> ## Documentation Index > Fetch the complete documentation index at: https://docs.summerengine.com/llms.txt > Use this file to discover all available pages before exploring further. # Create asset sheet skill for AI agents > Generate a pack of 2D assets from one prompt (tile sheet, UI kit, character pack, biome), sliced. A Summer Engine skill for AI agents. `create-asset-sheet` is a skill from the [Summer skill library](/mcp/skills): a guide your AI agent reads when the task matches, so it builds the good version on the first try. Generate a pack of 2D assets from one prompt (tile sheet, UI kit, character pack, biome), sliced. | | | | - | - | | Status | Stable | | Domains | 2D art, Asset pipeline | | Version | `1.0.3` | | Engine version | `>=4.6` | | Recommended set | No, installed by `--all` or by name | ## When your agent uses it * Generating a pack of 2D game assets from a single prompt — a tile sheet, UI kit, menu screen, character pack, or biome set * Many matching sprites, tiles, or UI pieces are needed in one consistent style at once ## Install `summer setup` installs every skill for your agent. To add only this one: ```bash theme={null} npx -y summer-engine@latest skills install create-asset-sheet --agent claude-code ``` Swap `claude-code` for your agent, such as `codex` or `cursor`. See [Skills](/mcp/skills#quick-start) for every option. ## The skill This skill turns a single prompt into a categorized pack of isolated, named 2D assets ready to drop into a game. Generating assets one by one loses visual coherence between them and leaves you matting backgrounds by hand; one sheet keeps the pack consistent. **Pipeline:** 1. **Generate a sheet** of N isolated assets in one image-gen call. 2. **Remove the background** so each asset can stand on its own. 3. **Detect, name and classify** each asset in one vision pass (bounding box + snake\_case name + category per region). 4. **Crop** each region. 5. **Optionally upscale** any small slice, preserving aspect. 6. **Save** as a single pack ArtAsset with `packFiles: [{url, name, type}]` and `metadata.sliceBboxes`. Categories the classifier outputs (used to route into downstream pipelines): `character | terrain | nature | lighting | water | decorative | buildings | ui | vfx` ## When to use * "Make me a Japanese village tileset." * "Generate a sci-fi UI kit — buttons, panels, icons." * "I need 12 fantasy props for a dungeon — chest, torch, skeleton, gold, etc." * "Give me a character pack: 6 cute monsters." * "Build a forest biome — trees, rocks, plants, ground tiles." ## When NOT to use * The user wants a **single** asset → `pixel-art` or `character-portrait`. * The user wants character **animation** (walk cycle, attack frames) → `sprite-sheet`. * The user wants **3D models** of a planned pack → not yet supported in one shot; loop `concept-art` → image-to-3D per item, or use `asset-strategy` to pick the right path. * The user wants **terrain tiles that connect seamlessly** (auto-tiling / Wang tiles) → `tileable-texture` is the right home for edge logic; this skill produces standalone tiles, not edge variants. ## The cleanest path: the studio wizard The most reliable way to run this flow is the **Create Asset Sheet** wizard in Summer Studio's guided workflows. Open it for the user with `summer open workflows` (or `studio.open`) if they're working in the browser. The wizard: * Offers a 2D / 3D mode toggle (2D is the slice flow described here; 3D is a soft pointer to `concept-art` + per-asset image-to-3D for now) * Surfaces six prompt templates (tile sheet, UI kit, menu, character pack, biome, freeform) * Lets the user upload an existing sheet if they have one (skip generation) * Shows variants in a grid with full-screen lightbox + arrow-key toggling * Runs the full slice pipeline on click * Has per-slice HD upscale + bulk "Upscale all" * Saves as a pack ArtAsset visible in the user's library If the user is in a chat / agent context, use the programmatic path below. It calls the same server-side slicer as the Studio wizard. ## Programmatic path (chat / agent driving the engine) 1. **Load the exact current recipe.** Call `summer_call({op: "docs.workflows", input: {workflowId: "asset-pack"}})`. Follow its ordered steps and report any `manual` handoff instead of pretending it ran. 2. **Generate the sheet.** Call `assets.generate_image` with a prompt like: ``` asset sheet: . Each item isolated with empty space around it, transparent or neutral background. ``` * Pick model by style: pixel art → `grok-imagine`, painterly / illustrative / structured grids → `gpt-image-2`. * Square (`aspectRatio: "1:1"`, the default, about 1024x1024) is the sweet spot. Larger sheets fragment in the slicer when individual assets get below \~64px. * Keep the asset list to 6–20 items per sheet. Past 20, model attention degrades and slices get muddy. 3. **Slice, remove background, detect, name, classify, crop, and save.** Pass the returned image asset id to: ``` assets.slice_sheet({ assetId: "" }) ``` This is the same cloud slicing pipeline used by the Studio flow. It answers `slices` (each with `url`, `name`, `category`, `bbox`) and `source`; keep the names and categories, and do not reimplement the vision boxes locally. Slicing spends credits: `dryRun: true` shows how many. 4. **Optional upscale.** The Studio wizard has per-slice HD upscale. Over MCP, for any crop where the longest side is under 256px, call `assets.generate_image` with the slice `url` as `referenceImageUrl` and this prompt: ``` Recreate this exact at high resolution. Preserve every detail, the exact pose, the exact style. Sharper edges, more detail. Transparent background. Single isolated asset, no scene. ``` * Don't upscale everything: each upscale is a paid generation, and large slices gain little. 5. **Import what the game needs.** The slices are image URLs, not assets: import them with `summer_import_from_url_batch` (upscaled ones by their `assetId` with `summer_import_asset_by_id`). Keep the source pack in My Assets so the agent and the human Studio session see the same result. ## Prompt patterns that work **Tile sheet (terrain + props + buildings):** ``` tile sheet: , , . Each item isolated with empty space around it. ``` **UI kit:** ``` game UI kit: round button, square button, panel background, slider, toggle switch, progress bar, icon set, banner header. ``` **Menu screen:** ``` main menu UI: title banner, Start Game button, Settings button, Quit button, , ornate frame, decorative element. ``` **Character pack:** ``` character pack, single front-facing frame each: , , ... . Each isolated. ``` **Biome:** ``` biome assets: , , . Each item isolated. ``` ## Common failure modes | Symptom | Cause | Fix | | - | - | - | | Slicer returns 1 giant bbox covering the whole sheet | Items overlap / no gaps in the source | Re-prompt with "each item fully isolated, empty space around each item". Re-generate. | | Slicer misses items | Items too small in the source, classifier dropped them as noise | Generate at higher resolution (2048) or with fewer items per sheet | | Two items merge into one slice | Items touching in the source | Re-prompt with more isolation. Or accept and let the user split manually in step 2's review. | | Slice has a sliver of neighbor in it | Vision bbox is off by 5–15px | Expected. The slicer pads but doesn't snap-to-content yet. Live with it or upscale the slice (upscaling often cleans the edge) | | Upscaled slice looks invented | Source was too small / too ambiguous | Don't upscale slices below \~32×32. Or accept the hallucination and edit | | Detection returns wrong category | Model misjudged context | User can override in the review step; not a blocker | ## Without Summer Engine In a session without Summer Engine tools (the assets profile; the `summer-assets` skill has the whole loop), the studio wizard path works as written. On the programmatic path, stop after `assets.slice_sheet` and skip `summer_import_asset_by_id`: save each piece where the person asked with `assets.get` and `out` (the `summer-assets` skill says how), and tell them the paths. ## What this skill does NOT do (yet) * Per-asset planning and individual generation, where each asset is generated separately at full resolution. * 3D pack assembly. The 3D mode in the wizard is a placeholder pointer to `concept-art` + image-to-3D for now. * Character animation routing. Once a slice is classified as `character`, the next step (sprite-sheet generation) is a separate skill that the user has to invoke manually. * Terrain auto-tiling / Wang-tile generation. Use `tileable-texture` for that. * Level composition / scene assembly. Use `design-level`. ## From a shell No Summer MCP tools in this session? Run each one as a command; when `summer --version` is missing or below 4.0, use `npx -y summer-engine@latest` in place of `summer`. Fields are flags in kebab-case (`--scene-path res://main.tscn`) or one `--input ''`, and `summer ops describe ` prints the exact input. The `summer-cli` skill has the rest. | In this skill | Command | | - | - | | `assets.generate_image`, `summer_assets_generate_image` | `summer assets generate-image` | | `assets.get` | `summer assets get` | | `summer_assets_search` | `summer assets search` | | `assets.slice_sheet`, `summer_assets_slice_sheet` | `summer assets slice-sheet` | | `docs.workflows` | `summer docs workflows` | | `summer_import_asset_by_id` | `summer engine import-asset-by-id` | | `summer_import_from_url` | `summer engine import-from-url` | | `summer_import_from_url_batch` | `summer engine import-from-url-batch` | | `studio.open` | `summer studio open` | ## Related skills * [`character-portrait`](/skills/character-portrait): Generate one polished character bust for dialogue UI, character select, lore cards or codex entries. * [`concept-art`](/skills/concept-art): Explore art direction with 3-4 rough concept variants of a character, environment or prop. * [`pixel-art`](/skills/pixel-art): Generate pixel-art sprites, items, tiles and portraits at a set resolution with a limited palette. * [`sprite-sheet`](/skills/sprite-sheet): Generate animated 2D character sprite sheets (walk, attack, idle, death) for AnimatedSprite2D. * [`tileable-texture`](/skills/tileable-texture): Generate a seamless tileable texture for walls, floors or terrain, wired as a StandardMaterial3D albedo. * [`asset-strategy`](/skills/asset-strategy): Route any 'I need a \[thing]' asset request to the right skill: 2D, 3D, audio, video, VFX or animation. * [`design-level`](/skills/design-level): Design one level (layout, pacing, encounters, secrets) as a design doc plus a node-tree skeleton. *** Source: [`library/skills/create-asset-sheet/SKILL.md`](https://github.com/SummerEngine/summer/blob/main/library/skills/create-asset-sheet/SKILL.md), rendered from `summer-engine@4.3.0` on npm. 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