Marketplace authoring spec

Baseline requirements for creator pack assets (aligned with server validation and ingest).

Asset kinds

• overlay — Second paint stack; decorative art on hex tiles (pack editor)
• decal — Third paint stack; tall billboard or square hex-cap (decal guide)
• tile — Terrain / base textures (pack editor)
• sprite — Animated overlay; optional JSON metadata (sprite guide)
• background — Map backgrounds (API only; not in pack editor UI yet)

File requirements

• Formats: PNG, JPEG, WEBP, GIF
• Max upload: 20MB per file (creator pack items)
• Max dimensions: 4096×4096; max pixels 16,777,216
• Bytes must match declared mime type (server content sniffing)

Terrain tiles

• Source must be square, 128–2048px per side.
• Pack editor center-crops and uploads 1024×1024 hex-clipped PNG.
• Server re-normalizes to the same 1024×1024 masked output.

Overlays

• Reference frame: 256×384 (built-in hexMountain03 standard).
• Correct aspect → contain; wrong aspect → cover crop to 256×384.
• Storage: long edge 1024 (~683×1024 for 2∶3 art).
• Editor runtime: 512×512 bleedFull atlas.
• Submit gate: every overlay must be 3D verified in Creator Studio.

Decals

Separate ingest path from overlays. Upload field decalFrame: tall (default) or square.

• Tall — Same normalize as overlay (256×384 → ~683×1024); renders as billboard above terrain/overlays.
• Square — Square normalize (256×256 → 1024×1024); renders on the hex cap (like Pro custom decals).
• Resolution/aspect issues → warnings only; frame mismatch → coerce + warn.
• Metadata: { "decalFrame": "tall"|"square", "decalFrameVersion": 1 }
• Cap: 50 per pack. Author in Studio with the frame switch — full decal checklist.

Pack editor features

• Queue multiple files, edit labels, upload all pending in one action.
• Hex outline + safe-zone guides in preview only (not baked into pixels).
• Submit requires provenance fields + at least one item (workflow).

Templates: tile, overlay / tall decal, square decal