solid_from_board: PCB to solid CAD part (inverse of board_from_solid)

[ecto]

Summary

Adds solid_from_board, the inverse operation of board_from_solid. This tool materializes a PCB session as a solid CAD part by extruding the board outline (with cutouts preserved as interior holes) and optionally adding simplified component keep-out volumes. The substrate is assigned a homogenized FR4+copper density so that inspect_cad and physics simulations see the real board mass rather than bare FR4.

Key Changes

• New tool solid_from_board (packages/mcp/src/tools/ecad.ts):

  • Extrudes board outline to thickness via hole-aware sketch path (cutouts become interior walls, no boolean pass needed)
  • Computes FR4 + copper mass from stackup and copper coverage (zones, traces, pads, vias)
  • Generates simplified component keep-out volumes: prefers kernel 3D body extents, falls back to courtyard × per-package-class default height
  • Injects into existing CAD session (document_id_target) or mints fresh session
  • Assigns homogenized density material so mass properties are realistic
  • Returns detailed mass breakdown, component part IDs, and optional inline document IR

• Helper functions:

  • loopArea() — shoelace area of closed polygon
  • loopToSegments() — convert polygon to Sketch2D line segments
  • padAreaMm2() — copper area per pad shape
  • copperAreaByLayer() — per-layer copper coverage (zones, traces, vias, pads)
  • estimateBoardMass() — FR4 + copper mass from outline area and stackup
  • componentKeepouts() — generate keep-out boxes from 3D meshes or courtyard fallback
  • packageHeightMm() — default body height by package class (0402, SOIC, DIP, etc.)

• Comprehensive test suite (packages/mcp/src/__tests__/solid-from-board.test.ts):

  • 58mm rotor board with bore and hub cutouts as reference geometry
  • Validates outline extrusion with cutouts intact (volume within 2%)
  • Verifies mass metadata against hand-computed FR4 + 2oz copper (within 5%)
  • Tests component keep-out volumes above board with plausible heights
  • Validates injection into existing CAD session (e.g., enclosure) and downstream check_enclosure_fit compatibility
  • Error handling for missing PCB and unknown target sessions

• Server integration (packages/mcp/src/server.ts):

  • Registered as MCP tool with schema and description
  • Cross-session writer: reads PCB from document_id, writes CAD to document_id_target (or mints new)
  • Handles durable persistence and event logging for target session

• Next-action hints (packages/mcp/src/tools/next-actions.ts):

  • Suggests render_view to visually cross-check the solid
  • Suggests inspect_cad to measure volume, bbox, and homogenized mass

Notable Implementation Details

• Hole-aware extrusion: Uses multi-loop sketch (outline + cutouts as holes) so bore/cutout polygons survive as real interior walls without needing a boolean Difference pass.
• Mass homogenization: Computes total FR4 + copper mass, then derives a single density for the extruded slab so that inspect_cad and physics engines read the correct mass off the material property.
• Copper coverage estimation: Sums zone fill (hatched pours count half), trace/arc length × width, pad copper per layer, and via annular rings; each layer capped at board area to avoid double-counting overlaps.
• Component fallback chain: Tries kernel 3D body extents first (exact XY + Z), falls back to courtyard/pad bbox extruded to package-class default height, skips mounting holes and NPTH-only footprints.
• Response truncation: Component

https://claude.ai/code/session_01GepcQepAbbTJLcEzsK1f8X

[vercel]

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Project	Deployment	Actions	Updated (UTC)
vcad-mcp	Ready	Preview, Comment	Jul 7, 2026 2:28pm

3 Skipped Deployments

Project	Deployment	Actions	Updated (UTC)
mecheval	Ignored		Jul 7, 2026 2:28pm
vcad	Ignored		Jul 7, 2026 2:28pm
vcad-docs	Ignored		Jul 7, 2026 2:28pm

[chojiai]

What shipped

You can now convert a PCB design directly into a solid 3D part, completing the round-trip between circuit board and mechanical CAD. The board outline — including any cutouts like mounting holes or bore openings — is extruded to the correct thickness, and each placed component can be represented as a simplified keep-out volume. The resulting part carries accurate mass properties based on the actual FR4 substrate and copper content, so weight estimates and physics simulations reflect the real board rather than bare fiberglass.

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