Consider the case where a 3D model family (an HVAC baffler, for example) is required to show up on a plan view as a symbol. Specifically, it is required that the detail item include a filled region.
When I first tried this, I discovered that the model family would not allow one to nest the detailed family as a shared component.
Generates the following error message:
Thankfully there is a workaround which I discovered in response to a question I posted to the forums (a great source of help and one that everyone should contribute to)
So, what this implies is that one would have to create, say, a list of shared parameters in a Detail Family category in the shared parameter file. If one gives these generic file names, then one can create parametric families that are driven by the containing families.
In the detail family, load in shared instance parameters for the dimensions.
In the model family, generated the required geometry parametrically.
Load the detail family and position, align and lock it as required. Select it and map (click on the little box next to the parameter) the shared instance parameter to the parameter that controls the geometry.
The symbol will now resize according to the model geometry.
While this workaround solves the issue, it is still a little cumbersome. To this end I created the following idea on the Revit Idea Station:
Vote for it if you think Revit should be able to share detail families into model families.