAUDE.md art pointer

Session log + DR-025 for the off-world natural-frontier world redo; mark PolygonNatureBiomes in-use in the Synty inventory; archive the long-form gotchas (PNB ring-mesh white-torus, edit-mode region-fog preview, EG-entity vs cosmetic, execute_code DeleteAsset block, shadow-cast hygiene). CLAUDE.md: net-zero art pointer to DR-025 (39882 B, under the 40KB budget).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Docs/Vault/06_Roadmap/Synty_Asset_Inventory.md

@@ -25,7 +25,7 @@ Catalog of the Synty Polygon packs under `Assets/Synty/`, produced by the [[DR-0
 
 ## Environment / world (no characters — map + set-dressing)
 
-- **PolygonNatureBiomes** (highest env value): **Arid_Desert** reads as an off-world expedition site out of the box (satellite, solar panels, turbines, beacons, artefacts, even a **Warpgate**) — perfect for the **+1000 expedition region** ([[DR-013_M6_Aether_Cycle_Region_Split]]). Meadow_Forest (ships a post-process volume) for the home base.
+- **PolygonNatureBiomes** ✅ **IN USE** ([[DR-025_World_Environment_Redo_Natural_Frontier]]): **Arid_Desert** = the **+1000 expedition region** (off-world survey site: satellite, solar panels, turbines, beacons, artefact, alien bones, craters; cliff/rock perimeter ring) and **Meadow_Forest** = the **home base** (tree-ring bowl, Warpgate gateway, cabin/windmill/well/pond). Built as cosmetic classic-URP roots in `Game.unity` (no conversion; colliders stripped). Ground = `Mat_Grass_Textures_01` / `sand 1` (both stock URP/Lit — AVOID the prop-atlas `S_General` mats as a floor).
 - **PolygonNature**: trees/rocks/foliage/water + skybox — terrain dressing, harvestable-node visuals.
 - **PNB_Core**: shared sky/weather/water/aurora atmosphere (rain/snow/fog FX, skydome, 9 ShaderGraphs — verify under URP 17.4; use the skydome in the classic-URP cosmetic root, not baked EG meshes).
 - **PolygonKaiju** (env half): 23 buildings incl. **pre-destroyed** highrises/blocks + 40 props (cars, boats, bridge+rubble, neon signs, powerlines, crane, jet, missile) — a ruined-city map + FX meshes (bullets/fire/stomp).

Docs/Vault/07_Sessions/2026/2026-06-08_World_Environment_Redo.md

@@ -0,0 +1,101 @@
+---
+date: 2026-06-08
+type: session
+tags:
+- session
+- art
+- synty
+- environment
+- world
+- urp
+- presentation
+- biomes
+permalink: gamevault/07-sessions/2026/2026-06-08-world-environment-redo
+---
+
+# Session 2026-06-08 — World environment redo (off-world natural frontier)
+
+> Driven by `/dots-dev` (Feature track) under **ultracode**. Major world cleanup using newly-imported Synty
+> nature packs (PolygonNature, PolygonNatureBiomes, PNB_Core).
+
+## Goal
+
+Operator: *"The world environment needs a major cleanup. I imported new assets — use them to redo the world.
+Utilize materials, terrain, new models, foliage. Whatever makes the world look good."* Intake fork resolved:
+**off-world natural frontier** (Meadow_Forest base + Arid_Desert expedition, sci-fi tech on top) · **both regions**.
+
+## Process (ultracode)
+
+- **Design fan-out Workflow** (3 read-only agents → verified build spec): Meadow base composition, Arid expedition
+  composition, atmosphere/lighting recipe extracted from Synty's own biome demo scenes. Every prefab/material path
+  verified by reading the `.prefab`/`.mat` YAML before listing.
+- **Implementation sequential via `execute_code`** (single editor — mutation can't race; the blessed DR-011/DR-018
+  pattern), in batches with `read_console` between each.
+- **4-lens adversarial review Workflow** (sim-isolation · performance · code-correctness · composition) over the
+  saved scene + new scripts + screenshots → confirmed findings fixed before sign-off.
+
+## Done
+
+- **Retired the old world** (`SyntyWorld` sci-fi colony + `BlightfieldDecor`/`ExpeditionGround`/`ExpedPillar*`/`Ground`,
+  8 roots) and built two cosmetic classic-URP roots in `Game.unity` (NOT the subscene; colliders stripped → inert to
+  the DOTS PhysicsWorld, per [[DR-011_Synty_World_VFX_Integration]]/[[DR-018_World_Space_Cohesion_Pass]]):
+  - **`BaseBiome`** (origin) — Meadow_Forest: grass ground plane, 195 deterministic foliage/tree/rock instances
+    (tree-ring bowl r20-30, wildflower band, bushes/rocks/ground-cover, flat interior cover only), 8 landmarks
+    (**Warpgate** hero gateway at (0,0,-20), stone cabin, windmill, well, pond + waterwheel + lilies, 2 sci-fi crates),
+    6 FX (butterflies/sunbeams/petals/glowing-dust/water), 4 cyan Aether point lights.
+  - **`ExpeditionBiome`** (+1000) — Arid_Desert: sand ground plane, 182+5 instances (cliff/spike ring r44-58, mid
+    rock/cactus/bramble bands, crater+alien-bone scatter, flat inner cover, background hills, **5 hero rock
+    silhouettes** added in review), 9 survey-outpost landmarks (satellite, solar array, 2 turbines, tent, survey
+    level, sign, alien artefact, rock arch), 6 FX (dust/ash/sunray/tumbleweed/vulture), 4 orange Aether point lights.
+- **Atmosphere:** warm daylight directional sun (euler 50,330; `#FFF4E0`; 1.6), Trilight ambient, a new
+  `Skybox/Procedural` material (`Assets/_Project/Rendering/Sky_DaytimeProcedural.mat`, infinite → covers both regions
+  unlike a Synty skydome mesh at origin), exp-squared fog, and a cloned daylight post-FX profile
+  (`PostFX_Daylight.asset` — kept ACES, trimmed bloom/contrast/vignette + neutralised the dark-colony cool cast).
+- **`WorldAtmosphereSystem`** (+ `WorldAtmosphereConfig`) — client-only presentation `SystemBase` that cross-fades
+  `RenderSettings` fog colour/density + ambient sky between the cool-green meadow and the warm-orange desert based on
+  camera world-X (mirrors `HudSystem`'s region split at X>500). Pure presentation, observe-only, zero sim impact;
+  live-tunable config mirroring the `WorldFeelConfig` idiom.
+
+## Validation
+
+- **EditMode 214/214** (unchanged; the new presentation code added no test but broke none). Console clean (only the
+  pre-existing benign Server-Tick-Batching/RPC-age warnings).
+- **Value-introspected:** 832 renderers across both biomes, **0 colliders** (all stripped), **0 error/magenta
+  materials**, 8 point lights (shadows off), 13 particle systems. All Synty shaders URP-native.
+- **Adversarial review (4 lenses):** isolation = *purely cosmetic confirmed* (no ghost/subscene/sim/PhysicsWorld
+  leak; system writes only `RenderSettings`); perf = Forward+ clustered lights + SRP batcher correct, **fixed**
+  realtime shadow-casting on 254 small props + ground planes (now off); code = correct vs sibling systems, **fixed**
+  fog-default drift; composition = **fixed** washed/flat desert (removed bad fog-ring meshes, saturated expedition
+  fog, added hero silhouettes). Hero shots: `Assets/Screenshots/redo_base_meadow3.png` (+ `redo_expedition_arid3.png`
+  previewed with expedition atmosphere baked).
+
+## Decisions
+
+- [[DR-025_World_Environment_Redo_Natural_Frontier]] — off-world natural-frontier biome world; cosmetic-GameObject
+  pattern reused; region-aware atmosphere cross-fade. Builds on [[DR-011_Synty_World_VFX_Integration]],
+  [[DR-018_World_Space_Cohesion_Pass]], [[DR-013_M6_Aether_Cycle_Region_Split]].
+
+## Gotchas recorded (→ archive)
+
+- **Synty PNB_Core fog-ring / cloud-ring MESHES render as a glaring white torus band** — don't place them; the
+  global `RenderSettings` fog gives the atmosphere. (Deleted all 4 in review.)
+- **Edit-mode screenshots show the BASE region's baked fog over the expedition** because the runtime cross-fade
+  system only runs in Play — to preview a region's true look, temporarily bake that region's `RenderSettings` then
+  revert. (The desert looked washed until previewed with expedition fog.)
+- **A cyan capsule at each region centre is a baked Gameplay-subscene ENTITY** (Entities-Graphics-rendered, Aether
+  material), NOT cosmetic dressing — `FindObjectsByType<MeshRenderer>` won't find EG entities; out of scope for an
+  art pass.
+
+## Open / deferred
+
+- **Live cross-fade Play-validation:** confirmed by-code + by a baked-atmosphere preview; a focused play-through to
+  eyeball the actual fog/ambient transition while walking base↔expedition is the remaining eyeball check.
+- **Global quality knobs (deferred, low-risk perf):** shadow distance 50u/4-cascade and PC `lodBias=2` are generous
+  for a top-down cam; `RequireOpaqueTexture` likely unused. Left to a dedicated perf pass (they touch global RP/quality).
+- **Polish opinions (optional):** stronger per-region brightness/contrast delta (hostile desert hotter), more visible
+  cyan at the base play area, procedural-skybox ground tint if the camera ever exposes the horizon.
+
+## Next
+
+A focused play-through to tune the atmosphere cross-fade + biome density/feel, then either the deferred global perf
+pass or resume the milestone track. The biome-cosmetic pattern + `WorldAtmosphereConfig` generalise to future regions.

Docs/Vault/07_Sessions/_Decisions/DR-025_World_Environment_Redo_Natural_Frontier.md

@@ -0,0 +1,92 @@
+---
+id: DR-025
+title: World environment redo — off-world natural frontier (Meadow_Forest base + Arid_Desert expedition) as cosmetic biomes + region-aware atmosphere cross-fade
+status: accepted
+date: 2026-06-08
+tags:
+- decision
+- art
+- synty
+- environment
+- world
+- urp
+- presentation
+- biomes
+permalink: gamevault/07-sessions/decisions/dr-025-world-environment-redo-natural-frontier
+---
+
+# DR-025 — World environment redo: off-world natural frontier
+
+## Context
+
+The world was a flat-shaded Synty **sci-fi colony** (`SyntyWorld` skyline ring + plaza + space skybox at origin,
+[[DR-011_Synty_World_VFX_Integration]]) with a 21-piece rock-basin Blightfield at +1000 ([[DR-018_World_Space_Cohesion_Pass]]).
+The operator imported the Synty **PolygonNatureBiomes** (Arid_Desert + Meadow_Forest), **PolygonNature**, and
+**PNB_Core** packs and asked for a *major cleanup — redo the world with the new materials/terrain/models/foliage*.
+The [[Synty_Asset_Inventory]] had already pre-scoped these: *Arid_Desert → the +1000 expedition region,
+Meadow_Forest → the home base*. Intake fork (one `AskUserQuestion`): **off-world natural frontier** (nature ground
++ foliage as the world's truth, sci-fi tech layered on top — keeps the locked cyan-ordered ↔ orange-wild duality of
+[[DR-015_The_Awakening_Engine_Fiction_Adoption]]) · **both regions** this pass.
+
+## Decision
+
+1. **Reuse the blessed cosmetic-GameObject pattern, full-replace the dressing.** All new world geometry is **cosmetic
+   classic-URP GameObjects in `Game.unity`** (two roots `BaseBiome`@origin, `ExpeditionBiome`@(1000,0,0)) — NOT the
+   `GameplaySubScene` (which owns collision/ghosts and is untouched). Every placed instance has its **colliders
+   stripped** (inert to the DOTS PhysicsWorld anyway; the player CC sweeps only the baked subscene). The 8 old
+   dressing roots were deleted. The 32×32 base buildable grid + the expedition walkable core stay **clear** — tall
+   props ring the perimeter (a natural "bowl"), only flat/low non-blocking cover goes inside. All Synty biome shaders
+   are **URP-native (`UniversalTarget` verified) → no conversion** (unlike the HDRP BefourStudios art).
+
+2. **Two biomes, deterministically scattered.** `BaseBiome` = Meadow_Forest (grass ground plane, ~195 instances:
+   tree-ring r20-30, wildflower/bush/rock/ground-cover bands, flat interior grass/flowers; landmarks: **Warpgate**
+   hero gateway at the south edge facing center, cabin/windmill/well, a NE pond + waterwheel + lilies, 2 sci-fi
+   crates staging the gate; 4 cyan Aether point lights; butterflies/sunbeam/petal/glow FX). `ExpeditionBiome` =
+   Arid_Desert (sand ground plane, ~187 instances: cliff+spike perimeter ring r44-58, mid rock/cactus/bramble,
+   crater + **alien-bone** scatter telling the dead-survey story, flat inner cover, far background hills, 5 hero rock
+   silhouettes; landmarks: an abandoned **survey outpost** cluster NE — satellite/solar/turbines/tent/survey-level/
+   sign — + an alien artefact + a rock-arch vista; 4 orange Aether point lights; dust/ash/sunray/tumbleweed/vulture
+   FX). Bulk authoring via `execute_code` + `PrefabUtility` with a seeded LCG (deterministic), missing-path-safe
+   preload (skip+report; 0 missing in practice).
+
+3. **One global daylight; per-region atmosphere cross-faded at runtime.** A single warm directional sun + Trilight
+   ambient + a `Skybox/Procedural` material (infinite → covers BOTH regions; a Synty skydome is a MESH at origin and
+   can't) + a cloned daylight post-FX profile (`PostFX_Daylight.asset`: keep ACES, halve bloom/contrast/vignette,
+   neutralise the dark-colony cool cast). Because the two regions share one scene/light/skybox, mood divergence is
+   carried by **`WorldAtmosphereSystem`** — a client-only presentation `SystemBase`
+   (`[WorldSystemFilter(ClientSimulation)]`, `PresentationSystemGroup`) that lerps `RenderSettings` fog colour/density
+   + ambient-sky between the cool-green meadow and warm-orange desert by camera world-X (mirrors `HudSystem`'s X>500
+   region split). Pure presentation, observe-only, no ECS query, no sim/netcode impact; knobs live in a live-tunable
+   `WorldAtmosphereConfig` MonoBehaviour (the `WorldFeelConfig`/`VFXConfig` bridge idiom, `SubsystemRegistration`
+   static reset, null-safe fallbacks). Guarded to the `"Game"` scene so the menu is never restyled.
+
+## Consequences
+
+- **Validated.** EditMode **214/214** (new presentation code broke none). Value-introspection: 832 renderers,
+  **0 colliders**, **0 error/magenta materials**, 8 shadow-off point lights, 13 particle systems. Both biomes read
+  as intended (hero shots in the session log). A **4-lens adversarial-review Workflow** confirmed the redo is
+  *purely cosmetic* (no ghost/subscene/PhysicsWorld/sim leak; the system writes only `RenderSettings`) and drove
+  three fixes before sign-off: (a) **perf** — disabled realtime shadow-casting on 254 small foliage instances + the
+  2 ground planes (kept it on 149 trees/cliffs/landmarks); (b) **code** — aligned the no-config fallback fog
+  densities to the tuned values; (c) **composition** — the desert read washed/flat, fixed by deleting bad fog-ring
+  meshes, saturating the expedition fog, and adding 5 mid-ring hero rock silhouettes.
+- **No new asmdefs.** New code: `…/Client/Presentation/WorldAtmosphereSystem.cs` + `WorldAtmosphereConfig.cs`. New
+  assets: `Sky_DaytimeProcedural.mat`, `PostFX_Daylight.asset`, and the two biome roots baked into `Game.unity`.
+  Orthogonal to + additive over all gameplay; the gameplay subscene, ghosts, region split, and save schema are
+  untouched.
+
+## Gotchas (→ `_Meta/CLAUDE_Build_Gotchas_Archive.md`)
+
+- **Synty PNB_Core fog-ring/cloud-ring MESHES render as a bright white torus** — don't place them; use
+  `RenderSettings` fog for atmosphere.
+- **Edit-mode screenshots show the BASE region's baked fog over the +1000 expedition** (the runtime cross-fade only
+  runs in Play) — preview a region's true look by temporarily baking that region's `RenderSettings`, then revert.
+- **A cyan capsule at each region centre is a baked Gameplay-subscene ENTITY** (Entities-Graphics-rendered, Aether
+  material) — `FindObjectsByType<MeshRenderer>` won't find EG entities; it is gameplay, not cosmetic dressing.
+- **`AssetDatabase.DeleteAsset` is blocked by `execute_code` safety-checks** — rely on `CopyAsset` over an absent
+  destination for idempotent asset clones (or run with `safety_checks=false`).
+
+Builds on + reuses [[DR-011_Synty_World_VFX_Integration]] (cosmetic-GameObject world, collider-strip, no-conversion
+Synty), [[DR-018_World_Space_Cohesion_Pass]] (region dressing via `execute_code`/PrefabUtility, Aether palette),
+[[DR-013_M6_Aether_Cycle_Region_Split]] (the +1000 region split + X>500 boundary), and the client-presentation
+idiom of [[DR-009_GameFeel_Identity_FirstBlood]]. Serves the cohesive-world pillar in [[Pillars]].

Docs/Vault/_Meta/CLAUDE_Build_Gotchas_Archive.md

@@ -321,3 +321,44 @@ Full rules: `~/.claude/skills/dots-dev/references/dots-conventions.md` (Windows:
 `.mcp.json` is committed + portable (`${CLAUDE_PROJECT_DIR}`); the **`dots-dev` skill travels with the repo** (`.claude/skills/dots-dev/`). Each machine still needs: (1) `uv`/`uvx` + Obsidian app + `obsidian-cli` (the `unity-mcp-skill` + native `memory/` are machine-local, don't sync); (2) basic-memory registration — `uvx basic-memory project add gamevault "<repo>/Docs/Vault" --default` then `uvx basic-memory reindex --full --search --embeddings --project gamevault`; (3) Unity 6.4 open + the Unity-MCP bridge connected (`mcpforunity://editor/state` → `ready_for_tools`).
 
 <!-- END snapshot -->
+
+## 2026-06-08 — World environment redo to Synty nature biomes ([[DR-025_World_Environment_Redo_Natural_Frontier]])
+
+Long-form lessons from the off-world-natural-frontier world redo (Meadow_Forest base + Arid_Desert expedition as
+cosmetic classic-URP biomes in `Game.unity`; region-aware `WorldAtmosphereSystem` fog/ambient cross-fade).
+
+- **Synty PNB_Core fog-ring / cloud-ring PREFABS are MESHES that render as a bright white torus band** at gameplay
+  scale — they do NOT read as soft haze. Do not place them for atmosphere; the global `RenderSettings` fog
+  (exp-squared, low density) gives the haze, and a `Skybox/Procedural` material gives the sky. (All 4 ring instances
+  were deleted in review.)
+- **Two regions, one scene → use a `Skybox/Procedural` MATERIAL on `RenderSettings.skybox`, never a Synty skydome
+  MESH.** All Synty biome "sky" materials use one `SkyDome.shadergraph` authored for a dome MESH centred at origin —
+  a single dome can't cover the expedition at x=1000, and per-region domes double the cost. The procedural skybox is
+  infinite and region-agnostic; per-biome mood comes from the cross-faded fog/ambient instead.
+- **Edit-mode screenshots show the BASE region's BAKED `RenderSettings` over the +1000 expedition**, because the
+  runtime cross-fade (`WorldAtmosphereSystem`, a `ClientSimulation` presentation `SystemBase`) only runs in Play.
+  The desert therefore looks washed/cool in an edit-mode capture. To preview a region's TRUE in-Play look without
+  entering Play: temporarily bake that region's `RenderSettings` (fog colour/density + ambientSkyColor) via
+  `execute_code`, screenshot, then revert. The desert read correctly the moment its warm-orange fog was baked.
+- **A cyan capsule at each region centre is a baked Gameplay-SUBSCENE entity** (rendered by Entities Graphics with
+  the Aether material), NOT cosmetic dressing and NOT removable in an art pass. `Object.FindObjectsByType<MeshRenderer>`
+  returns nothing for it — EG entities use `BatchRendererGroup`, not `MeshRenderer`. Confirms the cosmetic/gameplay
+  split: an art pass touches only `Game.unity` GameObjects, never the subscene.
+- **`execute_code` safety-checks BLOCK `AssetDatabase.DeleteAsset`** (and `File.Delete`, `Process.Start`, etc.) — the
+  whole snippet is rejected pre-execution (nothing runs, so no partial state). For idempotent asset clones, rely on
+  `AssetDatabase.CopyAsset` over an absent destination (it no-ops/false on an existing one and you load that), or
+  pass `safety_checks=false` deliberately.
+- **Shadow-cast hygiene for hundreds of cosmetic props:** nothing in the project set `ShadowCastingMode.Off`, so all
+  ~377 placed meshes + the 2 ground planes cast realtime soft directional shadows (4-cascade, soft-quality-3) — a
+  large depth-pass bill for sub-pixel foliage shadows that read as noise top-down. Fix: walk the biome roots and set
+  `Renderer.shadowCastingMode = Off` on small props (name heuristic + combined-AABB extent < ~1.6m) and the flat
+  ground planes, keeping it ON for trees/cliffs/landmarks (254 off / 149 kept here). Forward+ clustered lighting
+  makes 4 simultaneous additional point lights/region a non-issue (the per-object `AdditionalLightsPerObjectLimit`
+  is ignored under `RenderingMode: 2`); non-static cosmetics + SRP Batcher is the right batching choice (no static
+  combine, re-tint-friendly).
+- **Region-aware presentation cross-fade pattern:** a client-only `SystemBase` in `PresentationSystemGroup` that
+  reads `Camera.main.transform.position.x` and lerps `RenderSettings` (fog/ambient) across the X>500 boundary
+  (mirrors `HudSystem.ExpeditionRegionXMin`). No ECS query, observe-only, `"Game"`-scene guarded so the menu isn't
+  restyled; knobs in a `WorldFeelConfig`-style MonoBehaviour with `SubsystemRegistration` static reset + null-safe
+  fallbacks. Zero sim/netcode impact (writes only global managed `RenderSettings`; `ClientSimulation` filter keeps
+  it off the server/headless world).