Convert ASAT to IFC in your application
3D InterOp is a CAD interoperability SDK that lets your software read ASAT files and write IFC, writing the exact geometry into a format that can also hold facets.
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 IFC
- Exact geometry → mixed-geometry format
- C++ / C# APIs
ASAT to IFC at a glance
ACIS assembly stores exact geometry; IFC can hold exact solids and facets. What ends up in the IFC file depends on what the IFC writer writes, as detailed below.
| ACIS assembly (source) | IFC (target) | |
|---|---|---|
| Full name | ACIS assembly, text (ASAT) and binary (ASAB) | Industry Foundation Classes |
| Standard / owner | Spatial (3D ACIS Modeler) | buildingSMART, ISO 16739 |
| File extensions | .asat, .asab | .ifc, .ifczip |
| Geometry | Exact B-Rep | Exact B-Rep and tessellated geometry |
| Assemblies / structure | Yes | Yes: spatial and element hierarchy |
| 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 IFC.
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Preserved
Exact geometryExact B-Rep read from ASAT is written to IFC as exact geometry.
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Preserved
Product structureThe ASAT product structure is written to IFC.
Why software vendors add ASAT to IFC conversion
Open BIM deliverables
Many projects specify IFC deliverables. Writing it lets your users meet those requirements from your software.
Coordination and clash detection
Coordination tools gather models from every discipline in IFC. Your users can contribute without a round trip through another tool.
Facility and asset data
Owners and operators often receive building data as IFC for asset management after handover.
Things to check before you ship
- Written IFC versions: IFC2x3 to IFC4x3 ADD2 (.ifc).
- Exact B-Rep needs IFC4 or later; IFC2x3 files only get tessellation.
- ASAT has no BIM semantics: check which IFC class your application assigns to each object.
- Supported ASAT input: ACIS R1 to 2026 1.0.
- 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 an IFC (.ifc) file?
IFC is the open, vendor-neutral standard for exchanging building information models, maintained by buildingSMART and published as ISO 16739. It carries building elements with their geometry, properties and relationships.
Frequently asked questions
The exact B-Rep that 3D InterOp reads from ASAT is written to IFC.
Yes. 3D InterOp reads the ASAT product structure and writes it to IFC.
Write IFC4 or later to keep exact B-Rep: IFC2x3 files only get tessellation. 3D InterOp writes IFC2x3 to IFC4x3 ADD2.
ASAT has no BIM semantics, so your application decides which IFC class each object is written as.
3D InterOp reads ACIS R1 to 2026 1.0.
3D InterOp writes IFC2x3 to IFC4x3 ADD2 (.ifc).
Yes. 3D InterOp reads and writes both formats, so IFC to ASAT is supported too.
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Building software that needs to convert ASAT to IFC?
3D InterOp is an SDK that lets your application read ACIS assembly and write IFC alongside 30+ CAD and BIM formats.