msw-painter

A workflow for hand-drawing a pixel-art sprite and registering it as a sprite resource in the MSW (MapleStory Worlds) asset system. It is explicitly a fallback: callers should run msw-search first, and only invoke the painter when no suitable sprite RUID is found or when the user specifically wants a hand-drawn-looking character or icon. The skill is scoped to the sprite category alone and does not handle animation, audio, avatar, or atlas resources. Its end result is a sprite RUID obtained by rendering the drawing to PNG and uploading it through the msw-mcp asset_create_resource_storage_item two-step pattern.

The authoring path has the user pick a medium and a style. The medium is one of SVG (best for icons, logos, and shape-based pixel art with 1px rect dots), Canvas (best for procedural, loop-drawn patterns), or HTML (rarely the best fit). Minimal templates are provided for each, with a strong caveat to size SVG at 100% width/height and to derive Canvas scale from the canvas width rather than hard-coding pixel counts, so output fills the rendered viewport. Two styles are offered: chunky (retro, 8-bit, small logical grids like 16x16 or 32x32, 1px black or white outline, a few stepped shading levels and no anti-aliasing) and maple (MapleStory-inspired characters and NPCs on larger grids, selout outlines, more shading levels with selective AA and optional dithering). Defaults steer icons/buttons/tiles to chunky and characters/NPCs/monsters/cute requests to maple, and outputs below 64x64 fall back to chunky because maple lacks pixels for selout plus AA.

Rendering uses scripts/render.cjs after a one-time npm ci install of puppeteer, with the lockfile pinned for supply-chain integrity. The renderer runs headless Chromium with the OS sandbox enabled and all network requests blocked; input is served from a data: URL under a strict Content-Security-Policy and sanitized to strip scripts, foreignObject, inline handlers, and non-data URLs. A PAINTER_DISABLE_SANDBOX escape hatch exists for constrained CI or WSL environments but should not be used on a developer workstation. The final report returns the RUID plus a short description noting which style was used.