Convert IPT to STL in your application
3D InterOp is a CAD interoperability SDK that lets your software read IPT files and write STL, generating the STL 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 Inventor part · Writes STL
- Exact geometry → triangle mesh
- C++ / C# APIs
IPT to STL at a glance
Inventor part stores exact geometry; STL stores triangles. The translation is a tessellation, and the settings you choose decide how close the mesh stays to the original.
| Inventor part (source) | STL (target) | |
|---|---|---|
| Full name | Autodesk Inventor Part | Stereolithography |
| Standard / owner | Autodesk | Open format |
| File extensions | .ipt | .stl |
| Geometry | Exact B-Rep | Triangle mesh |
| Assemblies / structure | Part file (assemblies are IAM files) | No |
| 3D InterOp support | Read only | Read and write |
What's preserved, what changes
Here is what your application can expect to carry across from Inventor part to STL.
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Changes
Geometry is tessellatedThe exact Inventor part 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.
Why software vendors add IPT to STL conversion
Additive manufacturing
STL 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
- Supported IPT input: Inventor V6 to 2027.
- 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 IPT (.ipt) file?
An IPT file is an Autodesk Inventor part: one component with its exact geometry, sketches, features and properties. Assemblies of Inventor parts are IAM files.
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Target format
What is an STL file?
STL describes a 3D surface as a set of triangles, with no units, materials or assembly structure. Its simplicity makes it the usual input for 3D printing.
Frequently asked questions
3D InterOp tessellates the geometry it reads from IPT when it writes STL. Your application sets the tolerances, so it controls the trade-off between accuracy and file size.
No. STL stores triangles only, with no units, colors or textures. Agree on the unit with the application that reads the file; the 3D InterOp STL reader assumes millimeters.
Yes. Since 3D InterOp 2025 1.0.1, sketches from Inventor 2023 and later are imported as wire bodies.
3D InterOp reads Inventor V6 to 2027.
No. 3D InterOp reads IPT but doesn’t write it. To send data back to Inventor users, write a neutral format they can import, such as STEP.
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Building software that needs to convert IPT to STL?
3D InterOp is an SDK that lets your application read Inventor part and write STL alongside 30+ CAD and BIM formats.