kernelcad-drawings - SKILL.md Agent Skill

name: kernelcad-drawings description: Export 2D engineering-drawing sheets (SVG) from any model or assembly — third-angle front/top/left + isometric views with hidden-line removal, overall dimensions, and a title block. Use when the deliverable is a human-readable fabrication or review drawing.

kernelCAD — engineering drawings

export({ target: 'model', format: 'svg-drawing' }) renders a .kcad.ts model as a standard third-angle engineering-drawing sheet in SVG. It works on single bodies and on assemblies (assembly.model() / solvedModel(...)) — assembly parts are projected together in world frame, so one part occluding another renders correctly as hidden lines.

What the sheet contains

Views: front, top (above front), left (left of front) — third-angle arrangement with shared-axis alignment — plus an isometric pictorial in the upper-right cell. One drawing scale for all views, snapped to the standard series (…, 2:1, 1:1, 1:2, 1:5, …) and stamped in the title block.
Line styling per drafting convention: visible edges solid full-weight; hidden edges dashed half-weight; tangent edges (fillet boundaries, smooth face transitions) thin solid. The isometric view omits hidden lines.
Overall dimensions: bounding-box width (under the front view), height (right of the front view), and depth (left of the top view), with extension lines and arrowheads. Values are model millimetres.
Title block: model name, scale, units (mm), date, and the third-angle projection symbol.
Coincident projected segments (e.g. a bore's front and back rim landing on the same arc) are deduplicated visible-first — nothing renders twice or dashed underneath a solid line.

Quickstart

MCP:

{ "tool": "export", "input": { "target": "model", "file": "bracket.kcad.ts", "format": "svg-drawing", "output_path": "out/bracket-drawing.svg" } }

CLI:

kernelcad export svg-drawing bracket.kcad.ts -o out/bracket-drawing.svg

Options

Pass via options (MCP) — all optional:

sheet: 'a4' (default, 297×210 landscape) or 'a3' (420×297).
modelName: title-block name; defaults to the script's file name.
date: title-block date string; defaults to a placeholder so output stays byte-deterministic (stamp an ISO date when the drawing is released).

{ "options": { "format": "svg-drawing", "sheet": "a3", "modelName": "Clamp body", "date": "2026-06-10" } }

Conventions and behaviour

Model space is mm, z-up; the front view looks along +y (model front faces −y), matching the canonical render pose.
The SVG is structured for downstream tooling: <g id="view-front|top|left|iso"> per view with class="visible|hidden|tangent" subgroups, data-kc-scale / data-kc-units on the root element.
Curved edges are sampled to polylines at 0.02 mm chord tolerance — invisible at print scale.
A drawing is a derived artifact, not source-of-truth: change the .kcad.ts, re-export.

Current limits

Dimensions are overall bounding-box extents only. Feature-level dimensioning (hole callouts, param-bound dimensions), section views, and per-view scale overrides are not available yet.
Hidden tangent edges are intentionally omitted (noise, no contour information).
Partially overlapping collinear duplicates are kept; only exactly coincident segments deduplicate.

Verify before shipping

Render the SVG to PNG and look at it (e.g. google-chrome --headless --screenshot=sheet.png file://…/drawing.svg). Check: hidden bores dashed where expected, tangent fillet lines thin, views aligned, dimensions match the model's bbox, title block populated. A drawing with a wrong or unreadable view is not done even if the export succeeded.