Map generation pieces

The Map pieces workbench decomposes the six user-supplied Metroid Prime top-down maps into original parametric abstractions. It does not trace raster outlines, import Nintendo meshes, or infer exact heights from top-down views.

Structure before geometry

Reference	Useful structure
Pirate Frigate	Aligned deck spine; utility bypass loop; short service branches; airlock thresholds; central reactor landmark; explicit lift shafts.
Tallon Overworld	Large clearing hubs; canyon connectors; short alcoves; natural-to-constructed transitions.
Chozo Ruins	Multi-entrance plazas; side courts; bent access halls; radial landmarks; loops around a central hub.
Magmoor Caverns	Long chamber–neck sequence; faceted basins; irregular tunnels; small one-entrance alcoves; embedded station.
Phendrana Drifts	Shore basins and branching caves transition to aligned research halls; return paths at different heights.
Phazon Mines	Industrial hubs and narrow access links; cavern transitions; elevator-separated strata.

Reusable pieces

dist/map-pieces.mjs exports 18 definitions. Each contains a normalized footprint, environment family, role, suggested entrance sockets with outward normals, source motif, and placement rule. instantiatePiece scales and rotates a footprint into metre-based room volumes and transforms its sockets. Suggested sockets are library attachment candidates. boundarySocket places an actual connection on the footprint boundary toward its neighbor.

Craft pieces: chamfered hall, stepped bay, cross junction, U-shaped court, radial core, lift cell, service pocket, straight hall, dogleg hall.

Natural pieces: faceted basin, lobed cavern, bent ravine, shore chamber, pinch tunnel, bent tunnel, rock alcove.

Mixed pieces: terraced atrium, embedded station.

The U court’s recess is outside its footprint. The radial core’s central machinery is a placement rule, not a modeled hole or imported asset. Roof heights in the study are illustrative. Terrain clearance in the main generator continues to constrain room heights.

Generation and integration

generatePieceLayout({family, seed, scale}) creates a deterministic connected two-level study with a return loop and a terminal side branch on each level. Lift footprints share X/Z coordinates across levels. Connections meet actual boundary points; variable-width natural passages have a 2.1 m minimum width at the smallest supported scale. The export includes metre-based polygons, volumes, doors, walking edges and explicit elevator links.

The main generator’s pieceStyle selects existing, constructed, natural or mixed hall silhouettes for Plate-class, Systems-class and Orbital. It preserves existing transport and terrain constraints. Whole-ship room placement still uses the existing sparse hull-aware generator; the study demonstrates local topology independently.

The provided repository, https://github.com/JustinDMS/prime-map-tool, was inspected through its README, source and tree. It provides Randovania graph data, extracted room bounds and transparent per-room overhead renders. Its data can support future measurement of actual room proportions and door transforms, but no source code or game assets from that repository are incorporated here.

Verification

• node validate-pieces.mjs: 18 piece instances and rotated sockets; 36 deterministic study configurations; graph connectivity and two return loops; vertically aligned elevators; wall-boundary entrances; finite volumes and export; all three new families in all three main envelopes.
• node validate-ui.mjs: all 18 piece selections, top-down and volume projections, all generation families and both levels, plus existing map controls.
• node validate.mjs and node validate-garden.mjs: existing clearance, connectivity and garden regressions.
• Existing validate-plate.mjs still expects the superseded 90 × 60 × 20 km plate. Existing validate-volumes.mjs expects hall heights above the current 130 m clamp. These assertions already fail on the unchanged source and are not changed in this patch.