Convert ASAT to 3MF in your application
3D InterOp is a CAD interoperability SDK that lets your software read ASAT files and write 3MF, generating the 3MF mesh from the geometry it reads, with tessellation settings your application controls.
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 ACIS assembly · Writes 3MF
- Exact geometry → triangle mesh
- C++ / C# APIs
ASAT to 3MF at a glance
ACIS assembly stores exact geometry; 3MF stores triangles. The translation is a tessellation, and the settings you choose decide how close the mesh stays to the original.
| ACIS assembly (source) | 3MF (target) | |
|---|---|---|
| Full name | ACIS assembly, text (ASAT) and binary (ASAB) | 3D Manufacturing Format |
| Standard / owner | Spatial (3D ACIS Modeler) | 3MF Consortium, ISO/IEC 25422 |
| File extensions | .asat, .asab | .3mf |
| Geometry | Exact B-Rep | Triangle mesh |
| Assemblies / structure | Yes | Objects and build items |
| 3D InterOp support | Read and write | Read and write |
What's preserved, what changes
Here is what your application can expect to carry across from ACIS assembly to 3MF.
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Changes
Geometry is tessellatedThe exact ACIS assembly B-Rep is replaced by a triangle mesh, generated by 3D InterOp from the exact geometry it reads. Accuracy depends on the tessellation settings your application uses.
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Changes
Assembly structure3MF has no native assembly hierarchy. Decide in your application how ACIS assembly product structure is grouped or flattened before writing.
Why software vendors add ASAT to 3MF conversion
Additive manufacturing
3MF is still the input most slicers and print services expect. Writing it lets your users send parts to print directly.
Mesh-based processing
Inspection, scan comparison and mesh-editing tools work on triangles. A mesh output gives them a model they can open anywhere.
Lightweight sharing
A mesh is simpler than the native CAD file and needs no CAD system to open.
Things to check before you ship
- Written 3MF versions: 3MF 1.1.
- The 3MF writer is available through the UConnect interface only.
- Supported ASAT input: ACIS R1 to 2026 1.0.
- Test tessellation settings on your heaviest parts: finer meshes mean larger files.
- 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 StudyAbout the formats
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Source format
What is an ASAT (.asat) file?
ASAT and ASAB are the assembly versions of the ACIS save file, in text and binary form. They store the product structure of models built on Spatial’s 3D ACIS Modeler kernel.
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Target 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.
Frequently asked questions
3D InterOp tessellates the geometry it reads from ASAT when it writes 3MF. Your application sets the tolerances, so it controls the trade-off between accuracy and file size.
3MF has no assembly hierarchy, so your application decides how the ASAT structure is grouped or flattened before writing.
The 3MF writer is available through the 3D InterOp UConnect interface.
3D InterOp reads ACIS R1 to 2026 1.0.
3D InterOp writes 3MF 1.1.
Yes. 3D InterOp reads and writes both formats, so 3MF to ASAT is supported too.
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Building software that needs to convert ASAT to 3MF?
3D InterOp is an SDK that lets your application read ACIS assembly and write 3MF alongside 30+ CAD and BIM formats.