CGM Conversion Guide

CGM to SVG conversion for engineering documentation teams

Reforge is a Windows desktop converter for teams that publish technical illustrations. It targets the case where the same source file has to convert the same way every release — engineering, aerospace, defence documentation pipelines where rendering drift gets caught in QA.

Why CGM to SVG conversion is difficult in production

Many converters can open CGM files, but production workflows fail when output must stay consistent across profile variants, downstream CMS platforms, and repeated revision cycles. Teams typically see breakage in line styles, text placement, and color mapping when file sets come from mixed sources.

How Reforge keeps output consistent

  • Preserves geometry and styling details needed for technical publications.
  • Supports profile-sensitive workflows including WebCGM and ISO/IEC 8632 variants.
  • Runs locally — Windows desktop app or Linux CLI — so source files stay inside your environment.
  • Includes validation output to help QA teams review conversion exceptions quickly.

What the desktop app includes

The Reforge desktop application runs entirely on Windows 10/11 and processes all files locally. It is organized into three main tabs plus a dedicated Settings window:

  • Convert — drop one file or a whole folder, pick an output preset, and run. Real-time progress, pause/resume, ETA estimation, slow-file detection, retry of failed files, per-job override controls, validation-before-convert, and an interactive Preview & Compare view (SVG Preview, Side by Side, Native Compare, Overlay with blend/onion-skin/difference) all live inside this tab.
  • Profiles — browse the seven built-in output presets across three categories: Standards (S1000D, ATA iSpec 2200, WebCGM 2.1), Geoscience (CALS, PIP/CGGC), and Output scenarios (Default/balanced, High Quality Print). The CGM input profile is selected here and per-job tuning flows from the preset you pick.
  • Monitor — watch conversions in flight, review the JSONL conversion log, inspect completed jobs, and track folder-watch activity.
  • Settings — nine dedicated settings pages covering output format, file handling, performance, folder watch, fonts, profiles, licensing, appearance, and about.

Additional desktop-level features:

  • Notification bell in the title bar with a history popup and unread badge count — conversion results and warnings persist for review.
  • Keyboard shortcuts dialog (Ctrl+/) listing all major operations.
  • Density mode — Comfortable, Default, or Compact — to adapt the interface to different monitor sizes and workflow styles.
  • Status bar with a license quota progress bar so daily conversion usage is always visible.
  • Relative time display for the most recent conversion (e.g., "5 minutes ago").
  • Folder Watch — monitor a directory and auto-convert any CGM file dropped into it, configurable from the Settings page.

Seven built-in output presets

The Profiles tab ships with seven output presets across three categories so you can start from a known-good baseline rather than building settings from scratch:

  • Standards — S1000D (defence and civil aviation IETP), ATA iSpec 2200 (commercial aviation GREXCHANGE V2.13 legacy), WebCGM 2.1 (general technical graphics).
  • Geoscience — CALS (MIL-PRF-28003 U.S. DoD technical publications), PIP / CGGC (seismic and well-log).
  • Output scenarios — Default (balanced starting point for unknown targets), High Quality Print (600 DPI with text converted to paths for print fidelity).

Each preset sets DPI, hotspot encoding, region handling, APS preservation flags, companion-file handling, and validation behaviour. The Convert tab's sidebar lets you override any individual setting per job without modifying the preset itself.

Preview and comparison tools

Preview & Compare, available from the Convert tab, provides interactive inspection of converted output before saving or publishing:

  • Four view modes: SVG Preview (standalone), Side by Side (source and output), Native Compare (raw CGM alongside output), and Overlay — with blend, onion-skin, toggle, and difference sub-modes for precise visual comparison.
  • Measurement tool — measure distances in the preview in SVG units, millimetres, or pixels.
  • Layer visibility controls — show or hide individual drawing layers extracted from the CGM source.
  • Quality metrics and warnings with remediation hints are surfaced in the preview panel alongside the SVG output.
  • Companion file discovery — automatically detects and associates XCF/IMF companion files alongside source CGM for merge during conversion.
  • Synchronized zoom and pan when Side by Side mode is active. Double-click to reset zoom.

Validation with issue explainer

Validation runs from the Convert tab (before or without converting) and shows per-file results with error, warning, and info counts, filterable by severity or issue code. Key capabilities:

  • Issue Explainer — every validation issue code links to a built-in reference covering 150+ issue codes. Each entry explains what the issue is, why it matters for your workflow, and how to fix it in the source file. A "Search online" shortcut is available for each code.
  • Advanced Pro-gated checks (Professional and Enterprise): Color Spaces, Text Encoding, References, and Coordinates. A small upgrade badge on gated controls links directly to the License settings page.
  • Export — validation results can be exported as CSV or JSON for QA handoff and audit trail.
  • Right-click context menu on any issue: copy, search online, filter by this code, and see the full explainer entry.

Profile detection and confidence scoring

Auto-detect mode scores each file against all supported profile signatures and reports a confidence level — High, Medium, or Low — alongside the primary match. A runner-up profile is also shown when a file sits near a boundary between two profile variants.

Detection confidence appears in the file list and in validation output. Low or Medium confidence files can be manually overridden with an explicit profile before conversion.

Need to test quickly? Start with the 30-day free trial, then compare plan options in pricing when you are ready to scale.

Run an evaluation with your own archive samples

Use representative files from your engineering or documentation pipeline to verify fidelity, validation output, and workflow fit before rollout.

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Who this page is for

This workflow fits teams managing technical illustrations in maintenance manuals, parts catalogs, and engineering archives where SVG output must remain accurate across frequent updates.

Need a workflow-specific next step?

If your main constraint is batch throughput, automation, or compliance review, use the guides below to evaluate the right implementation path.

Batch + CLI guide Validation guide