Environment kit skill for AI agents

​

When your agent uses it

• Generating a modular environment kit of snap-together pieces that form a level — dungeon kit, modular walls, interior pieces
• Building a dungeon, interior, or town kit from repeatable pieces that snap together in one style

​

Install

npx -y summer-engine@latest skills install environment-kit --agent claude-code

​

The skill

​

When to use

• “Build me a dungeon kit — walls, floor, door, pillar.”
• “I need modular wall pieces for a sci-fi corridor.”
• “Make a tileset for a wooden tavern interior.”
• “Generate the pieces for a stone temple — I’ll assemble the level.”
• The user wants to build a level out of repeating, snapping pieces.

​

When NOT to use

• A single hero prop (single chest, single throne) → prop-model.
• Open-world terrain (rolling hills, forests) → use a heightmap + scattered organic models from organic-model.
• Repeating flat surfaces only (just walls and floors, no decorative pieces) → asset-strategy Pipeline 2 (textures + CSG) is cheaper and snaps perfectly to grid.
• Characters or vehicles in the scene — those are separate skills.

​

The style anchor pattern

1. Generate the anchor piece first. Pick the most visually defining piece — usually the wall or the door. Iterate the prompt until the user approves it visually.
2. Extract the style suffix. Everything after the object description. Example anchor prompt:

   A stone dungeon wall section, mossy granite blocks with iron reinforcements, 
   torch-bracket sconce, weathered surface. Game asset, centered, stylized 
   low-poly game art, warm torchlight palette, white background, isolated object.

​

Snap-grid alignment

​

Steps

​

1. Confirm scope and pick the grid

About to build a dungeon kit. Suggested pieces: wall, floor, pillar, door, corner, arch (6 generations, ~5 min). Snap grid: 2m (standard interior). OK?

​

2. Generate the anchor (wall)

assets.generate_3d({
  prompt: "A 2 meter wide by 3 meter tall stone dungeon wall section, mossy granite blocks with iron reinforcements, torch-bracket sconce, weathered surface. Game asset, centered, stylized low-poly game art, warm torchlight palette, white background, isolated object.",
  model: "hunyuan",
  targetPolycount: 1500
})
jobs.wait({ jobId: "<job.id>", timeoutSeconds: 50 })   // again until finished; result.assetId
assets.get({ assetId: "<assetId>" })
summer_import_asset_by_id(assetId="<assetId>", path="res://assets/kits/dungeon/wall.glb")

​

3. Lock the suffix and generate the remaining pieces

# Floor
assets.generate_3d({ prompt: "A 2 by 2 meter square stone dungeon floor tile, mossy granite blocks with iron reinforcements, weathered surface. Game asset, centered, stylized low-poly game art, warm torchlight palette, white background, isolated object.", model: "hunyuan", targetPolycount: 800 })

# Pillar
assets.generate_3d({ prompt: "A 3 meter tall stone dungeon pillar, square base, fluted shaft, mossy granite blocks with iron reinforcements, weathered surface. Game asset, ...", model: "hunyuan", targetPolycount: 1500 })

# Door, Corner, Arch — same pattern. Then jobs.wait on each job id.

​

4. Import and stage in a kit scene

summer_instantiate_scene(scenePath="res://assets/kits/dungeon/kit_dungeon.tscn", parent="./KitRoot", scene="res://assets/kits/dungeon/wall.glb", name="Wall")
summer_set_prop(scenePath="res://assets/kits/dungeon/kit_dungeon.tscn", path="./KitRoot/Wall", key="position", value="Vector3(0, 0, 0)")
# ...repeat for floor, pillar, door, corner, arch with positions Vector3(2,0,0), Vector3(4,0,0), ...
summer_save_scene(scenePath="res://assets/kits/dungeon/kit_dungeon.tscn")

• A .glb is instantiated, not assigned. There is no scene property on Node3D, and an imported .glb is a scene, not a Mesh — ResourceLoader.get_recognized_extensions_for_type("Mesh") on the shipped 4.6.1 binary returns ["tres", "mesh", "res"], with no glb. Use summer_instantiate_scene, which adds the model as a child in one op.
• Every scene-mutating tool takes an explicit scenePath, and node paths are relative to that scene’s root (./).
• summer_set_prop’s property argument is named key, not property.

​

5. Verify scale and pivots

summer_inspect_resource(path="res://assets/kits/dungeon/wall.glb")

​

Anti-patterns

• Drifting style suffix. Each piece gets a slightly different suffix → the kit looks mismatched. Copy-paste the exact string.
• Different polycount per piece. A 5k-tri pillar next to a 500-tri wall reads as “the pillar is a hero piece” — wrong; they should feel like equal kit citizens. Match polycount within ~2× across the kit.
• Skipping the anchor approval. If you generate all six pieces in a batch, you bake in whatever the first call’s interpretation of the style was — and the user may hate it after six generations.
• Generating walls / floors as individual meshes when you only need a tileable texture. A flat wall section is cheaper as a textured CSGBox3D. Reserve the kit for pieces that need actual geometric detail (sconces, mouldings, doorways, arches).
• No scale cue in the prompt. Wall comes back 0.4m tall. Always include 2 meter wide by 3 meter tall (or your chosen grid).
• Forgetting the snap grid. A 1.87m-tall wall with no scale fix → level looks crooked when tiled.

​

Edge cases

• Curved or organic kit (cave, alien hive). Modular geometry resists snapping. Generate longer pieces (4m walls, transition tiles) and accept some overlap. Or switch to procedural — design-level can scatter cave pieces with rotation jitter.
• Outdoor kit (cliffs, ruins, forest path). Use the kit pattern but accept rotation/jitter at placement time. Mesh edges should fade naturally rather than snap cleanly. Pair with organic-model for foliage scatter.
• Sci-fi kit (corridors, doors, terminals). The style suffix becomes critical — clean panels, soft cyan emissive trim, brushed metal, white background, isolated object. Hard surfaces drift more than organic ones; review every piece.
• The user wants to add a piece later. The locked suffix lives in the kit’s notes (drop it in assets/kits/dungeon/STYLE.md if the user wants persistence). Reuse it verbatim for any addition — never re-derive.

​

Without Summer Engine

​

Fallback (no MCP)

1. Run each prompt at the Summer dashboard (or Hunyuan / Trellis web UIs), keeping the locked suffix.
2. Download each .glb.
3. Drop into res://assets/kits/<kit-name>/.
4. Build the kit-display scene manually in Summer Engine, with one of each piece snapped to the grid.
5. Hand to the level designer.

​

Handoff

Dungeon kit ready: res://assets/kits/dungeon/ with wall, floor, pillar, door, corner, arch on a 2m snap grid. Display scene at res://assets/kits/dungeon/kit_dungeon.tscn. Next: hand off to the level-design step — instantiate kit pieces into level_01.tscn, snap to the 2m grid, dress with props (prop-model) and foliage (organic-model). For lighting, see 3d-lighting.

​

See also

• prop-model — for the chests, statues, and decorative props that dress the kit.
• organic-model — for foliage and rocks that break up modular repetition.
• asset-strategy — Pipeline 2 (textures + CSG) is the cheaper alternative when pieces are flat.
• scene-composition — how to organize the kit scene and the level scenes that consume it.
• 3d-lighting — interior kit pieces typically need warm point lights at sconce positions.

​

From a shell

​

Related skills

• organic-model: Generate organic 3D shapes (trees, rocks, mushrooms, plants, crystals) where irregularity looks natural.
• prop-model: Generate one static 3D prop (sword, barrel, chest, lantern, statue): one object, no rig, a MeshInstance3D.
• asset-strategy: Route any ‘I need a [thing]’ asset request to the right skill: 2D, 3D, audio, video, VFX or animation.