Orthographic 1:1 mm FigCraft, CadCraft DXF & SVG Engineering Blueprint Skill (`svg-blueprint-drafter`)

Use this skill as the mandatory first design stage when creating or modifying 1:1 millimeter (1 px = 1 mm) third-angle orthographic 2D engineering drawings and blueprint boards (<ProjectName>_Blueprints.figcraft, <ProjectName>_Side_View.svg, <ProjectName>_Front_View.svg, <ProjectName>_Top_View.svg, and CAD/DXF/<ProjectName>_*_View.dxf) for any CAD project.

CRITICAL RULE: Blueprint-First Iteration Gate: Always draft ONLY the 2D orthographic blueprints first and stop for user review and iteration before creating any 3D CAD files (.solidcraft, .FCStd, .step, .stl, .3mf).

0. Step 0: CAD Toolchain & Target Use-Case Intake (Check .cad-tools.json or Ask User)

Before starting a new blueprint or running external CAD tools, check if .cad-tools.json exists in the project or workspace root. If it does not exist (and the user has not already specified their tools/target in the prompt), ask the user (via ask_question or direct prompt):

1. Which 2D/3D CAD tools are available on your system, and what are their paths/commands?
   • SolidCraft CLI (solidcraft-cli): Path to executable (configured in .cad-tools.json)?
   • CadCraft 2D CLI (cadcraft-cli): Path to executable (for .dxf, .svg, .png CAD drafting)?
   • FigCraft CLI (figcraft-cli): Path to executable (for .figcraft boards, .svg/.pdf/.png blueprint sheets & conversions)?
   • FreeCAD Headless (FreeCADCmd): Flatpak (flatpak run --command=FreeCADCmd org.freecad.FreeCAD), native freecadcmd, AppImage path, or null?
2. Will this model be 3D printed, or is it for another target (e.g., Game Design / 3D Asset, Mixed-Media Relief Sculpture, CNC / Sheet Metal, or Unconstrained CAD)?
   • If 3D Printed ("is_3d_printed": true): Ask for the target 3D printer's maximum build volume \((X \text{ x } Y \text{ x } Z\text{ mm})\) and design modular part splits and coplanar build-plate datum faces to fit the bed.
   • If NOT 3D Printed ("is_3d_printed": false): Do not impose 3D printer bed size limits or split parts for bed fit ("printer_max_bed_mm": null, "safe_part_limit_mm": null).
3. Save the answers to .cad-tools.json in the project root so all skills and subagents use the configured paths and target rules without searching the filesystem.

1. Translating User Descriptions into Standard Mechanical Engineering & CAD Terminology

Users often describe mechanical solutions in intuitive, everyday language. As a CAD & Mechanical Engineering specialist, you must immediately recognize these informal descriptions, map them to formal ASME Y14.5 / ISO GD&T and DFM (Design for Manufacturability) concepts, and implement them with engineering precision:

2. Two-Folder Blueprint Organization (Drafts/ vs. Working Drafts/), History/Steps.md, & Orthographic Naming

To keep blueprint review and project traceability clean inside <ProjectDir>/:

1. Multi-Option Exploration (<ProjectDir>/Drafts/):
   • Whenever there is more than one design option under consideration, generate all candidate option blueprints inside <ProjectDir>/Drafts/ (e.g., <ProjectDir>/Drafts/<ProjectName>_Option1_<Tag>_Side_View.svg, <ProjectName>_Option2_<Tag>_Side_View.svg, etc.).
2. Active Selected & Iterated Design (<ProjectDir>/Working Drafts/ & <ProjectDir>/):
   • Once the user selects an option (or when iterating on a single chosen design), place the active orthographic blueprints inside <ProjectDir>/Working Drafts/ and <ProjectDir>/ (<ProjectName>_Side_View.svg, <ProjectName>_Front_View.svg, <ProjectName>_Top_View.svg) and iterate on them there until approved for 3D CAD.
3. Project Step & Iteration History (<ProjectDir>/History/Steps.md & <ProjectDir>/Steps.md):
   • On every user ask and design step, append a new entry to <ProjectDir>/History/Steps.md (and <ProjectDir>/Steps.md) summarizing only the project-specific ask and design/file updates (omitting meta-updates to workspace agent/skill files) in the exact format:

     Step X
     User Ask:
     <Summary of user request>
     Updates:
     <Summary of design, dimension, direction, and file updates>
     

3. Core Orthographic Blueprint Rules (1 px = 1 mm)

1. Strict 1:1 Millimeter Scale:
   • Every coordinate, width, height, radius, and path segment in the SVG must be drawn at 1 SVG user unit (px) = 1.0 mm.
   • Include a background millimeter grid (<pattern id="mmGrid" width="50" height="50"> with \(10\text{ mm}\) minor lines and \(50\text{ mm}\) major lines) so any measurement can be visually verified against the grid.
2. Unified 3D World Coordinate Datums \((X, Y, Z)\) Across All 3 Views:
   • Define a clear, physical 3D origin \((X=0, Y=0, Z=0)\) anchored to the primary mating hardware features (e.g., machine centerline \(X = 0\), front or mounting datum face \(Y = 0\), top crown or reference deck \(Z = 0\)).
   • Every feature coordinate must satisfy exact projection identity across views:
     • \(X_{\text{Front}} \equiv X_{\text{Top}}\)
     • \(Y_{\text{Side}} \equiv Y_{\text{Top}}\)
     • \(Z_{\text{Side}} \equiv Z_{\text{Front}}\)
3. Design for Manufacturability (DFM) & Assembly Constraints:
   • When "is_3d_printed": true (Additive Manufacturing Mode):
     • Single-Piece Print Bed Envelope: Every modular component's 3D bounding box \((W, D, H)\) must fit within the user's configured safe_part_limit_mm in .cad-tools.json.
     • Coplanar Build-Plate Datum Face: Design each printed part with at least one completely flat, unencumbered outer face (0.0 mm boss stickout) so it lies directly on the print bed without supports.
   • When "is_3d_printed": false (Game Design / Sculpture / CNC / General CAD Mode):
     • No Print-Bed Splitting Required: Do not split components to fit a 3D printer build volume unless modular assembly is explicitly requested by the user.
   • Clearance & Keep-Out Envelopes (All Modes): Explicitly draw dashed outlines for moving lids, doors, screens, cables, or mating hardware and verify positive clearance in all views.

4. Standard SVG Layer & Visual Styling Architecture

Structure every <ProjectName>_*_View.svg into clean, semantic <g> groups from back to front:

1. <defs>: CSS stylesheet, arrow markers (#arrow-start, #arrow-end, #arrow-force), and #mmGrid pattern.
2. Background & Header Block: Dark engineering slate canvas (#0f172a), millimeter grid rect, title, scale (1 px = 1 mm), and datum summary.
3. Host Machine / Reference Environment Group (id="host-reference-*"): Reference hardware body, doors, screens, mounting bosses, and overhanging covers/bezels.
4. Payload / Supported Equipment Group (id="payload-*"): Supported device envelope, mounting feet/fasteners, and gravity/load vectors (class="force-line").
5. Designed CAD Assembly Group (id="<project>-parts-*"): Distinct color-coded classes for each structural part (Part A, Part B, Part C, Part D, etc.), plus dashed joint interface lines (class="joint-line").
6. Engineering Dimensions & Callouts (id="dimensions-*"): Extension lines (class="dim-ext"), double-arrow dimension lines (class="dim-line"), and bold monospace millimeter labels (class="dim-text").
7. Footer Legend & Part Summary: Color swatches and exact bounding-box dimensions (\(W \text{ x } D \text{ x } H\text{ mm}\)) for every part.

5. Automated Blueprint & Vector Authoring with figcraft-cli and cadcraft-cli

When FigCraft (figcraft_cli) or CadCraft (cadcraft_cli) is configured in .cad-tools.json, you can construct editable, parametric 2D vector blueprints, multi-view presentation boards, and CAD .dxf drawings programmatically:

A. FigCraft (figcraft-cli) Vector Blueprints, 2D Booleans & Multi-View Blueprint Boards

Use figcraft_cli to build an interactive <ProjectName>_Blueprints.figcraft master board containing all three orthographic views (Side_View, Front_View, Top_View), dimension callouts, BOM/parameter tables, and embedded 3D renders:

1. CLI Commands:

   # Execute a JSON command script and save native .figcraft file
   <figcraft_cli_path> run <blueprint_script.json> --out <ProjectName>_Blueprints.figcraft
   
   # Export individual top-level frames (Side_View, Front_View, Top_View) to SVG, PNG, or multi-page PDF
   <figcraft_cli_path> export <ProjectName>_Blueprints.figcraft -o . --format svg
   <figcraft_cli_path> export <ProjectName>_Blueprints.figcraft -o . --format png --scale 2
   <figcraft_cli_path> render <ProjectName>_Blueprints.figcraft -o <ProjectName>_Blueprint_Sheet.png --scale 2
   

2. Core figcraft-cli run Commands for Blueprint Drafting:
   • Orthographic View Frames & Grids (frame.create, grid.add, node.set):
     • Create top-level frames named <ProjectName>_Side_View, <ProjectName>_Front_View, and <ProjectName>_Top_View at 1 px = 1 mm scale with dark blueprint fill (#0f172a).
     • Attach \(10\text{ mm}\) minor and \(50\text{ mm}\) major grids via grid.add ({"kind": "grid", "size": 10, "color": "#1e293b"}).
   • Vector Primitives & Point Polygons (shape.*, vector.create, vector.offset):
     • shape.rectangle: {x, y, width, height, parent, props: {name, fill, stroke, strokeWeight, cornerRadius}} (Supports per-corner radii [tl, tr, br, bl] for fillets and rabbets!).
     • shape.ellipse: {x, y, width, height, parent, props: {name, fill, stroke, strokeWeight, dashes}} (For bores, counterbores, and spotfaces).
     • vector.create: {points: [[x1, y1], [x2, y2], ...], closed: true, parent, props: {name, fill, stroke, strokeWeight}} (Pass exact 2D millimeter coordinates [[u, v], ...] directly).
     • vector.offset: {ids, offset} (Generate uniform wall thicknesses, perimeter shells, or clearance envelopes).
   • Native 2D Boolean Operations (bool.union, bool.subtract, bool.intersect, bool.exclude, bool.flatten):
     • Construct complex 2D part silhouettes by combining outer profiles with cut shapes (bores, counterbores, rabbet reliefs, blind dovetail mortises, truss lightening pockets) using bool.subtract or bool.union.
   • Dimensions, Callout Arrows & Engineering Tables (shape.line, shape.arrow, board.connector, text.create, board.table):
     • Use shape.arrow or board.connector (style: "straight" | "elbow", startCap: "triangleArrow", endCap: "triangleArrow", label: "245.0 mm") for dimension lines and leader callouts.
     • Use board.table ({rows, columns, cells: [["Part", "Dimensions (mm)", "Qty", "Notes"], ...], x, y}) to auto-build clean Title Blocks, Revision Schedules, and Bill of Materials (BOM) tables.
     • Use image.place ({path: "CAD/SolidCraft/<ProjectName>_Studio_Render.png", x, y, width, height, mode: "fit"}) to embed reference ruler photos or SolidCraft Vulkan GPU renders directly onto the blueprint sheet.
   • Batching & Exporting Inside a Script (file.save, file.export, file.exportFramesPdf):
     • Save the native editable document with {"command": "file.save", "params": {"path": "<ProjectName>_Blueprints.figcraft", "overwrite": true}}.
     • Export each view frame to <ProjectName>_Side_View.svg, <ProjectName>_Front_View.svg, <ProjectName>_Top_View.svg via file.export ({"ids": [frame_id], "format": "svg", "path": "<ProjectName>_Side_View.svg"}) and export a print-ready multi-page engineering PDF via file.exportFramesPdf ({"path": "<ProjectName>_Blueprints.pdf"}).

B. CadCraft 2D (cadcraft-cli) Precision 1:1 mm DXF/DWG CAD Drafting

When cadcraft_cli is configured in .cad-tools.json, generate native 1:1 mm CAD .dxf, .dwg, .svg, .png, and .pdf sheets in CAD/DXF/:

<cadcraft_cli_path> run --metric <dxf_script.json>
<cadcraft_cli_path> convert CAD/DXF/<ProjectName>_Full_Assembly.dxf CAD/DXF/<ProjectName>_Full_Assembly.pdf

Using layer.new, line, polyline, circle, arc, dim.linear, dim.radius, dim.diameter, text, and file.export.