- History and Evolution of Revit
- Revit's Geometric Engine and Its Specificities
- Exchange Formats Supported by Revit
- IFC4 Format Support: A Decisive Step Towards Complete Interoperability
- CAD Interop Solutions for Revit Interoperability
- Revit Interoperability Tips
- Best Practices for Exchanging Revit Models
- Conclusion
Autodesk Revit has established itself as an essential tool for building and construction professionals. Its ability to create 3D parametric models that integrate project data makes it a preferred solution for Building Information Modeling (BIM). This article explores the essential aspects of data interoperability with Revit, a crucial issue for multidisciplinary collaboration in construction projects.
History and Evolution of Revit
Revit was originally developed by Charles River Software, founded in 1997 by Leonid Raiz and Irwin Jungreis, former developers of PTC's Pro/Engineer software. Their goal was to bring parametric modeling, common in mechanical CAD, to the building industry. The first version of Revit was launched on April 5, 2000.
The company was renamed Revit Technology Corporation in January 2000, then acquired by Autodesk for $133 million in 2002. This acquisition accelerated the development and improvement of the software. The name "Revit" is actually a contraction of "Revise-Instantly," reflecting the software's ability to update all linked elements when a modification is made to one part of the model.
Over the years, Revit has been enriched with new features:
- 2005: Introduction of Revit Structure
- 2006: Launch of Revit MEP
- 2011: Release of Dynamo in beta version
- 2012: Introduction of Revit LT, a lighter version of the software
In 2025, more than 14,302 companies worldwide use Revit as a CAD tool, with 1,610 specifically in the field of architecture. This massive adoption demonstrates its dominant position in the AEC (Architecture, Engineering and Construction) sector.
Revit's Geometric Engine and Its Specificities
Revit's geometric engine is based on specific technical choices that distinguish it from other CAD systems. Unlike software such as Inventor or AutoCAD, Revit uses parameterized curves and surfaces to represent geometric edges and faces respectively.
A notable peculiarity concerns the representation of cylindrical shapes: in Revit, a complete cylindrical face is generally divided into two half-cylinders. This approach results from a deliberate choice in the design of Revit's geometric core to avoid ambiguities in surface parameterization.
Developer John Mitchell from the Revit team explains this technical choice:
"Revit uses parameterized curves and surfaces to represent the geometry of edges and faces. For example, a spherical surface essentially uses latitude and longitude as coordinates. By prohibiting closed edges and faces, we represent the sphere using two hemispherical faces, which eliminates any ambiguity when determining coordinates."
This approach, although it may seem counter-intuitive for users accustomed to other CAD systems, offers advantages in terms of consistency and reliability of the parametric model.
Exchange Formats Supported by Revit
Revit supports a wide range of exchange formats to facilitate interoperability with other CAD and BIM applications. This flexibility allows AEC professionals to integrate Revit into various workflows and exchange data with different disciplines.
Standard Import and Export Formats
Revit supports the following formats for data import and/or export:
- DGN (MicroStation Design File): Used to exchange data with Bentley MicroStation users
- DWF/DWFX (Design Web Format): Lightweight format developed by Autodesk for sharing and visualization
- DWG/DXF (AutoCAD Drawing): AutoCAD native formats, widely used in the industry
- IFC (Industry Foundation Classes): Essential open format for BIM interoperability
- SAT (ACIS SAT): File format for solid geometry exchange
- SKP (SketchUp): SketchUp native format, used for importing architectural concepts
Formats Added in Revit 2023
Version 2023 extended interoperability capabilities with the addition of three important formats:
- AXM (FormIt): Autodesk FormIt native format, now supported for import and direct linking in Revit
- OBJ (Wavefront Object): Versatile 3D exchange format, initially supported for import in version 2022.1, then for linking in version 2023
- STL (Stereolithography): Standard format for 3D printing and additive manufacturing
Format Added in Revit 2025
- STEP/STP : ISO standard format widely used in mechanical and manufacturing industries, newly supported in Revit 2025
Recent Developments by Version
Revit 2025
- Improved support for open formats with optimized category mapping for IFC export
- Introduction of support for STEP format (STP), widely used in mechanical and manufacturing industries
- Tracking and visualization of changes in linked models stored on Autodesk Docs, including for IFC and NWC (Navisworks) links
- Enhanced integration with Twinmotion for visualization, with a new "Twinmotion Substitution" parameter
Revit 2023
- Improved workflows between Revit and FormIt Pro with the ability to directly link FormIt files (AXM) in Revit
- Better support for placement and appearance of imported CAD file formats
- New "Allow cut in views" parameter for 3D elements from CAD files
- Advanced features for mapping standard IFC attributes to model elements
Revit 2022
- IFC4 certification for architecture and structure export, making Revit the first software to support IFC4 reference view export for multiple disciplines
- Improved interoperability with Inventor, allowing export of Inventor assemblies to RVT files
These developments demonstrate Autodesk's ongoing commitment to improving Revit's interoperability with other platforms and formats, thus facilitating collaborative workflows in the AEC sector.
IFC4 Format Support: A Decisive Step Towards Complete Interoperability
The IFC (Industry Foundation Classes) format is essential for BIM interoperability, and Revit offers complete support for this format. For imports, Revit supports IFC files based on IFC4, IFC2x3, IFC2x2, and IFC2x standards. For exports, it supports IFC4, IFC2x3, and IFC2x2 standards.
Advantages of IFC4
IFC4 represents a major advancement over previous versions, with significant improvements:
- File size reduction : IFC4 offers much more efficient ways to store geometry, both for meshes and parametric shapes. For example, an IFC file produced from Revit of a single object weighing 16,098 kB can be reduced to 4,487 kB when re-exported in IFC4, without any loss of geometric detail.
- Better mesh representation : The new support for tessellated forms allows a much more efficient description of meshes compared to the faceted BREPs of IFC2X3.
- Improved parametric geometry support : IFC4 enhances Revit's ability to export parametric geometry, thus preserving the intelligence of the model.
IFC Export Tools in Revit
Autodesk regularly updates Revit's IFC exporter to integrate new features and fix bugs. The IFC Export Alternate UI offers additional flexibility in choosing export options. Both tools are available on the Autodesk App Store and must be downloaded and installed manually.
For English-speaking users, the "IFC Exporter for Revit" provides a set of parameter sets that can be used directly for exports. It is possible to add, delete, or modify an existing parameter set to adapt it to the specific needs of the project.
CAD Interop Solutions for Revit Interoperability
3DViewStation: Advanced Visualization and Analysis of Revit Models
3DViewStation is a high-performance solution distributed by CAD Interop that allows visualization and analysis of CAD models, including those created with Revit, without requiring installation of the original software. This solution offers several advantages for professionals working with Revit data:
- Fast and lightweight visualization of complex BIM models
- Geometric analysis tools to verify model quality
- Measurement and section features to examine different parts of the model in detail
- Ability to combine data from different sources for a global view of the project
- Export to various formats to facilitate communication with stakeholders who do not have BIM software
3DViewStation integrates perfectly into BIM workflows and is an ideal complement to Revit for teams that need to share and analyze complex models.
SimLab for Immersive Experiences from Revit Models
SimLab, also distributed by CAD Interop, is an innovative solution that transforms Revit models into immersive experiences. This platform facilitates:
- The creation of virtual reality (VR) environments from Revit models
- The development of augmented reality (AR) applications to visualize projects in their real context
- The development of interactive presentations for clients and stakeholders
- The simulation of space occupation and usage scenarios
- The optimization of designs through a more intuitive understanding of 3D spaces
SimLab transforms Revit's technical data into powerful communication tools, thus facilitating collaboration between designers, clients, and end users.
Revit Interoperability Tips
Optimizing DWG Exports
To ensure optimal conversion to DWG format:
- Configure layers and line styles in Revit before export
- Use project-specific export settings to maintain consistency
- Check the selected DWG version to ensure compatibility with recipients
Improving IFC Exchanges
To maximize the quality of IFC exchanges:
- Use the alternative IFC export UI for more precise control
- Create custom export parameter sets for different project types
- Verify that all elements are correctly mapped to the appropriate IFC classes
- Prefer using IFC4 to reduce file size and improve geometric accuracy
Managing Complex Assemblies
When transferring models with complex assemblies:
- Check the assembly hierarchy after import/export
- Use dedicated export views to precisely control what is shared
- Document relationships between components that might be affected during conversions
Best Practices for Exchanging Revit Models
Model Preparation
Before sharing Revit models:
- Clean the model of temporary or non-essential elements
- Check the consistency of schedules and annotations
- Ensure all links are properly managed
- Use the interference checking tool to identify and resolve potential conflicts
Data Structuring
Good data structuring facilitates interoperability:
- Organize the model with logical sub-projects
- Use well-named and documented families and types
- Apply consistent project standards to facilitate interpretation by other users
- Properly populate metadata for better utilization by other software
Exchange Documentation
For effective collaboration:
- Document software versions used
- Specify exchange formats and applied export parameters
- Clearly identify known limitations or elements requiring special attention
- Establish a BIM exchange protocol with all project stakeholders
Conclusion
CAD data interoperability with Revit is a crucial issue for professionals in the AEC sector. Revit's import and export capabilities, particularly with the IFC4 format, offer extensive possibilities for interdisciplinary collaboration. Solutions offered by CAD Interop, such as 3DViewStation and SimLab, enrich this ecosystem by providing complementary functionalities for visualization, analysis, and creation of immersive experiences.
By applying the best practices and tips presented in this article, Revit users can optimize their data exchange workflows and thus improve the overall efficiency of their BIM projects. Mastery of these technical aspects constitutes a significant competitive advantage in a sector where digital collaboration has become essential.
