There is an increasing desire to build custom designs that can more easily convert from traditional mechanical / industrial CAD tools into BIM-ready content that can be utilized inside of Revit. Autodesk Inventor has the capability to generate Revit-ready content, but often this requires specialized knowledge of the process. What if things didn’t have to be this way? The workflow presented here will utilize everyday Inventor techniques to set the stage for powerful iLogic capabilities to allow virtually any designer to configure Inventor models into Revit-ready content.
The Goal
Why Is This Topic Important?
As design, manufacturing, and construction industries increasingly become more sophisticated and intertwined, the way we do things must adapt to meet these new realities. With modular and prefabricated designs gaining huge traction in the construction industry, the time is right to take the same approach in the way we design products for building construction. If we can utilize this approach, we can drastically improve our efficiencies and produce models that are more ready for end-user consumption, with the added advantage of making this process available to as many users as possible.
How Do We Accomplish This (in a Nutshell)?
The approach that I’m proposing has both simple and more complex aspects. You may of course take on as much of this as you wish, as the process could be automated all the way to the point of preconfiguring all the BIM connectors and publishing the model in Revit family format. The general steps for this solution are as follows:
- Simplify the designs as much as possible (optional but highly recommended). Shrinkwrap will help with this (more on that later).
- Prepare the individual component models with the appropriate BIM-specific surfaces.
- Assemble the components and utilize the Shrinkwrap workflow to create the final configuration model.
- Use iLogic rules to configure the BIM connectors to the desired level and even export the model as a Revit family (optional).
Setting Up the Models
There are a handful of items that must be done to facilitate the process and improve the final performance for the Revit user, including:
- Simplify the model as much as possible
- Create and store the custom BIM-specific appearances.
- Apply the custom BIM appearances to Solid Faces.
- Apply the custom BIM appearances to Surface Bodies.
Simplify the Model as Much as Possible
When we’re designing components that are required to complete an actual engineering design, we must include an adequate amount of detail to complete the design. Often this may include displaying every single fillet edge for a part or every fastener used in an assembly. However, when we are producing models for downstream consumption in Revit, Plant 3D, Factory Design, etc., we must not put the full engineering details into this model, as this will decrease the performance in Revit and leave the end user frustrated with the model.
When considering the simplification of a model, there are a couple of different approaches. First, if possible, remove any unnecessary features. This could involve removing features that you yourself have modeled, like fillets. If you’ve imported a model, this could involve removing unwanted surfaces, like fastener heads, etc. Whatever we can do to “lighten” the load on the model is advisable, as long as we don’t compromise the overall design intent. (We still want to understand what the item is or have the information required to install the item.) See the image below as an example.
If you are not sure whether to keep a feature, this step could also be accomplished with an iPart or a derived part approach. With this approach, the original engineering model is preserved and a more Revit-friendly model can be utilized. If you have the luxury of standard equipment or treating this more like a product configurator or sales tool, but need to provide a 3D model for the customer, then you can build the model from scratch with only the level of detail required. This approach is also desirable because the model can be designed parametrically to cover a wide range of design scenarios and options. In the sheet metal hood example below, I utilized a multisolid body approach so I could create more detailed parts later, if we land the job. You could even make such approach a part of your Copy Design process, if you use Vault or some other data management tool.
Create and Store the Custom BIM-Specific Appearances
Once the model has been simplified with only the required geometry and features, we turn our attention to the most critical piece of the modeling process: defining the custom appearances that are going to be used to drive the creation of the BIM connectors. A natural and good question at this point is: Why have I chosen to base the solution on custom appearances? I had three reasons for going this route:
- Custom appearance names can convey valuable information for driving BIM connector configurations.
- Appearance color itself can serve as a visual cue that a surface is unique and help users better understand the component being utilized.
- When using the Shrinkwrap process, custom appearances will pass through to the final component configuration.
The last point is one of the most important, as usually an assembly model is far too detailed to pass along to a customer and the Shrinkwrap process helps us to reduce a model’s complexity and aids in the protection of intellectual property.
Custom Appearance Naming Considerations
There are a few different approaches that someone can take to defining the appearance name, generic or specific. If we take the generic path, then the BIM connectors that are generated will only be classified at a high level, ’Electrical’ or ’Duct,’ for example. However, if we use a more specific type of naming convention, then we can classify the connector with more detail; for example, ‘Electrical – Balanced Power – 240 Volts.’
Custom Appearance Color Considerations
While applying a specific color to the custom appearance technically isn’t necessary, there are some strong benefits. For example, a downstream user of the component will immediately understand that a particular surface is unique, and with time and standardization, what type of connection is required. Additionally, a user would be able to ascertain what type of positioning or tool clearance may be required for a given component configuration. We would want to ensure the designer leaves ample room for critical maintenance on a unit’s power supply connection. The color scheme I have used only serves as an example but illustrates the point well.
Because these custom appearances play a crucial role in the process and we may have dozens of components (or more) to configure, we must manage and reuse these appearances efficiently. The easiest and best way to accomplish this is to create a material / appearance library or add these appearances to your existing library. If you choose, these surfaces can further be organized into library categories, as shown below.
Once the desired custom appearances have been created, the components can be reconfigured to utilize these appearances to drive the automation of BIM connector generation. The custom appearances can be utilized in two different ways.
Apply the Custom BIM Appearances to Solid Faces
Depending on the models being used, solid faces are excellent candidates for receiving the custom appearances. This is also the most straightforward approach as no additional modeling is required, as is typically necessary to utilize surface bodies. Solid body faces work great for sales engineering models or for connections that don’t have a real “orifice” (electrical connections versus duct connections, for example).
Apply the Custom BIM Appearances to Surface Bodies
For some component types, solid faces simply aren’t appropriate. For example, if a component has fluid flow and may be used for a flow analysis, solid bodies will definitely not work. Additionally, if the design is derived from an existing engineering component, which contains orifices, we may not desire to create multiple versions that include solid faces. Thankfully, the custom appearance applied to surface bodies is as equally effective as using solid faces. While this will involve the extra work of creating the surface bodies, this approach offers the flexibility of utilizing existing components largely as-is. I won’t go into detail in creating surfaces, but please see the screenshots below as a general reference for the steps required and the results.
I wanted to show that the surfaces can be utilized in either the native translucent format or in opaque format. You should use whatever will be most consistent and easiest for your design group to work with. I will be using the opaque format for the rest of this process.
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Pete Strycharske is an implementation consultant with D3 Technologies, a Platinum Autodesk Partner and Authorized Training Center, based out of Minneapolis. His focus is primarily on the following areas: engineering design and manufacturability, design automation and configuration, process efficiency, and manufacturing layouts. Typically, he will partner with clients to perform an assessment of a design or process, determine some improvements, propose a path forward, and develop content/mentor users to implement the project. He’s also an Autodesk Certified Instructor and professionally certified in AutoCAD, Inventor Professional, and Fusion 360.