Back in 2010 I was asked to create a face-based lighting fixture that, when placed on a wall, would display a symbol in plan view. “No problem,” I thought, and happily set out to work on it. Little did I know that it couldn’t be done. Had I “known,” I might not have even tried. But as it turns out, it was possible after all.
The Issue
If you have a face-based lighting fixture family with a nested annotation, you will see the annotation in a project’s plan view when you place the lighting fixture in a ceiling, but not if you place it onto a wall.
It seems to be something that people would like to be able to do, yet, apparently, cannot in Revit. A quick search in Google will show that this is an old wish.
The issue lies within the chosen Revit family category. In certain family categories, a face-based family will display the option Maintain Annotation Orientation.
When checked, this option allows the nested annotation to rotate so that it shows both ways – when the family is placed vertically or horizontally, e.g. on a wall or in a ceiling. Lighting Devices, Fire Alarm Devices and Electrical Fixtures are examples of family categories that have the Maintain Annotation Orientation option. In other family categories, like Generic Models, Lighting Fixtures or Specialty Equipment, that same option isn’t available. In the latter categories, a nested annotation will display in a project’s plan view only if the family is placed on a horizontal plane, like a ceiling.
The images below show the two annotations nested within two families. The first family is set as a Lighting Device and has the option Maintain Annotation Orientation checked. The annotation then displays without a problem in plan view when the family is placed onto a wall. The second family is set as a Lighting Fixture. As such, there is no annotation orientation option.
The result is that when placed onto a wall, the annotation fails to display in plan view. The annotation will still display in plan view if we place the Lighting Fixture on a ceiling, but that’s not what we are after here.
While you could, for example, create a detail item to serve as the annotation when the family is placed on a wall, you would lose the automatic scaling afforded by a symbol created as a generic annotation.
Alternatively, you could change the Revit category in order to display the Maintain Annotation Orientation option. You could switch from Lighting Fixtures to Lighting Devices, for example, but we then lose access to other category specific features that we might require.
The Solution
The method described next works around the limitation of not having the Maintain Annotation Orientation in some Revit family categories. It allows the exit sign family shown above – faced-based light fixture – to display a symbol when viewed in plan.
In order to see the symbol in plan view, the nested annotation needs to be placed in a plane perpendicular to the plan view when the host family (Lighting Fixture) is placed in a project. And to do that, we need the nested annotation to be placed within the Lighting Fixture family as shown on the right in the image below. Unfortunately, Revit only allows for placing the nested symbol as shown on the left.
We will route around this limitation by first inserting the annotation family into another face-based family, and using this intermediary face-based family to place the annotation the way we want into the final Lighting Fixture.
The only key requirement for the intermediary family (aside from being face-based), is that it needs to be set as shared for the symbol to display in the project. With that done, now the family does what we want when placed in a project. Also note that, when placing the intermediary family into the Lighting Fixture family, you can’t see the annotation. But fear not, the force – sorry, the reference planes of the intermediary family will be there with you.
From here you can develop on top of this method to have a family that displays one symbol when hosted on a wall and another one when hosted on a ceiling (e.g. a camera), choose to allow your symbols to be tagged, and so on.
