Pixel Art

pixel-art — Pixel-Perfect Sprites and Tiles

This skill generates pixel-art assets — sprites, items, tiles, icons, portraits — at a target resolution (32×32, 64×64, 128×128, etc.). Pixel art has hard constraints (grid alignment, limited palette, no anti-aliased edges) that diffusion models violate by default. This skill encodes the prompt patterns and post-processing discipline that makes the output actually look like pixel art and not "blurry small image."

Backing tool: summer_generate_image with style: "pixel" and an explicit pixel-art prompt. Pass options.image_size: "square_hd" and have the agent enforce pixel-perfect by setting the project's default texture filter to Nearest (and downscaling to the target resolution post-gen). Output is upscaled by the model — you generally request a small generation (or downscale post-gen) to get crisp pixels.

When to use

• "Generate a 32×32 sword icon for the inventory."
• "I need a pixel-art portrait of the merchant for the dialogue UI."
• "Make a 64×64 enemy sprite — a slime monster."
• "Generate a tileset for a grass / dirt / stone biome at 16×16 per tile."
• The game has a pixel-art aesthetic and the user wants assets in-style.

When NOT to use

• The user wants a high-resolution painterly portrait → summer:2d-assets/character-portrait.
• The user wants animated frames (walk cycle, attack) → summer:2d-assets/sprite-sheet (pixel art is harder for sprite sheets — read that skill's caveats).
• The user wants a tileable seamless texture (not pixel art) → summer:2d-assets/tileable-texture.
• The game is 3D / non-pixel — verify the user actually wants pixel before generating.

Steps

1. Lock the resolution and palette

Ask the user (or read .summer/GameSoul.md):

• Resolution per asset: 16×16, 32×32, 64×64, 128×128 are standard. Sprites usually 32 or 64; portraits 64 or 128; icons 16 or 32.
• Palette: named retro palette (NES 56-color, Game Boy 4-color green, PICO-8 16-color, Sweetie-16) OR custom hex list OR "no palette restriction."
• Outline: hard black outline, colored outline, or no outline?

Write to .summer/pixel-anchor.md so the rest of the cast/tileset stays consistent:

## Pixel anchor

base resolution: 32x32 per sprite
palette: PICO-8 16-color
outline: hard 1px dark outline (NOT pure black — use the palette's darkest color)
shading: 3-tone (light, mid, shadow), no gradients, no AA

2. Search for existing assets

summer_search_assets(query=" pixel", filter={ kind: "image" })

3. Build the prompt

Pattern:

pixel art , , , , , no anti-aliasing, no blur, sharp pixel edges, transparent background

The model can't actually generate at 32×32 — it generates at 1024×1024 with pixel-art style. You then downscale to the target resolution post-import for crisp pixels.

4. Generate

summer_generate_image(
  prompt="pixel art slime monster, 32x32 sprite, PICO-8 palette, hard 1px outline in palette's darkest color, 3-tone shading, no anti-aliasing, no blur, sharp pixel edges, transparent background, front-facing",
  model="nano-banana-2",
  style="pixel",
  options={
    image_size: "square_hd",
    negative_prompt: "blurry, smooth gradients, anti-aliasing, photorealistic, 3D render, soft edges"
  }
)

negative_prompt is critical for pixel art — without it the model smuggles in soft edges and gradients.

5. Downscale to target resolution

The generated image is 1024×1024 pixel-style. To get true crisp pixels at 32×32:

• Import to the engine, then in the import dock set Filter: Nearest (no smoothing).
• For a true 32×32 atlas/icon, downscale in an external editor (Aseprite, GIMP "nearest neighbor") to 32×32 before importing. Aseprite's "Sprite > Sprite Size" with Nearest gives the cleanest result.
• In Godot, set Project Settings → Rendering → Textures → Default Texture Filter: Nearest if the entire game is pixel-art. This kills bilinear smoothing project-wide.

6. Import and wire

summer_import_from_url(url="", path="res://sprites/slime.png")

For a Sprite2D:

summer_set_resource_property(
  nodePath="/root/Game/Slime/Sprite2D",
  resourceProperty="texture",
  value="res://sprites/slime.png"
)

Confirm Filter: Nearest is set in the import dock OR project-wide.

Prompt patterns

| Goal | Prompt that works | Why | |---|---|---| | Item icon (32×32) | pixel art iron sword icon, 32x32, NES palette, hard outline, 3-tone shading, no AA, sharp edges, transparent background, three-quarter view | Three-quarter view reads better than pure side at 32px | | Character sprite (64×64) | pixel art knight character sprite, 64x64, PICO-8 palette, hard 1px outline, 3-tone shading, front-facing idle pose, no AA, sharp edges, transparent background | Specifying "idle pose" prevents action poses that don't tile into a sheet | | Pixel portrait (128×128) | pixel art portrait of a young witch, 128x128, custom muted fantasy palette, hard outline, 4-tone shading, bust framing, looking forward, no AA, no blur, transparent background | Higher resolution allows 4-tone shading; 32px is too small for that | | Tileset (16×16/tile) | pixel art top-down tileset, grass-to-dirt transition, 16x16 per tile, 3x3 grid layout, NES palette, hard outline between tiles, 3-tone shading, no AA, sharp edges | Tilesets render best in a labeled grid layout | | Background object (64×64) | pixel art mossy boulder, 64x64, fantasy palette, hard outline, 3-tone shading, no AA, transparent background, three-quarter view | Background props benefit from three-quarter for depth | | GB-style asset (Game Boy) | pixel art skeleton enemy, 32x32, Game Boy 4-color green palette (#0f380f, #306230, #8bac0f, #9bbc0f), hard 1px outline, 2-tone shading, no AA | Naming the 4 hex codes locks the palette |

Bad prompts (and why)

| Bad | Failure mode | |---|---| | 8-bit sword | "8-bit" is interpreted loosely. Returns a smooth render of a sword with vague pixel feel. Specify resolution + palette + "no AA" explicitly. | | pixel art knight, photorealistic | Conflicting directives. Model averages and gives you neither. | | pixel art at 32x32 (no negative_prompt) | Model adds soft edges and gradient shading. Always add negative prompt for AA / blur / gradients. | | pixel sprite walk cycle | Walk cycles need consistent frames — single-prompt sprite sheets fail. Route to summer:2d-assets/sprite-sheet. | | cute pixel art | "Cute" without subject is undefined. Specify what. |

Anti-patterns

• Skipping the downscale. The model returns a 1024×1024 pixel-style image. If you import that as a 1024 texture, the "pixels" are actually 32-pixel blocks of soft color. Downscale to true target resolution OR set Filter: Nearest so the up-rendering doesn't smooth.
• No Filter: Nearest. Default Godot texture filtering is bilinear. Pixel art bilinearly filtered looks like garbage. Set it on import or project-wide.
• No negative prompt. Without blurry, anti-aliasing, gradients, soft edges in the negative, ~50% of generations are off-style.
• Inconsistent palette across the cast. Pick a named palette (PICO-8, NES, custom hex list) and re-use across every asset in the project. Different palettes = the project doesn't read as one game.
• Generating walk-cycle frames as one image. Sprite sheets via single-prompt are unreliable. Route to summer:2d-assets/sprite-sheet.

Edge cases

• User wants animated pixel sprites. Generate base sprite here, then per-frame variants via img2img with the base as referenceImageUrl. For more than 2-3 frames, route to summer:2d-assets/sprite-sheet (and read its caveats).
• User wants the entire game in pixel art. Set Project Settings → Rendering → Textures → Default Texture Filter: Nearest once. Saves you from re-setting it on every import.
• User wants a high-res "pixel art" portrait that's not actually pixelated (faux-pixel-aesthetic at full resolution). That's summer:2d-assets/character-portrait with a "pixel art aesthetic" prompt — not this skill.
• User specifies a palette like "Sweetie-16" or "Endesga-32" and the model ignores it. Name the hex codes explicitly. Palette names alone are unreliable below the top 5-10 famous ones.
• Tilesets need to tile cleanly. Pixel-art tile-edge cleanliness from raw generation is poor. Generate the tile grid, then manually fix edge seams in Aseprite. The AI gets you 80% there.

Fallback (no MCP)

Print the call:

summer_generate_image(
  prompt="",
  model="nano-banana-2",
  style="pixel",
  options={ image_size: "square_hd", negative_prompt: "blurry, smooth gradients, anti-aliasing" }
)

Tell the user to run via the Summer dashboard, downscale in Aseprite/GIMP to true target resolution with nearest-neighbor, then summer_import_from_url (or drop into res://sprites/) and set Filter: Nearest.

If MCP is offline entirely: open Aseprite or Piskel and hand-author the asset. For pixel art at small resolutions, hand-authoring is often faster than fixing a generation.

Handoff

After the asset is wired:

• More assets in the same style → re-invoke this skill, re-use the pixel anchor.
• Animation frames for the sprite → summer:2d-assets/sprite-sheet with the base sprite as anchor.
• Pixel UI → re-invoke with UI subjects (icons, button frames) at appropriate resolution.
• Tilemap setup → summer:scene-composition for TileMap / TileMapLayer wiring.

See also

• summer:2d-assets/sprite-sheet — animated pixel frames.
• summer:2d-assets/character-portrait — high-res counterpart.
• summer:asset-pipeline/asset-strategy — meta-router.
• references/mcp-tools-reference.md — summer_generate_image schema.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: SummerEngine
• Source: SummerEngine/summer-engine-agent
• License: MIT
• Homepage: https://summerengine.com/

Install and usage instructions live in the source repository linked above.