Headless CAD: Generating and Nesting DXF Flat Patterns via Chromium

December 2, 2025 · 3 min read

CAD Automation Engineer

Traditional approaches to drawing generation rely heavily on bulky desktop software and proprietary APIs. The modern approach shifts the geometric kernel to the web.

In this article, we explore how to use the Chromium engine (via Puppeteer or Playwright) and JavaScript to automatically generate, validate, and nest DXF files.

Why Chromium?

For an engineer, a browser is not just a page viewer; it is a powerful vector rendering engine (SVG/Canvas) with hardware acceleration support.

Cross-platform: Generation works identically on Windows, Linux servers, and inside Docker containers.

Visual Debugging: You see exactly what goes to the machine.

Library Availability: The NPM ecosystem (Maker.js, OpenJSCAD) allows for 2D geometry manipulation faster than LISP or VBA.

Solution Architecture

The automation workflow for nesting or generating a flat pattern looks like this:

Frontend/Logic: A JS script generates part geometry (SVG path) based on parameters.

Engine (Chromium): The headless browser renders the geometry, calculates intersections (for nesting), or converts Bezier curves into arcs/polylines.

Output: Result serialization into DXF format.

Technical Implementation

Instead of drawing lines manually, we leverage the DOM for calculations.

Stack:

Node.js - Runtime environment.

Puppeteer - Headless Chromium control.

Maker.js - Library for CAD operations and DXF export.

Code Example (Node.js)

const puppeteer = require('puppeteer');
const fs = require('fs');

(async () => {
  // 1. Launch a "clean" browser
  const browser = await puppeteer.launch();
  const page = await browser.newPage();

  // 2. Inject construction logic (e.g., box flat pattern)
  // In a real project, maker.js would be injected here
  const dxfContent = await page.evaluate(() => {
    // Assume makerjs is loaded in the page context
    const model = new makerjs.models.Rectangle(100, 50);
    
    // Add holes or bend lines
    const hole = new makerjs.paths.Circle([10, 10], 5);
    makerjs.model.addPath(model, hole, 'hole_1');

    // Export to DXF string
    return makerjs.exporter.toDXF(model, { units: 'mm' });
  });

  // 3. Save file for production
  fs.writeFileSync('flat-pattern.dxf', dxfContent);
  
  console.log('DXF generated successfully.');
  await browser.close();
})();

Interactive Example

With MDX, you can even embed interactive elements directly in the post. Launch the DXF circle generator below, tweak the snippet, and download the updated DXF instantly:

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Application for Nesting

Nesting algorithms (like SVGnest or Deepnest) require heavy geometry calculations. Running them within the Chromium environment allows the use of WebAssembly (WASM) modules. This accelerates part placement calculations significantly compared to pure JS and allows for immediate export to DXF.

Summary

Using Chromium for CAD tasks removes the dependency on server-side SolidWorks or AutoCAD licenses. This enables the construction of cloud configurations (CPQ) that deliver ready-to-cut files for laser cutting instantly.

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