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For software developers · 3D InterOp SDK

Convert 3MF to IGES in your application

3D InterOp is a CAD interoperability SDK that lets your software read 3MF files and write IGES, writing the 3MF facets as faceted geometry, since 3MF stores triangles rather than solids.

Spatial does not offer an online converter or a desktop conversion app. 3D InterOp is a component that software vendors embed in their own products.

  • Reads 3MF · Writes IGES
  • Triangle mesh → faceted B-Rep
  • C++ / C# APIs
part.3mf3MF 1.1 · mesh with colors
Your application
3D InterOp SDK
3MF readerHealingIGES writer
bracket.igsIGES · exact surfaces and solids

3MF to IGES at a glance

3MF stores triangles; IGES is an exact-geometry format. The mesh is written as faceted geometry: 3D InterOp doesn’t rebuild smooth surfaces from triangles.

3MF (source)IGES (target)
Full name3D Manufacturing FormatInitial Graphics Exchange Specification
Standard / owner3MF Consortium, ISO/IEC 25422ANSI
File extensions.3mf.igs, .iges
GeometryTriangle meshExact B-Rep and surfaces
Assemblies / structureObjects and build itemsNo native assembly hierarchy
3D InterOp supportRead and writeRead and write

What's preserved, what changes

Here is what your application can expect to carry across from 3MF to IGES.

  • Changes
    Faceted geometry
    3MF stores triangles, so the IGES file holds faceted bodies, not solids. 3D InterOp doesn’t rebuild exact B-Rep from a mesh.

Why software vendors add 3MF to IGES conversion

Legacy CAD and CAM systems

Many established engineering tools still consume IGES first. Writing it lets your users hand data to them without leaving your application.

Supplier and partner exchange

Some suppliers and manufacturing partners still specify IGES in their exchange requirements. Your software can meet them directly.

Geometry-only workflows

When a downstream process needs exact part geometry and nothing more, IGES is a simple, widely readable target.

Things to check before you ship

  • Written IGES versions: IGES 5.3.
  • Supported 3MF input: 3MF 1.1.
  • Validate a sample of translated files in the target system your users actually work with.

Working with Spatial was a real milestone for us: Thanks to the powerful 3DInterOp library, we were able to successfully bring our complex CAD-based solutions to the cloud while remaining flexible to meet individual customer requirements. For us, Spatial is not just a technology partner, but a true enabler of our product strategy.

Dr. Arno Michelis, Founder, Simus Systems

Read the Case Study

About the formats

  • Source format

    What is a 3MF (.3mf) file?

    3MF is an open format for additive manufacturing, defined by the 3MF Consortium. It stores triangle meshes with units, colors and build information in a single package.

  • Target format

    What is an IGES (.igs) file?

    IGES is one of the earliest neutral CAD formats, an ANSI standard for exchanging 2D and 3D geometry. It stores exact curves, surfaces and solids, but not the product structure and manufacturing data STEP can carry.

Frequently asked questions

No. 3MF stores triangles, and 3D InterOp writes them to IGES as faceted geometry. It doesn’t rebuild exact B-Rep from a mesh.

Per-facet colors are imported. Textures and materials aren’t.

3D InterOp reads 3MF 1.1, as visualization data.

3D InterOp writes IGES 5.3.

Yes. 3D InterOp reads and writes both formats, so IGES to 3MF is supported too.

  • Building software that needs to convert 3MF to IGES?

    3D InterOp is an SDK that lets your application read 3MF and write IGES alongside 30+ CAD and BIM formats.