Note: This article is written and published in Ukrainian and is a translated version of the original published here.
In Revit, we're used to creating families directly in Family Editor. However, when it comes to fixed geometry with large volumetric weights, complex chamfers, or potential collisions — such as plumbing products or furniture with smooth shapes — this approach often has its limitations.
In such cases, Fusion, a tool with advanced 3D modeling capabilities, comes to the rescue. It is not yet as tightly integrated with Revit as we would like, however, thanks to export and import in SAT, IGES or DWG formats, we can establish an efficient workflow between these two environments.
In this article, we'll look at a few practical scenarios where Fusion can become an effective Revit family editor, as well as share helpful tips and tricks.
- Optimization of Fixed Family Forms (Revit → Fusion → AutoCAD → Revit)
When the Revit family has a fixed shape — such as a bathtub or washbasin without variable parameters — it is more convenient to move the geometry to the Fusion to optimize it without losing accuracy. Family Editor is difficult to work with smooth chamfers, complex intersections, or small radii, while Fusion performs these operations naturally through more advanced modeling.
To do this, just export the model from Revit to SAT or DWG format and open it in Fusion. The imported geometry becomes a basic outline that can be refined using standard editing tools: Press Pull for thickness changes,Fillet andChamfer for chamfering,Combine for combining bodies orShell for lightening volume. Fusion allows you to save the correct orientation and coordinate system, as well as set a zero point (Origin), so that the family is then correctly placed in Revit.
Tip: if we pass geometry to DWG and combine individual shapes into blocks, then in Fusion we also get components grouped in a tree.
After editing, the model is exported to SAT format, which provides pure solid geometry. Next, this SAT file is imported into the AutoCAD where preliminary preparation for Revit is performed. At this stage, it is important to divide the geometry into layers (Layers) — each logical element of the model should be on a separate layer, which can then be associated with a subcategory or material in the Revit.
After that, the file saved in DWG format. It is DWG that is imported into Revit because, unlike SAT, it allows Revit to recognize individual objects, assign them materials, subcategories, visibility categories and, if necessary, divide the model into components.
This approach allows you to get a clean, native geometry in Revit without the status of "Imported Body" and with full control over the graphics and specification of the family.
Using the example of a sofa model, it was this approach that made it possible to correct the initial geometric collisions, simplify the structure to one body and reduce the weight of the family by almost half, while maintaining all the key contours of the product.
The original table model in Revit. |
Sofa model in Fusion for editing. |
Edited model in Fusion. |
Imported model into Revit. |
2. Converting mesh geometry to solid in Fusion
Quite often, the models that we get from manufacturers or from open libraries have a mesh structure - usually these are files in . OBJ, . STL or .3DS. For Revit, such geometry looks terrible: it is not perceived as a solid object and does not allow editing, snapping, or correct intersection with other elements.
To make such a model suitable for Revit, it can be opened in Fusion, which has tools for working with polygonal geometry. After importing, the mesh model goes to a special environment Mesh Workspace, where it can be cleaned, the number of polygons reduced by the Reduce command, and small holes can be filled through Repair → Fill Holes. Reducing polygons significantly affects the success of the conversion — the simpler the mesh, the cleaner the conversion to solid.
Next, the main step is to use the Convert Mesh → BRep tool, which converts a polygonal shell into a solid. If the model has too many fine faces, Fusion may issue a warning that the surface limit is exceeded - in this case, you should re-reduce the polygonality or split the object into several parts.
After successful conversion, we get a clean solid, which can be further edited using Fusion tools — align planes, chamfer, reduce volume, or remove unnecessary small elements. And then, as described above, via AutoCAD, with the separation of geometry across layers and then imported into Revit in DWG format.
Using the example of a table model, this approach made it possible to convert a heavy polygonal mesh model into a correct solid that can be placed in Revit without artifacts, normal errors, or "holes" in geometry. After that, the family behaves like a regular Revit object: it has its own shapes, which can be cut hollow or parameterized if necessary.
The output mesh model of the table in Fusion.
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Optimized solid model after conversion.
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Displaying the same model in Revit after importing DWG.
3. Parameterization in Fusion
If we edit fixed families in Fusion only to optimize the shape, then for more complex elements — for example, furniture or plumbing products — Fusion Allows you to create parametric 3D models based on custom dependencies in which dimensions and proportions can be controlled without completely rebuilding the geometry.
Parameterization in Fusion is implemented through the User Parameters (Modify → Change Parameters system). Any size or geometric constraint can be associated with a custom parameter, such as _Length, _Width, _Height, or _Thickness. Such parameters are stored in a table, where they can be easily changed or combined using formulas. This allows you to quickly change the dimensions of the object on the fly without losing shape and proportions.
Using the example of a bathtub: changing several parameters allows you to vary the length, depth of the bowl or wall thickness, getting several model options from one base. This is significantly faster than modeling each version separately as in Family Editor.
Unfortunately, it is not yet possible to transfer these parameters to Revit — after exporting to SAT or DWG format, Revit sees only geometry, without parametric logic. Therefore, if Autodesk ever decides to do two-way synchronization between Fusion and Revit, it will probably be the most anticipated update since the arrival of Dark Mode😄
However, even in the current state of affairs, Fusion remains a convenient editor for creating variable shapes, which can then be turned into Revit families. This approach allows you to prepare "smart prototypes" in Fusion, and configure parameters and behavior directly in Revit. This is an intermediate but effective way to combine the accuracy of CAD modeling with BIM logic.
Bathtub in Fusion with User Parameters table. |
Same model in Revit after exporting DWG. |
- Tips and tricks
When working with models between Fusion and Revit, the rule of thumb is to simplify everything that can be simplified.
Fusion does an excellent job with shapes that Revit is reluctant to "digest", but before importing, you should always check that the model does not contain unnecessary faces, microradii or "floating" bodies. The optimal weight of the family is always a compromise between the detail and stability of the project.
Before exporting to the SAT, make sure that the units of measurement in Fusion are set to millimeters — otherwise, the bathtub may arrive in Revit the size of a football field🏟️. After importing, it is advisable to check the zero point and the orientation of the axes: sometimes models with Fusion have their own idea of "where they have the bottom".
It is equally important not to get carried away with materials and textures: Revit doesn't read them anyway. If the model is to be visually beautiful, it is better to assign materials directly to Revit.
And as for the parameters... well, here we come back again to our favorite Autodesk magic🪄. The parameters from Fusion to Revit are not "moving" yet, but we optimistically believe that somewhere on the sidelines, the developers are already testing the "Sync Parameters to Revit" button — and are simply afraid to release it earlier than the dark theme😄
In general, the approach "Revit for BIM, Fusion for form" is quite working, but if only without AutoCAD in between))). Revit gives structure, Fusion gives precision and freedom of geometry. Together, they allow you to create clean, realistic, and balanced families that not only look good, but also don't make your Revit hover thoughtfully with every zoom.
Note: This article is written and published in Ukrainian and is a translated version of the original published here.
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