Convert IGS to AI

A print, laser-cut layout, technical illustration, or Adobe Illustrator editing workflow may require CAD geometry as an .ai file. Because AI is a 2D artwork format, converting an IGS model requires selecting a view and exporting projected curves rather than transferring the 3D model unchanged.

What the IGS format is

IGS, commonly stored as .igs or .iges, is the Initial Graphics Exchange Specification for exchanging CAD data between different systems. An IGES file can contain NURBS curves, wireframes, trimmed surfaces, dimensions, annotations, and, in some cases, solid geometry; many files do not provide the unified solid model or feature history available in the source CAD application.

Mechanical CAD users encounter IGS when receiving legacy engineering data, exchanging geometry with suppliers, or moving designs between incompatible applications. CATIA, Siemens NX, SOLIDWORKS, Autodesk Inventor, AutoCAD, Rhino, and FreeCAD can import or export IGES, although supported entities and translation quality vary.

What the AI format is

AI is Adobe Illustrator's native format for 2D vector artwork. It stores paths, fills, strokes, text, layers, and Illustrator-specific editing data for diagrams, technical illustrations, signage, and page artwork.

AI paths scale without rasterization, but AI cannot preserve an IGS model's 3D topology, parametric constraints, feature tree, materials, or CAD surface relationships. The result is a 2D projection, section, or drawing view—not an equivalent 3D CAD model.

How to convert IGS to AI

Rhino: direct 2D AI export

1. Open the file with File → Open and select the .igs or .iges file.
2. Set the required camera or orthographic view. Select the model and run Curve → Curve From Objects → Make2D. Enable hidden-line output only when the artwork requires hidden edges.
3. Inspect the generated curves for duplicate edges, gaps, construction geometry, and unwanted hidden lines. Delete or repair those curves before export.
4. Select the cleaned curves and choose File → Export Selected. Select Adobe Illustrator (*.ai), then set the scale, units, and curve options.
5. Open the exported file in Illustrator, verify its dimensions and paths, and use File → Save As to save the working file as .ai.

Rhino is a practical choice when a 3D part must become a clean front, top, side, or axonometric drawing. Its Illustrator export contains 2D curves only.

FreeCAD: export a drawing through SVG

1. Open the IGS file in FreeCAD with File → Open. Imported geometry may appear as separate surfaces, shells, or shape objects.
2. For a technical drawing, create a TechDraw page with TechDraw → Insert Page, add a view with TechDraw → Insert View, and set the projection direction, scale, and hidden-line visibility.
3. Export the page using TechDraw → Page → Export Page as SVG. For simple planar geometry, File → Export may also create an SVG, depending on the selected object.
4. Open the .svg file in Illustrator, check the document units and line weights, and use File → Save As with Adobe Illustrator (*.AI).

SVG is a 2D vector intermediate format. It transfers paths to Illustrator but does not retain the source model's CAD structure.

Online conversion

Online services are suitable for non-confidential files when a desktop CAD application is unavailable. Services such as Aspose.CAD, CloudConvert, or Convertio may accept IGES or produce SVG, PDF, or another intermediate format; available input and output formats change, so verify the current format list before uploading.

When a service produces SVG or PDF rather than AI, open that file in Illustrator and save it as .ai. Online converters generally cannot infer the required projection, hidden-line policy, scale, or section view reliably, and confidential supplier or product data should not be uploaded.

Quality and compatibility limits

• The same IGS model can produce different artwork depending on the selected view, camera angle, section plane, scale, and hidden-line settings. Define and record these settings before export.
• Curves that appear joined in CAD may arrive as many separate Illustrator paths. Use Object → Path → Join only after confirming that endpoints coincide; joining unrelated endpoints changes the geometry.
• IGES units may be absent or interpreted differently by applications. Confirm the source units and check a known dimension in Illustrator before printing or sending the file for fabrication.
• CAD splines can become dense or fragmented Illustrator paths. Simplify them only after comparing the result with the source, because excessive simplification can change manufactured dimensions.
• IGES annotations, dimensions, colors, and line styles may be omitted, altered, or converted to ordinary paths. Rebuild critical dimensions and text in Illustrator when exact typography or layer organization is required.
• For manufacturing or continued CAD editing, retain the original IGS file and use a CAD-native or CAD exchange format; AI is intended for 2D artwork, not parametric engineering data.