Native CAD interfaces
Direct support for the CAD formats listed here.
Autodesk Viewer
Open Inventor, Navisworks, and Revit files
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The 3D-Tool Viewer opens Autodesk Inventor, Navisworks, and Revit files without Autodesk software.
The 3D-NativeCAD Converter converts Autodesk models to a wide range of formats such as STEP, IGES, JT, SAT, Parasolid X_T, STL, OBJ, 3DS, PLY, 3D-PDF, 3D-HTML, FBX, 3MF, and glTF.
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Windows support
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What are IAM and IPT files?
Files with the IAM and IPT file extensions are native 3D files from Autodesk Inventor CAD/CAM software. IPT is the part file format and contains 3D geometry and, in some cases, Product Manufacturing Information (PMI). IAM is the assembly file format and is linked to at least one, but usually several, IPT files and often additional IAM files.
What are NWD files?
Files with the NWD file extension are published projects from Autodesk Navisworks CAD software. They contain all 3D models and project-related data from a Navisworks project in a single compressed file.
What are RVT and RFA files?
RVT and RFA files are Autodesk Revit formats for BIM projects (Building Information Modeling). RVT files (Revit project files) contain the entire 3D model of a project, while RFA files (Revit families) contain individual, reusable components such as doors, windows, or furniture.
IAM and IPT Versions
Inventor 1 was released in 1999, and through Inventor 11 the versions were simply numbered. Since 2007, versions have been named using the year after the release year; for example, the version released in 2024 is called Inventor 2025. File versions created with newer releases cannot be opened with older releases.
NWD Versions
The NWD format is used by all Navisworks versions, such as Navisworks 2025. When creating an NWD file, you can choose to save it in an older version. Through Navisworks 2015, this was required if you wanted to provide the NWD file to a user of an older version. Since 2016, NWD files have been backward compatible, so a Navisworks 2025 NWD file can also be opened with Navisworks 2016.
RVT and RFA Versions
Revit version names are based on the release year, for example Revit 2025. Revit RVT and RFA files are neither backward nor forward compatible. Older files must be updated before they can be opened in a new version, which makes them inaccessible in the older version.
Additional native Autodesk file formats
- idw Native 2D drawing from Inventor, derived from IPT or IAM. Can only be opened in Inventor or Inventor View.
- dwg Native 2D drawing from AutoCAD. Because of the close relationship, it can be used in AutoCAD and Inventor. However, a DWG created with Inventor can only be modified in Inventor; a DWG created with AutoCAD can only be modified in AutoCAD.
- dxf The 2D DXF format was developed because early AutoCAD versions on Windows, MacOS, and Linux required different DWG data. The DXF format was later retained because it proved useful for exchange with other CAD programs. However, compared with DWG, a number of CAD functions are lost.
- nwf Native Navisworks assembly files. An NWF file contains links to the original native files as well as Navisworks-specific data, such as markups. No model geometry is stored in this file format, so an NWF file is significantly smaller than an NWD file.
How do I open Inventor, Navisworks, and Revit files?
For IPT and IAM files, you would typically use an Inventor installation. Alternatively, the files can be opened with CAD/CAM software such as Siemens NX that includes an Inventor interface. Inventor can be used free of charge in read-only mode.
In addition to a commercial Navisworks installation, the free Navisworks Freedom opens NWD files.
Like Inventor, Revit can be used free of charge in Viewer Mode to view RVT and RFA files.
Autodesk now also offers a web viewer for Inventor, Navisworks, and Revit models. Using the viewer requires registration with Autodesk.
The 3D-Tool CAD Viewer opens IPT, IAM, NWD, RVT, and RFA files and combines easy operation with many measurement and analysis tools. 3D-Tool can be tested free of charge for 14 days.
How do I convert Inventor, Navisworks, and Revit files?
Without the appropriate CAD interfaces, the design must be exported by the creator into a common 3D exchange format, such as STEP.
Converting IPT, IAM, NWD, RVT, and RFA files to STEP is also possible with a 3D converter.
The 3D-NativeCAD Converter in 3D-Tool Premium converts IPT, IAM, NWD, RVT, and RFA models and models from many other CAD systems reliably into the standard 3D exchange formats STEP, IGES, SAT, and Parasolid X_T.
Test the Inventor, Navisworks, and Revit viewer and converter for free
3D-Tool is a CAD Viewer with many native CAD interfaces, including Inventor, Navisworks, and Revit. It provides professional measurement tools, draft analysis, and wall thickness analysis.
- Open IPT, IAM, NWD, RVT, and RFA files, add dimensions and comments, and publish them for the 3D-Tool Free Viewer or as 3D PDF
- Open IPT, IAM, NWD, RVT, and RFA files and save them as STL, 3DS, PLY, WRL, or OBJ
- Convert IPT, IAM, NWD, RVT, and RFA files to STEP, IGES, SAT, X_T, and JT
- Convert Inventor, Navisworks, and Revit models to 3D product visualizations such as 3D-HTML, FBX, Collada, 3MF, and glTF
Free, no-obligation 14-day trial with all features, the Autodesk interfaces, and the 3D-NativeCAD Converter. The trial key activates all 3D interfaces, including CATIA, Siemens NX, SolidWorks, Creo, STEP, and SAT.
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