How to use the Game Asset Pipeline agent skill (asset-pipeline)

What does the asset-pipeline skill make the agent do?

The skill focuses on turning art into files a game can load. Generation tools make pictures; this skill makes the files the game accepts. It covers sprite cutout, trimming, nearest-neighbour fitting to frame sizes, pixelation to a palette, sprite sheets and strips, player or team-colour masks, seamless textures, and rendering a 3D model into sprite frames from a game-style camera.

The agent runs the project's own 'um' command-line tool for these jobs. It is also told to check the game's existing assets first and to test converted files in the game before shipping.

• Cut out flat or shadowed backgrounds to transparency
• Trim and fit sprites to exact frame sizes without blurring pixel art
• Pixelate painted art to a limited palette with an outline
• Build sprite sheets or strips and slice them back apart
• Create player-colour masks and seamless textures
• Render a 3D model into 8 or 16 headings, side view or top-down frames with Blender

How do you install the asset-pipeline skill?

Download the skill ZIP from this page. The skill ships as a single file, SKILL.md, inside the asset-pipeline folder. Unzip it into one of two places depending on how you use your agent.

For a personal setup, unzip it into ~/.claude/skills/. For a single project, unzip it into the project's .claude/skills/ folder so it only applies there. In the Claude apps, you can instead upload the skill under Settings → Capabilities → Skills.

• Personal: ~/.claude/skills/
• Per project: .claude/skills/ inside your project folder
• Claude apps: Settings → Capabilities → Skills, then upload

What do you need installed before it works?

The skill depends on several tools. Without them, the commands fail. Check these before your first request.

The 'um' command-line tool must provide the 'um sprite', 'um render3d', 'um fal' and 'um win' subcommands. Blender must be installed and either on your PATH or set through the BLENDER environment variable, which is needed only for 3D rendering. Image, 3D model and texture generation use fal API access through the fal-assets and fal commands.

• The 'um' tool with the sprite, render3d, fal and win subcommands
• Blender, on PATH or set via the BLENDER environment variable (3D rendering only)
• fal API access for image, 3D model and texture generation
• Python with UnityPy, only if you convert a guest game's Unity assets
• Optional: texconv (DirectXTex) or ImageMagick 'magick' for DDS textures

How do you ask the agent to use it?

You do not need special syntax. The skill triggers when you ask for sprites, sprite sheets, animation frames, isometric unit sprites or icons for a game, or when you have just generated assets and want them converted. Describe the target game or engine and the size you need if you know it.

Good requests name the result and the constraint. The agent will read the game's existing assets first and record the target format in MODLOG.md.

• Make a 64x26 sprite of this item with a transparent background from raw.png
• Turn these three generated frames into a Terraria-style vertical strip
• Render this GLB as 16-heading isometric sprites for my RTS unit
• Make a blue team-colour mask for this unit sprite
• Pixelate this painting to 32x32 with 16 colours and a dark outline

What commands does the skill use for 2D sprites?

For 2D work the agent chains small commands. Each one has a --help flag with examples. Use nearest-neighbour scaling for pixel art and scale it only once, to its final size. For painted or HD art, use fit --smooth instead.

• um sprite info raw.png shows size, alpha coverage and corner colour
• um sprite cutout raw.png cut.png removes a flat background
• um sprite fit cut.png item.png --size 64x26 --hard-alpha trims and scales once
• um sprite pixelate cut.png px.png --size 32x32 --colors 16 --outline makes pixel art
• um sprite sheet sheet.png frames/*.png --vertical builds a strip
• um sprite preview item.png look.png --scale 6 lets you inspect the result

How do you turn a 3D model into sprite frames?

The skill can render a 3D model from a game's own camera so every angle and animation stays consistent. Pick a preset that matches your game. Set --length to the model's longest horizontal side in pixels at 1x so it matches stock units, and use --forward-yaw to turn the model so its nose faces +X. Check the first frame after each change.

Presets are aoe2 (16 headings, clockwise from east), iso8 (8 headings), trueiso (35.264° camera), topdown (8 headings), side (right and left facings) and turntable (24 perspective frames, for promo or icon spins). Motions include bob, walk, lunge, die, wreck and spin. Add --shadows if your engine keeps shadows in a separate layer.

• Presets: aoe2, iso8, trueiso, topdown, side, turntable
• Motions: bob, walk, lunge, die, wreck, spin
• Cycles uses the GPU when available
• Dark textures: raise --sun or --ambient, or brighten in post

How do you check the result in the game?

Before batch-converting, put one converted asset into the game and compare it with stock art. Check scale, facing, pivot, outline and palette. Fix the recipe, then run the same commands on the rest of the set. Keep the commands in a small script or Makefile so the pipeline can be rerun from assets/gen/.

The skill also covers textures and materials. Use um sprite tile-preview to check tiling, and um sprite seamless to repair seams in other images. For DDS output, use BC7 for quality, BC1 for cutout sprites and BC3 when alpha is soft.

• Screenshot one asset in the game with um win shot next to stock art
• Batch-convert only after one asset looks right
• Keep the pipeline reproducible from assets/gen/