Anyone who has spent much time in Revit is almost undoubtedly aware of the hierarchical structure of Revit model families. All model families are assigned to a Category, and each Family usually has both multiple Types and Instances (though not always).
This hierarchy can be used when selecting Revit elements in Dynamo. And while the Dynamo primer does include a nice diagram of this hierarchy, it does not thoroughly demonstrate how each level of the hierarchy can be used to select elements.
One of the first issues a new user, particularly a landscape architect, might encounter in Revit is the general lack of control. How do you control the graphics? How do you get the results that you want? It can be a bit overwhelming. Understanding Categories and Subcategories is the first part of controlling the model (and thus graphics) and they are also critical for exporting and sharing your data properly.
Categories are the different types of Families within Revit. Each Family Category has different properties and parameters. The Main Categories are hardwired into Revit; they cannot be renamed, created, or deleted. But within the Categories there are Subcategories. Some of these are hardwired (again, cannot be deleted) but you can create as many Subcategories (Subcats) as you want and delete the unnecessary ones.
In the 2015 Architectural Template, the Site Category has 8 Subcategories, but only Hidden Lines, Pads, Project Base Point, and Survey Point are necessary. Continue reading